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THE NORTH AMERICAN SLIME-MOULDS

The Macmillan Company
New York · Boston · Chicago · Dallas
Atlanta · San Francisco

Macmillan & Co., Limited
London · Bombay · Calcutta
Melbourne

The Macmillan Co. of Canada, Ltd.
Toronto


[Illustration: PHYSARUM NOTABILE (Enlarged one half)

In the field; sporangia in varied magnification, due to inequality in
background.]


THE NORTH AMERICAN SLIME-MOULDS

A Descriptive List of
All Species of Myxomycetes
Hitherto Reported from the Continent of
North America

With Notes on Some Extra-Limital Species

by

THOMAS H. MACBRIDE
State University of Iowa

New and Revised Edition







New York
The Macmillan Company
London: Macmillan and Co., Ltd.
1922

All rights reserved

Copyright, 1899,
By The Macmillan Company.

Copyright, 1922,
By The Macmillan Company.

The Clio Press
Iowa City, Iowa, U. S. A.




  · IN · MEMORIAM ·
  · SAMUELIS · CALVINI ·
  · SCIENTIAE · NATURALIS · IN · UNIVERSITATE · IOWENSI ·
  · NUPER · PROFESSORIS ·
  · PRAECEPTORIS · COMITIS · AMICI ·
  · HUNC · LIBRUM ·
  · GRATO · ANIMO · DEDICAT ·
  · DISCIPULUS ·


    "Ihr naht euch wieder schwankende Gestalten,
    Die früh sich einst dem trüben Blick gezeigt."

    GOETHE.


"Diese Kinder der Natur, welche aus einer ungeformten Gallert, und einem
unsichtbaren Saamen entstehen, sind im stande, in dem sie sich nach und
nach entwickeln und ihre scheinbar nachlässige Bildung genau beobachten
(lassen), eben so sehr als die schönste Pflanze, einem empfindenden
Herzen die tiefe Achtung und das paradiesische Vernügen zu verschaffen,
welches einzig die Betrachtung der Heere der Natur und ihre
gleichbleibende Erhaltung durch eine ewige Kraft hervorbringen kann."

A. J. G. C. BATSCH 1783.




TABLE OF CONTENTS


                                                          PAGE

  PREFACE                                                   ix

  PREFACE TO SECOND EDITION                               xiii

  BIBLIOGRAPHY                                              xv

  INTRODUCTORY                                               1

  THE MYXOMYCETES                                           17

  ADDENDA                                                  282

  INDEX OF GENERA                                          289

  INDEX OF SPECIES                                         290

  PLATES, WITH EXPLANATIONS                                301




CORRIGENDA


The indulgent student will please notice the following for the new
edition _North American Slime Moulds_--

On p. 63, No. 17, read _Physarum megalosporum_ Macbr. Last line should
  read 1917 Physarum _melanospermum_ Sturgis, _Mycologia_, Vol. IX, p.
  323.

On p. 67, last line but one, at the end, read, p. 323.

On p. 67, insert just before No. 23, Vicinity of
  Philadelphia,--_Bilgram_.

On p. 327, Plate XIII, lacks numbers. These may readily be supplied by
  consulting descriptive text.

On p. 344, in explanation figure 2, last word read hour.

On p. 346, for name of species read _Fuligo rufa_ Pers., p. 28.




PREFACE TO THE FIRST EDITION[1]


The present work has grown out of a monograph entitled _Myxomycetes of
Eastern Iowa_, published by the present author about eight years ago.
The original work was intended chiefly for the use of the author's own
pupils; but interest in the subject proved much wider than had been
supposed, and a rather large edition of that little work was
speedily exhausted. At that time literature on the subject in
question--literature accessible to English readers--was scant indeed.
Cooke's translation of Rostafinski, in so far as concerned the species
of Great Britain, was practically all there was to be consulted in
English.

In 1892 appeared in London Massee's _Monograph of the Myxogastres_, and
two years later in the same world's centre the trustees of the British
Museum brought out Lister's _Mycetozoa_. Although these two English
works both claim revision of the entire group under discussion, the
latter paying special attention to American forms, nevertheless there
still seems place for a less pretentious volume which for American
students shall present succinct descriptions of North American species
only. The material basis of the present work consists of collections now
in the herbarium of the State University of Iowa. In accumulating the
material the author has had the generous assistance of botanists in all
parts of the country, from Alaska to Panama, and the geographical
distribution is in most cases authenticated by specimens from the
localities named. The descriptions, in case of species represented in
Europe, are based upon those of European authors; for forms first
described in this country, the original descriptions have been
consulted. A bibliography follows this preface.

In reference to the omnipresent vexed question of nomenclature, a word
is perhaps necessary. De Candolle's rule, "The first authentic specific
name published under the genus in which the species now stands," may be
true philosophy, but it is certainly an open question how that rule
shall be applied. If an author recognized and defined a given species in
times past, and, in accordance with views then held, assigned the
species to a particular genus, common honesty, it would seem, would
require that his work be recognized. To assume that any later writer who
may choose to set to familiar genera limits unknown before shall thereby
be empowered to write all species so displaced his own, as if, forsooth,
now for the first time in the history of science published or described,
is not only absolutely and inexcusably misleading, but actually
increases by just so much the amount of _débris_ with which the taxonomy
of the subject is already cumbered.

In face of a work so painstaking and voluminous as that of Rostafinski,
and in view of the almost universal confusion that preceded him, it
would seem idle to change for reasons purely technical the nomenclature
which the Polish author has established. Especially is this true in the
case of organisms so very perishable and fragile as those now in
question where comparative revision is apt to result in uncertainty. We
had preferred to leave the Rostafinskian, _i. e._ the heretofore current
nomenclature, untouched; but since other writers have preferred to do
otherwise, we are compelled to recognize the resultant confusion.

Slime-moulds have long attracted the attention of the student of nature.
For nearly two hundred years they find place more or less definite in
botanical literature. Micheli, 1729, figures a number of them, some so
accurately that the identity of the species is hardly to be questioned.
Other early writers are Buxbaum and Dillenius. But the great names
before Rostafinski are Schrader, Persoon, and Fries. Schrader's judgment
was especially clear. In his _Nova Genera_, 1797, he recognizes plainly
the difference between slime-moulds and everything else that passed by
the name of fungus, and proposed that they should be set off in a family
by themselves,[2] but he suggested no definite name. Nees (C. G.) also
made the same observation in 1817, and proposed the name _Ærogastres_;
but he cites as type of his ærogastres, _Eurotium_, and includes so
many fungi, that it seems unsafe now to approve his nomenclature.
Schrader also has left an excellent account of the cribrarias, the basis
of all that has since been attempted in that genus.

Persoon, in his _Synopsis_, 1801, attempts a review of all the fungi
known up to that time. His notes and synonymy are invaluable, enabling
us to understand the references of many of the earlier authors where
these had otherwise been indefinite if not unintelligible. He makes a
great many changes in nomenclature, and excuses himself on the ground
that he follows, in this particular, illustrious examples!
Unfortunately, so do we all!

Fries, in his _Systema Mycologicum_, 1829, summed up in most wonderful
way the work of all his predecessors and the mycologic science of his
time. In reading Fries the modern student hardly knows which most to
admire, the author's far-reaching, patient research, the singular acumen
of his taxonomic instinct, the graceful exactness of the Latin in which
his conclusions are expressed, or the delicate courtesy with which he
touches the work even the most primitive, of those his predecessors or
contemporaries. Nevertheless in our particular group even the
determinations of Fries are not conclusive. He himself often confesses
as much. The microscopic technique of that day did not yield the data
needful for minute comparison among these most delicate forms.

It remained for DeBary and Rostafinski to introduce a new factor into
the description of species, and by spore-measurement and the delineation
of microscopic detail to supply an element of definiteness which has no
parallel in the work of any earlier student of this group. Under these
conditions the revision undertaken by Rostafinski was of a most heroic
sort. His work was almost a new beginning; and while in nomenclature he
was inclined to follow the Paris Code, yet the inadequacy of the earlier
descriptions often made such a course impracticable. The synonymy of
Rostafinski is largely that of Fries, and upon this the Polish author
attempts to apply the law of priority. In the historical note, _wzmianka
historyczna_, accompanying the description of each specific form, he
generally states the reason for the nomenclature he adopts, whether
selected from the mass of supposed synonymy or introduced by himself _de
novo_. Unfortunately, Rostafinski is sometimes purely arbitrary in his
selections. He sometimes changes a specific or even generic name,
otherwise correctly applied, simply because in primary etymological
significance the name seems to him inappropriate. In such cases it is
proper to restore the earlier name. Nevertheless Rostafinski is still
our most trustworthy guide.

Of course, where later investigations have served to obliterate the
once-thought patent distinctions between supposed genera or species, it
is proper to unite such forms under the older determinable titles and
this we have attempted. But wherever in the present work a name has been
changed, the name of the earlier author will be found in parenthesis,
followed immediately by that of him who made the change, and in general,
recent practice, especially as expressed in the rules of the various
codes, has determined the puzzling questions of nomenclature.

In justification of the use of _Myxomycetes_ as a general title it may
be said that in this case prevalent usage is not inconsistent with a
rational application of the rules of priority. The Friesian designation
_Myxogastres_ was applied by its author in 1829 to the endosporous
slime-moulds as a section of gasteromycetous fungi. Four years later
Link, perceiving more clearly the absolute distinctness of the group,
substituted the name _Myxomycetes_. In the same year Wallroth adopted
the same designation, but strangely confused the limitations of the
group he named. Wallroth seems to have thought _Myxomycetes_ a synonym
for _Gasteromycetes_ Fries. In 1858 DeBary applied the title _Mycetozoa_
to a group which included the then lately discovered _Acrasieae_ with
the true slime-moulds, both endosporous and exosporous. For all except
the _Acrasieae_ DeBary retained the old appellation, Myxomycetes.
Rostafinski adopted DeBary's general name, but changed its application.
As it has been shown, since DeBary's time, that the _Acrasieae_[3] have
no true plasmodium, and are therefore not properly, or at least not
necessarily, associated with the slime-moulds, there appears no
necessity for the term _Mycetozoa_, and the question lies between
_Myxogastres_ and _Myxomycetes_. Of these two names the former, as we
have seen, has undoubted priority, but only as applied to the
endosporous species. The same thing was true of Link's designation until
DeBary redefined it, but having been taken up by DeBary, redefined and
correctly applied, Myxomycetes (Link) DeBary must remain the undisputed
title for all true slime-moulds, endosporous and exosporous alike.

In arranging the larger divisions of the group the scheme of Rostafinski
has been somewhat modified in order to give expression to what the
present author deems a more natural sequence of species. The highest
expression of myxomycetan fructification is doubtless the isolated
sporangium with its capillitium. This is reached by successive
differentiations from the simple plasmodium. The æthalium may be
esteemed in some instances a case of degeneration, in others of arrested
development. In any event in the present arrangement, æthalioid forms
are first disposed of, leaving the sporangiate species to follow from
plasmodiocarpous as directly as may be.

The artificial keys herewith presented proceed on the same plan and are
to be taken, as such keys always are, not as definitive in any case, but
simply as an aid to help the student more speedily to reach a probably
satisfactory description.

FOOTNOTES:

[1] _The North American Slime Moulds_, 1899.

[2] Schrader, _Nova Plantarum Genera_, 1797, pp. vi-vii.

[3] Cf. Edgar W. Olive, _Monograph of the Acrasieae_; Boston, 1902.




PREFACE TO THE SECOND EDITION


The first edition of this little book having been exhausted long ago,
the writer in this second issue takes opportunity to correct sundry
errata, typographical and other, and at the same time to incorporate
such new information in reference to individual species and to the
subject entire as the researches of more recent years may afford.

To Miss Gulielma Lister, of London, the writer expresses his sense of
deep obligation for much assistance in settling difficult matters of
nomenclature and identification; it will be found as a result that in
most instances the same thing in the two volumes, English and American,
appears under the same name. There are still differences; these result
in most cases from different points of view, different estimates or
emphasis of characteristics in these ever elusive objects.

To Professor Torrend, formerly of Lisbon, the writer is indebted for a
set of European types, and to Professor Bethel, pathologist of Denver,
for rich material from the fertile mountains of Colorado and California.
To Professor Morton Peck, of Oregon, we are indebted for many notes of
the color of plasmodia and for collections of Pacific coast forms. Mr.
Bilgram, of Philadelphia, read the manuscript of the genus _Physarum_
and has contributed many rare species. To Dr. Sturgis, of Massachusetts,
we are indebted for material from both east and west.

The present volume is intended especially for American readers and is
accordingly particularly devoted to a discussion of species so far
reported on the western continent; nevertheless it has seemed wise to
include a brief description of some other forms as well, and reference
to many extra-limital species now generally recognized will be found
here and there in connection with the more extended treatment of related
American forms.

_February twenty-eight, 1921._

    At the last moment, nearly all plates and drawings of the first
    edition disappeared! necessitating a quick renewal of drawings
    and plates. This may in part explain lack of uniformity, and
    various minor irregularities sure to grieve the intelligent
    student.




BIBLIOGRAPHY


The following are the principal works consulted in the prosecution of
the investigations here recorded:--

1763. Adanson, M. Familles des Plantes.

1805. Albertini--see under Schweinitz.

1841. Annals and Magazine of Natural History. London, various volumes:
        1841, Ser. I., vol. vi.; 1850, Ser. II., vol. v.

1887. Annals of Botany, vols. i-xxxi.

1783. Batsch, A. J. G. C. Elenchus Fungorum; with Continuatio I. 1786;
        Continuatio II. 1789.

1775. Battara, A. Fungorum Agri Arimensis Historia.

1860. Berkeley, M. J. Outlines of Fungology.

1789. Bolton, J. History of Funguses about Halifax.

1851. Bonorden, H. F. Mycologie.

1875. Botanical Gazette, The. Various volumes to 1921.

1843. Botanische Zeitung. Various volumes to 1898.

1892. Bulletin Laboratories Nat. Hist. Iowa, vol. ii.

1873. Bulletin Torrey Botanical Club. Various volumes to 1898.

1791. Bulliard, P. Histoire des Champignons de la France.

1721. Buxbaum, J. C. Enumeratio Plantarum.

1863. Cienkowski, L. Zur Entwickelungsgeschichte der Myxomyceten.

1893. Celakowsky, L. Die Myxomyceten Boehmens.

1871. Cooke, M. C. Handbook of British Fungi.

1877. Cooke, M. C. Myxomycetes of Great Britain.

1877. Cooke, M. C. Myxomycetes of the United States.

1837. Corda, A. I. C. Icones Fungorum.

1854. Currey, F., in Quart. Journal Microscopical Science.

1848. Curtis, M. A. Contributions to the Mycology of North America; Am.
        Journal of Science and Arts.

1859. De Bary, A. H. Die Mycetozoen.

1866. De Bary, A. H. Morphologie der Pilze, Mycetozoen und Bacterien.

1802. De Candolle, A. P. Flore Française.

1719. Dillenius, J. J. Catalogus Plantarum circa Cissam nascentium.

1813. Ditmar, L. P. F., Sturm, Deutschlands Flora, 3te Abtheil; Die
        Pilze Deutschlands.

1878. Ellis, J. B. North American Fungi. _Exsiccati. et seq._

1818. Ehrenberg, C. G. Sylvæ Mycologicæ Berolinenses.

1761. Flora, Danica, vol. i.; also vols. iii. iv. v.

1817. Fries, Elias M. Symbolæ Gasteromycetum.

1818. Fries, Elias M. Observationes Mycologicæ.

1829. Fries, Elias M. Systema Mycologicum.

1873. Fuckel, I. Symbolæ Mycologicæ.

1791. Gmelin, C. C. Systema Naturæ, Tom. II., Pars. ii.

1823. Greville, R. K. Scottish Cryptogamic Flora.

1872. Grevillea, various volumes to 1897.

1751. Hill, Sir John. A History of Plants.

1795. Hoffman, G. C. Deutschlands Flora.

1773. Jacquin, N. I. Miscellanea Austriaca.

1885. Journal of Mycology and _seq._

1878. Karsten, Mycologia Fennica.

1809. Link, H. F. Nova Plantarum Genera.

1753. Linné, C. Systema Naturæ--to 1767.

1894. Lister, Arthur. The Mycetozoa; 1911, Second Edition, revised by
        Gulielma Lister.

1892. Massee, George. Monograph of the Myxogastres.

1729. Micheli, P. A. Nova Plantarum Genera.

1892. Morgan, A. P. Myxomycetes of the Miami Valley--to 1895.

1816. Nees, Ch. G. D. Das System der Pilze und Schwamme.

1837. Nees, T. F. L. et A. Henry. Das System der Pilze.

1869. Peck, Charles H. Reports N. Y. State Museum Nat. History--to 1898.

1795. Persoon, C. H. Observationes Mycologicæ, Pars prima.

1799. Persoon, C. H. Observationes Mycologicæ, Pars secunda.

1797. Persoon, C. H. Tentamen Dispositionis Methodicæ Fungorum.

1801. Persoon, C. H. Synopsis Methodica Fungorum.

1844. Rabenhorst, L. Deutschland's Kryptogamenflora.

1884. Raciborski, M. Myxomycetes Agri Krakov. Genera, Species et
        Varietates novæ.

1888. Raunkiær, C. Myxomycetes Daniæ.

1769. Retzius, A. J. In Handlungen, Kon. Svensk. Vet. Acad.

1890. Rex, George A. In Proceedings Philad. Acad. of Nat. Sciences--to
        1893.

1873. Rostafinski, J. Versuch eines Systems der Mycetozoen.

1875. Rostafinski, J. Sluzowce Monografia.

1778. Roth, A. W. Tentamen Floræ Germanicæ.

1888. Saccardo, P. A. Sylloge Fungorum, vol. vii., _et seq._

1841. Sauter, A. Flora, vol. xxiv., p. 316.

1762. Schaeffer, J. C. Fungi qui in Bav. et Pal. nascuntur--to 1774.

1797. Schrader, H. A. Nova Genera Plantarum.

1890. Schroeter, J. Myxomycetes, in Engler u. Prantl Pflanzenfamilien.

1885. Schroeter, J. Kryptogamenflora von Schlesien, die Pilze.

1801. Schumacher, C. F. Enumeratio Plant. Sæll. crescentium.

1805. Albertini, I. and Schweinitz, L. D. de. Conspectus Fungorum.

1822. Schweinitz, L. D. de. Synopsis Fungorum Car. Sup.

1834. Schweinitz, L. D. de. Synopsis Fungorum in America Boreali.

1797. Sowerby, J. English Fungi--to 1809; 3 vols.

1760. Scopoli, J. A. Flora Carniolica--to 1772.

1797. Trentepohl, K. Observations Botanicae,--to Roth, Catalecta
        Botanica, Fasc. i.

1833. Wallroth, C. F. Flora Cryptogamica Germaniae.

1787. Willdenow, K. L. Florae Berolinensis Prodromus.

1886. Wingate, Harold, Jour. Mycol. ii., 125.

1889. Wingate Harold, In Proc. Acad. Nat. Sci. Philad.

1890. Wingate, Harold--in Revue Mycologique.

1873. Woronin u. Famintzin, Ueber Zwei neuen Formen von Schleimpilzen.

1885. Zopf, W. Die Pilzthiere oder Schleimpilze.

To these may be added the many contributions on the general subject, as
these are found in all sorts of current botanical literature; cited
everywhere in this volume as occasion offered.




INTRODUCTORY


The Myxomycetes, or slime-moulds, include certain very delicate and
extremely beautiful fungus-like organisms common in all the moist and
wooded regions of the earth. Deriving sustenance, as they for the most
part do, in connection with the decomposition of organic matter, they
are usually to be found upon or near decaying logs, sticks, leaves, and
other masses of vegetable detritus, wherever the quantity of such
material is sufficient to insure continuous moisture. In fruit, however,
as will appear hereafter, slime-moulds may occur on objects of any and
every sort. Their minuteness retires them from ordinary ken; but such is
the extreme beauty of their microscopic structure, such the exceeding
interest of their life-history, that for many years enthusiastic
students have found the group one of peculiar fascination, in some
respects, at least, the most interesting and remarkable that falls
beneath our lens.

The slime-mould presents in the course of its life-history two very
distinct phases: the _vegetative_, or growing, assimilating phase, and
the _reproductive_. The former is in many cases inconspicuous and
therefore unobserved; the latter generally receives more or less
attention at the hands of the collector of fungi. The vegetative phase
differs from the corresponding phase of all other plants in that it
exhibits extreme simplicity of structure, if structure that may be
called which consists of a simple mass of protoplasm destitute of
cell-walls, protean in form and amoeboid in its movements. This phase
of the slime-mould is described as plasmodial and it is proper to
designate the vegetative phase in any species, as the _plasmodium_ of
the species. It was formerly taught that the plasmodium is unicellular,
but more recent investigation has shown that the plasmodial protoplasm
is not only multinuclear but karyokinetic; its cells divide and
redivide, as do the _reproductive_ cells of plants and animals
generally. Nevertheless, in its plasmodial phase, the slime-mould is
hardly to be distinguished from any other protoplasmic mass, may be
compared to a giant amoeba, and justifies in so far the views of those
systematists who would remove the slime-moulds from the domain of the
botanist altogether, and call them animals. The plasmodium is often
quite large. It may frequently be found covering with manifold
ramifications and net-like sheets the surface of some convenient
substratum for the space of several square feet.

The substance of the plasmodium has about the consistency of the white
of an egg; is slippery to the touch, tasteless, and odorless. Plasmodia
vary in color in different species and at different times in the same
species. The prevailing color is yellow, but may be brown, orange, red,
ruby-red, violet, in fact any tint, even green. Young plasmodia in
certain species are colorless (as in _Diderma floriforme_), while many
have a peculiar écru-white or creamy tint difficult to define. Not only
does the color change, sometimes more than once in the course of the
life history of the same species, but it may be the same for several
forms, which in fruit are singularly diverse indeed, so that the mere
color of the plasmodium brings small assistance to the systematist. In
fact, the color depends no doubt upon the presence in the plasmodium of
various matters, more or less foreign, unassimilated, possibly some of
them excretory, differing from day to day.

In its plasmodial state, as has been said, the slime-mould affects damp
or moist situations, and during warm weather in such places spreads over
all moist surfaces, creeps through the interstices of the rotting bark,
spreads between the cells, between the growth-layers of the wood, runs
in corded vein-like nets between the wood and bark, and finds in all
these cases nutrition in the products of organic decomposition. Such a
plasmodium may be divided, and so long as suitable surroundings are
maintained, each part will manifest all the properties of the whole.
Parts of the same plasmodium will even coalesce again. If a piece of
plasmodium-bearing wood be brought indoors, be protected from
desiccation by aid of a moist dark chamber, not too warm (70° F.), the
organism seems to suffer little if any injury, but will continue for
days or weeks to manifest all the phenomena of living matter. Thus,
under such circumstances, the plasmodium will constantly change shape
and position, can be induced to spread over a plate of moist glass, and
so be transferred to the stage of a microscope, there to exhibit in the
richest and most interesting and abundant fashion the streaming
protoplasmic currents. As just indicated, the plasmodia follow moisture,
creep from one moist substance to another, especially follow nutritive
substrata. They seem also to secure in some way exclusive possession. I
have never seen them interfered with by hyphæ or enemies of any sort,
nor do they seem to interfere with one another. Plasmodia of two common
species, _Hemitrichia clavata_ and _H. vesparium_ are often side by side
on the same substratum, but do not mix, and their perfected fruits
presently stand erect side by side, each with its own characteristics,
entirely unaffected by the presence of the other. On the other hand, it
is probable that some of the forms which, judged by their different
fructifications, and by this alone, are to us distinct, may be more
closely related than we suspect, and puzzling phases which show the
distinctive marks supposed to characterize different species are no
doubt sometimes to be explained on the theory of plasmodial crossing;
they are hybrids.

Under certain conditions, low temperature, lack of moisture, the
plasmodium may pass into a resting phase, when it masses itself in heaps
and may become quite dry in lumps of considerable size, and so await the
return of favorable conditions when former activity is quickly resumed.
Sometimes the larger plasmodia pass into the resting phase by undergoing
a very peculiar change of structure. In ordinary circumstances the
abundant free nuclei demonstrable in the plasmodium afford the only
evidence of cellular organization. In passing now into the condition of
rest, the whole protoplasmic mass separates simultaneously into numerous
definite polyhedral or parenchymatous cells, each with a well-developed
_cellulose wall_.[4] When the conditions essential to activity are
restored, the walls disappear, the cellulose is resorbed, and the
plasmodium resumes its usual habit and structure.

The plasmodial phase of the slime-mould, like the hyphal phase of the
fungus, may continue a long time; for months, possibly for years. The
reason for making the latter statement will presently appear. But
however long or short the plasmodial phase continue, the time of fruit,
the reproductive phase, at length arrives. When this time comes, induced
partly by a certain maturity in the organism itself, partly no doubt by
the trend of external conditions, the plasmodium no longer as before
evades the light, but pushes to the surface, and appears usually in some
elevated or exposed position, the upper side of the log, the top of the
stump, the upper surface of its habitat, whatever that may be; or even
leaves its nutrient base entirely and finds lodging on some neighboring
object. In such emergency the stems and leaves of flowering plants are
often made to serve, and even fruits and flowers afford convenient
resting places. The object now to be attained is not the formation of
fruit alone, but likewise its speedy desiccation and the prompt
dispersal of the perfected spores. Nothing can be more interesting than
to watch the slime-mould as its plasmodium accomplishes this its last
migration. If hitherto its habitat has been the soft interior of a
rotten log, it now begins to ooze out in all directions, to well up
through the crevices of the bark as if pushed by some energy acting in
the rear, to stream down upon the ground, to flow in a hundred tiny
streams over all the region round about, to climb all stems, ascend all
branches, to the height of many inches, all to pass suddenly as if by
magic charm into one widespread, dusty field of flying spores. Or, to be
more exact, whatever the position ultimately assumed, the plasmodium
soon becomes quiescent, takes on definite and ultimate shape, which
varies greatly, almost for each species. Thus it may simply form a flat,
cake-like mass, _aethalium_, internally divided into an indefinite
number of ill-defined spore cases, sporangia; or the plasmodium may take
the form of a simple net, _plasmodiocarp_, whose cords stand out like
swollen veins, whose meshes vary both in form and size; or more commonly
the whole protoplasmic mass breaks up into little spheroidal heaps which
may be sessile directly on the substratum, or may be lifted on tiny
stems, stipitate, which may rest in turn upon a common sheet-like film,
or more or less continuous net, spreading beneath them all, the
_hypothallus_. In any case, each differentiated portion of the
plasmodium, portion poorly or well defined, elongate, net-like,
spheroidal, elliptical, or of whatever shape, becomes at length a
sporangium, spore-case, receptacle for the development and temporary
preservation of the spores.[5]

The slime-moulds were formerly classed with the gasteromycetous fungi,
puff-balls, and in description of their fruiting phase the terms
applicable to the description of a puff-ball are still employed,
although it will be understood that the structures described are not in
the two cases homologous; analogous only. The sporangium of the
slime-mould exhibits usually a distinct _peridium_, or outer limiting
wall, which is at first continuous, enclosing the spores and their
attendant machinery, but at length ruptures, irregularly as a rule, and
so suffers the contents to escape. The peridium may be double, varies in
texture, color, persistence, and so forth, as will be more fully set
forth in the several specific descriptions. The peridium blends with the
hypothallus below when such structure is recognizable, either directly,
when the sporangium is sessile, or by the intervention of a _stipe_. The
stipe may be hollow, may contain coloring matter of some sort, or may
even contain peculiar spore-like cells or spores; is often furrowed, and
in some cases shows a disposition to unite or blend with the stalks of
neighboring sporangia. In many cases the stipe is continued upward, more
or less definitely into the cavity of the sporangium, and there forms
the _columella_, sometimes simple and rounded, like the analogous
structure in the _Mucores_, sometimes as in _Comatricha_, branching
again and again in wonderful richness and complexity.

Each sporangium is at maturity filled with numerous unicellular spores.
These are usually spherical, sometimes flattened at various points by
mutual contact; they are of various colors, more commonly yellow or
violet brown, are sometimes smooth (?), but generally roughened either
by the presence of minute warts, or spines, or by the occurence of more
or less strongly elevated bands dividing reticulately the entire
surface. The spores are in all cases small 3-20 µ, and reveal their
surface characters only under the most excellent lenses.

Associated with the spores in the sporangium occurs the _capillitium_.
This consists of most delicate thread-or hair-like elements, offering
great variety both in form and structure. The threads composing the
capillitium are not to be regarded, even when free, as cells, nor even
of cellular origin; probably, as would appear from the researches of
Strasburger and Harper, all forms of capillitial threads arise in
connection with vacuoles in the protoplasmic mass. "Whether the thread
is hollow or solid, simple or branched, free or connected with the
peridium or a columella,--these are entirely secondary conditions,
depending on the extent and form of the vacuoles."[6] They may occur
singly or be combined into a net, they may be terete or flat, attached
to the peridial wall or free, simple or adorned with bands or spires and
knobs in every variety, uniform or profusely knotted and thickened at
intervals, and burdened with calcic particles. In many cases, the
capillitium contributes materially to the dispersal of the spores; in
others, it doubtless contributes mechanically to the support of the
peridial wall, and renders so far persistent the delicate sporangium.
For more exact description the reader is again referred to the specific
delineations which follow.

The transition from phase to phase requires, as intimated, no great
length of time. _Tilmadoche polycephala_ completed the transition from
vegetative to fruiting phase in less than twelve hours.

The germination of the spores ensues closely upon their dispersal or
maturity and is unique in many respects.[7] The wall of the spore is
ruptured and the protoplasmic content escapes as a zoöspore
indistinguishable so far from an amoeba, or from the zoöspore of our
chytridiaceous fungi. This amoeboid zoöspore is without cell-wall,
changes its outline, and moves slowly by creeping or flowing from point
to point. At this stage many of the spores assume each a flagellate
cilium, and so acquire power of more rapid locomotion. The zoöspores,
whether ciliate or not, thus enjoy independent existence and are capable
of continuing such existence for some time, assimilating, growing, and
even reproducing themselves by simple fission, over and over again. This
takes place, of course, only in the presence of suitable nutrient media.

Nevertheless the spores of many species germinate quickly simply in
water, and a drop suspended in the form of the ordinary drop-culture on
a cover-glass affords ample opportunity. In the course of time, usually
not more than two or three days, the swarm spores cease their activity,
lose their cilia, and come to rest, exhibiting at most nothing more than
the slow amoeboid movement already referred to. In the course of two
or three days more, in favorable cases, the little spores begin to
assemble and flow together; at first into small aggregations, then
larger, until at length all have blended in one creeping protoplasmic
mass to form thus once again the plasmodium, or plasmodial phase with
which the round began. Small plasmodia may generally be thus obtained
artificially from drop-cultures. Such, however, in the experience of the
writer, are with difficulty kept alive. Hay infusions, infusions of
rotten wood, etc., may sometimes for a time give excellent results.

The spores of _Didymium crustaceum_ were sown upon a heap of leaves in
autumn. An abundant display of the same species followed in the next
June; but, of course, the intervening phases were not observed. The most
satisfactory studies are obtained by plasmodia carefully brought in
directly from the field. A plasmodium that appeared suddenly and passed
to fruit on agar in a petri dish offers a valuable suggestion for
further research.

With such a life-history as that thus briefly sketched, it is small
wonder that the taxonomic place of the slime-moulds is a matter of
uncertainty, not to say perplexity. So long as men studied the ripened
fruit, the sporangia and the spores, with the marvellous capillitium,
there seemed little difficulty; the myxomycetes were fungi, related to
the puff-balls, and in fact to be classed in the same natural order. The
synonymy of some of the more noticeable species affords a very
interesting epitome of the history of scientific thought in this
particular field of investigation. Thus the first described slime-mould
identifiable by its description is Lycogala epidendrum (Buxbaum) Fries,
the most puff-ball looking of the whole series. Ray, in 1690, called
this _Fungus coccineus_. In 1718, Ruppinus described the same thing as
_Lycoperdon sanguineum_; Dillenius at about the same time, as _Bovista
miniata_; and it was not until 1729, that Micheli so far appreciated the
structure of the little puff-ball as to give it a definite, independent,
generic place and title, _Lycogala globosum_ ..., etc.[8]

But Micheli's light was too strong for his generation. As Fries, one
hundred years later quaintly says, ... "immortalis Micheli tam claram
lucem accendit ut succesores proximi eam ne ferre quidem potuerint."
Notwithstanding Micheli's clear distinctions, he was entirely
disregarded, and our little Lycogala was dubbed _Lycoperdon_ and _Mucor_
down to the end of the century; and so it was not till 1790 that Persoon
comes around to the standpoint of Micheli and writes _Lycogala miniata_.
Fries himself, reviewing the labors of his predecessors all, grouped the
slime-moulds as a sub-order of the gasteromycetes and gave expression to
his view of their nature and position when he named the sub-order
_Myxogastres_. In 1833, Link, having more prominently in mind the
minuteness of most of the species collocated by Fries, and perceiving
perhaps more clearly even than the great mycologist the entire
independence of the group, suggested as a substitute for the sub-order
_Myxogastres_, the order _Myxomycetes, slime-moulds_. Link's decision
passed unchallenged for nearly thirty years. The slime-moulds were set
apart by themselves; they were fungi without question and, of course,
plants.

If the hypha is the morphological test of a fungus, then it is plain
that the slime-moulds are not fungi. No myxomycete has hyphæ, nor indeed
anything at all of the kind. Nevertheless, there are certain parasitic
fungi, _Chytridiaceae_ for example, whose relationships plainly entitle
them to a place among the hyphate forms that have no hyphæ whatever in
the entire round of their life-history. These are, however, exceptional
cases and really do not bear very closely on the question at issue.

Physiologically, the fungi are incapable of independent existence, being
destitute of chlorophyl. In this respect the slime-moulds are like the
fungi; they are nearly all saprophytes and absolutely destitute of
chlorophyl. Unfortunately this physiological character is identically
that one which the fungi share with the whole animal world, so that the
startling inquiry instantly rises, are the slime-moulds plants at all?
Are they not animals? Do not their amoeboid spores and plasmodia ally
them at once to the amoeba and his congeners, to all the monad,
rhizopodal world? This is the position suggested by DeBary in 1858, and
adopted since by many distinguished authorities, among whom may be
mentioned Saville Kent, of England, and Dr. William Zopf, of Germany, in
_Die Pilzthiere_, 1885. Rostafinski was a pupil of DeBary's. However,
his volume on the slime-moulds was written after leaving the laboratory;
and no doubt with the suggestion of his master still before his mind, he
adopts the title Mycetozoa, as indicating a closer relationship with the
animal world, but our leading authority really has little to say in
regard to the matter.[9]

Dr. Schroeter, a recent writer on the subject, after showing the
probable connection between the phycochromaceous Algae and the simplest
colorless forms, namely, the _Schizomycetes_, goes on to remark: "At the
same point where the Schizomycetous series take rise, there begin
certain other lines of development among the most diminutive
protoplasmic masses.... Through the amoebæ one of these lines gives
rise on the one hand to rhizopods and sponges in the animal kingdom, on
the other to the _Myxomycetes_ among the fungi." This ranges the
Myxomycetes, in origin at least, near the _Schizomycetes_.

The brilliant studies of Dr. Thaxter, resulting in the discovery and
recognition of a new group, a new order of the schizomycetes, strikingly
confirm the judgment of Schroeter.[10] Here we have forms that strangely
unite characteristics of both the groups in question. If on the one hand
the _Myxobacteria_ are certainly schizomycetes, on the other they just
as certainly offer in their developmental history "phenomena closely
resembling those presented by plasmodia or pseudo-plasmodia...." Now the
schizophytes certainly pass by gradations easy to the filamentous algæ,
and so to relationship with the plants, and the discovery of the
_Myxobacteriacae_, brings the myxomycetes very near the vegetable
kingdom if not within it.

All authorities agree that the myxomycetes have no connection in the
direction of upward development, "keinen Anschluss nach oben," if then
their only relationship with other organisms is to be found at the
bottom (centre) of the series only, it is purely a matter of
indifference whether we say plant or animal, for at the only point where
there is connection there is no distinction.

But why call them either animals or plants? Was Nature then so poor that
forsooth only two lines of differentiation were at the beginning open
for her effort? May we not rather believe that life's tree may have
risen at first in hundreds of tentative trunks of which two have become
in the progress of the ages so far dominant as to entirely obscure less
progressive types? The Myxomycetes are independent; all that we may
attempt is to assert their near kinship with one or other of life's
great branches.

The cellulose of the slime-mould looks toward the world of plants. The
aerial fructification and stipitate habit of the higher forms tends in
the same direction. The disposition to attach themselves to some fixed
base is a curious characteristic of plants, more pronounced as we ascend
the scale; but by no means lacking in many of the simplest, diatoms,
filamentous algae, etc., and it is quite as reasonable to call a
vorticella, or a stentor, by virtue of his stipitate form and habit, a
plant as to call a slime-mould an animal because in one stage of its
history it resembles an amoeba. The total life of an organism in any
case must be taken into account.[11] At the outset plants and animals
are alike; there is no doubt about it; they differ in the course of
their life-histories. The plasmodium is the vegetative phase of the
slime-mould. It needs no cell-walls of cellulose, no more than do the
dividing cells of a lily-endosperm; both are nourished by organic food
and resort to walls only as conditions change. The possession of walls
is an indication of some maturity. In the slime-mould the assumption of
walls is indeed delayed. Walls at length appear and when they do come
they are like those of the lily; they are cellulose. The myxomycetes may
be regarded as a section of the organic world in which the forces of
heredity are at a maximum whatever those forces may be. Slime-moulds
have in smallest degree responded to the stimulus of environment. They
have, it is true, escaped the sea, the fresh waters in part, and become
adapted to habitation on dry land, but nothing more. It is instructive
to reflect that even in her most highly differentiated forms the channel
which Nature elects for the transmissal of all that heredity may bestow,
is naught else than a minute mass of naked protoplasm. Nature reverts,
we say, to her most ancient and simple phases, and heredity is still
consonant with apparent simplicity; apparent we say, for as becomes
increasingly evident, nothing that lives is simple!

The fact is the Myxomycetes constitute an exceedingly well-defined
group, and the question of relationship in any direction need not much
perplex the student. Least of all is the question to be settled by
anybody's dictum, which is apt to be positive inversely in proportion to
the speaker's acquaintance with the subject. No one test can be applied
as a universal touchstone to separate plants from animals. Such is
simply _petitio principii_. Nor is there any advantage at present
apparent in attempts to associate slime-moulds with other presumably
related groups. Saville Kent's effort to join them with the sponges was
not happy, and Dr. Zopf's association of the slime-moulds and monads
appears forced, at best; for when it comes to the consideration of the
former, their systematic and even morphological treatment, he is
compelled to deal with them by themselves under headings such as
"Eumycetozoen," "Höhere Pilzthiere," etc. One rather commends the
discreetness of DeBary, whose painstaking investigations first called
attention to the uncertain position of the group. After reviewing the
results of all his labors DeBary does not quite relegate the
slime-moulds to the zoölogist for further consideration, but simply
says:[12] "From naked amoeba, with which the Mycetozoa (=Myxomycetes)
are connected in ascending line, the zoölogists with reason derive the
copiously and highly developed section of the shell-forming
Rhizopoda.... And since there are sufficient grounds for placing the
rhizopods outside the vegetable and in the animal kingdom, and this is
undoubtedly the true position for the amoebæ, which are their earlier
and simpler forms, the Mycetozoa, which _may_ be directly derived from
the same stem, are at least brought very near to the domain of zoölogy."

Notwithstanding all the controversy in regard to the matter, the study
of the slime-moulds still rests chiefly with the botanists. A simple
phylogenetic scheme for thallophytes is offered in the Strasburger text
as follows:--

THALLOPHYTA

  1. SCHIZOPHYTA
               BACTERIA
               CYANOPHYCEÆ

  2. FLAGELLATA
             { MYXOMYCETES
             { PERIDINEÆ
         _a_ { CONJUGATÆ
             { HETEROCONTÆ

             { CHLOROPHYCEÆ
         _b_ { CHARACEÆ

  3. RHODOPHYCEÆ

  4. FUNGI

About 500 species of slime-moulds have been described. Saccardo
enumerates 443, inclusive of those denominated doubtful or less
perfectly known. These 443 species are distributed among 47 genera, of
which 15 are represented by but a single species each,--monotypic. In
the United States there have been recognized about 300 species. Of those
here described, some are almost world-wide in their distribution, others
are limited to comparatively narrow boundaries. The greater number occur
in the temperate regions of the earth, although many are reported from
the tropics, and some even from the arctic zone. Schroeter found
_Physarum cinereum_ at North Cape. Our Iowa forms are much more numerous
in the eastern, that is, the wooded regions of the state. _Physarum
cinereum_ has however been taken on the untouched prairie, and on the
western deserts, as also _Physarum contextum_ on the decaying stem of
_Calamagrostis_, far from forest.

As to the economic importance of our myxomycetes, there is no long
chapter to write. Fries says: "Usu in vita communi parum admodum sese
commendant, sed in oeconomia naturæ certe non spernendi. Multa
insectorum genera ex eorum sporidiis unica capiunt nutrimenta." However
this may be, there is one species which has come to light since Fries's
day which is the source of no inconsiderable mischief to the
agriculturist. _Plasmodiophora brassicae_ occasions the disease known as
"club-root" in cabbage, and has been often made the subject of
discussion in our agricultural and botanical journals.[13] Aside from
the injurious tendencies, possible or real, of the forms mentioned, I
know not that all other slime-moulds of all the world, taken all
together, affect in any slightest measure the hap or fortune of man or
nation. And yet, if in the economic relations of things, man's
intellectual life is to be considered, then surely come the uncertain
myxos, with their fascinating problems proffered still in forms of
unapproachable delicacy and beauty, not without inspiration.


COLLECTION AND CARE OF SLIME-MOULD MATERIAL

On this subject a word may here be appropriate. As just now intimated,
specimens may be taken at the appropriate season in almost any or every
locality. Beginning with the latter part of May or first of June, in the
Northern states, plasmodia are to be found everywhere on piles of
organic refuse: in the woods, especially about fallen and rotting logs,
undisturbed piles of leaves, beds of moss, stumps, by the seeping edge
of melting snow on mountain sides, by sedgy drain or swamp, nor less in
the open field where piles of straw or herbaceous matter of any sort
sinks in undisturbed decay. Within fifty years tree-planting in all the
prairie states has greatly extended the range of many more definitely
woodland species, so that species of _Stemonitis_, for instance, are
common in the groves on farms far into Nebraska and Dakota. In any
locality the plasmodia pass rapidly to fruit, but not infrequently a
plasmodium in June will be succeeded in the same place by others of the
same species, on and on, until the cold of approaching winter checks all
vital phenomena. The process of fruiting should be watched as far as
possible, and for herbarium material, allowed to pass to perfection in
the field.

Specimens collected should be placed immediately in boxes in such a way
as to suffer no injury in transport; beautiful material is often ruined
by lack of care on the part of the collector. Once at the herbarium,
specimens may be mounted by gluing the supporting material to the bottom
of a small box. Boxes of uniform size and depth may be secured for the
purpose. Some collectors prefer to fasten the specimen to a piece of
stiff paper, of a size to be pressed into the box snugly, but which may
be removed at pleasure. Every pains must in any case be taken to exclude
insects. Against such depredators occasional baking of the boxes on the
steam radiator in winter is found to be an efficient remedy.

For simple microscopic examination it will be found convenient to first
wet the material with alcohol on the slide, then with a weak solution of
potassic hydrate, to cause the spores and other structures to assume
proper plumpness. A little glycerine may be added or run under the cover
if it is desired to preserve the material for further or prolonged
study. For permanent mounting nothing in most cases is better than
glycerine jelly. As a preparation, the material should lie for some time
in Häntsch's fluid,[14] opportunity being given for evaporation of the
alcohol and water. When the material shows the proper clearness and
fulness, it may be mounted in jelly in the usual way. Kaiser's formula
gives beautiful results. After mounting, the preparation should be
sealed with some good cement, as Hollis's glue.

FOOTNOTES:

[4] DeBary, _Morphology and Biology of the Fungi,_ p. 428.

[5] See, however, _Ceratiomyxa_, p. 18, following.

[6] Harper in _Botanical Gazette_, Vol. XXX., p. 219.

[7] The following germination periods are furnished by
Dr. Constantineanu (_Inaugural Dissertation ueber die
Entwickelungsbedingungen der Myxomyceten_; Halle, 1907).

  _Reticularia lycoperdon_                           30 to 60 min.
  _Fuligo ovata_                                     30 to 90 min.
  _Stemonitis splendens_                              5 to  6 hrs.
  _Perichaena depressa_                               5 to  8 hrs.
  _Amaurochaete atra_                                 6 to 10 hrs.
  _Arcyria incarnata_                                 8 to 10 hrs.
  _Lycogala epidendrum_                                 to 60 hrs.
  _Physarum didermoides_                              1 to 10 da.
  _Dictydium cancellatum_                             1 to 20 da.

These records are for sowings in drop cultures, in distilled water, kept
at temperature of 65°-70° F. (18°-20° C.).

Our own experiments have been made both with distilled water and
tap-water with the advantage in favor of the latter. _Dictydium
cancellatum_ germinates in tap-water at temperature 70°-80° F. in 12-15
hours fresh from the field. _Fuligo ovata_ spores were all swarming in
about one hour at the same temperature. Jahn (_Myxomycetenstudien; Ber.
der Deutschen Bot. Ges._ Bd. XXIII., p. 495) finds that the germination
in some cases as _Stemonitis_ species, is hastened by wetting, then
drying, then wetting again.

Pinoy thinks microbes aid in germination (_Bull. Soc. Myc. de France_ T.
XVIII.).

[8] The plasmodium in this case chances to be red, scarlet, etc.

[9] "Die Myxomyceten sind ebenso den Pilzen wie den echten Thieren
verwandt."--Rostafinski; closing sentence of the _Versuch_, thesis for
his doctorate at the University of Strasburg, 1873.

[10] _Botanical Gazette_, XVII., pp. 389, etc.; 1892.

[11] Researches of Olive, _Trans. Wis. Acad. Sci., Arts and Let._, XV.,
Pt. 2, p. 771, and of Jahn, _Ber. d. Deutsch Bot. Ges._ XXVI., p. 342,
and XXIX., p. 231, demonstrate synapsis, and accordingly some form of
alternation among the slime-moulds. From the protracted and painstaking
investigation of the German author it appears that in _Didymium_ at
least, and probably _Badhamia_ synapsis immediately precedes
spore-formation as in _Ceratiomyxa_; that the amoeboid issue of the
spores are haploid; the nuclei of the plasmodium, diploid; that the
ordinary vegetative plasmodium is accordingly sporophytic. That is, the
sporophytic phase is dominant, as in higher plants.

[12] Cf., 1884, _Ver. Morph. u. Biol. der Pilz. Mycet. u. Bact._, p.
478. Italics, in quotations, ours.

[13] See _Journal of Mycology_, Washington, D. C., Vol. VII., No. 2;
also _Bulletin No. 66, Agric. Station of Vermont_. See also Bull. _33
Arizona Agric. Ex. Station_: An Inquiry into the Cause and Nature of
Crown-Gall. J. W. Tuomey. Also _Bull. Torrey Bot. Club_, Vol. 21, p. 26,
where it appears that club-root may attack crucifers generally.

Professor B. M. Duggar in _Fungous Diseases of Plants_, pp. 97-102,
gives to club-root an illustrated chapter.

[14]

  Häntsch's Fluid:--
    Alcohol 90%                  three parts
    Water                        two parts
    Glycerine                    one part




THE NORTH AMERICAN SLIME-MOULDS


THE MYXOMYCETES (_Link_) _DeBary_

Chlorophyl-less organisms whose vegetative phase consists of a naked
mass of multinuclear protoplasm, the _plasmodium_; reproduced by spores
which are either free or more commonly enclosed in sporangia, and which
on germinating produce ciliated or amoeboid zoöspores, whose
coalescence gives rise to the plasmodium.


The Myxomycetes are,--

  _A._ _Parasites_, in the cells of living plants            PHYTOMYXINÆ

  _B._ _Saprophytes_, developed in connection with decaying
          vegetable matter:

      _a._ With free spores                                    EXOSPOREÆ

      _b._ With spores in receptacles or sporangia           MYXOGASTRES


Sub-Class PHYTOMYXINÆ _Schroeter_

  1889. _Phytomyxinae Schroeter, Engl. u. Prantl._, I., i., pp. 1 and 5.

The parasitic Myxomycetes affecting plants include but few (four or
five) species, distributed among four genera. All are parasites in the
cells of particular hosts; their vegetative phase is plasmodial and
their spores are formed by the simultaneous breaking up of the
plasmodium into an indefinite number of independent cells. But a single
genus need here concern us,--


=Plasmodiophora= _Woronin_

  1879. _Plasmodiophora_ Woronin, _Pringsh. Jahrb._, XI., p. 548.

Parasitic in the parenchymatous cells of the roots of living plants,
causing noticeable enlargement of the affected organ, producing at
length galls, knots, and various deformities and distortions. Spores
spherical, smooth, colorless, 16 µ.


I. PLASMODIOPHORA BRASSICÆ _Woronin_.

  1879. _Plasmodiophora brassicae_ Woronin, _op. cit._

This species, typical of forms so far reported in this country, infests
the roots of cabbages,[15] and produces a very serious disease of that
vegetable. In England the malady has long been known under the names
"clubbing," "fingers and toes," etc. The roots affected swell greatly,
and at length resemble sometimes the flexed fingers of the human hand;
hence the English name. As the disease progresses, the roots speedily
rot away, to the serious injury of the leaf-bearing portion of the
plant. In badly affected fields, sometimes one-half of the crop is
utterly destroyed. Careful search continued through several years has
not availed to bring this species to my personal acquaintance.

For a full account of the parasitism of this species and its
distribution in the United States see _Jour. Myc._, VII., p. 79; also
_Bull._ 66, Agric. Sta. of Vermont.


Sub-Class EXOSPOREÆ _Rost._

  1873._ Exosporeae_ Rostafinski, _Versuch_, p. 2.

Spores developed, superficially, outside the fructification, which
consists of sporophores, membranous, or slender and branching; spores
white, stalked. A single genus,--


=Ceratiomyxa= _Schroeter_

  1889. _Ceratiomyxa_ Schroeter, _Engl. u. Prantl_, I., i., p. 16. For
           further synonymy, see under first species.

Sporangia none; spores superficial, borne on erect papillæ or pillars,
or even on the inside of minute depressions or pits; each spore
surmounting a delicate pedicel or stalk. The spores on germinating give
rise to amoeboid zoöspores, which undergo repeated divisions, later
become ciliate, and at length again amoeboid to blend into genuine
plasmodia. At maturity the plasmodium gives rise to numerous minute
divisions, each of which may lengthen in a direction perpendicular to
the surface and bear a spore at the tip.

The homologies between the structures just described and the
fructification of the ordinary slime-mould are somewhat obscure, if
indeed any really exist. Are these minute reproductive bodies
spores?--their behavior on germination is unique; are they
sporangia?--the arrested development they exhibit is none the less
puzzling. Perhaps the sporiferous pillars represent incipient stipes,
the spores the uncombined fragments of what might otherwise have
coalesced at the summit of the pillar to form a true sporangium.[16]

Several species have been recognized, all referable probably to one or
two, or at most, four forms. That universally recognized alike in the
literature of the past and in recent studies is,--


1. CERATIOMYXA FRUTICULOSA (_Muell._) _Macbr._

PLATE I., Figs. 7 and 7 _a_.

  1729. _Puccinia ramosa, bifurcata_, etc. Micheli, p. 213, Tab. 92,
           Fig. 2.
  1775. _Byssus fruticulosa_ Müller, in _Fl. Dan._, t. 718, Fig. 2.
  1778. _Tremella hydnoidea_ Jacquin, _Misc._, Vol. I., t. 16.
  1783. _Clavaria puccinia_ Batsch, _Elench. Fung._, p. 139, Fig. 19.
  1791. _Puccinia byssoides_ Gmelin, _Syst. Naturae_, p. 1462.
  1791. _Clavaria byssoides_ Bulliard, _Champ. de la France_, t. 415,
           Fig. 2.
  1794. _Isaria mucida_ Pers., Römer, _N. Mag. Bot._, I., p. 121.
  1801. _Isaria mucida_ Pers., _Syn. Meth._, p. 688.
  1805. _Ceratium hydnoides_ Alb. & Schw., _Consp. Fung._, p. 258.
  1811. _Ceratiomyxa porioides_ (A. & S.) Schroet., _Mycet._, p. 26,
          _var._
  1829. _Ceratium hydnoides_ Fries, _Syst. Myc._, III., p. 294.
  1872. _Ceratium hydnoides_ Wor. & Fam., _Mem. Acad. Imp._, Petersburg.
  1887. _Ceratium hydnoides_ DeBary, _Comp. Morph. Fung._, p. 432.
  1889. _Ceratiomyxa mucida_ Schroeter, _Engl. u. Prantl Nat. Pflanz._,
           I., i., p. 16.
  1893. _Ceratiomyxa mucida_, Pers., Macbr., _Bull. Nat. Hist. Iowa_,
           II., p. 114.
  1894. _Ceratiomyxa mucida_ Schroet., Lister, _Mycetozoa_, p. 25.

Plasmodium in rotten wood, white or nearly transparent; when fruiting,
forming on the substratum mould-like patches composed of the minute
sporiferous pillars, generally in clusters of three or more together;
spores white, ovoid, or ellipsoidal, smooth, 10-12×6 µ.

Very common, occurring in summer on shaded rotten logs, especially
after warm showers and in sultry weather. Easily distinguishable from
all similar moulds by the absence of mycelium or of anything like a
hypha. In Europe the plant seems to be in autumn exceedingly common.
Micheli not only described the form but figured it, nearly two hundred
years ago. Micheli's figure is good, as is that of Mueller, _Fl. Dan._,
l. c. Mueller referred the species to a Linnean genus _Byssus_, which
seems to have included Algæ rather than anything else, if one can
determine its limits at all. The same thing is true of _Tremella_; but
this name is now otherwise applied, as are all the other generic names
down to _Ceratium_, Alb. & Schw. But this had been by Schrank
preoccupied, 1793. See the reference above for 1889. As for specific
name, there seems no reason to depart from the rule of priority, since
Mueller's work is determinative.

_Ceratiomyxa arbuscula_, Berk. & Br., apparently a form of this, is
cited from Toronto by Miss Currie. Massee gives it recognition; Lister
as varietal. The sporophores are inclined to be simple, stipitate and
dendroid.

_C. filiforme_ of the English authors latest named is a wonderful thing
and deserves a paragraph here, if not recognition as a distinct species.
It occurs rarely; but once it appears, attracts attention. As in the
historic species, the sporifers are white, stand more or less erect, but
are every way finer and larger. Each individual sporifer rises like a
stiff stem, as of white thread, 2-3 mm. high; at top a tuft of fruiting
branchlets, more or less distinct. All taken together, we have a dense
mat completely concealing the substratum and spreading out sometimes
over an area of surprising extent, several centimetres square.

Common everywhere in summer on decaying sticks and wood of every
description, especially in wet places. Alaska to Nicaragua, and probably
around the world.


2. CERATIOMYXA PORIOIDES (_Alb. & Schw._) _Schroeter._

  1805. _Ceratium porioides_ Alb. & Schw., _Consp. Fung._, p. 359.
  1829. _Ceratium porioides_ Fries, _Syst. Myc._, III., p. 295.
  1873. _Ceratium porioides_ Fam. & Wor. _Acad. Imp._, XX., 3, p. 5.
  1889. _Ceratiomyxa porioides_ Schroet., _Engl. u. Prantl_, I., i.,
           p. 16.
  1894. _Ceratiomyxa mucida_ Schroet. var. _porioides_ Lister,
          _Mycetozoa_, p. 26.
  1899. _Ceratiomyxa porioides_ Alb. & Schw. (Schroet.), Macbr., _N.
           A. S._, p. 19.
  1911. _Ceratiomyxa porioides_ Alb. & Schw., Schroet., _List.
           Mycet._, p. 26, _var._

Entire fructification confluent forming a mucilaginous mass, porose.
Pores ample, angulate, at length radiate-dentate. Spores as in the
preceding. Plasmodium yellow.

Of these two species Fries remarks: "... Duæ sunt distinctissimæ, inter
has vero longa formarum intermediarum series." Famintzin and Woronin not
only concur, but consider it were more fitting to place the present
species in a distinct genus, as _Polyporus_ is set off from _Hydnum_. A
species based upon the color of the vegetative phase only, unconfirmed
by any subsequent differential character in the fruit would seem
somewhat hazardous. The color of the plasmodium is incident probably to
varied nutrient environment. Pores, however, are usually in evidence.

Iowa, Tennessee, Missouri, etc.; probably common everywhere.


Sub-Class MYXOGASTRES (_Fries_) _Macbr._

  1829. Sub-order _Myxogastres_ Fries, _Syst. Myc._, III., p. 67.
  1833. Sub-order _Myxomycetes_ Link, _Handb. der Gew._, 3, p. 405.
  1833. Sub-order _Myxomycetes_ Wallroth, _Fl. Crypt._, II., p. 333, in
          part.
  1858. Class _Mycetozoa_ DeBary, _Bot. Zeitung_, 1858, pp. 357-365, in
          part.
  1889. Class _Myxogastres_ Schroeter, _Engl. u. Prantl_, Nat. Pflanz.,
          I., i., p. 16.
  1892. Class _Myxogastres_ (Fries) Massee, _Monograph_, p. 28.
  1894. Class _Mycetozoa_ Lister, _Mycetozoa_, p. 21, in part.

Except as just described, the slime-moulds present abundant, minute,
unicellular spores, enclosed in sporangia more or less perfectly
defined, and attended by peculiar thread-like structures, free or
variously attached and conjoined, the so-called _capillitium_.

So far as known, the spores on germination give rise to zoöspores, at
first amoeboid, later ciliate, again amoeboid, conjugating in pairs,
then, in some cases, at least, coalescing and dividing indefinitely to
form the plasmodial or vegetative phase.[17]


=Key to the Orders of the Myxogastres=

  Spore-mass black or violaceous, rarely ferruginous            Series A

  Spore-mass never black; usually some shade of brown or
  yellow, rarely purplish or rosy, etc.                         Series B

SERIES A

  1. Capillitium present, delicate, thread-like;
       sporangia calcareous more or less throughout        I. PHYSARALES

  2. Capillitium present, thread-like, arising
       usually as anastomosing branches from a
       well-developed columella, which in a single
       genus contains lime; sporangia otherwise
       non-calcareous                                   II. STEMONITALES

    SERIES B

  3. Capillitium none, or very imperfectly developed; spores of some
       shade of brown, rarely purplish                 III. CRIBRARIALES

  4. Capillitium the inwardly produced irregular extremities of plates
       or tubules, which by their interweaving outwardly make up the
       aethalial wall; spores pale, ashen                IV. LYCOGALALES

  5. Capillitium made up of more or less distinctly sculptured threads,
       parietal or free, simple, branched, or reticulate; spores
       commonly yellow                                     V. TRICHIALES

This sequence is meant to convey the idea that the presence of lime is
indicative of differentiation less complete. That the plasmodium should
at the outset eliminate, by refusing the unnecessary lime, is indicative
of higher rank than that the lime should be carried until the last and
then be crystallized out, or excreted by simple desiccation. The
circumstance that the excreted lime may sometimes serve a protective
purpose in the fruit, does not vitiate the general principle. In Series
B the differentiation reaches a climax in the sculptured capillitium of
the trichias.

ORDER I

=PHYSARALES=

Spores violaceous-black. The capillitium usually delicate and
thread-like; peridium and capillitium, one or other or both, more or
less extensively surcharged with lime. Peridium simple or double.
Fructification various.

This order is recognizable by several characteristics, but is especially
marked by the peculiar calcareous deposits which affect the capillitium
or peridium, now one, now the other, more often both.

As here defined, the order Physarales includes two distinct families; of
the one _Physarum_, of the other _Didymium_, is type.


=Key to the Families of the Order Physarales=

  _A._ Fructification often calcareous throughout;
         capillitium intricate                             _Physaraceae_

  _B._ Calcareous deposits, when present, affecting the
         peridium only, or sometimes the stipe, in the
         typical genus plainly crystalline; capillitium
         simple
                                                           _Didymiaceae_


A. PHYSARACEÆ

=Key to the Genera of the Physaraceæ=

  _A._ Fructification æthalioid                              1. _Fuligo_

  _B._ Fructification plasmodiocarpous or of distinct
         sporangia.

     _a._ Peridium evidently calcareous.

          i. Capillitium calcareous throughout             2. _Badhamia_

         ii. Capillitium largely hyaline.

              O Sporangia globose, etc.;
                  dehiscence irregular                     3. _Physarum_

             OO Sporangia vasiform or more or less
                  tubular

                 + Dehiscence by a lid or more
                     or less circumscissile               4. _Craterium_

                ++ Dehiscence irregular,
                     peridium introverted                5. _Physarella_

     _b._ Peridium apparently limeless, at least outside.

          i. Plasmodiocarpous                           6. _Cienkowskia_

         ii. Sporangia distinct                           7. _Leocarpus_

  C. Extra-limital.

     _a._ Sporangia stipitate, saucer-shaped, following
            No. 3.                                        _Trichamphora_

     _b._ Sporangia elongate allantoid, etc., following
            No. 1.                                            _Erionema_


=1. Fuligo= (_Haller_) _Pers._

  1753. _Mucor_ Linn., _Sp. Pl._ II., No. 1656 (?).
  1768. _Fuligo_ Haller, _Hist. Helv._, Nos. 1233-1235, in part.
  1801. _Fuligo_ Haller, _Pers. Syn._, p. 159.
  1809. _Æthalium_ Link, _Diss._, I, p. 42.
  1829. _Æthalium_ Fries, _Sym. Myc._, III., p. 92.

Sporangia undefined, obscurely woven in and out among each other forming
usually a cushion-shaped æthalioid mass. The outer layer sterile, often
calcareous, forming a fragile crust, more or less defined. The middle
layer sporiferous with calcigerous capillitium. The lowest layer a
membranous hypothallus.

The identity of this genus seems to have been recognized first by
Haller, _op. cit._, but by Persoon more closely defined and illustrated.
Link simply translated the name into Greek, for reasons less evident
now, and in this was followed by Fries. Haller's designation is now
probably securely fixed.

The sporigerous median structure of the fructifications, under whatever
specific name or names, is entirely confused. Sporangial walls, if ever
such there were, are hardly as such recoverable, seemingly _indicated_
only, in the changes to which the æthalium submits as in the ripening
the sporogenic plasm passes on to spores.

In the present state of our knowledge the forms of this genus present
withal a most perplexing problem. Are they simply phases of a single
species, or are they in style and in structure sufficiently constant in
their admitted variety, to claim specific rank and separate description?

To follow the example of Greville and recognize in all the literature of
two hundred years varied descriptions of a single type,--this were
perhaps the easier and speedier disposal of the case. Fries thought so
to treat the problem but was unable to keep faith with his own decision;
for no sooner he states the genus monotypic than he proceeds forthwith
to offer four varieties, a. b. c. d., viz. those by Persoon and others
duly recognized as species.

Recent students all, however, seem to find convenience in specific
division. All seem disposed to honor Dr. Peck's _Fuligo ochracea_
whether or not by the name he gave; and of other varieties some seem
impressed by the constancy of one, some of another characteristic, thus
indicating that to careful observers all over the world there are
differences that may be recognized, that have been recognized again and
again. If there are two species there are certainly more. Out of the
gatherings of many years one may set in order not less than five
variations in the fruiting of _Fuligo_, five distinct types of
fructification, to all appearing sufficiently constant for specific
recognition.

It will be said, has been said, was said by Fries, that these variations
are insignificant, "pendent ex æris constitutione"; but as a matter of
fact the several types now in question may be found on the same day, so
that evidently something other than the atmospheric environment must
determine.

Again it is said that the differences are in external form or color
only, the spores in all cases almost if not quite the same. This is
true; but specific characters are _surface_ characters in fact: a
species morphologically is merely the form in which a _kind_ or _genus_
presents itself. If the presentation be constant, for our convenience we
say so, in bestowing a name. Whether in our present treatment the
convenience is purely personal, students may decide.

However it all may be, there are in this part of the world many varying
presentations of _Fuligo_ capable of illustration and description; the
same forms, perhaps, which have attracted the notice of the more acute
mycologists in the older history of the subject. Some of these forms we
here venture to describe, with such annotation as may show something of
present knowledge.


=Key to the Species of Fuligo=

  _A._ Æthalium 1 cm. or less; spores spherical         1. _F. muscorum_

  _B._ Æthalium larger, or plasmodiocarpous, even
         sporangi-form, crust white, smooth, even,
         spores elliptical                               2. _F. cinerea_

  _C._ Æthalia larger, 2 cm. or more.

       1. Cortex yellow, etc., not white; spores 6-8 µ   3. _F. septica_

       2. Cortex nearly or quite wanting; spores
            10-12                                     4. _F. intermedia_

       3. Cortex white, a foamy crust; spores 15-25    5. _F. megaspora_


1. FULIGO MUSCORUM _Alb. & Schw._

  1894. _Fuligo muscorum_, Alb. & Schw. Lister, _Mycetozoa_, p. 67.
  1875. _Licea ochracea_ Peck, N. Y. _Rep._, XVIII., p. 55.
  1879. _Fuligo ochracea_ Peck, N. Y. _Rep._, XXXI., p. 56.
  1894. _Fuligo muscorum_, Alb. & Schw., Lister, _Mycetozoa_, p. 67.
  1911. _Fuligo muscorum_ Alb. & Schw., Lister, _Mycetozoa, 2nd ed._,
           p. 87.

Plasmodium orange-yellow. Æthalium globoid, very small, 1 cm. or less,
the cortex very thin, greenish yellow; sporangial walls not evident;
capillitium well-developed, the numerous calcareous nodes fusiform or
often branching, and connected by rather short, transparent internodes;
spores coarsely warted, 10-11 µ.

This form seems to differ from _F. septica_ chiefly in its constant
diminutive habit of fruiting, in its delicate cortex, and in its spores,
brighter, larger, and more coarsely warted. The descriptions and figure
by Schweinitz seem referable to nothing else. First reported by
Albertini and Schweinitz from Germany; by Schweinitz from the Carolinas;
then by Dr. Peck described as a _Licea_ from New York. It seems less
commonly collected in the United States.


2. FULIGO CINEREA (_Schw._) _Morg._

PLATE X., Figs. 3, 3 _a_, and 3 _b_, and Plate XXIII.

  1831. _Enteridium cinereum_ Schw., _N. A. F._, No. 2365.
  1875. _Physarum ellipsosporum_ Rost., _Mon. App._, p. 10.
  1884. _Æthaliopsis stercoriformis_ Zopf., _Pilzthiere_, p. 150.
  1894. _Fuligo ellipsospora_ Lister, _Mycetozoa_, p. 67.
  1896. _Fuligo cinerea_ (Schw.) Morg., _Cin. Soc. Nat. Hist._, p. 105.
  1899. _Physarum ellipsosporum_ Rost., Macbr. _N. A. S._, p. 27.
  1911. _Fuligo cinerea_ Morg., List., _Mycetozoa_, 2nd ed., p. 88.

Plasmodium milk-white, watery. Plasmodiocarp long and widely effused,
anon winding, here and there reticulate, always applanate; sometimes in
form an æthalium, the peridial cortex membranous, firm, thick, and
white. Capillitium well-developed, furnished with lime. Spores
thin-walled, ellipsoidal, violaceous, plicate-rugose, 14-16 x 11-12 µ.

Not common. Found occasionally in shaded situations on piles of rotting
straw or in the woods, especially on detritus of the bracken. The spores
are many of them ellipsoidal; some are spherical; all are decidedly
spinulose, perhaps might appear plicate-rugulose when dry or shrunken.
Calcareous nodules very large and irregular, white.

Schweinitz, _loc. cit._, described this form as _Enteridium cinereum_.
Rostafinski referred it to the genus _Physarum_, but was obliged to
adopt also a new specific name, as that suggested by Schweinitz was
already in use in the genus _Physarum_. Zopf, _Die Pilzthiere_, p. 149,
founds a new genus on what seems to be the same form as here considered.
This he publishes as _Æthaliopsis stercoriformis_ Z. Massee regards the
specimens discovered by Zopf as belonging to the genus _Fuligo_, and
Lister regards Rostafinski's type as _Fuligo_, and includes Zopf's
material under the Rostafinskian species.

This has been described as properly an American form; Lister cites other
far localities.


3. FULIGO SEPTICA (_Linn._) _Gmel_.

  1753. _Mucor septicus_ Linn., _Sp. Pl._ II., No. 1656 (?).
  1763. _Mucor ovatus_ Schaeff., _Fung. Bav._, p. 132, Fig. 192.
  1791. _Fuligo septica_ (Linn.) Gmel., _Syst. Nat._, p. 1466.
  1826. _Fuligo varians_ Sommf., _Fl. Lapl. Sup._, p. 231.
  1809. _Æthalium flavum_ Link, _Diss._, I., p. 42.
  1829. _Æthalium septicum_ Fr., _Syst. Myc._, III., p. 93.
  1875. _Fuligo varians_ Sommf., Rost., _Mon._, p. 134.
  1892. _Fuligo varians_ Sommf., Macbr., _Bull. Lab. Nat. Hist. Ia._
           II., p. 160.
  1894. _Fuligo septica_ (Linn.) Lister, _Mycetozoa_, p. 66.
  1899. _Fuligo ovata_ (Schaeff.) Macbr., _N. A. S._, p. 23.
  1911. _Fuligo septica_ Gmel., Lister, _Mycetozoa, 2nd ed._, p. 86.

This remarkable and universal species presents as stated many forms and
phases. Of these five have been selected as representative.

  1. Form _a._ Plasmodium yellow; cortex yellow, or
       orange-brown, strongly calcareous friable; form
       indefinite                                             _F. ovata_

  2. Form _b._ Cortex less calcareous porose, yellowish brown,
       fructification definite, pulvinate                      _F. rufa_

  3. Form _c._ Cortex smooth, persistent; fructification
       small, less than two inches                           _F. laevis_

  4. Form _d._ Plasmodium yellow; cortex none; capillitium
       yellow, fructification thin, sometimes wide-spread     _F. flava_

  5. Form _e._ Plasmodium violaceous, dark; cortex almost
       none; whole mass reddish or violet                  _F. violacea_


1. Form _a._ _Fuligo ovata_ (Schaeff.) Pers.

Plasmodium bright yellow; æthalium pale brown, or yellowish-ochraceous,
of variable size and shape, one to many cm. in diameter, and one to two
cm. thick, enclosed by a distinct calcareous crust, which varies in
texture, thickness, and color; capillitium well developed but variable
in color, form, and extent; spore-mass dull black, sooty; spores
spherical, purplish brown, nearly smooth, 7-9 µ.

Under this name may be placed our most common form. Rising with an
abundant yellowish creamy plasmodium from masses of decaying vegetation,
lumber, sawdust, half buried logs, it creeps about with energy
unsurpassed, coming to rest only in some position specially exposed, as
the top of a log or stump, the face of a stone or post, or even the high
clods of a cultivated field! The fructification is large, yellow, or at
most pale ochraceous, the surface when mature extremely friable like dry
foam. Bulliard figures this phase well on Plate 424, Fig. 2, and calls
it _Reticularia_ (_Fuligo_) _hortensis_, from its affecting the soils of
gardens. More than thirty fructifications have appeared at one time,
varying in size from one to twenty cm. in a field of potatoes, well
tilled, and less than an acre in extent! Such is life's perennial
exuberance on this time-worn old world of ours!

Schæffer's plate CXII represents probably the same thing. So also
Bolton's plate, CXXXIV. Sowerby's Fig. 2 on plate 199, and figures 1 and
2 on Greville's plate 272 possibly also depict this form. Persoon calls
this _F. vaporaria_ because it frequents hotbeds and the like, and
believes this to represent the "_untuosus flavus_" of Linnée, although
he thinks Schæffer's specimens do not. The calcareous internal structure
is white.


2. Form _b_, _F. rufa_ Pers.

This type of Fuligo is very different from the preceding in form, habit,
and color. In form it is much more definite, usually thick, well-rounded
and with some solidity. The interior fructification is gray throughout,
much less expanded than in _a_; in fact does not resemble _a_ at all!
The cortex is porose but firm, orange at first, but becoming tawny with
age, even in the herbarium. Bulliard figures it well, plate 380, Fig. 1,
and Sowerby's Fig. 1 on plate 399 is also good, as are also Greville's
figure 3 on plate 272 showing the two colors referred to. Not uncommon
in the forest from June till September, but far more rare than _a_:
always well-marked, with no other forms associated.


3. Form _c_, _F. laevis_ Pers.

This is a still more specialized type of the group. The fructification
is usually small, smooth, about an inch in diameter and sometimes nearly
as thick; the cortex rusty brown, enduring, persisting often when all
the sporiferous grayish mass has been distributed through chinks, or
from below. The figure 2 on plate X. shows this form. This also is a
forest species, is autumnal rather, but may be taken sometimes as early
as July. The cortex is not at all porose or spongy, in color reddish or
brown, fragile indeed, but not to the touch, in the herbarium enduring
for years.

4. Form _d_, _F. flava_ Pers.

PLATE X, Figs. 2, 2 _a_, 2 _b_.

This is hardly _F. flava_ of Persoon; rather of Morgan who uses
Persoon's specific designation. Persoon cites Bolton's fig. CXXXIV,
which is yellow indeed but is the ordinary presentation of _F. septica_.
The form here considered is remarkable for its delicacy; extremely thin,
perhaps one layer only of overlying elongate flexuous sporangia(?),
covered by the merest shadow of a cortex in the form of yellow dust,
soon lost: the capillitial structure yellow throughout; occurring upon
fallen logs in moist dark woods; not common.

5. Form _e_, _F. violacea_ Pers.

Plasmodium (Morgan _teste_) dark red, or wine-colored; the æthalium
thin, two or three inches wide, covered by a cortex at first dull red
and very soft, at length almost wholly vanishing, so that the entire
mass takes on a purple-violet tint, upper surface varied with white;
capillitium rather open, the more or less inflated, large, irregular
nodes joined by long, slender, delicate, transparent filaments; spores
dark violet, minutely roughened, spherical, about 7.5 µ.

Ohio, Tennessee. Probably everywhere, but not distinguished from 1.

Professor Morgan, who gave the genus under consideration much attention,
regarded _F. violacea_ as a form particularly well-defined. What the
value of plasmodic color as a specific character in general, and how far
such character is in the present case definitive, because constant, are
points yet to be determined.


4. FULIGO INTERMEDIA _Macbr. n. s._

Æthalium two to three cm. in greatest diameter, .5-1 cm. thick, covered
with a thin, fragile, but not calcareous, greyish or brownish cortex;
the spore-mass grey or violaceous-grey, firm, not at all sooty, the
sporangia intricate, their walls more or less calcareous; capillitium
not conspicuous; spores globose, pale purple, slightly roughened, 10-12
µ.

This form has been repeatedly sent me from Denver, Colorado, by
Professor Bethel. I have refrained from publishing it, still anxious to
believe that all fuligos on the face of the earth were of one species.
In the species next following it must be admitted that the
spore-variations are too wide to remain comfortably under shelter of a
single specific name. The present species is not _F. septica_, neither
is it _F. megaspora_; it is _F. intermedia_.

Colorado; Iowa.


5. FULIGO MEGASPORA _Sturg._

  1913. _Fuligo megaspora_ Sturg., _Col. Coll. Pub._, p. 443.

Æthalium pulvinate one to three inches in diameter, covered with a thick
spongy incrustation of lime, white or yellowish toward the base:
sporangia convolute, the walls membranous, brittle, charged throughout
with round white granules of lime, 1.5-2 µ in diameter: columella none:
capillitium of delicate, colorless, anastomosing tubules, bearing toward
the center large, white, branching calcareous nodules; spores spherical,
or somewhat oval, dark purple-brown, rough-tuberculate, 15-20 µ.

This species differs as pointed out by Professor Sturgis, chiefly in the
character of the spores, their unusual size and roughness.[18]

Colorado; Africa!--_Robert Fries._


=EXTRA-LIMITAL=


=Erionema= _Penzig_

  1898. _Erionema_ Penzig, _Die Myx. d. Fl. v. Beutenzorg_, p. 36.

Sporangia plasmodiocarpous but distinct, cylindrical; capillitium
intricate, elastic; nodules few.


1. ERIONEMA AUREUM _Penzig_

  1898. _Erionema aureum_ Penz. _l. c._

Sporangia elongate, clustered, pendulous, yellow or grayish yellow,
generally stipitate on long flaccid stalks, or sessile and interlacing:
stipes yellow, blending with the hypothallus; capillitium intricate,
expanding at maturity after the manner of _Arcyria_ to several times the
sporangial length, the nodules small, yellow; spores nearly smooth,
violaceous-brown, 5-6 µ.

This unique form is near the fuligos which it resembles, especially when
sessile, in its intricate sporangia. The spores also are those of the
common _Fuligo septica_. The habit is however entirely different. Mr.
Fetch describes clusters in Ceylon, hanging free, four to six cm. in
length!


=2. Badhamia= (_Berkeley_) _Rost._

  1852. _Badhamia_ Berkeley, _Trans. Linn. Soc._, XXI., p. 153.
  1875. _Badhamia_ Rostafinski, _Monograph_, p. 139.

Sporangia simple; peridial wall simple, thin, breaking irregularly;
capillitium formed of abundant, richly anastomosing tubules, filled
throughout their entire length with calcareous granules; the nodes often
feebly represented; stipe poorly developed or wanting entirely;
columella, except in forms sometimes assigned to the sub-genus
_Scyphium_, poorly developed or none; spores frequently adherent in
clusters.

    The whole genus calls for careful and protracted study; and the
    present so-called species are like something new on the world;
    as full of vagaries as though but just entered upon their
    phylogenetic race.

This genus is closely related to _Physarum_, but differs in having the
capillitium calcareous throughout. Forms occur and are included here, in
which the capillitium, especially in some parts, is physarum-like,
physaroid. Nevertheless, the distinctions hold good as a rule, and are
at once diagnostic.

In capillitial differentiation the badhamias are definite and beautiful.
The net in a typical species, as _B. papaveracea_, is throughout
uniformly evenly tubular, the calcareous deposits delicate in the
extreme, presenting, as the spores disappear, an elegant trabecular
structure as if to support the persisting peridium if not the original
content. In other forms the capillitium is physaroid, with swollen
nodes, but heavily calcareous but not quite throughout. _Badhamia_,
_Physarum_, _Tilmadoche_, _Craterium_ present a consistent group, of
which _Physarum_ is the generalized expression.

Berkeley's idea of the genus was expressed as follows: "Peridium naked
or furfuraceous. Spores in groups, enclosed, at first, in a hyaline
sack." Rostafinski, while accepting Berkeley's generic name, redefined
it, emphasized the calcareous capillitium, and made reference to the
spore-adherence only to assert that Berkeley's description was, in this
particular, based on mistaken observation. In some species, the spores
do, in fact, show a tendency to cling together, a characteristic which
Badham was perhaps first to notice; but that this is occasioned by their
being surrounded by a sac or common pellicle has not been proved nor
even suggested, by any subsequent investigator. Berkeley's genus was
therefore founded upon a slight mistake; but we may conserve his rights
in the premises if we write _Badhamia_ (Berk.) Rost., and so keep
history straight.


=Key to the Species of Badhamia=

  _A._ Spores ovoid or ellipsoidal

     _a._ Spores free                                   1. _B. ovispora_

     _b._ Spores adherent                             2. _B. versicolor_

  _B._ Spores spherical

     _a._ Sporangia yellow

          i. Spores free                               3. _B. decipiens_

         ii. Spores adhering                              4. _B. nitens_

     _b._ Sporangia grey, spores free

          i. Always sessile                              5. _B. panicea_

         ii. Stalked, at least some of them

              O Stipe when present black

                 + Globose, small .5 mm.                 6. _B. affinis_

                ++ Larger, spores strongly spinulose  7. _B. macrocarpa_

               +++ Discoidal or annulate              8. _B. orbiculata_

             OO Stipes membranous yellowish

                 + Stipes long, sporangia iridescent       9. _B. magna_

                ++ Stipes short or none; iridescent   10. _B. foliicola_

     _c._ Sporangia grey, spores adherent

          i. Stipe when present yellowish

              + Wall iridescent, spores uniformly
                  marked                           11. _B. utricularis_

             ++ More calcareous, spores strongly
                  marked on one side                12. _B. capsulifera_

            +++ Colorado, spores anon barred          13. _B. populina_

         ii. Stipe when present black              14. _B. papaveracea_

     _d._ Sporangia brown, lilacine

          i. Sessile                                  15. _B. lilacina_

         ii. Stipitate, columellate                 16. _B. rubiginosa_


1. BADHAMIA OVISPORA _Racib._

  1884. _Badhamia ovispora_ Racib., _Myx. Ag. Cracov._, XII., p. 72.

Sporangia sessile depressed-globose or plasmodiocarpous, white or
ochraceous, covered by dense calcareous scales; capillitium white, the
lime-granules sometimes aggregate at the center to form a
pseudo-columella; spores not adhering, brownish-purple ellipsoidal, 8 ×
10-10 x 15 µ.

Reported from Bohemia, England, Pennsylvania.


2. BADHAMIA VERSICOLOR _Lister_.

  1901. _Badhamia versicolor_ List., _Jour. Bot._, XXXIX., p. 81.
  1911. _Badhamia versicolor_ List., _Mycetozoa 2nd ed._, p. 35.

Sporangia scattered or clustered, minute, .3-.5 mm., grey or
flesh-colored, sessile, the calcareous deposits slight; capillitium
white or apricot-colored; spores ovoid, 8 × 10-9 × 12 µ, clustered,
purplish, and warted at the broader end, elsewhere colorless and smooth.

This little species, as it comes to us, is grey, very uneven in size,
.2-.5 mm. and generally irregular in form and habit, perhaps scarce
mature. The capillitium is white, physaroid. The spores furnish the
distinguishing character. Sometimes globose, about 9-10. They are most
of them definitely and permanently affected in shape by the fact of
cluster-association, narrower in the direction of the cluster center.
The indications are that these may become globose with maturity.

Colorado,--_Bethel_; Scotland.


3. BADHAMIA DECIPIENS (_Curtis_) _Berk._

  1848. _Physarum decipiens_ Curtis, _Am. Jour. Sci._, VI., p. 352.
  1873. _Badhamia decipiens_ Berk., _Grev._, II., p. 66.
  1873. _Physarum chrysotrichum_ Berk. & C., Grev. II., p. 66.
  1876. _Badhamia chrysotricha_ (Berk. & C.) Rost., _App._, p. 4.

Sporangia gregarious, depressed-spherical or ovate, sessile,
occasionally plasmodiocarpous, dull yellow, roughened by the rather
large numerous calcareous scales; columella none; capillitium dull
orange, strongly calcareous, only slightly widened at the nodes;
spore-mass black; spores pale violet, minutely spinulose, free, 10-12 µ.

Among badhamias this and the next species are at once distinguished by
the color. If the brief description (_Grev._, II., p. 66) can be
regarded as defining anything, this is the same as _P. chrysotrichum_
Berk. & C. It resembles somewhat _P. serpula_ Morg., but differs
externally in color and in the surface scales, which are not perceptible
in the _Physarum_. The present species also resembles _Cienkowskia
reticulata_ (Schw.) Rost., but has a different capillitium. See under
that species.

Chiefly eastern and American. New England, Pennsylvania, Ohio, South
Carolina; reported recently also from Sweden and Germany.


4. BADHAMIA NITENS Berk.

  1852. _Badhamia nitens_ Berk., _Trans. Linn. Soc._, XXI., p. 153.
  1863. _Badhamia inaurata_ Currey, _Trans. Linn. Soc._, XXIV., p. 156.
  1873. _Badhamia nitens_ Berk., Rost., _Mon. App._, p. 3.

Sporangia gregarious or closely crowded, globose or depressed-globose,
.5-1 mm. in diameter, yellow or greenish yellow, rugulose, sessile;
capillitium yellow, forming an open net with occasional thickenings at
the nodes; spores clustered, delicately roughened, violaceous-brown,
10-12 µ.

This much resembles the preceding species except in the clustered
spores, and more commonly aggregate habit. The spores, as usual when
clustered, are conspicuously echinulate on the outer side. This did not
escape the notice of the author of the species, _op. cit._

Colorado, Oregon. Reported from West Indies, Ceylon, various parts of
Europe.


5. BADHAMIA PANICEA (Fries) Rost.

  1829. _Physarum paniceum_ Fries, _Syst. Myc._, III., p. 141.
  1873. _Badhamia panicea_ (Fr.) Rost., Fuckel, _Sym. Myc. Nachtr._,
           2, p. 71.

Sporangia gregarious or aggregated in closely compacted clusters,
globose or hemispherical, sessile, the peridium thin, transparent,
thickly dotted with white calcareous scales; stipe none; columella none,
although a pseudo-columella sometimes appears, formed by a more dense
development of the capillitium near the centre of the sporangium below;
capillitium abundantly developed, quite uniformly thickened, but showing
an occasional delicate connecting thread, the nodes also somewhat
flattened and enlarged; spore-mass black; spores by transmitted light,
bright violaceous-brown, minutely roughened, 10-13 µ. Plasmodium is said
to be white.

In America this seems to be a purely western species. Specimens are
before us from western Iowa and from Colorado, South Dakota, Nevada, and
Southern California. It is very well marked, though liable perhaps to be
mistaken at first sight for sessile phases of _P. notabile_ or _P.
cinereum_. The capillitium is, however, at once determinative. Colorado;
_Bethel_. Europe generally.


6. BADHAMIA AFFINIS _Rost._

  1875. BADHAMIA AFFINIS Rost., _Mon._, p. 143.

Sporangia aggregated, cespitose and sessile, or sometimes stipitate,
depressed above, flat or umbilicate below, the wall grayish white,
rugulose, and more or less calcareous-scaly; the stipe when present
erect or sometimes nodding, black or brownish black; hypothallus scanty;
columella none; capillitium not abundant, white, the nodes somewhat
expanded; spores globose, minutely roughened, violet-brown, large, 16-17
µ.

Chiefly on moss, the pale ashen sporangia generally very small, mounted
on the tips of the leaves, sometimes sessile, sometimes with a distinct
black stipe in which case the peridium is distinctly umbilicate.
Specimens from Kansas referred here have the stipe pale, rugose, long,
about twice the sporangium; habitat bark.

Rare. New York, Ohio, Kansas; more recently reported from Scotland and
Japan.

There is nothing new to be added here; nor appears any other place to
which such material as we have may be referred. New collections no doubt
will one day appear, when the identity may, let us hope, be made secure.

Meantime we have a form closely related which may be entered as


BADHAMIA IOWENSIS _Macbr. n. s._

Sporangia gregarious or loosely scattered, depressed globose, .4-.6 mm.
in diameter, stipitate, grey, flecked by rather prominent but small
rounded calcareous scales: the stipe short, half the diameter of the
sporangium, black or very dark brown, without hypothallus but widening
above into a shallow expanded base for the sporangia; columella none:
capillitium dull yellow, sometimes white, strongly calcareous,
physaroid, heavy; spores free, dark brown in mass, pale violet by
transmitted light, minutely verruculose, the tiny warts in some areas
more densely placed, producing evident shadowy spots, 10-11 µ.

This interesting little species occurs on the lower surface of fallen
logs, blocks, etc., in colonies of considerable extent, hundreds of
sporangia in a place. The capillitium is comparable to that of _B.
decipiens_ or _B. panicea_; it is physaroid to the extent that an
occasional filament may be found non-calcic, and not typically
badhamioid as in _B. papaveracea_, _B. macrocarpa_. The sporangial base
persists, dark brown, bearing traces of the clumsy capillitium, but no
columella real or simulated. Blackhawk Co., Iowa; _communicavit Dr.
Jessie Parish_. See Plate XX., 1, 1 _a_, 1 _b_.

Reddish or roseate forms sometimes appear in colonies otherwise as
described. It differs from _B. affinis_ in the size and character of the
spores, in color and character of the capillitium, habit and surface
markings.


7. BADHAMIA MACROCARPA (_Ces._) _Rost._

  1855. _Physarum macrocarpon_ Cesati, _Flora_, XXXVIII., p. 271.
  1875. _Badhamia macrocarpa_ (Ces.) Rost., _Mon._, p. 143.

Sporangia scattered or closely aggregate, crowded globose or
sub-globose, generally sessile, rugulose, white; the peridium
membranous, white above, below yellowish or brown; capillitium not
abundant, thoroughly calcareous, the nodes broad, conspicuous, the
connecting tubules rigid; columella none; hypothallus scant or none;
spore-mass black, spores non-adherent, by transmitted light bright clear
brown, thickly spinulose all over, large spherical, 12-15 µ.

Closely resembles externally _B. panicea_, but is easily distinguished
by larger and remarkably _spinulose_ spores, in this particular
unrivalled in the entire genus. European authors describe both sessile
and stipitate forms. American specimens generally are sessile and for
the most part closely crowded, almost heaped; but--Prof. Bethel finds
this in winter everywhere on fallen rotting stems of Opuntia and on the
bases of dead Yucca leaves, still attached. Associated with the typical
phase and often _occurring alone on the Yucca_ leaves is a discoidal
form which when first sent in (1908) was called var. _gracilis_.
Presented alone to one ignorant of its history and associations, it
would surely pass for a distinct species. This stalked phase is very
delicate; the stipe pale brown, or yellow. See Plate II., Fig. 9. See
also Sturgis _Col. Coll. Pub._ XII., 408.


8. BADHAMIA ORBICULATA _Rex._

PLATE XIV., Fig. 4.

  1893. _Badhamia orbiculata_ Rex. _Proc. Phil. Acad._, p. 372.
  1894. _Badhamia macrocarpa Rost._, Lister, _Mycetozoa_, p. 34
           (in part).
  1911. _Badhamia orbiculata_ Rex., Lister, _Mycetozoa, 2nd ed._, p. 37

Sporangia stipitate or sessile, orbicular discoidal, irregularly
elongated or plasmodiocarpous, averaging about 1 mm. in width, generally
stipitate, and when stipitate, flattened or depressed above, plane or
slightly umbilicate below; the peridium simple, more or less translucent
from the varying number of innate granules, sometimes covered with
circular flat masses of lime, gray except the point of attachment to the
stipe which is brown; stipe short, black, rough, plicate; capillitium
dense at the centre, radiant at the periphery where it meets the
sporangial wall, white; spores violaceous black, minutely warted, 12-15
µ.

This is a beautiful species, easily known by its discoidal or almost
annulate sporangia mounted upon short dark black stipes. The stipe in
western collections is sometimes very short, but generally suffices to
raise the sporangium, a little at least, above the substratum. Sessile
and plasmodiocarpous forms do occur with the typical stipitate phase,
but may be regarded here as elsewhere as indicative of incomplete
development. Plasmodium cream-colored, or pale yellow.

Pennsylvania, Ohio, Iowa, Nebraska, South Dakota, Colorado.


9. BADHAMIA MAGNA _Peck._

PLATE XIV., Fig. 1.

  1871. _Dictydium magnum_ Peck, _Rep. N. Y. State Mus._, XXIV., p. 84.
  1879. _Badhamia magna_ Peck, _Rep. N. Y. State Mus._, XXXI., p. 56.
  1894. _Badhamia macrocarpa Rost._, Lister, _Mycetozoa_, p. 34,
           in part.
  1892. _Bahamia varia_ Mass. _Mon. Myxog._, p. 319, in part.
  1894. _Badhamia magna_ Peck, List., _Mycetozoa_, p. 33.
  1899. _Badhamia capsulifera_ (Berk.) Macbr., _N. A. S._, p. 68.
  1911. _Badhamia magna_ Peck, Lister, _Mycetozoa, 2nd ed._, p. 34.

Sporangia globose or ellipsoid, .7-1 mm., pale iridescent, stipitate;
peridium thin with slight calcareous deposits, rugulose, opening
irregularly, white; stipe long flaccid, straw-colored; capillitium an
elegant uniform net, its threads stiffened by slight deposits of lime,
the nodes little thickened, badhamioid; spores free, dusky with a shade
of violet, minutely spinulose, about 10 µ.

This beautiful species closely resembles some forms of _B. utricularis_
from which it differs chiefly in its unclustered smooth spores. _B.
foliicola_ as recognized here is hardly more than a smaller,
short-stemmed form of this; see species next following.

Not rare in the eastern United States and Canada; Iowa. Seems to take
the place of _B. capsulifera_ of Europe.


10. BADHAMIA FOLIICOLA _Lister_.

  1897. _Badhamia foliicola_ List., _Jour. Bot._, XXXV., p. 209.
  1911. _Badhamia foliicola_ List., _Mycetozoa, 2nd ed._, p. 34.

"Plasmodium orange." Sporangia smaller, about .5-.6 mm., globose or
ellipsoidal, iridescent-gray, stipitate or sessile, the peridium thin,
rugulose, sparingly calcareous, when empty white; the stipe when present
short but yellowish, of the flaccid sort; capillitium badhamioid; spores
free, delicately spinulescent, dusky-violaceous, about 12-13 µ.

This has been so far collected but once, on the shores of Lake Okoboji.
It was developed, no doubt, on the natural débris of a bur-oak prairie
border, and went to fruit on the leaves, stems, and fruiting spikes of a
species of _Setaria_. It may prove to be different from the _B.
foliicola_ of Europe; future collections and study must reveal that.
Meantime it seems wise to refer it here.

The color of the plasmodium is quoted from Miss Lister; a fact of some
importance only when constant and confirmed by other criteria.

Iowa; Toronto,--_Miss Currie._


11. BADHAMIA UTRICULARIS (_Bull._) _Berk._

  1791. _Sphaerocarpus utricularis_ Bull., _Champ._, p. 128, t. 417,
           Fig. 1.
  1826. _Physarum utriculare_ Chev., _Fl. Paris_, I., p. 337.
  1829. _Physarum utriculare_ Fries, _Syst. Myc._, III., p. 139.
  1852. _Badhamia utricularis_ (Bull.) Berk., _Tr. Linn. Soc._, XXI.,
           p. 153.

Sporangia clustered, spherical or ovoid, large, sessile or mounted on
long, thin, strand-like stalks, blue-gray, violet-iridescent or
cinereous, smooth or more often rugulose; the stipes when present poorly
differentiated, as if thread-like filaments and strips of the
plasmodium, often branched and always reclining or even prostrate;
hypothallus none; capillitium a large-meshed open network of rather
slender tubules, the nodes unequally developed, white with the enclosed
lime; spores not strictly adherent though not without some tendency to
stick together, delicately warted, bright violet-brown, 10-12 µ.

This species resembles _B. capsulifera_, but is distinguished by a more
strongly rugulose less calcareous peridium and a more profuse
development of filamentous stipes, but especially by the character of
the spores. The spores of the present species while inclined, when
mounted in a liquid, to stay together, nevertheless do not coalesce in
heaps as in the related species, nor do they show any differentiation in
the episporic markings, these being uniform over the entire spore.

This is one of the finest and perhaps the most beautiful species of this
fine genus. It is a forest species, generally to be found on trunks of
fallen _Populus_ or _Tilia_ where the fine soft gray colonies often
spread for several inches along the ridges and in crevices of the bark.

Colorado (_Bethel_); Mississippi valley and east.


12. BADHAMIA CAPSULIFERA (_Bull._) _Berkeley_.

  1791. _Sphaerocarpus capsulifer_ Bull., _Champ._, p. 139, t. 470,
           Fig. 2.
  1801. _Physarum hyalinum_ Pers., _Syn. Meth. Fung._, p. 170.
  1852. _Badhamia capsulifera_ Berk., _Tr. Lin. Soc._, XXI., p. 153.
  1852. _Badhamia hyalina_ Berk., _Tr. Lin. Soc._, XXI., p. 153.
  1875. _Badhamia hyalina_ (Pers.) Rost., _Mon._, p. 139.
  1875. _Badhamia capsulifera_ (Bull.) Rost., _Mon._, p. 141.
  1894. _Badhamia hyalina_ Lister, _Mycetozoa_, p. 30.
  1911. _Badhamia capsulifera_ Lister, _Mycetozoa, 2nd ed._, p. 31.

Sporangia clustered or gregarious, sessile or sometimes stipitate,
globose or obovoid, gray or greenish white, snow-white when empty; the
peridium thin, translucent; the stipe, when present, as in _B.
utricularis_, although generally shorter and better developed, yellow or
straw colored; capillitium a very loose, open network of white,
lime-filled tubules, not much expanded at the nodes; columella none;
spore-mass purplish-brown; spores adhering in clusters of five or six to
twenty or more, globose, but affected somewhat by mutual pressure, rough
throughout, the exposed surface in the cluster, more distinctly warted,
10-12 µ.

This is _Badhamia hyalina_ (Pers.) Berk., Rost., _Mon._, p. 139; but
Rostafinski himself admits that the two species, here united, as he
defined them, are very much alike, having "the same spores and
capillitium", differing in the form of the sporangium, an inconstant
feature. Bulliard's name has precedence; his descriptions of this and
the preceding species are remarkable.

The peculiarly adherent spores distinguish the species from _B.
utricularis_; and the sporangia sessile or with short but strand-like
stipes, distinguish it from _B. papaveracea_.

The description above is for the typical European form. Lister expresses
doubt whether this occurs in the United States. The form from Iowa which
is the basis for the inclusion of the species in N. A. S. is, we
believe, nothing else than _B. capsulifera_ (Bull.) Berk. The form
approaches _B. populina_ as this is presented in Colorado. The Iowa
specimens are white, aggregate, superimposed, etc., but have the
capillitium and spores exactly as described for the type. Accordingly
_B. populina_ as this occurs in Colorado has been for years referred to
the Berkeley species. The thicker more strongly calcareous peridia
constitute, as would appear, the principal difference in the forms from
Colorado. See next species.


13. BADHAMIA POPULINA _List._

  1904. _Badhamia populina_ List. _Jour. Bot._, XLII., p. 129.
  1911. _Badhamia populina_ List. _Mycetozoa, 2nd ed._, p. 32.

Plasmodium white; sporangia sessile, crowded, heaped, large, 1.5 mm.,
rarely stipitate, globose or ovoid, white; stipe when present brown;
capillitial strands broad, calcareous; spores clustered, 16-20 in a
cluster, purple-brown, roughened and sometimes marked by obscure ridges
and bands, 10-12 µ.

Generally distinguishable by its unusually large calcareous, white
sporangia. The peridia are strongly calcareous, shell-like in texture.
In some cases the color is tinted with rose.

This species is very near _B. capsulifera_ as recognized in the United
States. When white the Colorado material corresponds almost exactly with
the forms collected in Iowa, and regarded as representing the species
just named. The Colorado gatherings are more strongly calcareous and the
spores sometimes present the variations named. "The Colorado phase of
the American form."

Colorado,--_Bethel_. Europe?


14. BADHAMIA PAPAVERACEA _Berk. & Rav._

PLATE IX., Figs. 6, 6_a_, and 6_b_.

  1873. _Badhamia papaveracea_ Berk. & Rav., _Grev._, II., p. 66.
  1894. _Badhamia hyalina_ var. _papaveracea_ Lister, _Mycetozoa_,
           p. 30.
  1899. _Badhamia papaveracea_ Berk. & Rav., Macbr., _N. A. S._, p. 69.
  1911. _Badhamia papaveracea_ Berk. & Rav., List., _Mycetozoa,
           2nd ed._, p. 32.

Sporangia gregarious, globose, large, stipitate, iridescent-gray; the
peridium thin, translucent, and containing but little calcareous
deposits, smooth or slightly rugulose; stipe very short, but generally
distinct, black or very dark brown; hypothallus none; capillitium a
network of large meshes with expanded nodes, prominent, white,
persistent after the spores have been blown away; spore-mass deep brown;
spores adherent as in _B. capsulifera_, marked in much the same way, and
about the same size, 10-12.5 µ

Distinguished by its short, dark, stipe and adherent spores.

Not common. New England, Pennsylvania, Ohio, Maryland, South Carolina,
Wisconsin, Iowa.


15. BADHAMIA LILACINA (_Fries_) _Rost._

  1829. _Physarum lilacinum_ Fries, _Syst. Myc._, III., p. 141.
  1875. _Badhamia lilacina_ (Fries) Rost., _Mon._, p. 145.
  1892. _Craterium lilacinum_ Mass., _Mon._, p. 271.
  1894. _Badhamia lilacina_ (Fr.) Rost., Lister, _Mycetozoa_, p. 34.
  1911. _Badhamia lilacina_ (Fr.) Rost., List., _Mycetozoa_, 2nd ed.,
           p. 38.

Sporangia globose, sub-globose, or obconical, sessile, gregarious or
more or less clustered, supported by a thin, continuous, transparent
hypothallus; the peridium smooth pale, lilac-brown without, white
within; stipe none, although some sporangia have a narrowed base;
columella none, the pseudo-columella formed by a more densely aggregated
capillitium near the base; capillitium dense, white, strongly nodulose;
spore-mass black; spores dark, violaceous-brown by transmitted light,
distinctly warted, or reticulate, the reticulations resembling somewhat
those of some of the trichias, as _T. affinis_, 10-15 µ.

Easily recognizable, generally at sight, by its peculiar color. White
forms, however, occur; often lilac-tinted and white from the same
plasmodium. A perfectly white colony seems to be rare. Both colors are
shown in specimens distributed. _N. A. F._, 2494.

Common eastward, Ontario, New England, Pennsylvania, Ohio, etc. Not
reported west of the Mississippi River.

Whatever the color, the spores are in every case positively diagnostic.
The episporic markings are unlike those of any other species in the
present order. Dr. Rex describes some New York forms as provided with a
short but distinct stipe. Such forms resemble externally _Scyphium
rubiginosum_ (Chev.) Rost. The hypothallus is also unique. V. next
species.


16. BADHAMIA RUBIGINOSA (_Chev._) _Rost._

PLATE X., Figs. 1, 1_a_, 1_b_, 1_c_.

  1826. _Physarum rubiginosum_ Chev., _Fl. Par._, p. 338.
  1872. _Craterium obovatum_ Peck, _Rep. N. Y. Mus._, XXVI., p. 75.
  1875. _Scyphium rubiginosum_ (Chev.) Rost., _Mon._, p. 148.
  1876. _Badhamia rubiginosa_ (Chev.) Rost., _Mon. App._, p. 5.
  1892. _Craterium rubiginosum_ Massee, _Mon._, p. 270.

Sporangia gregarious, obovoid, grayish brown, stipitate, the peridium
simple, membranous, above thin, pale, more or less calcareous below,
more persistent blending with the stipe; stipe erect, reddish brown or
purplish, expanded below into a small hypothallus, above, prolonged
within the sporangia more than half its height as a definite columella;
capillitium very dense, snow white, long persistent with the lower
two-thirds of the sporangial wall; spore-mass dark brown; spores by
transmitted light, dark violet or purple-brown, minutely roughened or
spinulose, not adherent, 12-14 µ.

This is probably the most common badhamia in the country and in the
world. It is found every year, in the woods, on masses of decaying
leaves, especially those of various species of oak. The plasmodium is
yellow. The fructifications are very distinct, not likely to be
mistaken for those of any other species; the stipes constitute a very
prominent feature in every gathering I have seen. Sometimes these are
more or less coalescent, especially toward the base, where they are apt
to be also wrinkled or longitudinally striate; in other specimens the
stipes are well differentiated, long, terete, with little or no
hypothallus.

_Badhamia curtisii_ (Berk.) Rost. is according to Lister (Mon., p. 35) a
sessile phase of this species. The only specimens known are in the
herbarium of Berkeley, now at Kew. The species is based upon a gathering
from S. Carolina. Berkeley thought it a didymium, called it _D.
curtisii_.

Reported from western Europe; the typical form abundant in the forested
regions of eastern N. America, especially in the Mississippi valley.


17. BADHAMIA SUBAQUILA _Macbr._

  1899. _Badhamia subaquila_ Macbr., _N. A. S._, p. 64.

Sporangia closely gregarious or crowded, globose or sub-globose,
sessile, brown, the peridium a thin but persistent brown membrane,
rupturing above irregularly and remaining as a cup after spore
dispersal; hypothallus none; capillitium strongly developed, thoroughly
calcareous, the meshes large, the nodular thickenings broad, white;
spores globose, in mass black, by transmitted light brown, very
rough-warted, large, 15-18 µ.

The variety is founded on material sent from Maine by the late Mr. F. L.
Harvey. Professor Harvey, upon the authority of Mr. Morgan of Ohio,
quotes the species, _Bull. Tor. Bot. Club_, 24, 67, as _B. verna_
(Somm.) Rost. But the specimens certainly do not conform to description
of _B. verna_. Here the wall corresponds with what is seen in _B.
rubiginosa_; but the spores are much larger, and the capillitial
structure very different.

Miss Lister regards this a form of No. 16. So far, the original
gathering represents the species; but the woods of Maine are certain one
day to send added information.

Rare. On mossy logs, Maine.


=3. Physarum= (_Persoon_) _Rost._

  1794.[19] _Physarum_ Pers., _Rom. Neu. Mag. f. d. Bot._, I., p. 88,
               in part.
  1795. _Physarum_ Pers., _Ust. Ann. Bot._, XV., p. 5, in part.
  1801. _Physarum_ Pers., _Syn. Fung._, p. 168, in part.
  1829. _Physarum_ (Pers.) Fries, _Syst. Myc._, II., p. 127, in part.
  1875. _Physarum_ (Pers.) Rost., _Mon._, p. 93.

Sporangia plasmodiocarpous, æthalioid or distinct; the peridium usually
simple, sometimes double, irregularly dehiscent, more or less definitely
calcareous; capillitium a uniform irregular net, dilated and calcareous
at the nodes, adherent on all sides to the peridial wall.

This large and cosmopolitan genus is readily recognized by the
characters quoted. It may be added that the capillitial threads are
always exceedingly delicate, probably tubular, but never filled with
lime throughout; the peridium may be almost nude or encrusted with lime,
which, where present, is always amorphous, never crystalline; the
sporangia when distinct may be either sessile or stipitate, and the
stipe in the latter case is often hollow and charged with lime. In
capillitium intermediate between _Leocarpus_ and _Badhamia_, since in
the first the capillitium is unequally calcareous, diverse, while in
_Badhamia_ the capillitium is intricate and calcareous throughout.

As first set up by its founder, the genus included diverse forms, only
one or two of which would be included in the genus as now limited.[20]
Persoon, however, was left to develop the matter to suit himself, and in
successive works gave, under this generic name, more and more prominence
to forms now so referred. Fries, _Syst. Myc._, III., pp. 127 _et seq._,
still better establishes the genus, though still including forms that,
judging from the description, seem to belong elsewhere. Twenty years
later Fries revising somewhat his earlier work thought to improve the
chances of future students by reducing the number of physarums. This he
would do by setting out certain evidently inter-related forms to make a
new genus, _Tilmadoche_.

He named two or three species only, leaving his sucessors to add others
as occasion offered.[21]

Rostafinski approved the good intention of Fries, but in the
_Monograph_, he entirely re-cast the genus as constituted by Fries;
actually called the species 'first cited' a typical physarum! Would not
have it in the new genus at all, first or last; but instead took the
second species of Fries as the type and added several forms, some from
the Friesian list, to make up a respectable group.

Until quite recently writers on the subject have generally approved the
course adopted by the Polish author. The arrangement showed features of
convenience, even if artificial to a degree. Perhaps we gain advantage
in all directions if we treat the original genus _Physarum_ as a whole,
but in the key take advantage of Fries' suggestion. We may write--


=Key to the Species of Physarum=

  1. Capillitium irregularly reticulate throughout; calcic
       nodes various                                          _Physarum_

  2. Capillitium more regular, especially below, furcate;
       nodes fusoid                                         _Tilmadoche_


SECTION I. PHYSARUM

  I. Fructification not stipitate, more or less plasmodiocarpous.

     1. Peridium simple.

      _a._ Calcareous deposits yellow                    1. _P. serpula_

      _b._ Calcareous deposits reddish or orange      2. _P. lateritium_

      _c._ Calcareous deposits white, peridium rugulose   3. _P. vernum_

     2. Peridium double.

      _a._ Fructification flatly compressed             4. _P. sinuosum_

      _b._ Fructification less compressed, rounded.

           i. Outer peridium white                      5. _P. bitectum_

          ii. Outer peridium brown or brown-tinged    6. _P. bogoriense_

         iii. Outer peridium yellow; capillitium yellow  7. _P. alpinum_

  II. Fructification of sporangia more or less distinct.

      A. Sporangia sessile, globose, ovoid, reniform, etc.

         1. Peridium double.

          _a._ Sporangia white, peridium testaceous.     8. _P. diderma_

          _b._ Sporangia tinged with yellow.

               i. Sporangia as if interwoven,
                    compressed                         9. _P. contextum_

              ii. Sporangia more nearly free, distinct.

                   o Spores pale, inner peridium
                       brittle                    10. _P. conglomeratum_

                  oo Spores spinulose, dark violet      11. _P. mortoni_

          _c._ Sporangia brown, dehiscence revolute  12. _P. brunneolum_

         2. Peridium simple, calcareous, flaky.

          _a._ Sporangia grey, plasmodiocarpous;
                 spores dusky, 10-12 forms of 3

          _b._ Sporangia grey, more or less dense;
                 spores violet, 6-7                    13. _P. cinereum_

          _c._ Calcareous deposits yellow or greenish,
                 spores 7-9                           14. _P. virescens_

          _d._ Sporangia rusty or reddish brown,
                 more or less dense                 15. _P. rubiginosum_

          _e._ Sporangia minute, lignicolous,
                 the fructification much extended
                 upon a hypothallus, lime deposit
                 tawny                                16. _P. instratum_

          _f._ Sporangia white, depressed, annulate,
                 sometimes with short stipes       17. _P. megalosporum_

         3. Peridium simple, not flaky,
              small .2-.3 mm., heaped                 18. _P. confertum_

      B. Sporangia, at least some of them, stipitate.

       _a._ Sporangia columellate.

            i. Columella small, usually conical.

                O Sporangium yellow.

                   o Columella white                    19. _P. melleum_

                  oo Columella yellow                  20. _P. citrinum_

               OO Sporangium not yellow.

                   o Capillitial mass persistent.

                      + Sporangia globose,
                          pallid or white          21. _P. globuliferum_

                     ++ Sporangia blue or lilac,
                          rose, etc.                  22. _P. lilacinum_

                    +++ Sporangia drab or brownish      23. _P. murinum_

                   ++++ Sporangia wine-red         24. _P. pulcherrimum_

                  oo Capillitial-mass less
                       persistent; orange          25. _P. pulcherripes_

           ii. Columella long, 4-5 the sporangium
                 non-calcareous.                      26. _P. penetrale_

          iii. Columella large globose              27. _P. luteo-album_

       _b._ Sporangia without columella.

            i. Sporangia nucleate, calcareous at center.

                O Stipe yellow                        28. _P. nucleatum_

               OO Stipe white                        29. _P. wingatense_

           ii. Sporangia non-nucleate.

                O Sporangia purple                      30. _P. newtoni_

               OO Sporangia blue, spotted with red  31. _P. psittacinum_

              OOO Grey or white, iridescent betimes.

                   o Sporangia white, discoidal;
                       stipe yellow                  32. _P. discoidale_

                  oo Sporangia lightly calcareous,
                       iridescent, sub-globose,
                       diam. about = to the stout,
                       brown, slightly wrinkled
                       stipe                        33. _P. leucophaeum_

                 ooo Sporangia globose or sub-globose.

                     x. Small, .5 mm.

                         + Stipe erect, clear brown   34. _P. nodulosum_

                        ++ Stipe weak, yellow,
                             stuffed                  35. _P. maculatum_

                    xx. Larger, lime-capped; stipe
                          strand-like               36. _P. didermoides_

                   xxx. Stipe snow-white, fragile      37. _P. leucopus_

                  xxxx. Stipe generally distinctly fluted

                         + Sporangia laterally
                             compressed, fan-shaped  38. _P. compressum_

                        ++ Sporangia typically
                             globose, umbilicate
                             below, connate, etc.,
                             strongly calcareous       39. _P. notabile_

                       +++ Sporangia reniform,
                             concave below _P. affine_,
                             see under 38

                      ++++ Sporangia larger, to 1 mm.,
                             nearly limeless,
                             iridescent               40. _P. tropicale_

                oooo Sporangia obovate, compound,
                       clustered, the stipe fuscous,
                       fluted, short.              41. _P. nicaraguense_

             OOOO Sporangia yellow, rarely iridescent or brown.

                   o Capillitial nodes white.

                     x. Stipe also white             42. _P. sulphureum_

                    xx. Stipe flesh-colored,
                          spores smaller                43. _P. carneum_

                   xxx. Stipe red or reddish brown  44. _P. citrinellum_

                  xxxx. Stipe yellowish, flaccid,
                          sporangia leocarpine        45. _P. albescens_

                 xxxxx. Stipe very short or none,
                          sporangia cylindric, brown  46. _P. variabile_

                  oo Capillitium nodes yellow or orange-yellow.

                     x. Badhamioid,
                          larger,--to .8 mm.       47. _P. auriscalpium_

                    xx. Physaroid, base persistent      48. _P. oblatum_

                 ooo Capillitium nodes pure yellow.

                     x. Capillitial threads yellow      49. _P. galbeum_

                    xx. Capillitial threads hyaline     50. _P. tenerum_

                   xxx. Peridium iridescent.

                         + Capillitium persistent    51. _P. flavicomum_

                        ++ Capillitium less
                             persistent, larger        52. _P. bethelii_


  SECTION II. TILMADOCHE

  I. Æthalioid, gyrose or irregular                     53. _P. gyrosum_

  II. Fructification stipitate.

      1. Sporangia irregular, often convolute,
           involved                                54. _P. polycephalum_

      2. Sporangia simple, nutant, discoidal.

       _a._ Thin-walled, grey or white.                  55. _P. nutans_

       _b._ Vari-colored, yellow, greenish,
              orange, etc.                               56. _P. viride_


1. PHYSARUM SERPULA _Morgan._

PLATE IX., Figs. 6, 6_a_, and 6_b_.

  1831. _Physarum reticulatum_ Alb. & Schw., Schweinitz, _N. A. F._,
           No. 2295.
  1885. _Physarum gyrosum_ (Rost.) Wingate, Ellis, _N. A. F._, No. 1396.
  1892. _Physarum gyrosum_ Rost., Massee, _Mon._, p. 307.
  1892. _Cienkowskia reticulata_ Rost, Macbr., _Bull. Nat. Hist. Iowa_,
           II., 2, p. 150.
  1894. _Badhamia decipiens_ Berk., Lister, _Mycetozoa_, p. 33, in part.
  1896. _Physarum serpula_ Morg., _Cin. Soc. Nat. Hist._, p. 101.
  1899. _Physarum serpula_ Morg., Macbr., _N. A. S._, p. 29.
  1911. _Physarum serpula_ Morg., Lister, _Mycetozoa, 2nd ed._, p. 81.

Plasmodiocarp repent, reticulate, forming anon lines, circles, dots,
etc., venulose pale yellow, ochraceous, at length whitish, the peridium
thin, membranaceous, simple, fragile, but withal persistent, below
united with a hypothallus which is more or less widely produced;
capillitium rather scant, but abundantly charged with polygonal nodules
of lime, yellow; spore-mass black; the spores, by transmitted light,
violaceous, warted, globose, 10-13 µ. Plasmodium, at maturity,
greenish-yellow.

A very distinct species not likely to be confused with anything else,
although in description, so far as concerns external characters,
suggesting _Cienkowskia reticulata_. The two forms are not at all alike
when placed side by side. For details as to the difference, see the
description of the species last mentioned.

Apparently not rare in eastern United States, Pennsylvania, Virginia,
Ohio, Iowa.

In 1805, Albertini and Schweinitz, _Conspectus Fungorum_, p. 251, t. 7,
Fig. 2, described as _Physarum reticulatum_, a European form which
became the basis of Rostafinski's genus _Cienkowskia_; see under that
genus. Later, 1829, Schweinitz discovered in America a physarum-looking
specimen which he took to be the same thing, and accordingly placed in
his herbarium under this name, and entered _N. A. F._ 2295. Rostafinski
further renamed another Schweinitzian species _Fuligo muscorum_ calling
it, _Mon._, p. 111, _Physarum gyrosum_. Wingate and Rex apply in Ellis,
_N. A. F._, this latter name to No. 2295 of Schweinitz. Such a reference
is a mistake, judging from Rostafinski's descriptions and from the
description and figure of Albertini and Schweinitz (_Consp. Fung._, p.
86, t. 7, I), and by the testimony of Lister. For further concerning
Rostafinski's species, see under _Physarum gyrosum_, p. 111, _Mon._


2. PHYSARUM LATERITIUM (_Berk. & Rav._) Rost.

  1873. _Didymium lateritium_ Berk. & Rav., _Grev._, II., p. 65.
  1875. _Physarum ditmari lateritium_ Rost., _Mon._, _App._, p. 9.
  1879. _Physarum inequale_ Peck, _Rep. N. Y. Mus._, XXXI., p. 40.
  1892. _Physarum chrysotrichum_ Berk. & C., Massee, p. 300.
  1894. _Physarum inequale_ Peck, Lister, _Mycetozoa_, p. 60.
  1896. _Physarum lateritium_ (Berk. & Rav.) Morg., _Jour. Cin. Soc._,
           p. 95.
  1899. _Physarum lateritium_ (Berk. & Rav.) Morg., Macbr., _N. A. S._,
           p. 33.
  1911. _Physarum lateritium_ Morg., List., _Mycetozoa, 2nd ed._, p. 82.

Plasmodium scarlet. Sporangia gregarious, sessile, globose or
sub-globose, or sometimes plasmodiocarpous, yellowish or orange,
everywhere, when fresh, spotted with minute scarlet granules; the
peridium thin, more or less rugulose; columella none; capillitium
delicate, generally yellow, with nodules conspicuous, yellow or reddish;
spores violet-brown in mass, by transmitted light pale violet, minutely
roughened, 7-9 µ.

A well-marked species easily recognized by the characters cited. The
extent of lime deposit at the capillitial nodes varies; sometimes very
little. This accounts for Berkeley's generic reference. On the other
hand, Lister makes the rounded lime knots "each knot with a red centre
surrounded by yellow, round, lime-granules" diagnostic. This pied
condition does not come out in any of our specimens. The capillitium in
broken specimens soon fades, tends to white, etc.

New York, Pennsylvania, Ohio, Colorado, and south. Ceylon, Java, Brazil.


3. PHYSARUM VERNUM _Somm._

  1829. _Physarum vernum_ Somm., Fries, _Syst. Mycol._, III., p. 146.
  1875. _Physarum cinereum_ (Batsch), Rost., _Mon._, p. 102, in part.
  1875. _Badhamia verna_ Rost., _Mon._, p. 145.
  1894. _Badhamia panicea_ Rost., List., _Mycetozoa_, p. 34.
  1899. _Physarum cinereum_ (Batsch) Rost., Macbr., _N. A. S._, p. 34
          (in part).
  1911. _Physarum vernum_ Somm., Lister, _Mycetozoa, 2nd ed._, p. 75.

"Plasmodium white." Sporangia sessile, generally plasmodiocarpous white,
nearly smooth; peridium more or less testaceous not scaly, but breaking
irregularly; capillitium densely calcareous, the nodules angular,
branching, sometimes united to form a pseudo-columella; spores dusky
violaceous, rough, 10-12 µ.

Sommerfeldt's description quoted by Fries, _l. c._, evidently concerned
a less calcareous phase. Fries by his annotation relieves somewhat the
reader's uncertainty.

Rostafinski calls this a badhamia but describes a physarum, and the form
has, as is believed, been consistently confused with _P. cinereum_ by
every student of the group from the days of DeBary until now. In the
second edition of the _Mycetozoa_, Lister clears the situation by
transferring the species to _Physarum_, and calling attention to
spore-dimensions. The fact is, the species in external appearance so
much resembles _P. cinereum_, that the unaided eye cannot distinguish
one from the other. Curiously enough, Rostafinski describes the form he
had before him as "one of the rarest." Doubtless had he gone back to his
specimens of _P. cinereum_ he had found plenty, for in Europe it seems
abundant everywhere. In this country it is _P. cinereum_ as now defined,
that is rarer, although not uncommon. From all connection with
_Badhamia_, as representing _B. panicea_ it should, as would appear, be
withdrawn once for all.


4. PHYSARUM SINUOSUM (_Bull._) _Weinm._

PLATE VIII., Figs. 6 and 6_a_, and PLATE XIX, Fig. 15.

  1791. _Reticularia sinuosa_ Bulliard, _Champ._, p. 94; t. 446, Fig. 3.
  1796. _Physarum bivalve_ Persoon, _Obs. Myc._, I., p. 6; t. III.,
           Fig. 2.
  1828. _Physarum sinuosum_ Wein., Fries _teste, l. c._
  1828. _Angioridium sinuosum_ Grev., _Scot. Crypt. Fl._, 310.
  1829. _Physarum sinuosum_ Fries, _Syst. Myc._, III., p. 145.
  1875. _Physarum sinuosum_ (Bull.) Rost., _Monograph_, p. 112.
  1892. _Physarum sinuosum_ Rost., Massee, _Mon._, p. 305.
  1894. _Physarum bivalve_ Pers., Lister, _Mycetozoa_, p. 57.
  1896. _Angioridium sinuosum_ (Grev.), Morg., _Cin. Soc. Nat. Hist._,
           p. 75.
  1899. _Physarum sinuosum_ (Bull.) Wein., Macbr., _N. A. S._, p. 28.
  1911. _Physarum sinuosum_ Wein., Lister, _Mycetozoa, 2nd ed._, p. 76.

Sporangia distinct or plasmodiocarpous, the plasmodiocarp creeping in
long vein-like reticulations or curves, laterally compressed; sometimes
distinct and crowded, always sessile. Peridium double; the outer thick,
calcareous, fragile, snow-white; the inner delicate, the dehiscence by
more or less regular longitudinal fissure. Capillitium strongly
developed with abundant white, calcareous granules. Spores smooth, dull
violet, 8-9 µ. Plasmodium pale gray, or nearly white.

Easily recognized at sight by its peculiar form, bilabiate and sinuous.
Apart from microscopic structure, perfectly described by Fries, _Syst.
Myc._, p. 145. Bulliard called it _Reticularia sinuosa_. Habitat
various, but not infrequently the upper surface of the leaves of living
plants, a few inches from the ground. The two sorts of fructification
often occur side by side, or merge into one another from the same
plasmodium. Where the substratum affords room the plasmodiocarpous style
prevails; in narrower limits single sporangia stand. The calcareous
deposit on the peridium is usually very rich and under a lens appears
made up of countless snowy or creamy flakes. Forms occur, however, in
which these outer calcic deposits are almost entirely wanting; the
peridium becomes transparent, the capillitium visible from without.
Judging from material before us, this appears to be the common
presentation in western Europe. See also No. 5 following.

Widely distributed. New England to the Carolinas, and Louisiana west to
South Dakota and Nebraska, Iowa and Washington.


5. PHYSARUM BITECTUM _List._

PLATE XIX., Fig. 16.

  1891. _Physarum diderma_ Rost., List., _Jour. Bot._, XXIX., p. 260.
  1894. _Physarum diderma_ Rost., List., _Mycetozoa_, p. 57.
  1911. _Physarum bitectum_ List., _Mycetozoa, 2nd ed._, p. 78.

Sporangia gregarious, sub-globose, sessile or plasmodiocarpous, smooth
white or pallid, terete or somewhat compressed; peridium double, the
outer wall calcareous, free and deciduous above, recurved and persistent
below; the inner, smooth, pale purplish, more persistent; dehiscence
more or less irregular beginning at the top; capillitium of large white
nodules connected by short hyaline threads; spores generally spinulose,
violaceous brown, 9-10 µ.

As suggested by the author of this species it is properly a variety of
_P. sinuosum_; certainly is, as it presents itself in this part of the
world. Of the species last named we have compressed forms opening by
narrow fissure along their knife-edged summit, with scarce place for
capillitium at all between the approaching walls; again we have colonies
of sporangia quite terete, calcareous without, opening in fragmental
fashion at the top, displaying sometimes the thin membranous inner wall
but at length fissured and gaping as in the more usual phase figured by
authors, where the plasmodiocarp is simply compressed but not
extravagantly thin. Both types occur in the western mountains, forms
with and without calcium, fissured by wider or narrower cleft, _from the
same plasmodium_; forms bilabiate and forms opening at first to display
an inner peridium; forms globose with narrow base, but apex cleft, and
forms ellipsoidal, yet compressed, opening like the gaping of some
tiniest bivalve; did not Persoon say _P. bivalve_! all are bivalvular at
the last! Nay; but what are these? Here are some of the shorter forms
become suddenly obovate, and are actually mounted on _stipes_! Surely
variation in the same plasmodium can no farther go![22]

Not rare. Colorado to the Pacific Coast. Evidently a western-American
variation of Bulliard's European type. The latter occurs abundantly in
Iowa on the shores of Lake Okoboji; otherwise not common.


6. PHYSARUM BOGORIENSE _Racib._

  1898. _Physarum bogoriense_ Raciborski, Hedw., XXXVII., p. 52.

Sporangia sessile, elongate, creeping but not reticulate, semicircular
in transverse section, sometimes globose or depressed globose; peridium
double, the outer thick coriaceous, yellow or brown, dehiscing
stellately into persistent more or less triangular reflected lobes,
remote from the thin, colorless inner wall; columella none; capillitium
feebly developed, the nodes white, large, isodiametric; spores bright
violet, smooth, 7-8 µ.

This species is not uncommon in the mountains of Colorado where it has
been taken at various stations by Bethel. It is reported from
Pennsylvania and South Carolina. Raciborski describes it from Java.

In habit it is very much like some forms of _P. sinuosum_ but differs in
the depressed, rather than compressed sporangia, and in the brown color
of the outer peridium.


7. PHYSARUM ALPINUM _G. List._

  1910. _Physarum alpinum_ G. Lister, _Jour. Bot._, XLVII, p. 73.

Sporangia globose and sessile or plasmodiocarpous, dull yellow, smooth
or scaly; peridium double, the outer wall densely calcareous, separating
irregularly from the membranous inner wall; capillitium densely
calcareous, the nodes large, more or less branched, yellow; spores
purple brown, closely and minutely warted, 9-14 µ.

This species is based by its author upon a gathering made in California
by Dr. Harkness and named by Phillips who received it in England,
_badhamia inaurata_. He seems not to have described it. Since its first
appearance, the form has been found repeatedly in the Juras. Specimens
are before me from Mt. Rainier believed to be the same. The
plasmodiocarpous habit and yellow capillitium separate this from related
_P. contextum_ and _P. mortoni_.

Europe, California, Washington.


8. PHYSARUM DIDERMA _Rost._

PLATE XVIII., Fig. 9.

  1875. _Physarum diderma_ Rost., _Mon._, p. 110.
  1898. _Physarum didermoides_ var. _lividum_ List., _Jour. Bot._,
           XXXVI., p. 162.
  1899. _Physarum diderma_ Rost., Macbr., _N. A. S._, p. 30.
  1911. _Physarum testaceum_ Sturgis, List., _Mycetozoa, 2nd ed._,
           p. 79.

Sporangia snow-white, clustered, sessile or narrowly adnate, globose or
polygonal by mutual compression; peridium double, the outer dense,
fragile, thick, calcareous, the inner delicate, remote, translucent,
capillitium well developed, the calcareous nodules white, rounded or
angular, sometimes uniting to form a pseudo-columella; spore-mass black;
spores purplish, distinctly rough, 10-12 µ.

A beautiful and distinct species. As others in the group with which it
is here associated, it is a physarum with the outward seeming of a
diderma. It occurs in Europe, therefore it is safe to assume that
Rostafinski saw it. So well marked it is that any good description will
define it, and Rostafinski describes it perfectly, adequately.[23]

Mr. Lister having used for another species the name we here apply--see
under _P. bitectum_--referred this present form to _P. didermoides_
Rost., _l. c._ Professor Sturgis, convinced that such reference was at
least doubtful, gave to our American gatherings the distinctive name
above, citing specimens from Massachusetts, from Colorado, and from
California. Curiously enough he also includes specimens of _R.
didermoides_ var. _lividum_ List., sent from England!

Rare! Certainly rare in Europe and so far seldom seen in the United
States, though widely distributed. Specimens are before us from Ohio,
Michigan, Iowa, Oregon. No doubt the mountains of the north Pacific
coast, a region to-day almost unsearched, will yet afford the species in
abundance.

As stated Mr. Lister first applied the name _P. diderma_ to a
plasmodiocarpous form occurring in England and near _P. sinuosum_. More
lately, _Mon., 2nd ed._, p. 78, he adopts a new specific name, _P.
bitectum_ for the English specimens, and enters _P. diderma_ as a
probable synonym for _P. lividum_ R. Evidently our present form as
described above has not come to Mr. Lister's view. He says the original
type is not to be consulted.

There is really no more merit in this later comparison than in that
discarded. The species _P. diderma_ is not _P. lividum_, but stands as
originally delimited, and will, doubtless, some day yet again appear in
its own behalf upon the witness-stand of time; when, as before, a
Frenchman in DeBary's old-time haunts may rise to give it welcome,
brought back by some keen-eyed Polish student eager now in the arts of
peace, from Warsaw's shady groves.


9. PHYSARUM CONTEXTUM _Persoon._

PLATE IX., Figs. 3 and 3_a_.

  1796. _Diderma contextum_ Persoon, _Obs. Myc._, I., p. 89.
  1801. _Physarum contextum_ Persoon, _Syn. Meth._, p. 168.
  1829. _Diderma contextum_ Persoon, Fries, _Syst. Myc._, III., p. 111.
  1873. _Diderma ochroleucum_ Berk. & C., _Grev._, II., p. 52.
  1879. _Diderma flavidum_ Pk., _N. Y. Rep. State Mus._, XXXI., p. 55.

Sporangia distinct, sessile, densely crowded, sub-rotund reniform more
often elongate, interwoven; peridium double; the outer rather thick,
calcareous, yellow, or yellowish white, the inner thin, yellowish;
capillitium white, containing numerous large, irregular calcareous
granules; columella none; spores deep violet, 11-13 µ, covered with
minute spinules.

This singular species occurs not rarely upon the bark of fallen twigs,
upon bits of straw or grass-stems lying undisturbed upon the ground. In
such a position the slime-mould covers, as with a sheath, the entire
substratum. The outer peridium, especially its upper part, is entirely
evanescent, our Fig. 3 shows the sporangia with upper outer peridium
wanting. Not rare in summer and autumn.

New England, New York, Pennsylvania, Ohio, Wisconsin, Illinois, Iowa,
Colorado, Oregon, Nicaragua.


10. PHYSARUM CONGLOMERATUM (_Fr._) _Rost._

  1803. _Spumaria granulata_ Schum., _Enum. Pl. Saell._, II., p. 196,
           No. 1419.
  1803. _Spumaria minuta_ Schum., _l. c._
  1829. _Diderma granulatum_ Schum., Fries, _S. M._, III., p. 110.
  1829. _Diderma minutum_ Schum., Fries, _l. c._, p. 111.
  1829. _Diderma conglomeratum_ Fries, _l. c._, p. 111.
  1875. _Physarum conglomeratum_ (Fr.) Rost., _Mon._, p. 108.
  1892. _Physarum rostafinskii_ Massee, _Mon._, p. 301.
  1894. _Physarum conglomeratum_ Rost., Lister, _Mycetozoa_, p. 58.
  1899. _Physarum conglomeratum_ (Fr.) Rost., Macbr., _N. A. S._, p. 31.
  1911. _Physarum conglomeratum_ Rost., List., _Mycetozoa, 2nd ed._,
           p. 80.

Sporangia depressed, globose, or irregular, sessile, more or less
aggregated, ochraceous-yellow, peridium double, the outer, thick,
cartilaginous, at length irregularly ruptured, and reflexed, disclosing
the more delicate, ashen-gray, inner membrane which encloses capillitium
and spores; capillitium abundant, showing large, white irregular
calcareous thickenings which are often consolidated in some sporangia
tend to aggregate at the centre; spore-mass brown, spores violaceous,
slightly roughened, 8-10 µ.

This beautiful species shows a peridium as distinctly double as in any
diderma. The outer peridium is reflexed exactly as in some species of
that genus; is yellow without, white within, and withal long persistent.
The capillitium of course distinguishes the species instantly as a
physarum. By the size of the spores it is distinguished from the species
preceding. This being a decisive specific character the synonymy prior
to Rostafinski is somewhat uncertain. The specific name adopted by the
Polish author is therefore approved, although perhaps not the earliest.

Rare. The only specimens thus far are from Tennessee and Louisiana.


11. PHYSARUM MORTONI _Macbr. n. s._

PLATE XX., Figs. 2, 2 _a_.

Sporangia gregarious, clustered but distinct, sessile small, about .75
mm., bright yellow, peridium double. The outer rough, breaking up into
comparatively few rather large deciduous scales, the inner peridium
white, calcareous, both persisting below to form a distinct cup;
capillitium lax, the nodes white, large, angular; columella none;
hypothallus none; spores distinctly rough, dark brown with the usual
purple shadow, 10-12 µ.

A very distinct little species related, no doubt, to _P. contextum_,
but different in habit. It is never crowded, shows no plasmodiocarpous
tendencies, while the outer peridium is generally deciduous except at
the base and falls in flakes.

Collected several times in the Three Sisters Mountains of Oregon by
_Professor Morton E. Peck._


12. PHYSARUM BRUNNEOLUM (_Phillips_) _Mass._

PLATE XX., Figs. 7, 7 _a_.

  1877. _Diderma brunneolum_ Phillips, _Grev._, V., p. 114.
  1888. _Diderma brunneolum_ Phill., Saccardo, _Syll. Fung._, No. 1292.
  1892. _Physarum brunneolum_ Phill., Massee, _Mon._, p. 280,
           Figs. 221-222.
  1894. _Craterium pedunculatum_ Lister, _Mycetozoa_, p. 71.
  1911. _Physarum brunneolum_ Mass., Lister, _Mycetozoa, 2nd ed._,
           p. 63, Pl. 69, Fig. _a_.

Sporangia scattered or gregarious, but not crowded, sessile, globose or
sub-depressed; peridium double, thick, smooth or polished, yellow brown,
stellately dehiscent, the segments reflexed, white within; columella
none; capillitium dense, with nodes numerous, large irregular,
internodes thin and short; spores globose, lilac, minutely warted, 6-7
µ.

This form was first described in _Grevillea_, V., p. 114, as _Diderma
brunneolum_ Phillips. Later, students of the specimens preserved by Mr.
Phillips, concur that we have to do not with a diderma, but with a
craterium, Lister, or physarum, Massee. There seems no reason why we
should not respect the decision of Massee, whose description is here
quoted in form somewhat abridged. The peridium is about as double as in
the many physarums, not more so; the inner membrane so delicate as only
occasionally to be revealed except to scrutiny most searching. But the
appearance as a whole is as of some brown diderma; only the calcareous
capillitium abides to prevent mistaken reference.

When opened by irregular dehiscence from above, the persisting cup-like
base of the sporangium recalls _Leocarpus fragilis_; but then again the
capillitium is different.

California, Portugal; Colorado,--_Sturgis._


13. PHYSARUM CINEREUM (_Batsch_) _Pers._

PLATE IX., Figs. 4, 4 _a_, 4 _b_.

  1786. _Lycoperdon cinereum_ Batsch, _Elench. Fung._, p. 249, Fig. 169.
  1801. _Physarum griseum_ Link, _Diss._, I, p. 27.
  1805. _Physarum cinereum_ Persoon, _Synopsis_, p. 170.
  1829. _Didymium cinereum_ Batsch, Fries, _Syst. Myc._, III., p. 126.
  1829. _Physarum plumbeum_ Fries, _Syst. Myc._, III., p. 142.
  1875. _Physarum cinereum_ Batsch, Rost., _Mon._, p. 102, in part.
  1896. _Physarum plumbeum_ Fr., Morgan, _Myx. Mi. Val._, p. 98.
  1899. _Physarum plumbeum_ Fr., Macbr., _N. A. S._, p. 35.
  1909. _Physarum cinereum_ (Batsch) Pers., Torrend, _Flore des Myx._,
           p. 183.

Plasmodium watery white, or transparent, wide streaming on decaying sod,
etc. Sporangia sessile, closely gregarious, or even heaped, sub-globose,
elongate or plasmodiocarpous, more or less calcareous, gray; peridium
simple, thin, more or less densely coated with lime; capillitium
strongly developed, the nodes more or less richly calcareous, the
lime-knots rounded, angular; spore-mass brown, spores clear
violaceous-brown, 6-7µ, distinctly warted.

This delicate, inconspicuous species is well defined by the characters
given. It occurs not rarely on richly manured ground, in meadows, lawns,
or even on the open prairie. The plasmodium may form rings several
inches in diameter, scattered here and there over a surface several
square feet in extent, in fruit ascending the blades of grass,
completely covering these with the crowded sporangia. The color of the
fruit is well described in the specific name; gray or ashen gray. The
spores are very distinctly papillate; in some specimens, however, almost
smooth; in few instances, rough.

Common. New England west to the Black Hills and Pacific coast.
Cosmopolitan.

The present species well illustrates the difficulty confronting the
author of to-day who, discussing a group of microscopic organisms, would
fain use the nomenclature of his predecessors, honored, but equipped
with insufficient lenses. Here is a species reported common in Europe,
observed by every mycologist there, from Micheli down, and yet awaiting
adequate description until Rostafinski in his great book, gives the
results of microscopic analysis. We are now really dealing with _P.
cinereum_ Rost; _P. cinereum_ Batsch is a compliment to certain rather
clever water-color drawings.

Rostafinski gives a long list of synonyms, none, it is believed,
represent American forms; and without taking careful thought, surely no
one would rudely disturb such honorable interment; but, in his
description the range of spore-measurement, 7-13.3 µ, gives us pause,
and raises the suspicion that possibly, in one case or another, the
sepulture were perhaps premature. The range is too great! Perhaps, in
the series offered in confirmation, small-spored forms represent one
species, large-spored, something else?

European students may decide this at their leisure. But Rostafinski
having, not without much labor, practically completed his review of the
physaroid forms had almost finished the last genus _Badhamia_, when his
mind perhaps returned, no doubt with some lingering misgivings, to the
thirteenth species in his physarum list. There were there, he recalled,
some large-spored specimens which had rather badhamioid capillitium.
The sessile physarums of Fries were also before him, those especially,
"floccis albis." Of these one shall be _B. panicea_, one _B. lilacina_
and one _B. verna_, described as having rather delicate colorless
capillitial tubes combined in a loose net, the calcareous deposits about
the enlarged intersections scanty, the spores 12.5 µ.

The description of the fructification as a whole is a condensed
statement of that which describes _P. vernum_, and all taken together
indicates some physarum. See now No. 3 preceding, p. 51.

_P. plumbeum_ Fr. belongs here. It has similar spores, the only
difference is a less calcareous peridium and more scattered habit of
fructification with more nearly regular, depressed-globose sporangia.

_P. cinereum_ Pers. as cited by Link, _op. cit._, is apparently a
badhamia, may be _P. vernum_, while P. _griseum_ is probably the present
species.


14. PHYSARUM VIRESCENS _Ditmar_.

PLATE VIII., Figs. 7, 7 _a_, 7 _b_.

  1817. _Physarum virescens_ Ditmar, Sturm, _Deutsch. Fl. Pilze_, I.,
           p. 123, Pl. 61.
  1875. _Physarum ditmari_ Rost., _Mon., App._, p. 8.
  1892. _Physarum ditmari_ Rost., Macbr., _Bull. Lab. Nat. Hist. 1a._,
           II., p. 155.
  1894. _Physarum virescens_ Ditmar, Lister, _Mycetozoa_, p. 65.
  1909. _Physarum virescens_ Ditmar, Torrend, _Flo. d Myx._, No. 207.
  1911. _Physarum virescens_ Ditmar, Lister, _Mycetozoa, 2nd ed._,
           p. 83.

Sporangia sessile, crowded or heaped in small bunches, a dozen or more
sporangia in one pile, spherical, ovoid or elongate, yellow or greenish
yellow; peridium thin, fragile; capillitium delicate, with rather small,
irregular, yellowish, calcareous nodes; columella none; spores bright
violet, minutely roughened, 7-9 µ.

This species occurs more commonly on moss-tufts, with which it is
frequently con-colorless, or escaped on dead leaves, etc. The peridium
is flecked with calcareous scales or grains stained yellow or green, and
to these the whole fruit owes its peculiar color. The color and
aggregate, heaped sporangia are distinctive macroscopic characters.

In the _Monograph_, p. 113, Rostafinski adopted properly Ditmar's name
for this species. Upon later consideration, in the _Appendix_, p. 8, he
changed the name, writing _P. ditmari_, on the ground that _virescens_
was descriptive of a character to which the species in question
occasionally refuses to conform. Most authors since Rostafinski have
simply accepted his suggestion, so that the species is often entered _P.
ditmari_ Rost. _P. virescens_ is certainly to be preferred. _N. A. F._,
2692.

Canada, New England, New York, Pennsylvania, Ohio, Iowa, Black Hills,
South Dakota.


15. PHYSARUM RUBIGINOSUM _Fries_.

  1817. _Physarum rubiginosum_ Fries, _Symb. Gast._, p. 21.

Plasmodium scarlet. Sporangia globose or cylindric, sessile or sometimes
narrowed to a stem-like base as if short-stipitate, olivaceous brown
with sometimes a flush of red; the peridium simple, thin rugulose or
plain, the calcareous scales few, or apparently included; columella
none; capillitium dense, the nodules rather large, angular, rusty brown;
spores dull violaceous, gently roughened, about 10 µ.

A beautiful well-marked species, but evidently rare in North America.
Our only typical specimens are from the gatherings by Mr. Wingate, part
of which is by Lister referred to this species, _Mycetozoa, 2nd ed._, p.
82.

_P. rubiginosum_ Fr. in the _N. A. S._, 1899, is based on certain west
coast specimens now known as _Badhamia decipiens_ Berk.

In Colorado there occurs a plasmodiocarpous form of the species. It has
the characteristic spore and capillitium but in form and habit differs
very decidedly. The fructification is a delicate netted plasmodiocarp,
the tubule about .5 mm., bright red; the peridium simple, cartilaginous,
dehiscent from above, and flecked with just here and there a red
calcareous scale.

Collected at Palmer Lake; _Professor Bethel._


16. PHYSARUM INSTRATUM _Macbr. n. s._

  1899. _Physarum thejoteum_ Macbride, _N. A. S._, p. 36, not Fries,
           as cited.
  1911. _Physarum virescens_ Ditmar, Lister, _Mycetozoa, 2nd ed._,
           p. 83.

Sporangia very small, closely crowded on a delicate, more or less
visible hypothallus, often connate, but not superimposed, sub-spherical,
dull orange, brownish or tawny; peridium thin, violaceous, covered with
very minute yellow calcareous scales; columella none; capillitium lax,
sometimes almost wanting; the nodules small, yellowish or brownish,
occasionally confluent; spore-mass violaceous, spores by transmitted
light, violet-tinted, smooth or nearly so, 6-7 µ.

Not uncommon in the Mississippi valley, where it sometimes is passed by
the collector as an immature form of some other species. The appearance
is very characteristic, unlike _P. virescens_ in both habit, size, and
color. Colonies are quite often three inches in length. The most common
habitat seems to be rotten oak, especially fragments of charred logs,
etc.

Ohio, Illinois, Missouri, Iowa, Nebraska.

This species presents a decidedly well-marked form, so much so that it
may be easily recognized at sight, without a lens. It therefore requires
special discussion, and although in the spore-characters and some minor
but not determinative details it agrees with _P. virescens_ Ditm. to
which it is by European authors sometimes referred, it seems
nevertheless deserving of specific recognition, since in its entire
habit and expression it is not only completely different but is constant
in its specific peculiarities, much more so than is the suggested
related form.

In the first edition of this work, the form was referred to _Physarum
thejoteum_ of Fries. This was the judgment of our American colleague,
Professor A. P. Morgan whose work in this group is widely recognized.
Fries admits, _Syst. Myc._, III., p. 142, that while he deems _P.
thejoteum_ very distinct, he yet has not seen _P. virescens_ Ditm.!
Since our form apparently does not occur in Europe, specimens which the
distinguished author had before him were doubtless representatives of
the now commonly recognized species of Ditmar.

For these reasons it seems appropriate to give the American type a
suitably descriptive title.


17. PHYSARUM MEGALOSPORUM _Macbr._

PLATE XVI., Figs. 7 and 7 _a_.

  1917. _Physarum melanospermum_ Sturgis, _Mycologia_, Vol. IX, p. 323.

Sporangia gregarious, sessile, or short stipitate depressed, annulate,
or at least umbilicate above, white or anon roseate, about .75 mm;
stipe, when present, short, thick, black or dark brown! hypothallus
none; columella none; capillitium strongly calcareous, an abundance of
irregular white nodules burden the delicate net; spores dark sooty brown
with a shade of purple by transmitted light, verruculose, 12-13 µ.

This species is recognizable at once by its regular, uniform, depressed,
annulate or pitted sporangia, scattered evenly over the habitat of
rotten leaves or wood. It suggests a didymium in its form and habit, but
is near a badhamia. Colorado; _Bethel_, 1908.


18. PHYSARUM CONFERTUM _Macbr. nom. nov._

PLATE XV., Figs. 1, 1 _a_, 1 _b_.

  1899. _Physarum atrum_ Schw., Macbr., _N. A. S._, p. 36.
  1911. _Physarum atrum_ Schw., Lister, _Mycetozoa, 2nd ed._, p. 74.

Sporangia small about .2-.3 mm. in diameter, gregarious, confluent,
clustered or heaped, dull violaceous brown; peridium thin, more or less
transparent, generally limeless but sometimes lightly sprinkled with
minute white flecks: capillitium scanty, the calcareous nodes small,
rounded, elongate, white! columella none; spores violet-brown,
distinctly warted, 10-12 µ.

Having been assured on information believed trustworthy that the
Schweinitzian herbarium confirmed the identity of the species before us,
in the first edition of this work the form was listed as _P. atrum_
Schw. Meantime in the herbarium referred to, at Philadelphia the
original type of _P. atrum_ still exists. My valued correspondent, Mr.
Hugo Bilgram, has recently given it careful study. It is a limeless _P.
didermoides_ (Pers.) R.! Small wonder we have had trouble! Exit
_Physarum atrum_ Schw.

The species is not uncommon, especially eastward; has been generally
ignored for reasons cited.

Distinguished from everything else by the color and small size of the
heaped sporangia. It resembles some phase of _P. virescens_ where the
sporangia are small and somewhat heaped or rather aggregated, and
scantily supplied with lime; but in such case the lime is yellow and the
spores are small.

This species has also been constantly referred to our confused _P.
cinereum_, _P. plumbeum_, etc., but Schweinitz, who certainly had seen
_P. cinereum_ in Europe, since he cites it, under several forms, in the
_Conspectus_, found the species in America and proceeded in Pennsylvania
in December to find something else, very different as he thought, and in
fact. He called this new discovery _P. atrum_, "beautifully
_reticulate_", he says "like _P. cinereum_ but larger."

Most American students in an effort to keep faith with their pioneer
mycologist, have taken cue from the specific name, looking for something
_black_, heedless that in Pennsylvania almost any delicate thing has
'dark looks' in the middle of the winter! Berlese in Saccardo _Syll._
VII., p. 350, regarding _P. atrum_ as a synonym, writes for the black
American specimens, _P. reticulatum_, emphasizing another Schweinitzian
descriptive adjective. But _P. atrum_ Schw. has had place in literature
to this hour.


19. PHYSARUM MELLEUM (_Berk. & Br._) _Mass._

  1873. _Dydymium melleum_ Berk. & Br., _Jour. Linn. Soc._, XIV., p. 83.
  1873. _Didymium chrysopeplum_ Berk. & C., _Grev._, II., p. 53.
  1876. _Physarum schumacheri_ Spr. var. _melleum_ Rost., _Mon., App._,
           p. 7.
  1892. _Physarum melleum_ Massee, _Mon._, p. 278.
  1896. _Cytidium melleum_ (Berk. & Br.), Morg., _Jour. Cin. Soc._,
           p. 83.
  1899. _Physarum melleum_ (Berk. & Br.), Mass., Macbr., _N. A. S._,
           p. 47.
  1911. _Physarum melleum_ Mass., Lister, _Mycetozoa, 2nd ed._, p. 46.

Sporangia scattered, stipitate, globose, flattened below, clear yellow
or honey colored; stipe short, about equaling the sporangium, pure
white, somewhat wrinkled; columella small but distinct, white;
hypothallus none, capillitium abundant, open, snow-white, with rather
large angularly stellate nodes; spore-mass brown, almost black; spores
by transmitted light, pale violet or lilac-tinted, almost smooth, 7.5-10
µ.

Easily distinguished by its white stipe, columella and capillitium in
contrast with yellow peridial walls. _N. A. F._, 1395. Massee refers
this number erroneously to _P. schumacheri Rost._ The description and
specimen do not correspond. By that name the species has however, been
hitherto known in the United States.

Eastern United States, common; rare west of the Mississippi.

Reported from Brazil, Japan and the tropic islands round the world.
Portugal.


20. PHYSARUM CITRINUM _Schumacher_.

  1803. _Physarum citrinum_ Schum., _Enum. Pl. Saell._, II., p. 201.
  1911. _Physarum citrinum_ Schum., List., _Mycetozoa, 2nd ed._, p. 51.

Sporangia gregarious, scattered, globose, somewhat flattened below, pale
yellow, citrine, stipitate; the peridium thin, covered almost completely
with small calcareous scales; stipe stout, erect, fragile, tapering
upwards, furrowed, opaque, arising from a small hypothallus which is
anon continuous from one sporangium to the next; columella small,
conical, yellow; capillitium a rather dense, delicate network, the
calcareous nodules yellow, numerous, roundish, and generally small;
spore-mass black; spores under the lens violaceous, almost smooth, about
8 µ.

This species seems to be rare in the United States. It resembles
somewhat _P. melleum_, from which it is distinguished by its yellow
stipe. _P. galbeum_ is a smaller form, and lacks the columella.
Rostafinski strangely confused the synonymy here, including even _P.
rufipes_ Alb. & Schw.

New England, Ohio, Colorado.


21. PHYSARUM GLOBULIFERUM (_Bull._) _Pers._

  1791. _Sphaerocarpus globuliferus_ Bull., _Champ._, Pl. 484, Fig. 3.
  1801. _Physarum globuliferum_ Pers., _Syn._, p. 175, T. III.,
           Figs. 10, 11, 12.
  1829. _Diderma globuliferum_ Fries, _Syst. Myc._, III., p. 100.
  1876. _Physarum petersii farlowii_ Rost., _Mon., App._, p. 6.
  1879. _Physarum albicans_ Peck, _Rep. N. Y. Mus._, XXX., p. 50.
  1893. _Physarum columbinum_ Macbr., _Bull. Lab. Nat. Hist. Iowa_,
           II., 384.
  1899. _Physarum globuliferum_ (Bull.) Pers., Macbr., _N. A. S._,
           p. 45.
  1911. _Physarum globuliferum_ Pers., Lister, _Mycetozoa, 2nd ed._,
           p. 48.

Sporangia gregarious, stipitate, globose, or slightly depressed above,
pale blue-gray or pure white; stipe sometimes equal to the sporangium,
generally longer, slender, slightly wrinkled, white, or yellow, pallid,
when longer tapering upward; columella white, conical, sometimes
obsolete; hypothallus none; capillitium dense, but delicate, persistent,
a close network of hyaline threads, with white or yellowish nodes
sparingly thickened and calcareous, many without lime; spore-mass brown;
spores by transmitted light, violet, minutely warted, 7.5-9 µ.
Plasmodium greenish-yellow.

This species, very common eastward, rare west of the Mississippi, is at
once very beautiful and very variable. Its several phases have been
again and again observed and described too often by distinct specific or
varietal names. A form from New York, with long, white stems and almost
pure white sporangia, is _P. albicans_ Peck. Forms occur like _P.
albicans_, but flushed with _rose_ throughout. From New England,
specimens sent Rostafinski were by him deemed a variety of _P. petersii_
Berk. & C., and called _P. petersii_ var. _farlowii_ Rost. By this name
the species has been generally distributed in this country. _N. A. F._,
1120. Most gatherings of this species have small, somewhat ochraceous,
sporangia, and pale yellow, or somewhat rusty, stipes. These latter,
with somewhat heavier stem, represent _Physarum simile_ Rost. A form
collected sparingly in Iowa has short, white stipes and blue gray
sporangia one-third larger than observed in the eastern types. This was
recorded, _l. c._, as _P. columbinum_ Macbr.; name already in use. The
spores in the Iowa specimens are also a little larger, 8-10 µ. Pale
cyanic and roseate forms also sometimes occur in late fruitings; see
next species.

In all phases the persistent tenacity of the capillitium is a striking
characteristic well noticed by Fries (_l. c._, p. 101): "Peridia a gleba
omnimo libera, dein tota diffracta, evanescentia, ... capillitio
compacto forma servata persistente." The peridium, except a small part
below, all falls away, leaving the capillitium apparently intact,
crowded with spores.

From England to Iowa; Canada, south to Louisiana and Mexico; apparently,
in one form or another, cosmopolitan.


22. PHYSARUM LILACINUM _Sturgis & Bilgram._

  1917. _Physarum lilacinum_ Sturg. & Bilg., _Mycologia_, Vol. IX.,
           p. 323.

Sporangia gregarious, stalked, globose, erect, pale-lilac to pale
Indian-red in color, 0.5 mm. in diameter; sporangium-wall membranous,
beset with rounded masses of lilac or reddish lime. Stipe erect,
broad-based, tapering upwards, calcareous, furrowed, paler than the
sporangium or concolorous, 0.7-0.9 mm. long, about 0.1 mm. thick,
columella conical or columnar, capillitium delicate, rigid, persistent;
lime-knots small, rounded, composed of large, pale lilac, or reddish,
spherical granules. Spores pale-brown, almost smooth, 8-9 µ.

Vicinity of Philadelphia,--Bilgram.

23. PHYSARUM MURINUM _Lister_.

  1894. _Physarum murinum_ Lister, _Mycetozoa_, p. 41.
  1899. _Physarum ravenelii_ (Berk. & C.) Macbr., _N. A. S._, p. 48.
  1911. _Physarum murinum_ Lister, _Mycetozoa, 2nd ed._, p. 50.

Sporangia scattered, globose or perfectly spherical, ashy-brown,
rugulose, stipitate; stipe elongate, pale brown, erect, generally
tapering upward, calcareous, brittle; hypothallus none; columella short,
hemispherical or bluntly conical; capillitium dense, much as in _P.
globuliferum_, the calcareous nodules, umber, brownish or orange-yellow,
small; spore-mass brown; spores by transmitted light, bright lilac,
almost smooth, 7-9 µ.

A very distinct species, easily known by its peculiar drab-colored
peridium and dull brown stalks. The author of the species allows for the
capillitial nodes none other tint but brown. Under direct illumination
many gatherings, especially where the sporangia are well blown out, show
nodules of a bright orange tint.

Not rare in the eastern United States, to Missouri and Iowa. Reported
also from western Europe.

Mr. Lister finds _Didymium ravenelii_ Berk. & C., on which _P.
ravenelii_ (Berk. & C.) Macbr. is founded, referable to _P.
pulcherripes_ Pk.


24. PHYSARUM PULCHERRIMUM _Berk. & Rav._

  1873. _Physarum pulcherrimum_ Berk. & Rav., _Grev._, II., p. 65.
  1875. _Physarum pulcherrimum_ (Berk. & Rav.) Rost., _Mon._, p. 105.
  1879. _Physarum atrorubrum_ Peck, _Rep. N. Y. Mus._, XXXI., p. 40.
  1899. _Physarum pulcherrimum_ Berk. & Rav., Macbr., _N. A. S._, p. 49.
  1911. _Physarum pulcherrimum_ Berk. & Rav., Lister, _Mycetozoa,
           2nd ed._, p. 50.

Plasmodium dark red. Sporangia scattered or gregarious, globose, even,
or somewhat wrinkled, dark red, stipitate; stipe cylindric, even,
sub-concolorous or blackish; columella small or none; capillitium free
from spores, whitish, with a slight pinkish tinge; spores dark brown in
mass, dark red when separated, globose, smooth, 7.5-8.5 µ.

The capillitium is very delicate, and when cleared of spores the
knot-like thickenings are seen to be very small and of a dark red color,
to which is probably due the pinkish tinge which marks the whole. A part
only of the thickenings are filled with lime granules. The dark red
granules of the sporangium walls are abundant and appear to form a
continuous crust.

This is _P. atrorubrum_ Peck, and his description, _l. c._, has been
closely followed. The very brief description in _Grevillea_, however,
antedates the New York publication and, all inadequate as it is, no
doubt applies to the same thing.

Not rare. New York, Pennsylvania, Ohio, Missouri, Iowa.


25. PHYSARUM PULCHERRIPES _Peck._

  1805. _Physarum aurantiacum_ var. _rufipes_ Alb. & Schw., _Consp.
           Fung._, p. 94.
  1829. _Diderma rufipes_ (Alb. & Schw.) Fries, _Syst. Myc._, III.,
           p. 101.
  1873. _Physarum pulcherripes_ Peck., _Bull. Buff. Soc. Nat. Hist._,
           I., p. 64.
  1873. _Didymium erythrinum_ Berk., _Grev._, II., p. 52.
  1873. _Didymium ravenelii_ Berk. & C., _Grev._, II., p. 53.
  1873. _Physarum petersii_ Berk. & C., _Grev._, II., p. 66.
  1875. _Physarum schumacheri_ Spr. var. _rufipes_ Alb. & Schw., Rost.,
          _Mon._, p. 99.
  1894. _Physarum pulcherripes_ (Peck), Lister, _Mycetozoa_, p. 41.
  1896. _Cytidium rufipes_ (Alb. & Schw.) Morg., _Jour. Cin. Soc. Nat.
           Hist._, p. 81.
  1899. _Physarum rufipes_ (Alb. & Schw.) Morg., Macbr., _N. A. S._,
           p. 50.
  1911. _Physarum pulcherripes_ Peck., List., _Mycetozoa, 2nd ed._,
           p. 49.

Sporangia gregarious, dark-colored, sprinkled with orange flakes of
lime, globose, the wall thin, deciduous, stipitate; stipe slender,
erect, deep red, sometimes black below, pale or orange above, and
supported on a well-developed hypothallus; columella scant or none;
capillitium dense, the meshes and nodes unusually small and delicate,
the latter reddish or yellow; spore-mass black; spores by transmitted
light, violet-tinted, 8-10 µ., almost smooth.

The striking contrast of color between sporangia and stipes renders this
species at sight, quite distinct from any related form. The peridia in
the specimens before us are black or iridescent-black sprinkled more or
less profusely with orange lime granules which sometimes cover all but
the base. The stipe, springing from a small hypothallus, is dark red
below for about one-fourth its height, then vermillion, above expanding
slightly beneath the peridium; the columella scant or none. The
capillitium is an elegant delicate net, with numerous small, uniformly
regular, calcareous nodes, orange; by transmitted light, yellow. The
spores, brown in mass, are, by transmitted light, pale violet, slightly
papillose, 8-10, mostly about 8 µ. The plasmodium is probably yellow.

This species is no doubt related to _P. psittacinum_. It is, however,
much smaller, has a calcareous stipe, and a much less variegated
peridium, and generally a small columella.

It is also akin to _P. globuliferum_ and to _P. murinum_, _P. petersii_
Berk. & C. is reported the same thing.


26. PHYSARUM PENETRALE _Rex._

PLATE XV., Figs. 6, 6 _a_.

  1891. _Physarum penetrale_ Rex., _Proc. Phil. Acad._, p. 389.
  1899. _Physarum penetrale_ Rex., Macbr., _N. A. S._, p. 55.
  1911. _Physarum penetrale_ Rex., List., _Mycetozoa, 2nd ed._, p. 36.

Sporangia scattered, erect, stipitate, generally ellipsoidal, pyriform,
rarely globose; peridium membranaceous semi-transparent, studded
sparsely with rounded, pale yellow or yellow-gray lime-granules,
rupturing to the base into two or four segments; stipe variable,
slender, subulate, rugulose, flattened laterally toward the base,
translucent, dull red or golden red in color; columella four-fifths the
height of the sporangium, concolorous with the stipe, acuminate;
capillitium dense, persistent, the nodes frequently calcareous, rounded,
yellow; spore-mass brown, spores nearly smooth, brownish, 6-7 µ.

Readily recognizable by the elongate sporangia and the lengthened
columella unique among physarums. The capillitial nodes are at first
pale yellow, but tend to whiten on exposure. The spores when highly
magnified show delicate spinulescence.

Maine, New York, Pennsylvania, Ohio, Europe, Java.


27. PHYSARUM LUTEO-ALBUM _Lister_

  1904. _Physarum luteo-album_ List., _Jour. Bot._, XLII., p. 130.
  1911. _Physarum luteo-album_ List., _Mycetozoa, 2nd ed._, p. 48.

Sporangia gregarious, sub-globose, large, about 1 mm. in diameter,
yellow shading into white, orange or olivaceous, smooth or rugulose,
stipitate; stipe stout, smooth, .5-1 mm. high, yellow or orange above,
white below, cylindric, lime-stuffed; columella large, sub-globose or
clavate, yellow; capillitium either of very slender pale yellow,
threads, branching at acute angles and anastomosing or of broad, yellow
simple or forked strands, persistent after spore-dispersal; nodules few,
small, linear or fusiform; spores purple-brown, spinulose, 10-12 µ.

This species, originally described from England and northern Europe has
more recently been identified in material sent by Professor Sturgis from
Colorado. In description the form is well marked; evinces apparently
great variation alike in form, color, and structure.

The material we have, however, is poor, badly weathered.

The general plan of structure corresponds very well with Fries' idea of
his genus Tilmadoche, although the present species would seem, by very
grossness, strangely out of place with the tilmadoches. But the
singular, didermoid, evenly branching, threads of the capillitium,
bearing their slender spindle-shaped burdens of lime are very
suggestive; it is a diderma gone wandering into the camp of the
physarums if one may judge from Miss Lister's graphic plate.

The specific name selected for this peculiar form has once before done
service, but apparently for something quite dissimilar. Schumacher,
_Enum. Pl. Saell._ II., p. 199, has _P. luteo-album_. Fries thinks he
had a perichæna on hand; at any rate, not a physarum, and makes
Schumacher's combination a synonym for _Perichaena quercina_ Fr., which
Rostafinski in turn makes synonymous with _P. corticalis_ (Batsch) R. If
"once a synonym always a synonym" be esteemed good taxonomic law, this
species must one day have another name. The present author, unwilling to
change his colleague's preference in this case, nevertheless begs to
suggest that such a binomial as _P. listeri_ would probably at once make
future history of the species less eventful, and honor the memory of
England's latest and most distinguished student of the group he loved.


28. PHYSARUM NUCLEATUM _Rex._

  1891. _Physarum nucleatum_ Rex., _Proc. Phil. Acad._, p. 389.

Sporangia gregarious, spherical, ½ mm., white, stipitate; peridial
wall membranaceous, rupturing irregularly, thickly studded with rounded
white lime-granules; stipe about 1 mm., subulate, yellowish-white,
rugose; columella none, capillitium dense, snow-white, with minute,
white, round or rounded nodes, in the centre a conspicuous mass of lime
forming a shining ball, not part of the stipe although sometimes
produced toward it; spore-mass black; spores brown-violet, delicately
spinulose, 6-7 µ.

This species most nearly resembles in appearance and habit of growth _P.
globuliferum_ Pers., but may be distinguished from it by the absence of
a columella, by the central ball of lime, and the very small rounded
lime-granules in the meshes of the capillitium. Exceptionally the lime
granules of the sporangium wall are sparse or absent entirely, in which
case the wall has a silvery or coppery metallic lustre.

Pennsylvania, Nicaragua.


29. PHYSARUM WINGATENSE _nom. nov._

PLATE XVI., Figs. 3, and 9.

  1876. _Tilmadoche columbina_ (Berk. & C.) Rost., _Mon., App._,
           p. 13 (?).
  1889. _Tilmadoche compacta_ Wing., _Proc. Acad. Nat. Sci._, p. 48.
  1894. _Physarum compactum_ List., _Mycetozoa_, p. 45.
  1896. _Physarum compactum_ (Wing.) Morg., _Jour. Cin. Soc._, p. 91.
  1899. _Tilmadoche compacta_ Wing., Macbr., _N. A. S._, p. 61.
  1916. _Physarum columbinum_ (Rost.) Sturg., _Mycologia_, Vol. VIII.,
           p. 4.

Sporangia gregarious, or somewhat crowded, erect or cernuous, stipitate,
gray or brownish gray, globose; peridium thin, metallic brown or bronze
in color, splitting at maturity in floriform manner into six to twelve
segments; stipe white or yellowish white, often shading to black or
fuscous below, rather long, tapering upward; hypothallus none; columella
none; capillitium extremely delicate, white or colorless, radiating from
a central lime-mass or nucleus, and with ordinary nodules small and few,
fusiform; spore-mass brown; spores by transmitted light, violet-brown,
delicately warted, 7-8 µ.

This species is well marked by several characteristics; the brilliant
wall of the peridium, white-flecked and laciniate, the delicate
_Didymium_-like capillitium running from centre to peridium, and
especially the peculiar aggregation of lime at the center of the
sporangium, like nothing else except a similar structure found in
_Physarum nucleatum_ Rex. The variations affect the stipe and the
distribution of the capillitial lime. Some eastern specimens show stipes
melanopodous, black below; specimens from Ohio and Nicaragua show stipes
milk-white throughout. As to the capillitium, in some of the Nicaragua
collections the lime is more uniformly distributed through the
capillitium, and accordingly the nucleus is not conspicuous, its place
being taken by two or three nodes plainly larger than the others. The
peculiar brown metallic lustre of the peridial wall, and the strongly
developed calcareous patches with which the peridium is covered are
constant features.

That this is the _Didymium columbinum_ Berk., or _T. columbina_ (Berk.)
Rost., is very doubtful; the specific name given by Wingate becomes
inapplicable when the series is transferred to _Physarum_, since in that
genus the combination is already a synonym. See _P. compactum_
Ehrenberg, _Syl. Myc. Berl._, p. 21 (1818), cited repeatedly in the
synonymy; Fries, _op. cit._, Vol. III., p. 101. So also _P. columbinum,
l. c._, pp. 133, 135, etc., to say nothing of the fate of Persoon's
first record, _Obs. Mycol. pars prim._, p. 5, 1796. This is Wingate's
species, let it bear his name.


30. PHYSARUM NEWTONI _Macbr._

PLATE XIV., Figs. 5, 5 _a_, 5 _b_.

  1893. _Physarum newtoni_ Macbr., _Bull. Lab. Nat. Hist. Iowa_, II.,
           p. 390.
  1899. _Physarum newtoni_ Macbr., _N. A. S._, p. 37.
  1911. _Physarum newtoni_ Macbr., Lister, _Mycetozoa, 2nd ed._, p. 54.

Sporangia simple, gregarious, short-stipitate or sessile, globulose or
flattened, when not globose, depressed and deeply umbilicate above,
purple, smooth, thin-walled, stipe when present very short and
concolorous; columella none; hypothallus none; capillitium abundant,
delicate, with more or less well-developed nodules, which are also
concolorous; spores by transmitted light, dark brown, thick-walled,
rough, nucleated, about 10 µ.

A very handsome little species collected by Professor G. W. Newton in
Colorado, at an altitude of several thousand feet. Easily recognized by
its almost sessile, rose purple, generally umbilicate sporangium.


31. PHYSARUM PSITTACINUM _Ditm._

  1817. _Physarum psittacinum_ Ditm., Sturm, _Deutsch. Fl. Pilze_,
           p. 125.
  1829. _Physarum psittacinum_ Ditm., Fries, _Syst. Myc._, III., p. 134.
  1873. _Physarum psittacinum_ Ditm., Rost., _Mon._, p. 104.
  1911. _Physarum psittacinum_ Ditm., Lister, _Mycetozoa, 2nd ed._,
           p. 55.

Sporangia scattered or gregarious, globose or depressed-globose, or
reniform, iridescent-blue, mottled with various tints, red, orange,
yellow, white, stipitate; stipe equal, or tapering slightly upward,
rugose, orange or orange red, without lime, rising from a small
concolorous hypothallus; columella none; capillitium dense, crowded with
calcareous, brilliant orange nodules which are angular in outline and
tend to aggregate at the centre of the sporangium; spore-mass brown;
spores by transmitted light, pale brown, slightly but plainly warted,
about 10 µ. _N. A. F._, 2492.

Differs from _P. pulcherripes_ Pk. in external coloration, the peridium
a rich blue, mottled but not with lime; in the capillitium, dense,
calcareous, with large angular or branching nodes; in the stipe without
lime; in the spores, a little larger than in _P. pulcherripes_, and by
transmitted light much more distinctly brown in color. The sporangia are
also broader in the present species, reaching 1 mm.

Rare. Maine, New York, Massachusetts, Pennsylvania. Reported common in
Europe, Ceylon, Japan, etc.


32. PHYSARUM DISCOIDALE _Macbr. n. s._

PLATE XX., Figs. 3 and 3 _a_.

Sporangia gregarious, scattered, discoidal, depressed or umbilicate
above, sometimes almost annulate, snow-white, small, .5-.7 mm.,
stipitate; stipe about twice the sporangium, pale yellow, strand-like,
but erect, even; hypothallus none; columella none; capillitium strongly
calcareous, almost as in _Badhamia_, aggregate at the center, and
forming a pseudo-columella at the base of the peridium; peridial wall
firm, covered with innate patches of lime, somewhat yellow at the base;
spores minutely spinulose, violaceous, 7-9 µ.

This little species reaches us from California. It appears in late
winter in undisturbed grass tufts and the sporangia are scattered over
the lower leaves. It displays a remarkable amount of lime. The nodules,
however, are not large; they are rounded and connected here and there by
the ordinary retal tubules characteristic of a physarum.


33. PHYSARUM LEUCOPHÆUM _Fr._

  1818. _Physarum leucophaeum_ Fr., _Symb. Gast._, p. 24.
  1875. _Physarum leucophaeum_ Fr., Rost., _Mon._, p. 113, Figs. 77, 78.
  1899. _Physarum leucophaeum_ Fr., Macbr., _N. A. S._, p. 21.
  1911. _Physarum nutans_ Pers., sub-species _leucophaeum_ (Fr.) Lister,
          _Mycet., 2nd ed._, p. 67.

Sporangia scattered or gregarious, stipitate; the peridium globose or
sub-depressed, plano-convex, but never umbilicate below, erect,
bluish-ashen; the stipe short, rugose, sub-sulcate, fuscous, brown, or
sometimes almost white, even or slightly attenuate upward from a
thickened base or sometimes from an indistinct hypothallus; capillitium
dense, intricate; the nodules white, with comparatively little lime,
thin, expanded, angular or branching; columella none; spore-mass black,
spores violaceous, minutely roughened, about 8-10 µ.

This extremely delicate and beautiful form is certainly not to be
referred to _Tilmadoche alba_ (Bull.) Fr. Fries, who seems to have known
of _P. compressum_ A. & S. and refers _it_ to _P. nutans_ Pers., _op.
cit._, p. 130, annotates the present species: "Species especially
remarkable in the stipe, in the internal structure, and in its whole
habit, nor is there any other with which it may be compared. Peridium
thin, not uniform, presently breaking up into laciniate scales; at first
yellow, then bluish-ashen; when empty, white. The form inconstant,
globose, depressed, but never umbilicate at the base." If we may judge
by what Fries says on the subject, he certainly distinguished clearly
between this species and _T. alba_ (Bull.), to say nothing of the
stouter, larger, in every way coarser forms called by Rostafinski _P.
nefroideum_, _P. compressum_, _P. lividum_, etc.

The shadowy little species has had an eventful history, dipping in and
out of our story in most uncertain fashion. Beginning with Fries, as
noted, it received confirmation at the hands of DeBary, and by
Rostafinski was given priority over a long list of synonyms, and
figured. The earlier English authors follow Rostafinski, but for Lister
in the _Mycetozoa_, p. 51, the species becomes a synonym of _T. alba_ as
_P. nutans_, the description appropriately enlarged to receive it.
Meantime American students generally confused it with the tilmadoches on
the one hand and _P. nefroideum_ R. (supposed) on the other. In 1897,
Robt. Fries in _Sver. Myxom. Flora_, brings the species again to view as
co-partner with _P. nutans_ and in the _Mycetozoa, 2nd ed._, p. 67, it
appears as sub-species to the same.

The resemblance to _P. album_ or _P. nutans_, is chiefly as intimated, a
matter of definition; real differences are found in the irregular
capillitium, fitting a globose sporange, in the character of the stipe
and the consequent pose. See under _P. nutans_ and _P. notabile_.


34. PHYSARUM NODULOSUM _Cke. & Balf._

  1881. _Physarum nodulosum_ Cke. & Balf., _Rav. N. A. F._, Exsic., 479.
  1889. _Badhamia nodulosa_ Massee, _Jour. Myc._, Vol. V., p. 186.
  1891. _Physarum calidris_ Lister, _Jour. Bot._, Vol. XXIX., p. 258.
  1896. _Craterium nodulosum_ (Cke. & Balf.) Morg., _Jour. Cin. Soc._,
           p. 87.
  1899. _Physarum nodulosum_ Cke. & Balf., Macbr., _N. A. S._, p. 51.
  1911. _Physarum pusillum_ List., _Mycetozoa, 2nd ed._, p. 64.

Sporangia gregarious; minute, globose, bluish-white, the sporangial wall
thin and more or less encrusted with lime, breaking up irregularly,
stipitate; stipe slender, longer than the sporangium, attenuate upward
or even, bright brown, rugose, expanded above into a shallow cup-like
base for the sporangium; columella none; capillitium with lime-knots
more or less abundant, white, often uniting, badhamioid; spore-mass
black; spores by transmitted light, pale lilac-brown, almost smooth,
10-12 µ.

Pennsylvania, Ohio, Iowa; Canada.

One of the smallest species of the genus, by its proportionally long
stipe and small round sporangium reminding one somewhat of _P.
globuliferum_; much smaller, however, and in every way different. The
generic characters are mixed, and the species has been accordingly
variously referred. The lower part of the peridium is sometimes
persistent after the dehiscence, and so far reminds of _Craterium_. But
this character is not constant, and even at best the persisting part is
very small, not greater than in _P. melleum_, for example. On the other
hand, the capillitium in some sporangia is strongly calcareous, reminds
of _Badhamia_, but in most sporangia the _Physarum_ characters are
sufficiently clear.

In the Kew Herbarium, it is said, are two American specimens under one
label, "_Didymium pusillum_." One specimen is a didymium indeed, but, as
it appears, _D. proximum_ Berk., already described. The other is a
physarum. It is proposed in _Mycetozoa, 2nd ed._, to use the combination
thus set free, as if applied by the original author to the second
specimen, _not_ didymium, and to make the new combination date from 1873
and so take precedence of the binomial applied in 1881 by Cooke and
Balfour here retained by the law of priority.


35. PHYSARUM MACULATUM _Macbr._

PLATE XIV., Figs. 6, 6 _a_, 6 _b_.

  1893. _Bull. Lab. Nat. Hist. Iowa_, II., p. 383.
  1899. _Physarum maculatum_ Macbr., _N. A. S._, p. 47.
  1911. _Physarum tenerum_ Rex., Lister, _Mycetozoa_, p. 52, in part.

Sporangia scattered or gregarious, very small, .3-.4 mm., dull gray,
thin-walled, dotted with minute, white calcareous granules, stipitate;
stipe long, about 2 mm., stout, attenuated upward, striate
longitudinally or wrinkled, filled with irregular yellow masses of lime
and accordingly bright yellow in color; columella none; capillitium
forming a dense net, with comparatively small yellow nodular
thickenings; spores globose, purplish, each minutely papillose and
displaying several scattered spots occasioned by local development of
the papillae; diameter of the spores 9-10 µ.

This species was set up for the reception of certain material collected
by Professor Shimek, in 1892, in Nicaragua. It remains so far unique.
The small globose sporangium mounted upon a long upwardly tapering
stipe, .5 mm. thick below, but narrowed at the extreme base where it is
lightly attached, a stem which is simply a sack stuffed with yellow
lime-granules;--this and the yellow capillitium are distinguishing
features. The capillitium and spores suggest _Tilmadoche viride_, but
the entire habit precludes such reference. Perhaps nearest to _P.
melleum_.

Castillo, Nicaragua.

Miss Lister thinks this the same as _P. tenerum_ Rex. But the whole
habit and external appearance are different; the stipe notably long,
clumsy, surcharged with lime; a very singular form.


36. PHYSARUM DIDERMOIDES (_Pers._) _Rost._

PLATE IX., Figs. 1, 1 _a_, 1 _b_, 1 _c_.

  1801. _Spumaria (?) didermoides_ Acharius, Pers., _Syn. Fung._,
           p. xxix.
  1829. _Diderma oblongum_ Fr., _Syst. Myc._, III., p. 103.
  1831. _Spumaria licheniformis_ Schw., _N. A. F._, p. 261, No. 2364.
  1832. _Physarum atrum_ Schw., _Syn. Fung., Am. Bor._, p. 258.
  1875. _Physarum lividum_, Schw., Rostafinski, _Mon._, p. 96.
  1875. _Physarum didermoides_ (Ach.) Rost., _Mon._, p. 97.

Plasmodium pale, watery-white or gray; sporangia crowded, ovoid or
cylindric, stipitate or sessile, blue-gray, often capped with white;
stipe variable in length and structure, where well developed pure white,
often flattened, expanded and diaphanous, connate with others through
the irregular reticulate or sheet-like hypothallus; columella none;
capillitium ample, the lime knots angular or rounded, white connected by
hyaline threads; spores in mass black, by transmitted light dark violet,
decidedly spinulose, 12-15 µ.

A very variable species in many particulars. The sporangia in the same
cluster are stipitate and sessile, ovoid and spherical. Our description
does not quite agree with that of Rostafinski. As may be seen from the
plate, it is the _outer_ peridium that is with us white, burdened with
lime, the inner is simpler and comparatively thin. The whiteness of the
outer peridium is however, easily displaced. The colony may not show it
at all, in which case the peridia remaining give to the fructification
entire a pale lead color, very characteristic. The disposition of the
lime in the capillitium is also notably variable. Specimens occur which
in so far realize Rostafinski's _Crateriachea_; that is, the lime is
massed as a snow-white pseudo-columella in the centre of each
sporangium. In such cases the lime of the outer peridium is scant or
limited in amount, never forming the calcareous cap shown in Fig. 1. The
size of the spores is also variable. Rostafinski gives 12.5-14.2 µ; not
infrequently a single spore reaches 16 µ, a very unusual range of
variation.

The species is not common in the upper Mississippi valley, but can be
obtained in quantity where once it appears, as the plasmodia are
profuse.

Ohio, Carolinas, Tennessee, Iowa, South Dakota, Kansas. Especially to be
looked for on the bark of fallen stems of _Populus_ and _Negundo_.

Brazil, India, Japan.

_Physarum lividum_ Rost., _Mon._, p. 95, is but a less calcareous form
of this, as is evident even by the author's description. Professor
Morgan thought _P. lividum_ a phase of _P. griseum_ Lk. Link, however,
reckons _P. griseum_ the same as _P. cinereum_. Link, _Diss._, I., p.
27.


37. PHYSARUM LEUCOPUS _Link._

PLATE IX., Figs. 7, 7 _a_, 7 _b_.

  1809. _Physarum leucopus_ Link, _Diss._, I, p. 27.

Sporangia gregarious, stipitate, globose snow-white, with a didymium
like covering of calcareous particles; stipe white, not long, conical or
tapering rapidly upward, slightly sulcate, brittle, from an evanescent
hypothallus; columella none or small; capillitium, consisting of rather
long hyaline threads, connecting the usual calcareous nodes, which are
large, angular, snow-white; spore-mass black; spores by transmitted
light, violet-brown, distinctly warted, about 10 µ.

The snow-white, nearly smooth stem, the small sporangium (½ mm.)
covered with loose calcareous granules, distinguish this rare species.
It looks like a small _Didymium squamulosum_. Fries called it _D.
leucopus_, _Syst. Myc._, III., p. 121.

Rare. Iowa, Ohio, Maine; Portugal.


38. PHYSARUM COMPRESSUM _Alb. & Schw._

PLATE XVIII., Fig. 14, and PLATE XIX., Fig. 12 and Fig. 4.

  1805. _Physarum compressum_ Alb. & Schw., _Fung. Lus._, p. 97.
  1875. _Physarum nefroideum_ Rost., _Mon._, p. 93, in part.
  1875. _Physarum affine_ Rost., _Mon._, p. 94.
  1909. _Physarum compressum_ Alb. & Schw., Torrend, _Fl. des Myx._,
           p. 197.
  1911. _Physarum compressum_ List., _Mycetozoa, 2nd ed._, p. 70.

Sporangia more or less scattered, _compressed_-globose, or
compressed-reniform, i. e. often umbilicate, stipitate, sessile, or
elongate as if plasmodiocarpous, calcareous, white or ashen; peridium
thin, covered with squamules, opening irregularly, usually by apical
cleft; stipe, when present, short, stout, more or less sulcate, dark
brown or ashen; capillitium a rather loose net, the nodules white,
variable in size and shape; spores purplish-brown, delicately roughened,
about 10-12.5 µ.

_P. affine_ R. was in this connection set up for European types
compressed indeed, but more strongly _reniform_. The author says in his
further description that the form _affine_ is less definitely
umbilicate, has white stems, etc.; allantoid, one would now say. Such
forms now begin to appear in America; and if for these a specific name
is needed, it is provided, _P. affine_ Rost., Plate XIX., Fig. 4.

This seems to be a cosmopolitan species, now that we have found it.
However, in North America it is rare. It is reported from Pennsylvania,
from Colorado; Harkness found it in California, and the writer has often
collected it in Oregon, on Mt. Rainier, Washington, and in California.
Europe.


39. PHYSARUM NOTABILE _nom. nov._

PLATE IX., Figs. 2, 2 _a_, 2 _b_; PLATE XV., Fig. 2; and Frontispiece.

  1873. _Didymium connatum_ Peck, _Rep. N. Y. Mus._, XXVI., p. 74.
  1879. _Physarum polymorphum_ (Mont.) Rost., Peck, _Rep. N. Y. Mus._,
           XXXI., p. 55.
  1893. _Physarum leucophaeum_ Fr., Ellis, _N. A. F._, No. 2396,
          _second exhibit_.
  1893. _Physarum leucophaeum_ Fries, Macbr., _Bull. Lab. Nat. Hist.
           Iowa_, II., p. 156.
  1894. _Physarum compressum_ Alb. & Schw., List., _Mycetozoa_, p. 53,
           in part.
  1896. _Physarum connexum_ Link., Morg., _Jour. Cin. Soc._, p. 92,
           in part.
  1896. _Physarum confluens_ Pers., Morg., _l. c._, p. 94.
  1899. _Physarum nefroideum_ Rost., Macbr., _N. A. S._, p. 41, in part.
  1911. _Physarum connatum_ Lister, _Mycetozoa, 2nd ed._, p. 71.

Sporangia gregarious, sessile, stipitate, or even plasmodiocarpous; when
stipitate, depressed, varying at times to irregular reniform in the same
colony; globose, the peridium strongly calcareous, cinereous-white;
stipe variable, generally tapering upward, always distinctly deeply
plicate-furrowed throughout, in color dark, opaque, sometimes touched
with white or gray; capillitium abundant, the white lime-knots, varying
in size and shape, connected by rather long hyaline threads, with here
and there an empty node; spore-mass black, by transmitted light, dark,
sooty brown, minutely papillose, 10-11.5 µ.

This remarkable species, while not at all difficult of recognition to
one familiar with its phases, is withal very difficult to define.
Normally stipitate, it often shows from the same plasmodium all sorts of
forms, the shape of the fructification dependent apparently upon
external conditions prevalent at the time. The amount of calcium also
varies, especially in the capillitium, where there is usually much, with
a tendency to the formation of something like a pseudo-columella; the
outer net in such cases nearly destitute. The calcium in the stipe also
varies; the black or brown stipes are, of course, free from it; the gray
or white, calcareous.

In this large and difficult genus, since spore-color is receiving
increased consideration,--see No. 31 preceding,--it is proper to note
that in the present case two types appear, one with spore-color under
the lens, as described, the other with spores violaceous with no trace
of black; unshadowed.

The preceding description is based on material assembled during forty
years. The form is easily discoverable by any collector throughout the
entire valley of the Mississippi and eastward to Nova Scotia. For its
naming, students in America have vainly waited the decision of those
having access to mycologic types in Europe. It seems now certain that
the species is extremely rare in the old world if there occurrent; never
seen by any of the earlier taxonomists including Fries and Rostafinski;
perhaps adventitious in these later years, although thus far no specimen
from Europe has reached this table.[24] _P. nefroideum_ of Strasburg
herbarium turns out, after all, _teste_ Lister, to be _P. compressum_
Alb. & Schw., which accordingly shall now enjoy state and station of
its own; our concern in European nomenclature, in the present instance,
almost disappears, and we return to our synonymy from this side of the
sea.

Mr. Lister would recur to Dr. Peck's _Didymium connatum_, which indeed
represents the present species. In such disposition, how gladly would
all concur, were the thing possible! But _Physarum connatum_ is already
a synonym twice over.[25] Unless we are done with the rules entirely,
_P. connatum_ cannot stand. _P. polymorphum_ and _P. leucophaeum_ are
names already in use, of course; and so under the circumstances, much as
it is to be regretted, there would seem nothing left to do but to cancel
all past synonymy and impose a new name whose permanence may at least be
hoped for, if not expected.


40. PHYSARUM TROPICALE _Macbr._

  1899. _Physarum tropicale_ Macbr., _N. A. S._, p. 45.

PLATE XV., Figs. 4, 4 _a_, 4 _b_.

Sporangia scattered, gregarious, turbinate, short stipitate, blue-gray,
about 1 mm. in diameter; peridium above iridescent, green, blue, etc.,
dotted with minute flecks of white, below limeless, purple or bronze
shading to the brown of the stipe; stipe short, stout, slightly rugose,
cylindric, non-calcareous, brown; columella none; hypothallus none;
capillitium abundant, the nodes generally calcareous, small, uniform,
angular, white, uniformly distributed; spore-mass, black; spores dark
violet-brown, distinctly and closely warted, 12-15 µ.

A large handsome species recognizable by the peculiar turbinate
sporangium, with its iridescent peridial wall in which green strongly
predominates above, bronze below. The distinction between the upper and
lower peridium would suggest _Craterium_, but the internal structure is
not at all _Craterium_-like. The capillitium is typically of _Physarum_.
The color suggests _P. leucophaeum violascens_ Rost. From this species
it is at once distinguished by its much longer sporangia, larger and
rougher spores.

Mexico; _C. L. Smith_: Sure to be again collected once that unhappy
country shall again open its forests to research.


41. PHYSARUM NICARAGUENSE _Macbr._

PLATE XV., Figs. 7, 7 _a_, 7 _b_; XVII., 11 and 11 _a_.

  1893. _Physarum nicaraguense_ Macbr., _Bull. Lab. Nat. Hist. Iowa_,
           II., p. 383.
  1894. _Physarum compressum_ Alb. & Schw., List., _Mycetozoa_, p. 53,
           in part.
  1910. _Physarum nicaraguense_ Macbr., Petch, _Mycetozoa Ceylon_,
           p. 334.
  1911. _Physarum reniforme_ List., _Mycetozoa, 2nd ed._, p. 72,
           in part.

Sporangia multilobate or compound-contorted, below obconic, gray, ribbed
with calcareous thickenings; stem short, fuscous, longitudinally
wrinkled; hypothallus distinct, black; columella none, although the lime
massed at the centre of each sporangium simulates one; capillitium
white, densely calcareous, with heavy angular nodules connected with
comparatively short threads; spores violet, globose, spinulose, about 12
µ in diameter.

Ometepe, Nicaragua. _Professor B. Shimek_.

This species resembles in some particulars No. 39, especially in the
amount of lime present in both capillitium and peridium, in the fluted,
sooty stipe, and the rough spores. Mr. Lister once regarded it as the
same. Nevertheless, it differs from _P. notabile_ in many definite
particulars. In the first place, the sporangia are different in form and
habit. They are obconic, nearly always compound, convolute, or botryoid,
in this respect somewhat resembling _P. polycephalum_. Besides, the
sporangia are uniformly much smaller, and show constantly the strongly
calcified centre, much transcending anything seen in _P. notabile_. The
stipe also is peculiar, quite short, an upward extension or sweep of the
common hypothallus which is usually very distinct or prominent; and,
while the stipe is longitudinally wrinkled, it is much less so than in
the related species, and in a different way. The spores are about the
same in size, but differ in color, in this respect agreeing rather with
_P. leucophaeum_.

In the _Mycetozoa, 2nd ed., l. c._, the present species is entered as a
synonym of two described by Massee: _Tilmadoche reniformis_ Mass., Mon.,
p. 336, and _Didymium echinosporum_ Mass., _Mon._ 239. But Massee's
description of his tilmadoche is, naturally enough, at variance in every
important point with the facts in the species before us. Massee says:
"... sporangia deeply umbilicate _below_, sausage-shaped and curved; the
stem elongated slender erect, pale brown; capillitial nodes scattered,
fusiform, colorless or yellow; spores 16-17 µ." It is evident that
whatever Massee may have had in hand as he wrote it was _not P.
nicaraguense_, which has spores 10-12 µ and reverses the remaining
description.

But _Didymium echinosporum_ also defines _T. reniformis_ since Lister,
_Mon._, p. 54, says they are based on two gatherings of one species. Of
this second species Massee says: "A superficial resemblance to _T.
nutans_, but distinct in the capillitium which contains _no trace of
lime_; spores 12-14 µ!" Again it is evident that whatever Massee had in
hand when he wrote, it was not _P. nicaraguense_ which "has capillitium
almost Badhamia-like," i. e., burdened with lime!

Worse than all; Mr. Massee's _alleged_ types are in evidence; one
labelled _P. reniforme_[26] includes forms of _P. didermoides_ and of
_P. nicaraguense_; the other labelled by Berkeley _P. nutans_ is _P.
nicaraguense_. So Mr. T. Petch, _Mycet. Ceyl._, who enters our species
as from Ceylon, and the names cited from Berkeley, Massee, and others,
as synonyms. He remarks, "Probably Thwaites' 135 and 55 were mixed
during examination"! Doubtless! and some other things too! What Massee
did have beneath his lens, no one now may say but apparently not in
either case cited, the physarum of Central America.


42. PHYSARUM SULPHUREUM _Alb. & Schw._

  1805. _Physarum sulphureum_ Alb. & Schw., _Consp. Fung._, p. 93,
           Tab. VI, f. 1.
  1818. _Physarum flavum_ Fries, _Symb. Gast._, p. 22.
  1875. _Physarum sulphureum_ Alb. & Schw., Rost., _Mon._, p. 101.[27]

Sporangia gregarious, sub-globose, rugulose-squamulose, .6-.8 mm.,
sulphur-yellow, stipitate; peridium membranous, covered with calcareous
scales; stipe stout, white, charged with lime, furrowed; columella none;
capillitium strongly calcareous, the nodules large, white; spores
violaceous, rough, 9-11 µ.

Northern Europe. (Lusatia) Lausitz, Alb. & Schw.; dim old Wendish
region on the south borders of Brandenburg. Reported also from Sweden.

The description and figure given by Schweinitz, 1805, _l. c._, leave no
doubt as to what he had in hand. Twenty or thirty years later, having
spent the interval in this country,--bishop, indeed, of the Moravian
churches, but a student of fungi all the while,--he reports the same
thing from this country; _Proc. Phil. Acad. Sci._, 1834. Cooke also
lists it in _Myxomycetes of the U. S._ It surely will be found again.
Mr. Lister thinks _P. variable_ Rex may be the same thing.


43. PHYSARUM CARNEUM _G. Lister and Sturgis_.

  1910. _Physarum carneum_ G. Lister and Sturgis, _Jour. Bot._,
           Vol. XLVIII, p. 63.

Sporangia gregarious, stipitate, sub-globose, .5 mm. in diameter,
ochraceous-yellow above, flesh-colored below; peridium membranous, pale
yellow, lime-granules evenly distributed; stipe short, translucent,
pinkish flesh-colored; capillitium dense, nodules white; spores
purplish-brown, spinulose, 8 µ.

Differs from _P. citrinellum_ in the membranous peridium, flesh-colored
stalks and smaller spores.

Colorado; _Dr. W. C. Sturgis._


44. PHYSARUM CITRINELLUM _Peck._

  1831. _Physarum caespitosum_ Schw., Syn. _N. A. F._, No. 2301 (?).
  1869. _Diderma citrinum_ Peck, _Rep. N. Y. Mus._, XXII., p. 89.
  1870. _Physarum citrinellum_ Peck, _Rep. N. Y. Mus._, XXXI., p. 55.
  1894. _Craterium citrinellum_ List., _Mycetozoa_, p. 74.
  1899. _Physarum caespitosum_ Schw., Macbr., _N. A. S._, p. 37.
  1911. _Physarum citrinellum_ Peck, List., _Mycetozoa, 2nd ed._, p. 62.

Sporangia gregarious, or scattered globose, short-stipitate, pale yellow
or ochraceous, smooth or slightly roughened by the presence of minute
lime-particles; peridium more or less distinctly double, the outer
calcareous, fragile, the inner very delicate, with here and there a
calcareous thickening, ruptured irregularly; stipe very short, half the
sporangium, fuliginous, furrowed, expanded below into an imperfectly
defined hypothallus; capillitium abundant, the nodes stellate-angular,
large, the internodes delicate, short; spore-mass black, spores
violaceous-brown by transmitted light, strongly spinulose, 10-12.5 µ.

A very distinct and handsome species. Easily recognizable at sight by
its large, globose, almost sessile and yet distinctly stalked sporangia.
The color to the naked eye is pale ochraceous or buff. Only under a
moderate magnification do the citrine tints come out.

In the _Twenty-second N. Y. Report_, Dr. Peck incorrectly referred this
species to _Physarum citrinum_ Schum. On the appearance of Rostafinski's
_Monograph_, Dr. Peck in his revised list, _l. c._, writes _P.
citrinellum_ Peck, with description on p. 57, following. Under the last
name the species has been generally recognized in the United States and
distributed. _N. A. F._, 2490.

In the former edition, this species was referred to _P. caespitosum_
Schw., of which the original description is as follows: "_P.
caespitosum_ L. v. S., pulcherrimum. In foliis et stipitibus
Rhododendri, Bethlehem. Physarum substipitatum aut saltem basi
attenuata, caespitosim crescens et sparsim. Caespitulis 3 linearibus;
peridiis stipatis, turbinatis, ovatis, basi contracta membranula
exterori luteosquamulosa aut punctato-squarrulosa. Sporidiis
nigro-brunneis, floccis citrinis inspersis." _Synopsis N. A. Fungi_,
2301.

The type from the Schweinitz herbarium is no longer in evidence. Without
it, the reference cannot be sustained.

Not uncommon in the eastern United States; reported also from Japan.


45. PHYSARUM ALBESCENS _Ellis._

PLATE XVI., Figs. 4, 4 _a_.

  1889. _Physarum albescens_ Ellis _in litt_: not described.
  1893. _Physarum auriscalpium_ Cke., Macbr., _Bull. Lab. N. H. Iowa_,
           No. 2, p. 155, in part.
  1894. _Physarum virescens_ var. _nitens_ List., _Mycetozoa_, p. 59,
           in part.
  1899. _Physarum virescens_ var. _nitens_ List., Macbr., _N. A. S._,
           p. 34, in part.
  1899. _Leocarpus fulvus_ Macbr., _N. A. S._, p. 82.
  1911. _Physarum fulvum_ Lister, _Mycet., 2nd ed._, p. 60.
  1911. _Physarum virescens, nitens_ List., _Mycet., 2nd ed._, p. 84,
           in part.

Sporangia gregarious, scattered, ovoid or globose, pale yellowish or
fulvous, opening irregularly above, stipitate; the peridium double, the
outer layer more or less calcareous, the inner delicate, almost
indistinguishable, persistent below as a shallow cup; the stipe long,
weak, striate, fulvous or yellow; hypothallus distinct, venulose, or
more or less continuous; capillitium pallid or white, dense, with here
and there below large continuous yellow calcareous nodules; columella
none; spore-mass black; spores by transmitted light, dark brown, rough,
13-15 µ. Varies to forms with single (inner) peridium and simple
physaroid capillitium. _Vid._ descriptions cited for _P. auriscalpium_,
_P. nitens_, etc.

This interesting form is from our western mountains, and suggests at
first a diderma; but the capillitium is entirely unlike that of a
diderma in color and structure, and plainly belongs here. Plasmodium
yellow, on fallen leaves and twigs. Our material is from Prof. Bethel,
Denver; and Lake Tahoe, Nevada; later from Dr. Weir, Montana. No doubt
common at high altitudes near the snow-line in mountainous regions,
probably around the world.

As indicated above, this was originally entered as of the genus
_Leocarpus_; the taxonomic history of the form may interest readers who
note with surprise the presentation in synonymy here developed.

About thirty-five or forty years ago Dr. Harkness of California sent to
Mr. Ellis of New Jersey a slime-mould which the sender referred to
_Diderma albescens_ Phillips, (_Grev._ V., p. 114, 1877). Ellis sent a
small bit to the Iowa herbarium without other comment, save that he
thought it a physarum. Sometime later Mr. Ellis received from Father
Langlois, a correspondent in Louisiana, specimens he esteemed the same
thing. He expressed the opinion that if this were what Phillips had
found in California, it should perhaps be called a physarum. The
Louisiana material by his courtesy came also to this table. The material
was scanty, in poor condition, and all waited further light. To these
specimens the writer paid less attention. They were in the hands of his
correspondents and the courtesy of the case required their further
consideration by Dr. Rex.

In 1889 Mr. Holway found in Iowa, a physarum of which he sent part to
Ellis and the remainder to the writer who, then engaged on the
_Myxomycetes of East. Iowa_, referred his part of this Iowa gathering
to the _Physarum auriscalpium_ Cke. as found in New York. Under this
caption a specimen was later sent to Mr. Lister, who has, as we see,
consistently regarded the thing as a variety of _P. virescens_ Ditmar,
_P. nitens_ List.

Meantime in 1898 Colorado material from Professor Bethel reached the
University. This did not recall any of the materials sent from Ellis.
_Diderma albescens_ had meanwhile come again from California, and been
recognized as _Diderma niveum_ Rost.

Accordingly, in _N. A. S._ the latest arrival from Colorado was
described as a new species, and with some temerity perhaps, offered as a
second species of the hitherto monotypic _Leocarpus_, all on account of
the peculiar capillitium. Sometime after publication our most valued
correspondent Mr. Bilgram called attention to the resemblance between
the Colorado and Louisiana material already referred to. The University
specimens as stated were small, broken, and in every way poor, but
enough remained to indicate the evident justice of our correspondent's
suspicion. Further investigation of the Holway material in Philadelphia
showed that _it too was entitled to consideration_! Inasmuch as the
Holway sending was all from one plasmodium, all difficulties vanished at
once. The Iowa gathering showed two phases: one at the University
represents _P. nitens_, physaroid, single-walled; while the Philadelphia
part of the gathering corresponds, poorly it is true, but in fact, as
_now_ appears, to the form coming in perfection from Colorado;
leocarpine in structure, published as _Leocarpus fulvus_; _P. fulvum_
Lister. Since the combination _P. fulvum_ is already in use, synonym of
_P. rubiginosum_, it seems better to write the name suggested by Ellis;
_Physarum albescens_ never having been published, because _Diderma
albescens_, as noted took care of itself.

Since Rostafinski we separate all these physaroid forms chiefly by
capillitial characters: capillitial structure separates genera.
_Physarum diderma_ is a physarum despite its double wall. And so here
_Leocarpus_ was set out by its differentiating capillitium. In good
specimens of the present species a large part of the capillitial net is
entirely free from lime, so that when the peridium first opens at the
summit, sometimes no trace of lime appears; the calcareous deposits are
below, and tend to occupy not the nodal intersections as in _Physarum_,
but in large masses involve portions of the net itself, nodes and all,
as in _Leocarpus_. Miss Lister's beautiful figures, _op. cit._, Figs. 66
and 82, show this very well.

In The _Journal of Botany_, 52, p. 100, the distinguished author and
artist records the discovery of this species in the mountains of
Switzerland. She says: "This specimen shows a striking resemblance to
_Leocarpus fragilis_ Rost., both in the shape of the sporangia and in
the capillitium and spores; but although the color of the sporangia
varies in both these species, the walls of _P. (L.) fulvum_ are
membranous and rugose with included deposits of lime granules and show
nothing of the polished cartilaginous layers characteristic of _L.
fragilis_."

The species is a boundary type at best, and shows again how artificial
all our taxonomy is apt to prove, when the number of presentations of
some particular type becomes larger.

For these reasons, the present author writes _Physarum_, and believes
the question of identity in a perplexing case fortunately settled.


46. PHYSARUM VARIABILE Rex.

  1893. _Physarum variabile_ Rex, _Proc. Phil. Acad._, p. 371.
  1911. _Physarum variabile_ Rex, List., _Mycetozoa, 2nd ed._, p. 47.

Sporangia scattered, stipitate, sub-stipitate or sessile, about 1 mm.
high; regularly or irregularly globose, ellipsoidal, obovate or
cylindric-clavate in shape; sporangium wall sometimes apparently thick,
of a dingy yellow or brownish-ochre color, slightly rugulose on the
surface, crustaceous, brittle, rupturing irregularly, sometimes thin,
translucent, covered externally with flat circular calcic-masses falling
away in patches; stipes nearly equal, occasionally much expanded at the
base, rough, longitudinally rugose, variable in size, sometimes
one-third of a millimetre high, sometimes a mere plasmodic thickening of
the base of the sporangium; color of stipes varying from a
yellowish-white to a dull brownish-gray; capillitium a small-meshed
network of delicate colorless tubules with large, many-angled, rounded
masses of white, or rarely yellowish-white lime-granules at the nodes;
no true columella, but often a central irregular mass of white
lime-granules; spores dark violet-brown, verruculose, 9-10 µ.

Pennsylvania. _Dr. Rex._

Lister, _op. cit._, describes a variety, _sessile_, presenting
plasmodiocarpous fructification, from Ceylon, also from Antigua, but
there are some doubts as to the identity of these with American sessile
and plasmodiocarpous forms. Vid. _Jour. Bot._ XXXVI., p. 113.


47. PHYSARUM AURISCALPIUM _Cooke_.

  1877. _Physarum auriscalpium_ Cooke, _Myx. U. S._, Am. Lyc. Nat. Hist.
           N. Y., XI., p. 384.
  1877. _Physarum auriscalpium_ Cke., _Myx. Gr. Brit._, Pl. 24,
           f. 253-4.
  1893. _Physarum sulphureum_ (Alb. & Schw.), Sturgis, _Bot. Gaz._,
           XVIII., p. 197.
  1898. _Physarum auriscalpium_ Cke., List., _Jour. Bot._, XXXVI.,
           p. 115.
  1911. _Physarum auriscalpium_ Cke., List., _Mycetozoa, 2nd ed._,
           Syn. excl.

Sporangia scattered, stipitate or occasionally sub-sessile spherical,
.8-1 mm. high; peridium granulated, bright golden yellow; stipe, when
present, one-half to two-thirds the height of the sporangium,
blackish-brown; hypothallus, minute, thin, brown; columella absent;
capillitium rather dense, composed of large angular nodes, completely
filled with bright yellow granules of lime, and connected by very short,
delicate, colorless internodes destitute of lime; spores globose
minutely verruculose, or asperate, 10.7-11.8 µ in diameter,
brownish-violet by transmitted light, black in the mass.

This is the original description, 1893, of _P. sulphureum_ (Alb. &
Schw.) Sturgis; the author last named having compared certain stalked
New England forms with what he could find of _P. sulphureum_ in the
herbarium of Schweinitz at Philadelphia, and having, as he thought,
established identity.

Meantime Mr. Lister had been inclined to refer _P. auriscalpium_ Cke. to
_P. rubiginosum_ Fr., _Mycetozoa_, p. 61.

In 1898 Professor Sturgis and Mr. Lister agreed that the New England
specimens, owing to color and character of stipe and some other
differences could not be the Schweinitzian species, but did indeed
conform much better with those in London labelled _P. auriscalpium_ Cke.

Accordingly _P. sulphureum_ is something else, very different, (v. A. &
S., Cons. _Fung. Tab._, VI., f. 1), and by aid of recent[28] discoveries
in Sweden goes its own way again. Meanwhile _P. sulphureum_ Sturgis
stands, a new type for _P. auriscalpium_ Cke., the description modified
to suit; the lamented pioneer-author receives honor due, and his
handsome species, with its "golden graving," may now march, let us hope,
under appropriate banner far down the fair highway to future fame!


48. PHYSARUM OBLATUM _Macbr._

PLATE III., Fig. 6; PLATE XIV., Figs. 3, 3 _a_, 3 _b_.

  1879. _Physarum ornatum_ Peck, Rep. _N. Y. Museum_, XXXI., p. 40 (?).
  1893. _Physarum oblatum_ Macbr., _Bull. Lab. Nat. Hist. Iowa_, II.,
           p. 384.
  1896. _Craterium maydis_ Morg., _Myx. Miam. Vall._, p. 87.
  1909. _Physarum maydis_ Torr., _Flor. des Myxo._, p. 193.
  1911. _Physarum maydis_ Torr. List., _Mycet., 2nd ed._, p. 59.

Sporangia gregarious, stipitate, small, bright yellow, globose or
depressed-globose, rough; stipe reddish-brown or fuliginous, even,
short, slender; hypothallus scant, black, or none; columella none;
threads of the capillitium yellow, delicate, connecting the rather dense
and abundant yellow lime-granules; spore-mass brownish-black, spores
violaceous, minutely but distinctly spinulose, 9-11 µ.

This species is easily recognizable by its brilliant yellow color,
somewhat rugose, sometimes scaly peridium, its richly calcareous
capillitium, also bright yellow where not weathered or faded, its dark
brown, translucent, non-calcareous stem. In dehiscence, the base of the
peridium in cup-form, sometimes persists. This circumstance, with the
fact that decaying maize-stalks and leaves are a favorite habitat, led
Professor Morgan to its description as _Craterium maydis_. But it is
doubtless a physarum, occurring on habitats of all sorts, from Ohio to
Iowa, Colorado and Washington. Ceylon(?).

_Physarum ornatum_ Peck is doubtfully cited here, although Professor
Morgan thought it the same as _P. oblatum_. As a matter of fact the
original brief description, _op. cit._, does not suggest either _P.
oblatum_ or _P. maydis_; rather a form of _Tilmadoche viridis_.
Professor Sturgis, _Notes on Some Type Specimens of Myxo., in the N. Y.
Museum, Trans. Conn. Acad. Arts and Sci._, Vol. X., Pt. 2, p. 470, says
that of the type almost nothing remains, that the name _P. ornatum_ Pk.
"should be discarded."


49. PHYSARUM GALBEUM _Wing._

  1890. _Physarum galbeum_ Wing., Ell., _N. A. F._, 2491
          (no description).
  1892. _Physarum petersii_ Berk. & C., Mass., _Mon._, p. 296, in part.
  1894. _Physarum berkeleyi_ Rost., List., _Mycetozoa_, p. 48, in part.
  1899. _Physarum galbeum_ Wing., Macbr., _N. A. S._, p. 53.
  1911. _Physarum galbeum_ Wing., List., _Mycetozoa, 2nd ed._, p. 59.

Sporangia scattered, globose, stipitate, often nodding, golden yellow,
the peridium exceedingly thin, breaking up into patches on which the
yellow lime granules are conspicuous; stipe non-calcareous, pale brown
or amber-colored, longitudinally wrinkled, about one and one-half times
the diameter of the peridium; columella none; hypothallus none;
capillitium dense, extremely delicate, the nodes only here and there
calcareous, the lime knots when present small, angular, yellow;
spore-mass pale brown; spores almost smooth, lilac- or violet-tinted,
7.5-10 µ.

Distinguished among the small delicate species with which it will be
naturally associated, by the yellow, richly calcareous wall of the
globose sporangium and the almost limeless capillitium. The stipe is
hollow and contains irregular masses of refuse granular matter, but no
lime so far as we have been able to discover. _P. flavicomum_, to which
the species is related most closely, differs in having the wall
non-calcareous, iridescent, as well as in the color throughout; the
character of the capillitium, in which lime is abundant; the absence of
refuse-matter in the stem.

Pennsylvania, Iowa, Minnesota.


50. PHYSARUM TENERUM _Rex._

  1890. _Physarum tenerum_ Rex., _Proc. Phil. Acad._, p. 192.
  1894. _Physarum polymorphum_ Rost. var. _obrusseum_, Lister,
          _Mycet._, p. 48.
  1899. _Physarum obrusseum_ (Berk. & C.) Rost., Macbr., _N. A. S._,
           p. 52.
  1911. _Physarum tenerum_ Rex., List., _Mycetozoa, 2nd ed._, p. 52.

The peridium thin, membranaceous, thickly studded with circular,
flattened, yellow granules of lime; stipe long, slender, subulate,
opaque, pale brown, striate and black below, pale yellow above;
columella none; capillitium yellow or white, delicate, forming a loosely
but regularly meshed network with numerous small round or rounded
granules at the intersections; spores dark brown, delicately warted, 7-8
µ.

This delicate physarum, very fragile and evanescent, seems to be
distinct, by reason of its characteristic rounded lime granules, from
any similar, stipitate species. It varies a little according to
locality. Ohio specimens are a little larger and have thicker and more
calcareous stipes than is usual in those from Philadelphia. The walls of
the sporangia when fully matured generally break into several petal-like
segments which finally become reflexed. The description given by
Berkeley is entirely insufficient.

In an earlier edition this species was entered as _P. obrusseum_
following the Polish text. Miss Lister who has the type of _Didymium
obrusseum_ at hand considers it as representing a phase of _Physarum
polycephalum_ Schw. _D. tenerrimum_ Berk. & Curt. is judged the same.
_P. tenerum_ Rex is, in any event, certain, and the combination is
adopted.

Rare:--Pennsylvania, Ohio, Louisiana, Texas, Iowa, Portugal, Japan.


51. PHYSARUM FLAVICOMUM _Berk._

PLATE XV., Figs. 3, 3 _a_.

  1845. _Physarum flavicomum_ Berk., _Hook. Jour. Bot._, IV., p. 66.
  1873. _Physarum cupripes_, Berk. & Rav., _Grev._, II., p. 65.
  1875. _Physarum berkeleyi_ Rost., _Mon._, p. 105.
  1894. _Physarum berkeleyi_ Rost., List., _Mycetozoa_, p. 57.
  1899. _Physarum flavicomum_ Berk., Macbr., _N. A. S._, p. 53.
  1911. _Physarum flavicomum_ Berk., List., _Mycetozoa, 2nd ed._, p. 58.

Sporangia gregarious, small, spherical, at first fuliginous throughout,
stipitate; the peridium thin, destitute of lime, iridescent, breaking up
and deciduous in patches, except at the base; stipe twice the diameter
of the peridium, brown, fluted, not hollow, tapering upward from a small
but distinct, radiant hypothallus; columella none; capillitium dense,
persistent, the nodes frequently calcareous, elongate and vertical,
especially below, yellow; spore-mass brown; spores by transmitted light,
bright violaceous-brown, slightly papillose, 9-10 µ.

This species is instantly distinguishable from all cognate forms by its
peculiar sooty color. Not less is the species structurally marked by its
capillitium. The latter below is exactly as in the species of
_Tilmadoche_. Indeed, the present species unites characters supposed to
distinguish _Physarum_ from _Tilmadoche_, and would so far justify those
authors who bring all the species of both genera together under one
generic name. In any case the species is by its capillitium entirely
distinct from _P. galbeum_, as well as by the structure of the stipe and
the peridial surface. The plasmodium, at first watery, emerges from
decayed elm logs and soon takes on a peculiar greenish tint preserved
somewhat in the mature fruit.

Rostafinski, _Monograph_, pp. 105, 106, rejects Berkeley's specific
name, _flavicomum_, because it refers to the somewhat indefinite,
characteristic color. As this is no valid reason for change, we have
restored Berkeley's specific name, which by general consent has
priority. _N. A. F._, 3299.

Not common. New Jersey, Ohio, South Carolina, Iowa.


52. PHYSARUM BETHELII (_Macbr._) _Lister_.

  1899. _Tilmadoche bethelii_, Macbr., _Exempl. ad Herbaria._
  1911. _Physarum gyrosum_ Rost., List., _Mycetozoa, 2nd ed._, p. 75.

Sporangia scattered, globose, umbilicate below, .5-1 mm. in diameter,
iridescent blue, or sometimes tinged by the presence of delicate pale
yellow calcareous scales, stipitate; stipe rather short, black or dark
brown, equal; capillitium dense, radiating from the black, slightly
intrusive summit of the stipe, and from the base of the peridium
ascending; the nodules not numerous, elongate, branching betimes, pale
yellow; spores minutely roughened, 10-12 µ.

This beautiful delicately tinted little species is clearly tilmadochoid
in the Friesian sense. The capillitium persists after the fall of the
upper filmy peridium, adherent below to the persisting peridial base.
Collected thus far twice only; by Professor Bethel and by Professor
Sturgis, Colorado.


SECTION 2

_=Tilmadoche= Fries_


53. PHYSARUM GYROSUM (_Rost._) _Jahn._

  1875. _Physarum gyrosum_ Rost., _Mon._, p. 111.
  1902. _Physarum gyrosum_ Rost., Jahn, _Ber. Deutsch. Bot. Ges._, XX.,
           p. 272, t. XIII.
  1911. _Physarum gyrosum_ Rost., List., _Mycetozoa, 2nd ed._, p. 75.

Sporangia gyrose, variable in form, or plasmodiocarpous and irregular,
venulose, sessile upon a common, strongly developed hypothallus,
sometimes isolated and irregularly globose, dehiscing irregularly or by
longitudinal fissure, yellowish or greyish white; columella none;
capillitium delicate, the nodules elongate, variable in size; spores
pale violaceous, minutely spinulose, 7-10 µ.

This is a European species recently resuscitated by Dr. Jahn. It perhaps
might more correctly be recorded as _P. gyrosum_ Jahn, since Rostafinski
certainly attempted in his description to cover two apparently distinct
things. He seems to have had before him _Fuligo muscorum_ Schw. and "_P.
gyrosum_," but he thought them the same, and his description touches now
one, now the other. Since _F. muscorum_ Schw. has all along held its own
and received due recognition, it is interesting to note the recovery of
this gyrose form.

Judging by description and figures, it resembles a very large, sessile
phase of _P. polycephalum_. See further under that species.

Europe, Japan, Eastern United States (?).


54. PHYSARUM POLYCEPHALUM _Schw._

PLATE VIII., Figs. 2, 2 _a_, 2 _b_.

  1822. _Physarum polycephalum_ Schw., _Syn. Fung. Car._, No. 382.
  1829. _Didymium polycephalum_ (Schw.) Fries, _Syst. Myc._, III.,
           p. 122.
  1837. _Didymium polymorphum_ Mont., _Ann. Sci. Nat._, Ser. 2, 8,
           p. 361.
  1837. _Didymium gyrocephalum_ Mont., _op. cit._, p. 362.
  1875. _Physarum polymorphum_ (Mont.) Rost., _Mon._, p. 107.
  1875. _Tilmadoche gyrocephala_ (Mont.) Rost., _Mon._, p. 131.
  1899. _Tilmadoche polycephala_ (Schw.) Macbr., _N. A. S._, p. 57.
  1911. _Physarum polycephalum_ Schw., List., _Mycetozoa, 2nd ed._,
           p. 58.

Sporangia spherical or irregular, impressed, gyrose-confluent,
helvelloid, umbilicate below; peridium thin, ashy, covered with
evanescent yellow squamules, fragile; stipe from an expanded
membranaceous base, long-subulate, yellow; spores smooth, violet, 9-11
µ.

A most singular species and well defined is this, occurring in masses of
decaying leaves or on rotten logs. The plasmodium at first colorless; as
it emerges for fructification, white, then yellow, spreading far over
all adjacent objects, not sparing the leaves and flowers of living
plants; at evening slime, spreading, streaming, changing; by morning
fruit, a thousand stalked sporangia with their strangely convoluted
sculpture. The evening winds again bear off the sooty spores, and naught
remains but twisted yellow stems crowned with a pencil of tufted silken
hairs. August.

Although Rostafinski's description of this species is accurate and marks
exactly a _Tilmadoche_ and is very different from his description of
_Physarum polymorphum_, nevertheless it is probable that both
descriptions have reference to the same thing. All specimens on which
both species were based were American; _P. polymorphum_, North American.
But the only North American form to which reference can be made is that
by Schweinitz called _P. polycephalum_ and, fortunately, sufficiently
described. Furthermore, Rostafinski, under _T. gyrocephala_, himself
affirms the probable identity of Montagne's _Didymium gyrocephalum_ with
the Schweinitzian species, and uses Montagne's specific name
provisionally. For these reasons it seems proper to write the species as
above.

Widely distributed and common, from Maine and Canada to Nebraska, and
Washington and south to Nicaragua.

This species is so common that its plasmodium and fructification may be
easily observed. Professor Morton E. Peck, who has been for years a
close observer of the vegetative phases of our Iowa species, says of _P.
polycephalum_: "In one instance I observed a plasmodium for twelve
successive days on the surface of a decaying stump. During this period
it crept all around the stump and from top to bottom several times. At
one time the color was bright yellow; at another, greenish yellow; and
once, shortly before fruiting, it became clear bright green. A heavy
rain fell upon the plasmodium but it appeared to sustain little injury
and ultimately developed normal sporangia."


55. PHYSARUM NUTANS _Pers._

  1791. _Sphaerocarpus albus_ Bull., _Champ._, p. 137, t. 407, III.,
           and t. 470, I, A-L.
  1791. _Stemonitis alba_ (Bull.), Gmel., _Syst. Nat._, p. 1469 (?).
  1795. _Physarum nutans_ Pers., _Ust. Ann. Bot._, XV., p. 6.
  1803. _Trichia cernua Schum., Enum. Pl, Saell._, II., p. 241.
  1829. _Physarum cernuum_ (Schum.) in part, Fr., _Syst. Myc._, III.,
           pp. 130, 147.
  1848. _Tilmadoche cernua_ (Schum.) Fr., _Summ. Veg. Sc._, p. 454.
  1873. _Tilmadoche nutans_ (Pers.) Rost., _Versuch_, p. 10.
  1899. _Tilmadoche alba_ (Bull.) Macbr., _N. A. S._, p. 58.
  1911. _Physarum nutans_ Pers., List., _Mycet., 2nd ed._, p. 67,
           in part.

Sporangia gregarious, depressed-spherical, stipitate, umbilicate, gray
or white, thin-walled, nodding; stipe long, tapering upward, brown or
black below, ashen white above, lightly striate, graceful; capillitium
abundant, threads delicate, intricately combined in loose persistent
network with occasional minute, rounded, or elongate calcareous nodules;
spores minutely roughened, globose, about 10 µ.

The nodding, lenticular, umbilicate sporangium, barely attached to the
apiculate stipe, is sufficient to distinguish this elegant little
species, recognized and quite aptly characterized by mycologists for
more than one hundred years. As _Sphaerocarpus albus_ Bulliard first
prescribed the limits by which the species is at present bounded. The
description by Fries (_Syst. Myc.,_, III., 128) is especially graphic;
"Peridium very thin, in form quite constantly lenticular, umbilicate at
base, at first smooth then uneven, generally laciniate-dehiscent, the
segments persistent at least at base."

The stipe is usually white above, fuscous below, at the apex almost
evanescent; hence the cernuous sporangia. The same character is less
strikingly manifest in the species next following.

The plasmodium is bright yellow, sometimes greenish. Brought in from the
field and maturing under a bell-jar, the color changes to a watery white
just before the sporangia rise in fruit. _P. album_ Fuckel, _Rhen. Fl._,
No. 1469, 1865, is believed to be _P. cinereum_ (Batsch) Pers.

Persoon changed Bulliard's specific name in this case to furnish one
himself, more descriptive as he thought and distinctive. His success in
this attempt must be esteemed but partial since all the related forms,
immediately listed, _nod_ as well. Bulliard's name as applied by Persoon
is therefore to be preferred. But the transfer from _Tilmadoche_ to
_Physarum_ loses for us one step in the ladder of priority. _P. album_
(Bull.) may not enter here, since Fries has given us one species under
that title. So Persoon comes next on the list, all the world now nodding
approbation, let us hope!

Under the name _Physarum gracilentum_, Fries cites an extremely delicate
form of this species. The sporangia are of the most minute, about .2-.3
mm. in diameter, globose, slightly umbilicate below, the stipe usually
white at top, but sometimes black throughout. This graceful form occurs
rarely in undisturbed woods.

Widely distributed in the eastern United States, apparently rare in the
west. Reported from various parts of the world; Europe, Japan,
Australia, etc.


56. PHYSARUM VIRIDE (_Bull._) _Pers._

PLATE VIII, Figs. 8, 8 _a_, 8 _b_.

  1791. _Sphaerocarpus viridis_ Bull., _Champ._, t. 407, Fig. I.
  1791. _Sphaerocarpus luteus_ Bull., _Champ._, t. 407, Fig. II.
  1791. _Sphaerocarpus aurantius_ Bull., _Champ._, t. 484, Fig. II.
  1791. _Stemonitis viridis_ (Bull.) Gmel., _Sys. Nat._, p. 1469.
  1794. _Physarum aureum_ Pers., Römer, _Neu. Mag. f. die Bot._, I.,
           p. 88.
  1795. _Physarum viride_ Pers., Usteri, _Ann. Bot._, XV., p. 6.
  1801. _Physarum aurantium_ Pers., _Syn. Meth._, p. 173.
  1829. _Physarum nutans_ var. Fries, _Syst. Myc._, III., pp. 128-129.
  1875. _Tilmadoche mutabilis_ Rost., _Mon._, p. 129.
  1880. _Tilmadoche viridis_ (Bull.) Sacc., _Michelia_, II., p. 263.
  1894. _Physarum viride_ Pers., List., _Mycetozoa_, p. 50.
  1899. _Tilmadoche viridis_ (Bull.) Sacc., Macbr., _N. A. S._, p. 59.
  1911. _Physarum viride_ Pers., List., _Mycetozoa_, 2nd ed.

Sporangia globose, flattened or lenticular, beneath plane or concave,
variously colored, yellow, greenish yellow, rusty orange, stipitate,
nodding; the peridium splitting irregularly or reticulately; stipe
variable in length and color, through various shades of red and yellow,
subulate; capillitium strongly developed, concolorous with sporangium,
the tubes with colorless or yellow calcareous thickenings; spores
smooth, fuscous or violet-black, 8 µ.

A very handsome and rather common little species; like the preceding,
but generally greenish-yellow in color, and occasionally brilliantly
orange without a suggestion of green. Indeed, the color is so variable
that some authors have been disposed to discard the species entirely,
inasmuch as the chief specific character is color. The plasmodium is
pale yellow, in rotten logs, stumps, etc. In the paler yellow or
greenish forms the stipe is more commonly black.

This is _Physarum luteum_ (Bull.) Fries, and likewise also includes the
three varieties, _viride_, _aureum_, _coccineum_, listed by the same
author under _P. nutans_, while he at the same time remarks that they
might with equal propriety be elsewhere referred. Rostafinski considers
that all the colored forms agree in capillitium sufficiently to be
associated under one name and are in the same way unlike _T.
nutans_.[29] Rostafinski thinks to avoid confusion by suggesting a more
fitting specific name, _T. mutabilis_, but there seems no good reason
for not adopting the earliest identifiable specific appellation, which
in this case appears to be _viride_. The yellow phase is common in Iowa,
resembles in size, color, stipe, _P. galbeum_ Wingate, but is instantly
distinguishable by the capillitium. _N. A. F._, 1213.

Widely distributed specimens are before us;--from New England, New York,
Pennsylvania, Maryland, Ohio, Nebraska, Iowa, California, Oregon,
Canada, Nicaragua, Samoa, Alaska, India, etc.


=EXTRA-LIMITAL=[30]


PHYSARUM MUTABILE (_Rost._) _List._

  1875. _Crateriachea mutabilis_ Rost., _Mon._, p. 125.
  1892. _Crateriachea mutabilis_ Rost., Mass., _Mon._, p. 344.
  1894. _Physarum cinereum_ List., _Mycetozoa_, p. 55, in part.
  1895. _Physarum crateriachea_ List., _Jour. Bot._, XXXIII., p. 323.
  1910. _Physarum crateriachea_ List., Petch, _Mycetozoa Ceylon_,
           p. 336.
  1911. _Physarum mutabile_ List., _Mycetozoa, 2nd ed._, p. 53.

Sporangia cylindrical ovoid or sub-globose white, plasmodiocarpous,
sessile or stipitate, stipes when present yellow, with or without lime,
often connected by a hypothallus; peridium thin, squamulose;
capillitium persistent, intricate, the nodules white, more or less
confluent at the center to form a real or a pseudo-columella; spores
brownish-purple, spinulose, 7-8 µ.

Reported from Europe, Africa, Ceylon.


PHYSARUM ROSEUM _Berk. & Br._

  1873. _Physarum roseum_ Berk. & Br., _Jour. Linn. Soc._, XIV., p. 84.

Plasmodium rose-red; sporangia gregarious, stipitate, globose, rose-red;
the stipe erect, brown, rugulose, translucent; capillitium lax,
delicate, lilac, the nodules few, large, purple-red, branching; spores
reddish-lilac or brown, minutely spinulose, 7-10 µ.

Reported from Ceylon, Java, Borneo, Japan.


PHYSARUM DICTYOSPERMUM _List._

  1905. _Physarum dictyospermum_ List., _Jour. Bot._, Vol. XLIII.,
           p. 112.

"It is distinguished from the other known species of _Physarum_ by the
strongly reticulated spores. Its nearest ally is perhaps _P.
psittacinum_ which it resembles in having orange-red lime-knots and in
the sporangium-wall being studded with orange crystalline disks."
_Lister._

Reported collected once only; New Zealand.


PHYSARUM STRAMINIPES _List._

  1898. _Physarum straminipes_ List., _Jour. Bot._, Vol. XXXVI., p. 163.

Plasmodium white; sporangia greyish-white, obovoid or wedge-shaped, .7
mm. in diameter, clustered or scattered, stipitate or sessile, when
stipitate stalks long, weak; peridium membranous, pale purple;
capillitium a persistent rigid net, the nodules white, rounded,
sometimes aggregate as a pseudo-columella; spores purple-brown, 10-11 µ,
warted, the papillae in definite patches.

Related to _P. compressum_.

Reported from England; Germany.


PHYSARUM CRATERIFORME _Petch._

  _Physarum crateriforme_ Petch, _Ann. Perad._, IV., p. 304.
  _Physarum crateriforme_ Petch, List., _Mycetozoa, 2nd ed._, p. 69,
     Pl. 76.

Sporangia gregarious, globose, clavate or crateriform, sessile or
stipitate, white; stalk when present opaque conical, black below, white
above, in crateriform sporangia entering and developed as a columella;
capillitium various, strongly calcareous, the nodules either grouped in
a pseudo-columella, or in globose sporangia, rod-like, ascending; spores
closely spinulose, 11-15 µ.

Reported from Ceylon, Japan, West Indies; Lisbon.


PHYSARUM GULIELMÆ _Penzig._

  1898. _Physarum gulielmae_ Penzig., _Myx. Beut._, p. 34.
  1909. _Physarum gulielmae_ Penzig., Torrend, _Fl. des Myx._, p. 208.
  1911. _Physarum gulielmae_ Penzig., List., _Mycetozoa, 2nd ed._,
           p. 76.

Plasmodium yellow; sporangia sub-globose, sessile, brownish-orange or
chestnut brown, rugulose, clustered or heaped, often with a yellow
membranous hypothallus; peridium membranous with clustered deposits of
yellowish-brown lime granules; capillitium abundant, the nodes angular,
branching, white; spores purplish brown, spinulose, 10-12 µ.

Reported from Java, Sweden, Switzerland.


PHYSARUM ECHINOSPORUM _List._

  1899. _Physarum echinosporum_ List., _Jour. Bot._, XXXVII., p. 147.

This species is distinguished from the preceding chiefly in episporic
characters. "Spores purple, 8 µ, marked by strong ridges and spines," 8
µ.

Reported from Antigua.


PHYSARUM ÆNEUM (_List._) _R. E. Fries._

  1898. _Physarum murinum_ var. _aeneum_ Lister, _Jour. Bot._, XXXVI.,
           p. 117.
  1903. _Physarum aeneum_ Lister, R. E. Fries, _Arkiv. Bot._, I., p. 62.

Sporangia sessile, sub-globose or plasmodiocarpous, pinkish-brown or
bronze, glossy; peridium double, the outer somewhat cartilaginous,
brittle, falling back from the shining, membranous inner wall;
capillitium dense, the nodules not large, brown, sometimes aggregated to
form a pseudo-columella; spores pale brownish-violet, nearly smooth, 6-8
µ.

Reported from West Indies, Bolivia.


=Related Genus=


TRICHAMPHORA _Junghuhn_, p. 12.

  1838. _Trichamphora_, Junghuhn, _Fl. Crypt. Javanica_.

Sporangia discoidal, above concave, saucer-shaped, stipitate; the
capillitium variable, anon physaroid, badhamioid, or even as in
_Didymium_.

This genus is set up for the accommodation thus far of the single
species following. It differs from _Physarella_ in the apparently
constant discoidal shape, absence of trabecules, etc.


TRICHAMPHORA PEZIZOIDEA _Jungh._, _op. cit._

  1838. _Trichamphora pezizoidea_ Jungh., _op. cit._
  1854. _Didymium zeylanicum_ Berk. & Br., _Hook. Jour. Bot._, VI.,
           p. 230.
  1869. _Physarum macrocarpum_ Fuckel, _Symb. Myc._, p. 343.
  1875. _Chondrioderma pezizoidea_ Rost., _Mon._, p. 424, tab. VIII.,
           Fig. 122.
  1876. _Badhamia fuckeliana_ Rost., _Mon._, _App._, p. 2.
  1894. _Trichamphora pezizoidea_ Jungh., List., _Mycetozoa_, p. 89.
  1911. _Trichamphora pezizoidea_ Jungh., List., _Mycetozoa, 2nd ed._,
           p. 90.

Sporangia discoidal or saucer-shaped, gregarious, stipitate, erect or
nodding, grayish-white, the peridium thin, breaking irregularly and
persistent; stipe subulate, striate, reddish brown, transparent;
capillitium variable as above stated; spores pale violet-brown,
spinulose or nearly smooth, about 9 µ.

In _Mycetozoa, 2nd ed._, the spores are described as "dark or pale
purplish brown, spinose, spinulose or nearly smooth, 9-17 µ in
diameter." This would seem too great a variation even in this protean
species. The only specimens in our herbarium are from the Congo valley.
The spores are pale and nearly smooth, as in _Tilmadoche alba_, and 9 µ.
Spores 17 µ suggest immaturity; penultimate cell-division.

The synonymy above cited shows how this species has impressed careful
students. Doubtless in every case the reference is correct, judging from
the specimen each author had before him, although it is hard to see how
_Chondrioderma_ might have been suggested.

The species is evidently tropical, though reported from Europe.


=4. Craterium= _Trentepohl_

  1797. _Craterium_ Trentepohl, Roth, _Catal._, I., p. 224.

Sporangia more or less distinctly cyathiform, stipitate, the peridium
generally plainly of two layers or even of three, opening at the top by
circumscission more or less definite, or by a distinct lid, the upper
part calcareous often to a marked degree, the lower, cartilaginous, long
persistent as a vasiform cup containing the capillitium and spores, the
calcareous nodes aggregating more or less to form a pseudo-columella.

This genus is distinguished from _Physarum_ and _Badhamia_ chiefly by
the form of the sporangia and the method of dehiscence. The capillitium
is in some specimens particularly, of the _Physarum_ type; in others,
like that of _Badhamia_. There are accordingly species that receive at
the hands of different authors diverse generic reference as one feature
or another in the structure is emphasized in the different cases. It is
granted that it is hard to draw the line sometimes between forms in
which the dehiscence is irregularly circumscissile and those in which
the wall breaks without any regularity whatever, since, in all, the
breaking up of the peridium usually begins at the top. Species here
included will, however, offer little ambiguity.


=Key to the Species of Craterium=

  A. Dehiscence circumscissile or by the breaking up of the upper wall
       of the sporangium.

     _a._ Sporangia violet or purple                1. _C. paraguayense_

     _b._ Sporangia yellow                                2. _C. aureum_

     _c._ Sporangia white-capped.

        1. Sporangia obovoid or globoid            3. _C. leucocephalum_

        2. Sporangia cylindric, elongate             4. _C. cylindricum_

  B. Dehiscence by a distinct lid.

     _a._ Capillitium pale brown                       5. _C. concinnum_

     _b._ Capillitium white                              6. _C. minutum_


1. CRATERIUM PARAGUAYENSE (_Speg._) _List._

  1883. _Didymium paraguayense_ Speg., _Fung. Guar. Pug._, 1, p. 141.
  1893. _Craterium rubescens_ Rex, _Proc. Philad. Acad. Nat. Sci._,
           p. 370.
  1894. _Craterium rubescens_ Rex, List., _Mycetozoa_, p. 71.
  1899. _Craterium rubescens_ Rex, Macbr., _N. A. S._, p. 75.
  1904. _Iocraterium paraguayense_ (Speg.) Jahn, _Hedwigia_, XLII.,
           p. 302.
  1911. _Craterium paraguayense_ List., _Mycetozoa, 2nd ed._, p. 95.

Sporangia gregarious, cylindrical or elongate cyathiform, stipitate,
dark violet-red, the apex slightly roughened by pale calcareous
granules, the peridium longitudinally wrinkled below; dehiscence,
irregularly circumscissile; stipe darker, one-half the height of the
sporangium, longitudinally wrinkled; capillitium dense, abundantly
calcareous; spores violet-brown, minutely roughened, 7-8 µ.

In form resembling the following species, but instantly distinguished by
the color, which is red throughout, tinged with purple or violet. The
capillitium is badhamioid, as noted by Dr. Rex. Very distinct from _P.
newtoni_ in color, form, habit, epispore, etc.


2. CRATERIUM AUREUM (_Schum._) _Rost._

  1803. _Trichia aurea_ Schum., _Enum. Pl. Saell._, II., p. 207.
  1829. _Craterium mutabile_ Fries, _Syst. Myc._, III., p. 154.
  1875. _Craterium aureum_ (Schum.) Rost., _Mon._, p. 125.

Sporangia gregarious, globose or obovoid, stipitate, yellow, erect, the
peridial wall thin, especially at the summit, where at maturity it
breaks up somewhat reticulately, leaving the persistent lower portion
with an uneven margin above which projects the pale yellow capillitium;
stipe short, orange, or brownish-red, arising from a small hypothallus;
capillitium dense, yellow, the nodules not large, irregular, tending to
form a pseudo-columella in the centre of the cup; spores minutely
warted, violaceous-brown, 8-10 µ.

Fries regards this, which he names _C. mutabile_, the most distinctly
marked species of the genus; chiefly, as it appears, on account of the
bright yellow color. This, however, varies. Some specimens before us are
gray, showing only a trace of yellow below. In some European specimens a
reddish tinge prevails. The form of the sporangium also varies. In
typical specimens, unopened, the shape is almost pyriform; opened, we
have a cylindric, oftenest lemon-yellow vase, mounted on a short striate
stalk. But again, from the same plasmodium, we may have globose
sporangia, opening so as to leave only a shallow, salver-shaped base. In
this case the stipe is also longer. The plasmodium is said to be "clear
lemon yellow."--_Massee._

There seems little doubt that Schumacher had in mind the present
species in his _Trichia aurea_. Rostafinski shows that Fries's synonym,
_C. mutabile_, is founded on a mistake. The earlier specific name is
therefore on Rostafinski's authority adopted.

Not common. Pennsylvania, New Jersey, North Carolina, Ohio, Iowa.


3. CRATERIUM LEUCOCEPHALUM (_Pers._) _Ditmar_.

PLATE VIII., Fig. 5.

  1791. _Stemonitis leucocephala_ Gmelin, _Syst. Nat._, II., p. 1467.
  1801. _Arcyria_ (?) _leucocephala_ Persoon, _Syn. Fung._, p. 183.
  1801. _Craterium_ (?) _leucocephalum_, Persoon, _Syn. Fung._, p. 184.
  1813. _Craterium leucocephalum_ (Pers.) Ditmar, Sturm, _Deutsch.
           Flora, Pilze_, p. 21, Pl. 11.
  1889. _Physarum scyphoides_ Cke. & Balf., _Jour. Myc._, V., p. 186.
  1896. _Craterium convivale_ (Batsch) Morg., _Jour. Cin. Soc._, p. 86.

Sporangia gregarious, short-cylindric or ovate, pure white above, brown
or reddish-brown below, stipitate, dehiscence irregularly
circumscissile, the persistent portion of the peridium beaker-shaped;
stipe short, stout, expanded above into the base of the peridium with
which it is concolorous; hypothallus scant; capillitium white or
sometimes, toward the centre, brownish, the calcareous nodules large,
conspicuous, and persistent; spore-mass black, spores violaceous-brown,
minutely spinulose, 8-9 µ.

Distinguished by its white cap from all except the next, from which the
markedly different form serves as the diagnostic feature. In some
gatherings, curious patches of yellow mark the otherwise snow white cap
and sides; these are mere stains, or sometimes definite, crystalline,
flake-like bodies, standing out in plain relief on the sporangial wall,
or lurking in the larger nodules which are massed along the axis of the
cup to form the pseudo-columella here strongly developed. Mr. Lister
calls attention to these yellow flakes, and regards them as diagnostic.
European specimens show the capillitium yellow, sometimes throughout!

The nomenclature question is here somewhat difficult. Fries heads his
list of synonyms with _Peziza convivalis_ Batsch. Batsch simply
described Micheli's figure! Now there is nothing in Micheli's figure
(Pl. 86, Fig. 14) to enable one to say with certainty which craterium
Micheli had in mind, if craterium at all. Nor does Batsch help the
matter when he offers the description following: "Stipitata; acute
conica, patens; stipite subdistincto, lineari, brevi, valido. _Albicans.
In foliis hederae putridis._" (_Elenchus Fungorum_, Batsch, 1783, p.
121.) There is nothing definitive here but the one word "albicans"
quoted from Micheli. But this term is applicable the rather to _C.
minutum_, the cups of which whiten with weathering. It may be, as
insisted by Fries (_Syst. Myc._, III., p. 149), that Micheli drew
crateriums; but if so, we cannot determine which species.

The specific name here adopted was applied by Persoon probably to this
form; but Persoon likewise failed to distinguish the present species
from _C. minutum_ (see _Syn. Fung._, pp. 183, 184), and Fries, _op.
cit._, p. 153. Ditmar, _l. c._, leaves no doubt as to what he figures
and describes, and accordingly the name he first correctly uses is here
adopted.

Not common. New England, Pennsylvania, Ohio, North Carolina, Iowa,
Colorado, Washington, California; reported from Europe.


4. CRATERIUM CYLINDRICUM _Massee_.

PLATE XVI., Fig. 2.

  1873. _Craterium minimum_ Berk. & C., _Grev._, II., p. 67.
  1892. _Craterium cylindricum_ Massee, _Mon._, p. 268.
  1894. _Craterium leucocephalum_ Ditm., List., _Myc._, p. 72, in part.
  1899. _Craterium minimum_ Berk. & C., Macbr., _N. A. S._, p. 77.
  1911. _Craterium leucocephalum_ var. _cylindricum_ List., _Mycetozoa,
           2nd ed._, p. 97.

Sporangia closely gregarious, very small, .5 µ or less, slender,
cylindric, almost entirely white, stipitate, the peridium delicate,
transparent although calcareous nearly to the base, opening by a
dehiscence regularly circumscissile; stipe short, about one-third the
total height, clear orange-brown, somewhat furrowed, rising from an
indistinct hypothallus; capillitium very lax, physaroid, the calcareous
nodules large, rounded, pure white, aggregated at the centre of the cup;
spore-mass black, spores minutely roughened, violaceous-brown, 8-9 µ.

This is the common form in the United States. Massee describes it as _C.
cylindricum_ Mass., and it seems not to occur in Europe. Lister has put
it in with _C. leucocephalum_, from which its more delicate structure
and elegant cylindrical shape certainly distinguish it. The dehiscence
is even more regular than in the preceding species and approaches that
of _C. minutum_ Leers., with bleached forms of which it must not be
confused. _N. A. F._, 1400.

_C. minimum_ Berk. & C. has here priority. Massee regards this name as
indicating a distinct species. We have been unable to determine what the
authors really had before them, and adopt accordingly the first
available combination.

New England to Iowa and south; reported also from the orient.


5. CRATERIUM CONCINNUM _Rex._

  1893. _Craterium concinnum_ Rex, _Proc. Phila. Acad._, p. 370.

Sporangia scattered, usually minute, broadly funnel-shaped, stipitate.
The peridium simple, variously colored by innate lime granules, opening
by a regular cap or operculum, brownish white, darkest in the centre,
always more or less convex; stipe equalling the cup in height, dark
brown, longitudinally ridged; the capillitium a close-meshed network,
with small rounded or slightly angular masses of ochre-brown
lime-granules, larger toward the centre; spores pale brown, minutely
warted, 9-10 µ.

This species differs from the following, to which it seems most nearly
allied, in form, color, as in the capillitium, and color of the spores.
In habitat, however, it seems no less distinct, being found always (?)
on the spines of decaying chestnut-burs lying on the ground, and in
company with that other peculiar species _Lachnobolus globosus_.

The range is probably that of the chestnut, _Castanea dentata_
Borkhausen, east of the Mississippi River.


6. CRATERIUM MINUTUM (_Leers_) _Fr._

PLATE XV., Fig. 5.

  1775. _Peziza minuta_ Leers, _Fl. Herborn_, p. 277.
  1797. _Craterium pedunculatum_ Trent., Roth., _Catal. Bot._, I.,
           p. 224.
  1813. _Craterium vulgare_ Ditmar, Sturm, _Deutsch. Fl. Pilze_, p. 17.
  1829. _Craterium pedunculatum_ Trent., Fr., _Syst. Myc._, III.,
           p. 150.
  1829. _Craterium minutum_ Leers, Fr., _Syst. Myc._, III., p. 151.
  1893. _Craterium pedunculatum_ Trent., Macbr., _Bull. Lab. Nat. Hist.
           Iowa_, II, p. 385.
  1894. _Craterium pedunculatum_ Trent., Lister, _Mycetozoa_, p. 70.
  1899. _Craterium minutum_ (Leers) Fr., Macbr., _N. A. S._, p. 78.
  1911. _Craterium minutum_ Fr., List., _Mycetozoa, 2nd ed._, p. 94.

Sporangia scattered, gregarious, cyathiform or turbinate, grayish brown,
stipitate, the peridial wall rather thick, double, opening by a distinct
lid which lies usually below the slightly thickened and everted margin
of the cup; stipe paler, translucent, about equalling in height the
peridial cup, longitudinally wrinkled, with hypothallus scant or none;
capillitium physaroid, the calcareous nodules large, white, and
generally aggregated at the centre of the cup; spore-mass black, spores
by transmitted light violaceous, minutely warted, 8-10 µ.

This is the most highly differentiated of the whole series. The cup is
shapely and well defined, while the lid is not only distinct, but is a
thin, delicate membrane of slightly different structure when compared
with the peridial wall. It is in all the specimens before us much
depressed below the mouth of the sporangium, and the whole structure in
our specimens corresponds with Fries' description of _C. pedunculatum_
Trent., while specimens received from Europe correspond to Fries'
account of _C. minutum_ Leers. Nevertheless we are assured that the two
forms are in Europe developed from the same plasmodium, and therefore
adopt the earlier specific name as above. _N. A. F._, 2500. This is
probably _Fungoides convivalis_ of Batsch and Micheli.

In this species yellow sporangia are sometimes seen. Miss Currie reports
from Toronto such variation and in Europe the case seems not unusual.

In fact, there is a yellow tinge about the sporangia of every species
listed here, except the first. With the same exception, the plasmodium
in every case is yellow.

Common throughout the eastern United States, west to Iowa, Colorado, and
south to Louisiana; cosmopolitan.


=5. Physarella= _Peck._

  1882. _Physarella_ Peck, _Bull. Torr. Bot. Club_, IX., p. 61.

Sporangium pervious to the base, the interior walls forming a persistent
spurious columella; capillitium composed of filaments with here and
there minute knot-like thickenings, straight tubes containing
lime-granules extending from the exterior to the interior walls of the
sporangium, persistently attached to the former.[31]

Such is Dr. Peck's original description of this most peculiar genus. The
form of the sporangium in the only species is very variable, but in
typical cases is vasiform, the peridial wall at the apex introverted.
The capillitium is like that of _Tilmadoche_, except for the presence of
the "straight tubes" emphasized in the original description. These are
very remarkable and at once diagnostic. They take origin in the
sporangial wall and pass across to the "columella"; but at the
dehiscence of the sporangium, in typical cases, they remain attached at
the points of origin, projecting as stout spine-like processes.


PHYSARELLA OBLONGA (_Berk. & C._) _Morg._

PLATE VIII., Figs. 4, 4 _a_, 4 _b_, 4 _c_; PLATE XVI., Figs. 1, 1 _a_, 1
_b_, and 6.

  1873. _Trichamphora oblonga_ Berk. & C., _Grev._, II., p. 66.
  1876. _Tilmadoche oblonga_ (Berk. & C.) Rost., _Mon. App._, p. 13.
  1876. _Tilmadoche hians_ Rost., _Mon. App._, p 14.
  1882. _Physarella mirabilis_ Peck, _Bull. Torr. Bot. Club_, IX.,
           p. 61.
  1893. _Physarella oblonga_ (Berk. & C.) Morg., _Jour. Cin. Soc._,
           p. 79.
  1894. _Physarella mirabilis_ Peck, List., _Mycet._, p. 68.
  1899. _Physarella oblonga_ (Berk. & C.) Morg., Macbr., _N. A. S._,
           p. 71.
  1911. _Physarella oblonga_ Morg., List., _Mycet., 2nd ed._, p. 91.

Sporangia scattered or gregarious, typically cup-shaped or
sub-infundibuliform, stipitate, erect or cernuous, but varying through
low salver-shaped cups, to irregular applanate and sessile masses, the
peridium thin but firm, tawny, roughened by numerous yellowish
calcareous scales, at length ruptured above and often reflexed in the
form of petal-like segments from which project upwards the spiniform
trabecules of the capillitium; stipe when present long, terete, red,
arising from a scant hypothallus and extended within the sporangium to
meet the tubular "columella"; capillitium of delicate violaceous threads
seldom branched or united, radiating from the columella with few
calcareous nodular expansions, but supported by stout yellow calcareous
trabecules, running parallel to the capillitial threads, long adherent
to the sporangial wall; spores smooth, globose violet-brown, 7-8 µ.

Not uncommon in wet places. New York, Ohio, Iowa, South Dakota,
Louisiana, Nicaragua; reported also from Ceylon, Java, etc.

Not the least remarkable feature of this remarkable species is the
variation in the form of the fruit or sporangia. We have specimens from
Louisiana (Rev. Langlois) which show no trace of columella, the whole
structure involute and plicate, short stipitate, recalling the extremest
complexity of such a species as _P. polycephalum_. _Vid._ Pl. XVI., Fig.
6. Moreover, in these specimens the calcareous deposits are white and
not yellow, giving the entire fructification a grayish aspect. Yet there
is no doubt we have here simply an exaggerated abnormality of the
species; the spores are identical in size, color, and surface.
Plasmodium bright yellow. Dr. Peck gave to his forms the name
_Physarella mirabilis_; but specimens sent by Michener of Pennsylvania,
and by Berkeley and Curtis described as _Trichamphora oblonga_ (_Grev._,
II., p. 66), are the same thing. _N. A. F._, 1212.

_Physarella lusitanica_ Torrend is a globose form depressed above or
betimes discoidal, occurring on Eucalyptus trees in Portugal. _P.
oblonga_ is so variable in form that it sometimes suggests a different
genus. Forms of it have been mistaken for _Fuligo gyrosa_ R., etc.
Professor Torrend would include here _Physarum javanicum_ (Rac.), i. e.
_Tilmadoche javanica_ as Raciborski saw it! We may not too often reflect
that genera are purely artificial things set up for our convenience; but
surely _Physarella_ as a natural genus is distinct enough to all.


=6. Cienkowskia= _Rost._

  1873. _Cienkowskia_ Rost., _Versuch_, p. 9.

Fructification plasmodiocarpous, irregularly dehiscent, the wall a thin
cartilaginous membrane destitute of lime, except the capillitial
attachments within; capillitium scanty but rigid, and characterized
everywhere by peculiar hook-like branchlets, free and sharp-pointed, the
spores as in _Physarum_, etc.

The genus contains, so far, but a single species:--


CIENKOWSKIA RETICULATA (_Alb. & Schw._) _Rost._

PLATE XIV., Figs. 2, 2 _a_, 2 _b_.

  1805. _Physarum reticulatum_ Alb. & Schw., _Cons. Fung._, p. 90.
  1829. _Diderma reticulatum_ Fr., _Syst. Myc._, III., p. 112.
  1873. _Cienkowskia reticulata_ (Alb. & Schw.) Rost., _Versuch_, p. 9.

Plasmodiocarp an elongated, irregularly limited, close-meshed net,
closely applied to the substratum, the wall thin, transversely rugulose,
and roughened, dull orange-yellow, splashed here and there with scarlet,
anon entirely red, within marked by transverse calcareous ridges,
supporting in part the calcareous system of the capillitium; capillitium
of delicate, rigid, reticulating yellow tubules or threads with numerous
free, uncinate or sickle-shaped branchlets, and large, irregular,
calcareous plates, more or less transverse to the axis of the
sporangium, attached to the peridial walls, as if to form septa,
ordinary calcareous nodules few; spore-mass jet-black, spores, by
transmitted light, violaceous, minutely roughened, 9-10 µ.

A very rare species, as it appears, easily recognized by the Coddington
even, much more by the microscopic characters quoted; probably often
overlooked by the collector, as to the naked eye it presents the
appearance of some imperfectly developed, dried-up plasmodium. Very
unlike _Physarum serpula_ Morgan, not infrequently offered by collectors
as _Cienkowskia_. It is _Diderma reticulatum_ of Fries, who, strangely
enough, thought it might be a plasmodial phase of _Diderma_ (i. e.
_Leocarpus_) _fragile_ (_Syst. Myc._, III., p. 102).

Eastern United States, Europe, Java, Ceylon, California. See under _L.
fragilis_, next following.


=7. Leocarpus= (_Link_) _Rost._

  1809. _Leocarpus_ Link, _Diss._, I., p. 25.

Sporangia sessile, or short stipitate; peridial wall double, the outer
thick, destitute of lime, polished, shining within and without, the
inner very delicate, enclosing the capillitium and spores; capillitium
of two, more or less, distinct systems, the one a delicate network of
hyaline, limeless threads, the other calcareous throughout, or nearly
so, the meshes large and the threads or tubules broad; columella none,
although a pseudo-columella may sometimes be detected.

This genus was by Link established on characters purely external.
Rostafinski supplemented Link's definition by calling attention to the
peculiar character of the capillitium and to microscopic characters in
general. The outer peridium is thick and strong, unlike the ordinary
structure in _Physarum_. Some physarums, however, have a very similar
outer wall; _P. brunneolum_, for instance; compare the peridium of _P.
citrinellum_. In dehiscence and structure there is also some resemblance
to some species of _Diderma_, and by Persoon and Fries the common
species was so referred, but the capillitium is again definitive.

A critical study of all these things really begins with Rostafinski's
microscope. Under his definition of the present genus _P. squamulosum_
Wingate and _P. albescens_ Ell. might well be entered here. Such course
at present would but increase confusion, and until by future research
the ontogeny of all these, and so their relationship, shall be
more exactly known, the genus may be left with its historic
species,--montotypic.


LEOCARPUS FRAGILIS (_Dickson_) _Rost._

PLATE VIII., Figs. 3, 3 _a_, 3 _b_.

  1785. _Lycoperdon fragile_ Dickson, _Fasc. Pl. Crypt. Brit._, I.,
           p. 25.
  1795. _Diderma vernicosum_ Persoon, _Ust. Ann. Bot._, XV., p. 34.
  1809. _Leocarpus vernicosum_ Link, _Diss._, I., p. 25.
  1875. _Leocarpus fragilis_ (Dicks.) Rost., _Mon._, p. 132.

Sporangia gregarious or clustered, sessile or stipitate, obovoid, rusty
or spadiceous-yellow, shining; peridium opening at maturity in somewhat
stellate fashion; stipe filiform, white or yellow, weak and short;
spores dull black, spinulose, 12-14 µ.

A common species, distributed through all the world, Iowa to Tasmania.
Recognizable at sight by the form and color of the sporangia. In shape
and posture these resemble the eggs of certain insects, and, occurring
upon dead leaves, generally where these have drifted against a rotten
log, they might perchance be mistaken for such structures. With no other
slime-moulds are they likely to be confused. The outer peridium opens
irregularly, or more rarely stellately. At centre of the capillitium is
a calcareous core. The plasmodium is yellowish white, spread in rich and
beautiful reticulations. _N. A. F._, 1123.

A plasmodiform gathering of this species which will be mistaken for an
entirely different thing, is yellow, sessile, and has _adherent_ spores;
looks like a badhamia, but is after all a leocarpus and probably belongs
here. The spores are irregularly clustered and the badhamioid section of
the capillitium seems now dominant.

California.


B. DIDYMIACEÆ

=Key to the Genera of the Didymiaceæ=

  1. Fructification æthalioid                              1. _Mucilago_

  2. Fructification plasmodiocarpous, or forming more
       often distinct sporangia.

     _a._ Calcareous deposits crystalline, stellate        2. _Didymium_

     _b._ Calcareous deposits amorphous, peridium double    3. _Diderma_

     _c._ Calcareous deposits in form of scattered
            scales                                      4. _Lepidoderma_

     _d._ Peridium double, the outer gelatinous          5. _Colloderma_


=1. Mucilago= (_Mich._) _Adans._

  1729. _Mucilago_ Micheli, _Nov. Pl. Gen._, in part.
  1763. _Mucilago_ (Mich.) Adanson, _Fam. des Pl._, II., p. 7.
  1791. _Spumaria_ Pers. in Gmelin, _Syst. Nat._, II., p. 1466.

Fructification æthalioid, consisting generally of large cushion-shaped
masses covered without by a white foam-like crust; within, composed of
numerous tubular sporangia, developed from a common hypothallus,
irregularly branched, contorted and more or less confluent; the peridial
wall thin, delicate, frosted with stellate lime-crystals, which mark in
section the boundaries of the several sporangia; capillitium of delicate
threads, generally only slightly branched, terminating in the sporangial
wall, marked with occasional swellings or thickenings.

By the descriptions offered by most authors, and especially by
Rostafinski's figures (_Mon._, Pl. ix.), a pronounced columella is
called for in the structure of _Spumaria_. The individual sporangia rise
from a common hypothallus, and occasionally portions of this run up and
give to a sporangium the appearance of being stipitate. Sometimes also
this upper extension of the hypothalline protoplasm passes beyond or
behind the base of the sporangium or between two or more, and is more or
less embraced by these in their confluent flexures. This, it seems,
suggested Rostafinski's elaborate diagram, Fig. 158; at least, none
other form of columella is shown by American materials at hand.


1. MUCILAGO SPONGIOSA (_Leyss._) _Morgan._

PLATE VII, Figs. 6, 6 _a_, 6 _b_.

  1783. _Mucor spongiosus_ Leysser, _Fl. Hal._, p. 305.
  1791. _Reticularia alba_ Bull., _C. Fl. France_, p. 92.
  1791. _Spumaria mucilago_ Pers., Gmel., _Syst. Nat._, II., 1466.
  1805. _Spumaria alba_ (Bull.) DC., _Fl. Fr._, II., p. 261.
  1897. _Mucilago spongiosa_ (Leyss.) Morg., _Bot. Gaz._, XXIV., p. 56.

Æthalium white or cream-colored, of variable size and shape,
half-an-inch to three inches in length and half as thick, the component
sporangia resting upon a common hypothallus and protected by a more or
less deciduous calcareous porous cortex; peridial walls thin, and where
exposed iridescent, generally whitened by a thin coating of lime
crystals; capillitium scanty, of simple, mostly dark-colored, slightly
anastomosing threads; columella indefinite or none; hypothallus white,
spongy; spore-mass black, spores violaceous, exceedingly rough, large,
12-15 µ.

Very common in all the eastern United States and the Mississippi valley,
south to Texas. The plasmodium is dull white, of the consistence of
cream, and is often met with in quantity on beds of decaying leaves in
the woods. In fruiting the plasmodium ascends preferably living stems of
small bushes, herbaceous plants, or grasses, and forms the æthalium
around the stem some distance above the ground. The cortex varies in
amount, is also deciduous, so that weathered or imperfectly developed
forms probably represent the var. _S. cornuta_ Schum.

Two varieties of this species are recognized; the one from Bolivia, var.
_dictyospora_ described by Mr. R. E. Fries (_Arkiv. for Botanik_ Bd. 1,
p. 66) differs from the type chiefly in its finer capillitial threads
its darker spores with longer spines and fine reticulate sculpture; the
other from Colorado, var. _solida_ described by Professor Sturgis
differs, as the name implies, principally in its greater compactness and
slightly smaller calcareous crystals; a desert phase.


=2. Didymium= (_Schrad._) _Fr._

  1797. _Didymium_ Schrad., _Nov. Gen. Plant._, p. 20, in part.
  1829. _Didymium_ (Schrad.) Fr., _Syst. Myc._, III., p. 113.
  1875. _Didymium_ (Schrad.) DeBy., Rost., _Versuch_, p. 13.

Sporangia distinct, stipitate, sessile or even plasmodiocarpous, never
æthalioid; the peridium thin, irregular in dehiscence, covered with a
more or less dense coating of calcareous crystals; columella more
frequently present; capillitium of delicate threads, simple or sparingly
branched, extending from the columella to the peridial wall.

The genus _Didymium_, as set up by Schrader _l. c._, included a number
of species now assigned to _Diderma_, _Lepidoderma_ or _Lamproderma_.
Fries set out the didermas; DeBary and Rostafinski completed the
revision by setting out the remaining alien forms.

The genus is among Myxomycetes instantly recognized by the peculiar form
of its calcareous deposits, stellate crystals coating, or merely
frosting, usually distinct sporangia.


=Key to the Species of Didymium=

  1. Lime-crystals merely whitening the peridial wall.

     A. Fructification plasmodiocarpous.

      _a._ White.

            O Capillitium with adherent vesicles     1. _D. complanatum_

           OO Capillitium simple                         2. _D. anellus_

          OOO Capillitium much combined; spores
                10-13 µ                                3. _D. wilczekii_

         OOOO Capillitium crystal-bearing           18_a_. _D. anomalum_

      _b._ Yellow or tawny                                4. _D. fulvum_

     B. Fructification normally of distinct sporangia.

      _a._ Sporangia sessile or nearly so; outer
             calcareous wall conspicuously developed  5. _D. crustaceum_

      _b._ Sporangia plainly stipitate.

           i. Peridium much depressed; umbilicate below.

               O Stipe white                         6. _D. squamulosum_

              OO Stipe black.

                  + Larger, about 7.5-1 mm.        7. _D. melanospermum_

                 ++ Small, about .5 mm.                    8. _D. minus_

                +++ Sporangia discoid                     9. _D. clavus_

          ii. Peridium small, globose.

               O Stipe dark brown or black; columella
                   dark, obsolete or none.             10. _D. nigripes_

              OO Stipe generally paler, of various tints
                   of brown, orange, etc.

                  + Columella pale or white, nearly
                      smooth                          11. _D. xanthopus_

                 ++ Columella, yellow, discoid, rough   12. _D. eximium_

         iii. Peridium turbinate, columella
                hemispheric                             13. _D. trochus_

          iv. Peridium annulate 14. _D. annulatum_

  2. Calcareous crystals forming a distinct crust.

     A. Fructification wholly plasmodiocarpous           15. _D. dubium_

     B. Sporangia ill-defined, sessile, plasmodiocarpous.

      _a._ Spores generally nearly smooth              16. _D. difforme_

      _b._ Spores very rough, obscurely banded         17. _D. quitense_

  EXTRA-LIMITAL

      _a._ Sporangia discoid, spores reticulate     18. _D. intermedium_

      _b._ Stipe, columella, peridium, orange-brown    19. _D. leoninum_


1. DIDYMIUM COMPLANATUM (_Batsch_) _Rost._

PLATE XVI., Fig. 8.

  1786. _Lycoperdon complanatum_ Batsch, _Elench. Fung._, I., p. 251.
  1829. _Didymium serpula_ Fr., _Syst. Myc._, III., p. 126, Rost.,
          _App._, p. 21.
  1875. _Didymium complanatum_ (Batsch), Rost., _Mon._, p. 151.
  1899. _Didymium complanatum_ (Batsch) R., Macbr., _N. A. S._, p. 85.
  1911. _Didymium complanatum_ Rost., List., _Mycetozoa, 2nd ed._,
           p. 127.

Fructification plasmodiocarpous, creeping, flattened, vein-like,
annulate or reticulate, the dark-colored peridium covered with white,
but not numerous crystals; hypothallus none; columella none; capillitium
much branched, violaceous threads combined to form a rather dense net
which bears numerous, peculiar, rounded vesicles, yellowish in color,
30-50 µ in diameter; spores minutely warted, 7-9 µ, violaceous-brown.

The defining characteristics here are the curious supplementary
vesicles. These are evidently plasmodic, embraced, shot-through, by all
the neighboring capillitial threads, withal warted like a spore. They
remind of the curious, belated, spore-like but giant cells found in
stipes, as in arcyriaceous forms. With all the wealth of his prolix,
poetic, metaphoric tongue, the Polish author gives them abundant
consideration. In the _Mon._, Tab. IX., Figs. 166 and 180, he clearly
shows the structure, although in the explanation of the plate he has
strangely mixed this species with _D. crustaceum_ Fr. Under _D. serpula_
Fries may refer to the present species, although there is nothing in his
description to determine the fact. The same thing may be said of the
description and figures of Batsch. Rostafinski, in the _Monograph_,
seems to have been satisfied as to the identity of Batsch's materials:
in the _Appendix_, he writes _D. serpula_, but gives no reason.

Rare. New York. England, France, Germany.


2. DIDYMIUM ANELLUS _Morgan._

PLATE XVIII., Fig. 7.

  1894. _Didymium anellus_ Morgan, _Jour. Cin. Soc._, p. 64.
  1899. _Didymium anellus_ Morg., Macbr., _N. A. S._, p. 85.
  1911. _Didymium anellus_ Morg., Lister, _Mycetozoa, 2nd ed._, p. 134.

Plasmodiocarp in small rings or links, then confluent and elongated,
irregularly connected together, bent and flexuous, resting on a thin
venulose hypothallus, or sometimes globose, the peridium dark colored,
with a thin layer of stellate crystals, irregularly ruptured;
capillitium of slender, dark-colored threads, which extend from base to
wall, more or less branched, and combined into a loose net; columella a
thin layer of brown scales; spores globose, very minutely warted,
violaceous, 8-9 µ.

This minute species resembles a poorly developed, or sessile, phase of
_D. melanospermum_. Some of the sporangia (?) are spherical; such show a
very short dark stalk. The columella is scant, and the spores are
smaller than those of _D. melanospermum_.

Ohio. Reported more recently from Europe and Ceylon.


3. DIDYMIUM WILCZEKII _Meylan_.

  1908. _Didymium wilczekii_ Meyl., _Bull. Soc. Vaud. Sci. Nat._,
           XLIV., p. 290.
  1911. _Didymium wilczekii_ Meyl., List., _Mycetozoa, 2nd ed._, p. 134.

Plasmodiocarpous, dehiscing irregularly, columella scant; capillitium
abundant, the threads brown, anastomosing, forming an elastic net;
spores purple-brown, minutely spinulose, 10-12 µ.

Resembling plasmodiocarpous forms of _D. squamulosum_, a montane var.;
small and delicate, our specimen about 16 × 6 mm. Evidently not common;
collected but once by Professor Bethel at an altitude of 11,000 feet,
Rocky Mountains of Colorado.

Reported in Switzerland and Sweden.

In certain Swiss gatherings made in 1913 Miss Lister finds capillitial
threads with _spiral_ tæniæ as in _Trichia_! (_Jour. of Bot._, Apr.
1914.) The threads in our specimen are roughened, somewhat as in _D.
squamulosum_, though less strongly; the spores are nearly smooth,
fuliginous at first, paler and violaceous when saturate.


4. DIDYMIUM FULVUM _Sturgis._

  1917. _Didymium fulvum_ Sturgis, _Mycologia_, IX., p. 37.

Sporangia gregarious, sessile, elongate or forming curved
plasmodiocarps, sometimes confluent, rarely sub-globose, concave
beneath, pale-raw-umber in color, 0.5-0.8 mm. in diameter, occasionally
seated on a concolorous, membranous, lime-encrusted hypothallus which
may form pseudo-stalks; sporangium wall membranous, stained with yellow
blotches, thickly sprinkled with clusters of large acicular crystals of
pale-yellowish lime; columella very much flattened or obsolete;
capillitium an abundant network of delicate, almost straight or
flexuose, pale-purple or nearly hyaline threads, frequently with dark,
calyciform thickenings as in _Mucilago_, and occasionally showing
fusiform, crystalline blisters; spores dark-purplish-brown, coarsely
tuberculate, the tubercles usually arranged in curved lines, paler and
smoother on one side, 12.5 to 14.5 µ. Colorado.


5. DIDYMIUM CRUSTACEUM _Fr._

  1829. _Didymium crustaceum_ Fr., _Syst. Myc._, III., p. 124.

Sporangia closely aggregated, globose, or by compression deformed,
sessile, snow-white, by virtue of the remarkably developed covering of
calcareous crystals by which each sporangium is surrounded as if to form
a crust, the peridium membranous, colorless, usually shrunken above and
depressed; columella pale, small, or obsolete; hypothallus scant or
vanishing; capillitium of rather stout violaceous threads seldom
branched except at the tips, where they are pale and often bifid, or
more than once dichotomously divided; spores strongly warted, globose,
violet-brown, 10-13 µ.

This species has in some ways all the outward seeming of a diderma, but
cannot be referred to that genus because of the crystalline character of
its crust. This is a very marked structure; loosely built up of very
large crystals, it is necessarily extremely frail, nevertheless
persists, arching over at a considerable distance above the peridium
proper. Sometimes, however, caducous, evanescent.

The sporangia are said to be sometimes stipitate. This feature does not
appear in any of the material before us. Lister in _Mycetozoa_ Pl. XL.,
_c._ draws the capillitium much more delicate than it appears in our
specimens. The hypothallus is sometimes noticeable under some of the
sporangia where closely crowded, but is not a constant feature.

Rostafinski (by typographical error?) confused in the _Monograph_, pp.
164, 165, this species with Persoon's _Physarum confluens_. In the
_Appendix_ he substitutes the Friesian nomenclature. Persoon's
description of his species is insufficient, and throws no light on the
problem whatever.

Rare. Iowa; Black Hills, South Dakota. Reported common in Europe.
Canada; Vancouver Island to the St. Lawrence.


6. DIDYMIUM SQUAMULOSUM (_Alb. & Schw._) _Fries._

  1805. _Diderma squamulosum_ Alb. & Schw., _Consp. Fung._, p. 88.
  1816. _Didymium effusum_ Link, _Diss._, II., p. 42.
  1829. _Didymium squamulosum_ (Alb. & Schw.), Fries, _Syst. Myc._,
           III., p. 118.
  1875. _Didymium effusum_ (Link) Rost., _Mon._, p. 163.
  1894. _Didymium effusum_ (Link) List., _Mycetozoa_, p. 99.

Sporangia, in typical forms, gregarious, globose or depressed-globose,
gray or snow-white, stipitate; the peridium a thin iridescent membrane
covered more or less richly with minute crystals of lime; the stipe when
present, snow-white, fluted or channelled, stout, even; columella white,
conspicuous; hypothallus usually small or obsolete; capillitium of
delicate branching threads, usually colorless or pallid, sometimes with
conspicuous calyciform thickenings; spores violaceous, minutely warted
or spinulose, 8-10 µ.

This, one of the most beautiful species in the whole series, is
remarkable for the variations which it presents in the fruiting phase.
These range all the way from the simplest and plainest kind of a
plasmodiocarp with only the most delicate frosting of calcareous
crystals up through more or less confluent sessile sporangia to
well-defined elegantly stipitate, globose fruits, where the lime is
sometimes so abundant as to form deciduous flaky scales. The
hypothallus, sometimes entirely wanting, is anon well developed, even
continuous, venulose, from stipe to stipe. The capillitium varies much
in abundance as in color; when scanty, it is colorless and in every way
more delicate, when abundant, darker in color and sometimes with
stronger thickenings.

_D. fuckelianum Rost._, as shown in _N. A. F._, 2090, and in some
private collections, seems to be a rather stout phase of the present
species; the stipe is more abundantly and deeply plicate, is sometimes
tinged with brown, and the capillitium is darker colored and coarser
than in what is here regarded as the type of the species; but withal the
specimens certainly fail to meet the requirements of Rostafinski's
elaborate description and figure, _Mon._, p. 161 and Fig. 154.

_D. effusum_ Link, probably stands for a sessile form of this species,
but Link's brief description (1816) is antedated by the much better one
of Albertini and Schweinitz, _l. c._

Generally distributed throughout the wooded regions of North America,
from New England to Nicaragua, and from Canada to California. Not
uncommon about stable-manure heaps, in flower beds, and on richly
manured lands. July, August.

Nicaragua specimens not only show a continuous vein-like hypothallus,
but have the peridia often confluent, the columellæ in such cases
confluent, the stipes distinct. Furthermore, the largest spores reach
the limit of 12.5 µ, and perhaps the larger number range from 10-12.5 µ,
and all are very rough. This corresponds with _D. macrospermum_ Rost.,
which is distinguished, says the author (_Mon._, p. 162, _opis_),
"chiefly by the large and strongly spinulose spores." However, the same
sporangium in our Central American specimens yield spores 9.5-12.5 µ, a
remarkable range. So that _D. macrospermum_ on this side the ocean, at
least, cannot be distinguished from _D. squamulosum_, as far as spores
are concerned. A similar remark may be made relative to the form of the
columella which Rostafinski, in his figures especially, would make
diagnostic. The columella in the sporangia with largest and roughest
spores is that of a perfectly normal _D. squamulosum_.


7. DIDYMIUM MELANOSPERMUM (_Pers._) _Macbr._

PLATE VII., Figs. 3, 3 _a._

  1794. _Physarum melanospermum_ Pers., _Röm. N. Mag. Bot._, p. 89.
  1797. _Didymium farinaceum_ Schrader, _Nov. Gen. Pl._, p. 26, t. 5,
           Fig. 6.

Sporangia gregarious, hemispheric, depressed, umbilicate below,
stipitate or sessile; the peridium firm, dull brown in color, frosted
with minute crystals of lime, breaking irregularly; stipe, when present,
short, stout, dull black, opaque, arising from a broad base or
hypothallus; columella large, prominent; dark-colored, rough above,
concave below; capillitium of more or less sinuous, usually dark-colored
threads, sparingly branched, and often with calyciform thickenings;
spore-mass black, spores by transmitted light pale, purplish-gray,
spinulose or rough, 10-12 µ.

A well-marked and common species, distinguished by its depressed
sporangium and dark-colored, opaque stipe. The latter is usually very
short, almost completely concealed in the concavity of the umbilicate
sporangium. The columella is dark-colored, forming the floor of the
peridial cavity.

Persoon first named this species as here. Later on, _Uster's Ann._, XV.,
6, he substituted _villosum_ as a more appropriate specific name.
Schrader rejects both names given by Persoon as unsuitable, and suggests
_farinaceum_. Schrad., _op. cit._, p. 27.

New England, Ohio, Missouri, Alabama, Iowa, Nebraska; Europe; probably
cosmopolitan.


8. DIDYMIUM MINUS _Lister._

PLATE X., Figs. 4, 4 _a_, 4 _b_.

  1892. _Didymium farinaceum_ Schr., var. _minus_, List., _Mycetozoa_,
           p. 97.
  1896. _Didymium minus_ List., Morg., _Jour. Cin. Soc._, p. 61.
  1899. _Didymium minus_ List., Macbr., _N. A. S._, p. 89.

Sporangia gregarious, depressed-globose, umbilicate below, whitish or
gray, small, about ½ mm., stipitate; stipe erect, rather slender,
black, faintly striate, about equal to the sporangium in the horizontal
diameter; columella distinct, dark brown, globose or depressed-globose,
attaining in some cases the centre, rough; capillitium delicate, almost
colorless, radiating, sparsely branched; spores in mass dark brown, by
transmitted light violet-tinted, minutely roughened, 8-10 µ.

Probably more common than the preceding, and generally mistaken for it.
Distinguished by its smaller size, longer and more slender stem, and
general trim, well-differentiated appearance. Certainly very near the
preceding, of which Mr. Lister regards it as merely a variety. Professor
Morgan thought it in this country the more common form.

New York, Ohio, Iowa; reported from Europe, Africa, South America.


9. DIDYMIUM CLAVUS (_Alb. & Schw._) _Rabenhorst._

  1805. _Physarum clavus_ Alb. & Schw., _Consp. Fung._, p. 96.
  1829. _Didymium melanopus_ Fries, _Syst. Myc._, III., p. 114.
  1844. _Didymium clavus_ (Alb. & Schw.) Rabh., _Ger. Cr. Fl._,
           No. 2282.
  1875. _Didymium clavus_ (Alb. & Schw.) Rost., _Mon._, p. 153.
  1899. _Didymium clavus_ (Alb. & Schw.) Rabenh., Macbr., _N. A. S._,
           p. 90.
  1911. _Didymium clavus_ Rost., List., _Mycet., 2nd ed._, p. 128.

Sporangia gregarious, pale gray, discoid or pileate, depressed,
stipitate; the peridium dark-colored, frosted with calcareous crystals
above, naked below; stipe short, slender, tapering upward, furrowed,
arising from a hypothallus more or less distinct, black; columella
obsolete; capillitium of delicate threads, pale or colorless, little
branched; spores violaceous, pale, nearly smooth, 6-8 µ.

This species is well differentiated, easy of recognition by reason of
its peculiar discoid sporangium, calcareous above, naked and black
beneath. _D. neglectum_ Massee, reported from Philadelphia, is said to
be a slender form of the present species. The figures of _D. clavus_ by
Albertini and Schweinitz are excellent, as also the description.

Not common. Pennsylvania, Ohio, Iowa.


10. DIDYMIUM NIGRIPES (_Link_) _Fries._

PLATE VII., Figs. 2, 2 _a_, 2 _b_.

  1809. _Physarum nigripes_ Link, _Obs. Diss._, I., p. 27.
  1818. _Physarum microcarpon_ Fr., _Sym. Gast._, p. 23.
  1829. _Didymium nigripes_ (Link) Fr., _Syst. Myc._, III., p. 119.
  1875. _Didymium microcarpon_ (Fr.) Rost., _Mon._, p. 157.
  1896. _Didymium microcarpon_ Fr., Morg., _Jour. Cin. Soc._, p. 61.

Sporangia gregarious, globose or hemispheric, umbilicate beneath, small,
white, stipitate; the peridium smoky, covered with minute calcareous
crystals; stipe slender, erect, black, opaque; hypothallus scutate,
black; columella distinct, globose, black or dark brown; capillitium of
delicate threads, pale brown or colorless, with occasional brown
thickenings or nodes, sparingly branched; spores pale, violaceous by
transmitted light, minutely warted, 6-8 µ.

This is _D. microcarpon_ Rost. Fries, _l. c._, acknowledges the priority
of Link's appellation, and discards _microcarpon_. Rostafinski adopted
_microcarpon_ simply because he thought it more appropriate. Fries
describes the columella "none or black." It is doubtful whether we have
the typical Friesian form on this continent. The fructification is in
our specimens small, about .4 mm., and the spores, as noted by Morgan,
small; otherwise the species is hardly more than a variety of the next.
Under the name _D. nigripes_ Lister groups our Nos. 10, 11, 12. _N. A.
F._, 1393, represents Dr. Rex's conception of the present species.

Not common. New York, Ohio, Iowa.


11. DIDYMIUM XANTHOPUS (_Ditmar_) _Fr._

PLATE XVI., Fig. 10.

  1817. _Cionium xanthopus_ Ditmar, Sturm, _Deutsch. Fl._, III., p. 37,
           t. 43.
  1829. _Didymium xanthopus_ (Dit.) Fr., _Syst. Myc._, III., p. 120.
  1873. _Didymium proximum_ Berk. & C., _Grev._, II., p. 52.
  1892. _Didymium microcarpon_ (Fr.) Rost., Macbr., _Bull. Lab. Nat.
           Hist. Iowa_, II., p. 146, in part.
  1894. _Didymium nigripes_ Fr., List., _Mycetozoa_, p. 98, in part.

Sporangia gregarious, white, globose, slightly umbilicate, stipitate;
the peridium thin, and nearly or quite colorless, frosted with crystals
of lime; the stipe yellowish or yellowish brown, corneous, erect,
subulate, slender; hypothallus none; columella pale or white,
turbinate, globose or depressed-globose; capillitium of dull brown, or
colorless threads more or less branched, always white at the tips;
spores violaceous, nearly smooth, 7.5-8.5 µ.

This seems to be the most common form in the United States. It is
distinguished from the preceding by the longer, more delicate, generally
orange-yellow, stem with pale or white columella. The spores also
average a shade larger. _N. A. F._, 412 and 2089, are illustrations of
_D. xanthopus_. The columella in blown-out specimens is very striking,
well confirming the diagnosis of Fries, "_valde prominens, globosa,
stipitata, alba_." Berkeley makes the color of the capillitium
diagnostic of _D. proximum_, but this feature is insufficient.

Eastern United States; common.


12. DIDYMIUM EXIMIUM _Peck._

PLATE XVI., Figs. 11, 11 _a_, 11 _b_.

  1879. _Didymium eximium_ Peck, _Rep. N. Y. Mus._, XXXI., p. 41.

Sporangia scattered, dull grayish-yellow or gray, depressed-globose,
umbilicate, minute, stipitate; the peridium comparatively thick,
tenacious, especially persistent below, tawny or yellow; the stipe pale
brown or orange, erect, even or slightly enlarged at base; hypothallus
scant or none; columella prominent, more or less discoidal, rough, or
spinulose, especially on the upper surface, yellow; capillitium not
abundant, pale fuliginous, often branching and anastomosing so as to
form a loose net; spores nearly smooth, dark violaceous by transmitted
light, 8.5-9.5 µ.

The species differs from _D. xanthopus_ in several particulars,--in the
much firmer, more persistent, and less calcareous peridium, in the more
complex capillitium, in the darker and larger spores, and especially in
the peculiar and prominent columella, which is not only rough, but even
"sometimes spinulose even to the extent of long spicules penetrating to
one-third the height of the sporangia." _N. A. F._, 2493.

As stated under No. 8, these last two species are called varieties only
of _D. nigripes_. They are so retained in _Mycetozoa, 2nd ed._ Since,
however, they are the usual presentation of the species in the United
States, it seems wise to let them stand for the present, as here. They
are quite distinguishable; _D. eximium_ especially well marked.

Apparently rare, it yet ranges from New York to eastern Iowa, in
colonies rather large. Okoboji Lake;--fine!


13. DIDYMIUM TROCHUS _List._

  1898. _Didymium trochus_ List., _Jour. Bot._, XXXVI., p. 164.

Sporangia plasmodiocarpous, hemispherical or turbinate, white, sessile
or very short-stalked, cream-colored or white; peridium double, the
outer shell-like, the inner membranaceous, more or less adherent to the
outer, both caducous together, leaving the thickened base surrounding an
expanded columella; stipe, when present, very short, stout; capillitium
colorless, nearly simple; spores brownish-purple, strongly warted, 9-10
µ.

On decaying leaves, rotten cactus, yucca, etc., Monrovia, California;
_Bethel_.

Reported from England on beds of leaves or straw; in Portugal Dr.
Torrend finds it on or _in_ dead leaves of _Agave americana_! Evidently
an American species, and belonging to arid regions; its occurrence in
England surprising!


14. DIDYMIUM ANNULATUM _Macbr. n. s._

PLATE XX., Figs. 4, 4 _a_.

Sporangia small, scattered, annulate, not only without columella but
perforate when the stipe is broken, umbilicate above and below, grey,
coated with crystalline frustules, opening irregularly about the
periphery; stipe white, or pallid, fluted, tapering upward from a
distinct hypothallus; capillitium scanty consisting of delicate,
sparsely branching threads, the branchlets anastomosing more or less at
length, attached to the peridial wall, radiating from the rim of the
slightly depressed top of stipe, without special thickenings save at the
insertion of the ramules a triangular enlargement is usual and of dark
or pallid shade; spores smooth; however they show three or four spots
on the hemisphere and other minute but variable markings; 9-10 µ.
Seattle, Washington.

Differs from _D. nigripes_ in color of the stipes, capillitium,
spore-diameter, etc.


15. DIDYMIUM DUBIUM _Rost._

  1875. _Didymium dubium_ Rost., _Mon._, p. 152.
  1892. _Didymium listeri_ Mass., _Mon._, p. 244.
  1894. _Didymium dubium_ Rost., List., _Mycetozoa_, p. 95.
  1911. _Didymium dubium_ Rost., List., _Mycetozoa, 2nd ed._, p. 126.

Fructification wholly plasmodiocarpous, snow-white, small,
2-6 mm., flat and thin; the outer wall double, membranous within,
calcareous-crystalline without; columella none; capillitium simple of
rather thick, vertical, brown threads, sparingly united laterally, and
only occasionally furcate at the ends, especially above; spores minutely
spinulescent, violaceous pale, 12-15 µ.

Massee thought English specimens out of harmony with the original
description and gave them a new name. To refuse this, Lister enlarges
the range of spore-measurements and disregards some of Rostafinski's
specifications as to capillitium. Our specimens are as described.

Bohemia. England. Shores of Lake Okoboji, Iowa.

This is indeed a doubtful form. It differs from _D. difforme_ chiefly in
that the outer calcareous shell is not smooth, but is covered with
abundant loose crystals, frosted. The spores are paler but about the
same size. The frosting may be incident to local climatic conditions at
the time and place of desiccation.


16. DIDYMIUM DIFFORME _Duby._

  1797. _Diderma difforme_ Pers. _Tentamen Disp. Meth._, p. 19.
  1830. _Didymium difforme_ Duby., _Bot. Gall._, ii., p. 858.
  1875. _Chondrioderma difforme_ Pers., Rost., _Mon._, p. 177.
  1894. _Didymium difforme_ Duby., List., _Mycetozoa_, p. 94.
  1899. _Diderma personii_ Macbr., _N. A. S._, p. 96.
  1911. _Didymium difforme_ Duby., List., _Mycetozoa, 2nd ed._, p. 124.

Plasmodiocarpous, the smooth, white outer peridium separable from the
thin, colorless or purplish inner layer; capillitium of rather coarse,
flat, dichotomously branching threads, broader below; spores minutely
warted, or almost smooth, dark brown, 12-14 µ.

The white crust-like outer wall has more than once carried this species
into _Diderma_. It is still doubtful whether we are here dealing with
_Chondrioderma calcareum_ Rost. Miss Lister cites a variety, _S.
difforme comatum_, with more abundant capillitium which may represent
Rostafinski's species.

Evidently rare in the United States; reported more common in Europe and
eastward. In our specimens the crust-like outer peridium shows crystals
on the broken edge only; the body of the object, as its outer surface
seems to be amorphous.


17. DIDYMIUM QUITENSE (_Pat._) _Torr._

  1895. _Chondrioderma quitense_ Pat., _Bull. Soc. Myc. Fr._, XI.,
           p. 212.
  1909. _Didymium quitense_ (Pat.) Torr., _Flor. Myxom._, p. 150.
  1911. _Didymium quitense_ Torr., List., _Mycetozoa, 2nd ed._, p. 126.
  1913. _Didymium quitense_ (Pat.) Torr., Sturg., _Myx._, Col. II.,
           p. 446.

Sporangia more or less plasmodiocarpous, scattered, depressed, white;
the outer peridium distinct, crust-like, remote from the thin membranous
inner wall; columella undefined; capillitium brown, much branched,
forming a network especially outwardly; spores very dark
violaceous-brown, rough with a tendency to obscure reticulation; 12-14
µ.

This species is different from _D. difforme_ chiefly in the rougher and
somewhat banded epispore. It is reported from Ecuador by Father Torrend,
and from Colorado mountains by Dr. Sturgis to whose kindness I am
indebted for the specimens here described. Evidently a high mountain
species.

Colorado.


18_a_. DIDYMIUM ANOMALUM _Sturg._

PLATE XIX., Figs. 13 and 13 _a_.

  1913. _Didymium anomalum_ Sturg. _Myxomycetes of Col._, II., p. 444

Sporangia in the form of very thin effused grey plasmodiocarps, 2-10 cm.
long, 1 mm. or less in thickness. Wall single or membranous, hyaline or
yellowish, with rather scanty deposits of small, stellately crystalline
or amorphous lime. Columella none. Capillitium consisting entirely of
straight membranous, tubular, columns, extending from the base to the
upper wall of the plasmodiocarp, 7-22 µ thick and usually containing
small crystalline masses of lime. Spores bright violet-brown, minutely
and irregularly spinulose, 10-11.5 µ diam.

Hab. on the inner bark of Populus. Colorado Springs, Colo., July 1911.

Our specimens by the courtesy of Dr. Sturgis.


=EXTRA-LIMITAL=


18. DIDYMIUM INTERMEDIUM _Schroeter._

  1896. _Didymium intermedium_ Schroet., _Hedwigia_, Vol. XXXV., p. 209.
  1902. _Didymium excelsum_ Jahn, _Ber. Deut. Bot. Ges._, XX., p. 275.

Sporangia clustered or gregarious, discoidal and umbilicate below, or
lobed or convolute, greyish white, stipitate; stipe pale yellow,
tapering upwards, stuffed with lime crystals, expanding into the
yellowish, discoidal, recurving columella; capillitium colorless, more
or less branching; spores dark purple-brown, irregularly reticulate,
9-12 µ.

Differs from _D. squamulosum_ in the reticulate epispore. Brazil.


19. DIDYMIUM LEONINUM _Berk. & Br._

  1873. _Didymium leoninum_ Berk. & Br., _Jour. Linn. Soc._, XIV.,
           p. 83.
  1876. _Lepidoderma tigrinum_ Rost., _App. to Mon._, p. 23.
  1909. _Lepidodermopsis leoninus_ v. Höhnel, _Sitz. K. Ak. Wiss. Wien,
           Math. Nat. Ks._, CXVIII., 439.

Sporangia gregarious, sub-globose, covered more or less completely with
white or yellowish deposits of crystalline lime, stipitate; stipes
short, orange or brown, containing lime, enlarged to form the globose
orange columella and often connected at base by a venulose hypothallus;
capillitium of slender threads, anastomosing, colorless at the tips;
spores violet-grey, minutely warted, 7-9 µ.

Like _Lepidoderma tigrinum_, but has different calcic crystals.

Java and Ceylon.


=3. Diderma= _Persoon_

  1794. _Diderma Persoon_, _Röm. N. Mag. Bot._, I., p. 89.
  1873. _Chondrioderma_ Rost. _Versuch_, p. 13, _Mon._, p. 167.
  1894. _Chondrioderma_ Rost., List., _Mycetozoa_, p. 75.
  1899. _Diderma Persoon_, Macbr., _N. A. S._, p. 92.

Sporangia plasmodiocarpous or distinct, sessile or stipitate; the
peridium as a rule double, the outer wall generally calcareous with the
lime granules globular, non-crystalline, the inner wall very delicate
and often, in the mature fructification, remote from the outer;
columella generally prominent.

The genus _Diderma_ is usually easy of recognition, by reason of its
double wall, the outer, crustaceous, usually calcareous, and its limits
remain substantially as originally set by Persoon. His definition is as
follows:--

"Peridium ut plurimum duplex; exterius fragile; interius pellucens,
subdistans. Columella magna, subrotunda. Fila parca latentia."--_Syn.
Meth. Fung._, p. 168.

Rostafinski changed the name of the genus to _Chondrioderma_ (_chondri_,
cartilage), seemingly at De Bary's suggestion, and seems to have
regarded Persoon's definition as applicable to those species only in
which the wall is not only plainly double, but in which the two walls
are as plainly remote from each other. More especially he esteemed a new
generic name necessary, since he regarded several included species, as
_D. spumarioides_, _D. michelii_, etc., monodermic.

Since it is doubtful whether any diderma is really monodermic, and since
Persoon's definition in any case seems sufficiently elastic, we have
seen no reason to discard the older name. Persoon's _Diderma_ when
established, _l. c._, included _D. floriforme_. He made some confusion
in his later work by admitting some physarums. This induced Schrader to
throw all the didermas into his new genus, _Didymium_.

According to the nature of the sporangial wall, the species fall rather
naturally into two sections:--

  _A._ Outer sporangial wall distinctly calcareous, fragile;
         species generally sessile                             _Diderma_

  _B._ Outer sporangial wall cartilaginous, the inner less
         distinct, or concrete with the outer; species
         oftener stipitate                                    _Leangium_


  _A._ Sub-Genus DIDERMA

  1. Fructification wholly plasmodiocarpous              1. _D. effusum_

  2. Fructification of distinct sporangia.

    _a._ Sporangia on a common hypothallus.

         O Outer wall fragile, not widely remote from
             the inner                              2. _D. spumarioides_

        OO Inner wall lacking                            3. _D. simplex_

       OOO Outer wall crustaceous, porcelain-like.

           i. Spores 8-10                               4. _D. globosum_

          ii. Spores 12-15                            5. _D. crustaceum_

      OOOO Outer wall firm, not crustaceous              6. _D. lyallii_

    _b._ Sporangia isolated, or, at least, not on a common hypothallus,
              sessile.

         O Outer wall porcellanous, roseate            7. _D. testaceum_

        OO Outer wall white                               8. _D. niveum_

       OOO Outer wall ashen                             9. _D. cinereum_

    _c._ Sporangia stipitate                      10. _D. hemisphericum_


  _B._ Sub-Genus LEANGIUM

  1. Sporangia generally sessile.

    _a._ Inner peridium distinct.

         O Membranous colorless, columella scant         11. _D. sauteri_

        OO Colorless, columella prominent, red        12. _D. cor-rubrum_

       OOO Outer ochraceous, inner yellow              13. _D. ochraceum_

    _b._ Peridial layers inseparable.

         O Peridium multifid; columella small
            or none                                  16. _D. trevelyani_

        OO Peridium breaking into but few irregular lobes; columella
              prominent.

           i. Peridium umber brown                     14. _D. roanense_

          ii. Peridium ashen                           15. _D. radiatum_

         iii. Peridium chocolate without,
                inside white                         17. _D. asteroides_

  2. Sporangia stipitate.

    _a._ Peridium pallid, smooth                     18. _D. floriforme_

    _b._ Peridium white, rugulose                       19. _D. rugosum_


1. DIDERMA EFFUSUM (_Schw._) _Morgan._

  1831. _Physarum effusum_ Schw., _N. A. F._, p. 257.
  1896. _Diderma effusum_ (Schw.) Morg., _Jour. Cin. Soc._, p. 71.
  1899. _Diderma effusum_ (Schw.) Morg., Macbr., _N. A. S._, p. 94.
  1899. _Diderma reticulatum_ Rost., Macbr., _N. A. S._, p. 95.
  1911. _Diderma effusum_ Morg., Lister, _Mycetozoa, 2nd ed._, p. 102.

Fructification plasmodiocarpous, reticulate, creeping, applanate and
generally widely effused, white; the peridium thin, cinereous, covered
by a delicate, white, calcareous crust; the columella simply the base of
the plasmodiocarp, thin alutaceous; the capillitium pale, consisting of
short threads somewhat branched toward their distal extremities; spores
smooth, pale violaceous, 8-10 µ.

This is _Physarum effusum_ Schw., _vid. N. A. F._, No. 2297. It is
reported by Morgan from Ohio, and we have one specimen from eastern
Nebraska, so that it is probably of general distribution in the eastern
United States.

This species was in the previous edition distinguished from the
Rostafinskian _P. reticulatum_ with spores a little smaller, 6-8 µ, and
with a much stronger tendency to the formation of definite sporangia,
elongate indeed and branching but often globose or depressed globose.
This we may know as,


VAR. RETICULATUM Rost.

  1875. _Chondrioderma reticulatum_ Rost., _Mon._, p. 170.
  1894. _Diderma reticulatum_ (Rost.) Morg., _Jour. Cin. Soc._, p. 71.

Sporangia gregarious, generally rounded, not much depressed, flat,
sometimes, especially toward the margin of a colony, elongate, venulose
or somewhat plasmodiocarpous, dull white, the inner peridium ashen or
bluish, remote from the calcareous crust, which is extremely fragile,
easily shelling off; columella indistinguishable from the base of the
sporangium, thin, alutaceous; capillitium of short, generally colorless,
delicate, sparingly branching or anastomosing threads perpendicular to
the columella; spores black in mass, by transmitted light violet-tinted,
smooth, 6-8 µ.

Perhaps our most common form. Found in fall on dead twigs, leaves, etc.
Recognized by its rather large, white, depressed or flattened sporangia
tending to form reticulations, and hence suggesting the name. The lines
of fruiting tend to follow the venation of the supporting leaf; where
the sporangium is round, the columella is a distinct rounded or
cake-like body; where the fruit is venulose, the columella is less
distinct.

By these rounded forms we pass easily, as by a gate, to _D.
hemisphericum_, which, when wholly sessile, differs still in greater
diameter of the sporangia and in having somewhat larger spores. Usually
in such case the compared colony will show somewhere a very short and
stout but very real stipe supporting the discoid fruit.

Rostafinski divided the genus _Chondrioderma_, i. e. _Diderma_, into
three sections:--

_Monoderma_ to include those species in which the calcareous crust is
less distinct or connate with the true peridium.

_Diderma_, in which the two structures were plainly separate.

_Leangium_, used as in the present work. In his first section
Rostafinski placed _C. reticulatum_ and _C. michelii_; in the second,
_C. difforme_ and _C. calcareum_.

Lister has examined Rostafinski's type of _C. reticulatum_ and declares
that it has the usual didermic characters. Hence there is no doubt that
our small-spored American specimens are covered by Rostafinski's
description, No. 72. On the other hand, Lister makes _C. difforme_
(Pers.) Rost. a _Didymium_, by its crystalline coat. That species
therefore is removed from consideration in this connection. _C.
calcareum_ remains as applicable to American forms having the spores
10-12 µ, but according to the author of the species the capillitium is
abundant and definitive. Unhappily the type of _C. calcareum_ is lost
(Lister, _Mon._, p. 95), so that there is no other means of verification
than the description and Rostafinski's figure. Under these circumstances
we consider the name _calcareum_ inapplicable to any American forms we
have so far seen. See next species. As to the American species which
have been distributed as _C. calcareum_ (Lk.) Rost., they are, so far as
seen, referable to _D. reticulatum_ (Rost.), Morg. Here also belongs No.
1217, Ellis, _N. A. F._

New York, Pennsylvania, Ohio, Iowa, Nebraska. Probably to be found
throughout the eastern United States.


2. DIDERMA SPUMARIOIDES _Fries_.

  1829. _Diderma spumarioides_ Fries, _Syst. Myc._, III., p. 104.
  1833. _Physarum stromateum_ Link., _Handb._, III., p. 409.
  1876. _Chondrioderma stromateum_ (Lk.) Rost., _App._, p. 18.

Sporangia sessile, crowded, spherical, or by mutual pressure irregular,
white; the peridium plainly double, but the layers adhering, the outer
more strongly calcareous, but very frail, almost farinaceous;
hypothallus more or less plainly in evidence, white or pale alutaceous;
columella distinct, though often small, globose, yellowish; capillitium
variable in quantity, sometimes abundant, brown, somewhat branching and
anastomosing outwardly, the tips paler; spores minutely roughened, dark
violaceous, about 10 µ.

This species has the outward seeming of a didymium, but is plainly
different as that genus is here defined, since the calcareous crust,
although inclined to be pulverulent, is made up of minute granules, not
crystals, of lime. The hypothallus is sometimes hardly discoverable,
anon well developed, out-spread, rugulose, far beyond the limits of the
fructification. In his _Monograph_, p. 175, Rostafinski includes here
_Physarum stromateum_ Link. In the Appendix he is inclined to raise
Link's form to the dignity of a distinct species, basing the diagnosis
upon the superposition of the sporangia in certain cases, a feature
entirely unknown to Link's description and of extremely uncertain value,
since by their crowding the sporangia are liable always to be pushed
above each other. We therefore regard _C. stromateum_ (Link) Rost. as a
synonym of the present species, as the description, Link, Handb., III.,
409, indicates, so far as it goes.


3. DIDERMA SIMPLEX (_Schroet._) _Lister._

  1885. _Chondrioderma simplex_ Schroet., _Krypt. Fl. Schles._, III.,
           1, p. 123.
  1911. _Diderma simplex_ List., _Mycetozoa, 2nd ed._, p. 107.

"Plasmodium bright yellowish brown." Sporangia gregarious, sessile,
globose or depressed globose, .3-.5 mm., or anon plasmodiocarpous, brown
or brick-red when fresh, becoming paler, ochraceous, etc.; hypothallus
everywhere in evidence; columella ill-defined; capillitium scanty, the
threads delicate, pale, branching as they join the peridial wall; spores
dull violaceous, slightly roughened, 8-10 µ.

A rather crude, primitive representative of this beautiful genus. The
inner peridium seems to be lacking,--a comfort to Rostafinski! Rare. Our
best specimens are from New Jersey, by courtesy of Dr. C. L. Shear.
These went to fruit on leaves and branches of _Vaccinium_. It seems to
affect the heather of Europe, moorland, etc. I have also specimens from
the herbarium of the lamented Dr. Rex. These are more plasmodiocarpous,
but open beautifully by a median fissure as in _Physarum sinuosum_
Bull. In no American gathering that I have examined does the capillitium
show calcareous thickenings as described by the British text.


4. DIDERMA GLOBOSUM _Persoon._

PLATE VII., Figs. 5, 5 _a_.

  1794. _Diderma globosum_ Pers., _Röm. N. Mag. Bot._, I., p. 89.
  1875. _Chondrioderma globosum_ (Pers.) Rost., _Mon._, p. 180.

Sporangia more or less closely gregarious, sessile, globose or by mutual
pressure prismatic or polyhedral, white, the outer wall smooth,
polished, crustaceous, fragile, far remote from the inner, which is
thin, smooth, or rugulose, iridescent blue; hypothallus usually
pronounced and spreading beyond the sporangia, sometimes scanty or
lacking, columella variable, sometimes very small, inconspicuous,
sometimes large, globose, ellipsoidal, even pedicellate; capillitium
abundant, brown or purplish brown, branching and occasionally
anastomosing to form a loosely constructed superficial net; spores
globose, delicately spinulose, 8 µ.

This species seems rare in this country. We have specimens from Iowa. It
is distinguished by small spores and generally snow-white color.
Lister has thrown doubt upon Rostafinski's definition of this
form--_Mycetozoa_, p. 78. Almost everything distributed in the United
States under this name belongs in the next species. Reported also from
Ohio,--_Morgan._ Washington. But:--it should be found in Europe, where
first described!

There are two ways to meet the difficulty. In the first place it seems
probable that a small-spored form really hides somewhere in Europe. The
difference between the _Monograph_ measurement and the size admitted for
_D. crustaceum_ Pk., evidently considered by Mr. Lister as type and so
used in his illustration, Pl. 85, is too great to be esteemed merely an
error. That added .3 (Rost.) indicates caution, the average of several
measurements. Our _D. globosum_ may represent what the _Monograph_
describes.[32] In the second place we may as American students mistake
larger and more globular forms of something else, of _D. spumarioides_
Fr., whose spores are but little larger; or of _D. effusum_ (Schw.)
Morg., where the flattened plasmodiocarps anon splatter out to globose
drops of polished whiteness, and whose spores are 8 µ. But even here the
chances of error are small. In the species last named the columella or
sporangial base is alutaceous, not white; in Fries' species, while the
columella if present may be white, the peridial walls are different,
difficult to distinguish.

For these reasons, _D. globosum_ Pers. may stand, waiting further light
from Europe.


5. DIDERMA CRUSTACEUM _Peck._

PLATE VII., Fig. 7

  1871. _Diderma crustaceum_ Peck, _Rep. N. Y. Mus._, XXVI., p. 74.
  1889. _Chondrioderma crustaceum_ (Peck) Berl., _Sacc._, VII., p. 373.

Plasmodium at first watery, colorless, becoming at length milky white;
sporangia closely crowded or superimposed, in a cushion-like colony,
creamy white, globose, imbedded in the substance of the hypothallus, the
outer peridium smooth, delicate, crustaceous, fragile, remote from the
blue iridescent inner membrane; hypothallus prominent; columella
variable, generally present, globose; capillitium dark-colored, the
threads branching and combining to form a loose net; spore-mass black,
spores by transmitted light dark violaceous, delicately roughened, 12-15
µ.

Common. Readily to be distinguished from the preceding by the larger
spores and more crowded habit. New England west to Nebraska.

The didermas are generally delicately beautiful. The outer wall in the
present species is like finest unglazed china, softly smooth, and yet
not polished, often absolutely white, with porcellanous fracture. An
inter-parietal space separates the outer from the inner wall, so that
the former may be broken, bit by bit, without in the least disturbing
the underlying structure. The inner wall is ashen or gauzy iridescent
green, sending back all colors in reflected light. The spores are
violet, deeply so when fresh, the capillitium strong and likewise
tinted; the columella passing down and blending with the common
snow-white hypothalline base. The distinct habits of the two species are
represented in Figs. 5 and 7. In the one the distinct sporangia are
associated but not crowded; in the other all are massed together in
quite æthalioid fashion, forming circumambient, chalky masses of
considerable size, 2 or 3 cm., overcrowded, superimposed, where the
sporangia are regular in shape and size by reason of mutual pressure.
The plasmodium develops in forests and orchards, among decaying leaves,
but is inclined to rise as maturity draws near, to ascend some twig
erect, or the stem of a living plant to the height of several inches
where the sporangia at length appear "heaped and pent", an encircling
sheath, conspicuous after the fashion of a spumaria for which it is
indeed sometimes mistaken.


6. DIDERMA LYALLII (_Massee_) _Macbr._

PLATE XVIII., Figs. 5 and 5 _a_

  1892. _Chondrioderma lyallii_ Massee, _Mon._, p. 201.
  1894. _Chondrioderma lyallii_ Mass., List., _Mycetozoa_, p. 81.
  1899. _Diderma lyallii_ Mass., Macbr., _N. A. S._, p. 99.
  1911. _Diderma lyallii_ List., sub-species, _Mycetozoa, 2nd ed._,
           p. 105.

Sporangia obovate, more or less closely crowded, white, stipitate, about
1 mm. in diameter, the outer peridium firm, stout, encrusted, especially
above, with granular masses of lime, the inner well developed, more or
less cartilaginous, opaque, yellow or buff-colored; hypothallus well
developed, venulose, white, passing up unchanged to form the short,
stout stipe and lower outer peridium; columella prominent, half the
height of the sporangium, brown; capillitium of short, brown threads,
rigid, much branched, forming a net, widened irregularly and especially
at the net-nodes; spore-mass black, spores by transmitted light bright
brown, rough, 15-17 µ.

A very distinct species; large, fine, showy sporangia in more or less
crowded clusters spring from a snow-white, common hypothallus. First
reported from western Canada. Our first specimens were collected by the
late Mr. Charles Irish, on the eastern slopes of the Sierras, in Nevada;
now coming in abundantly from all the western mountains to the Pacific.


7. DIDERMA TESTACEUM (_Schrad._) _Pers._

PLATE VII., 4, 4 _a_, and 4 _b_.

  1797. _Didymium testaceum_ Schrad., _Nov. Gen. Plant._, p. 25.
  1801. _Diderma testaceum_ Persoon, _Syn._, p. 167.
  1873. _Chondrioderma testaceum_ (Schrad.) Rost., _Vers._, p. 13.
  1874. _Diderma mariae-wilsoni_ Clinton, _Rep. N. Y. Mus._, XXVI.,
           p. 74.
  1899. _Diderma testaceum_ (Schrad.) Pers., Macbr., _N. A. S._, p. 99.
  1911. _Diderma testaceum_ Pers., List., _Mycetozoa, 2nd ed._, p. 106.

Sporangia gregarious, sessile, depressed-spherical or sometimes
elongate, small, 1 mm. or less, rose-white, smooth, the outer peridium
crustaceous, rather thick and persistent, polished, slightly raised
above the inner, which is dull ashen and more or less wrinkled;
hypothallus none; columella prominent, hemispherical in the typical
rounded forms, slightly rough, reddish or reddish alutaceous;
capillitium usually abundant, of slender, delicate pale or colorless
threads, little branched, and smooth; spores violaceous-brown, minutely
roughened, 8-9 µ.

A very beautiful species occurring at the same time as the preceding and
in similar situations. All our specimens from the west are on dead
leaves of oak; some eastern gatherings are on moss. Easily recognized
when fresh by its delicate pink or roseate color; weathered specimens
are white, and might be confused with forms of _D. reticulatum_, but the
sporangia in the present species are less flattened and only rarely in
special situations run off to linear or plasmodiocarpous shapes
characteristic of _D. reticulatum_.

Not common, although widely distributed from east to west. New England,
New York, New Jersey, South Carolina, Ohio, Illinois, Iowa, Nebraska,
California (_Harkness_), Washington, Oregon.


8. DIDERMA NIVEUM (_Rostafinski_) _Macbr._

PLATE XVIII., Fig. 11 and 11 _a_

  1875. _Chondrioderma niveum_ Rost, _Mon._, p. 170.
  1877. _Diderma albescens_ Phillips, _Grev._, V., p. 114.

Sporangia gregarious, scattered, or more often crowded, sessile,
depressed-spherical, sometimes ellipsoidal or elongate, white, the outer
peridium crustaceous, chalky, smooth and fragile, the inner distinct,
delicate, ochraceous; hypothallus scant or none; columella well
developed, globose or hemispherical, orange-tinted or ochraceous;
capillitium abundant, made of threads of two sorts, some purplish or
dusky, with pale extremities, uneven, others more delicate and
colorless, and with wart-like thickenings, all sparingly branched;
spores violet-brown, minutely roughened, 9-10 µ.

This species is not common. From Colorado we have fine specimens typical
in every way. Specimens from Washington are flat so far as at present at
hand; probably represent _D. deplanatum_ (R.) List., which the last
named author regards as varietal of the present species, entering it and
_D. lyallii_ as sub-species 2 and 1 respectively. _D. deplanatum_ may
perhaps be best so disposed of; but _D. lyallii_ is distinguished at
sight, as well as by microscopic characters, spores nearly twice as
great, rougher and different in color.


9. DIDERMA CINEREUM _Morg._

  1894. _Diderma cinereum_ Morg., _Myx. Mi. Val._, p. 70.

Sporangia gregarious, more or less crowded or even confluent,
sub-globose, only slightly depressed, ashen white; the peridium not
obviously double, very smooth and thin, rupturing irregularly;
hypothallus an indistinct membrane or wholly wanting; columella large,
globose or hemispheric, white, the surface granulose; capillitium of
very slender colored threads, the extremities pellucid, more or less
branched; spores violaceous, minutely warted, 9-11 µ.

Growing on old wood, leaves, etc. The sporangium .3-.5 mm., thin and
smooth or rugulose. This elegant little species I know only from
specimens received from Mr. Morgan. It seems to be closely related to
_D. spumarioides_, from which it is distinguished by its color, darker,
and its smoother, or less spinulose spores. The author compares the
color and external appearance to that of _P. cinereum_,--_Jour. Cin.
Soc._, XVI., p. 154.

Ohio, Pennsylvania.


10. DIDERMA HEMISPHERICUM (_Bull._) _Horne._

  1791. _Reticularia hemispherica_ Bull., _Cham. de Fr._, I., p. 93.
  1829. _Didymium hemisphericum_ (Bull.) Fr., _Syst. Myc._, III.,
           p. 115.
  1829. _Diderma hemisphericum_ (Bull.) Horne., _Fl. Dan._, XI., p. 18.
  1832. _Didymium michelii_ Lib., _Pl. Ard._, No. 180.
  1873. _Chondrioderma michelii_ (Lib.) Rost., Fuckel, _Sym. Myc._,
           p. 74.

Sporangia gregarious, orbicular, discoid, depressed above and often
umbilicate below, stipitate or sometimes sessile, the outer peridium
white, fragile, crustaceous, soon breaking about the margins, closely
applied to the inner, which is delicate, cinereous, and ruptures
irregularly; stipe about equal to the diameter of the sporangium, 1 mm.,
rather stout, calcareous but colored, brownish or alutaceous, more or
less wrinkled longitudinally, the wrinkles when present forming veins on
the lower surface of the sporangium; hypothallus small; columella not
distinct from the thickened brownish or reddish base of the sporangium;
capillitium of delicate threads, mostly simple and colorless, often
scanty; spores pale violaceous, nearly smooth, 8-9 µ.

A very well marked species, easily recognized, at least when stipitate,
by its remarkable discoid or lenticular sporangia. After the
spore-dispersal, the stipes are long-persistent, surmounted by a
peculiar disk representing the consolidated columella, lower sporangial
wall, and expanded stem-top. Sessile specimens are like similar forms of
_D. reticulatum_, but in all the gatherings before us the stipitate type
is at hand to reveal the identity of the species.

Rostafinski's figures, 131, 146, 149, and 150, adapted from Corda,
exaggerate the hypothallus, but otherwise leave nothing to be desired.

As to synonymy, Bulliard has plainly the priority. His figure, t. 446,
Fig. 1, can refer to nothing else, especially reënforced as it is by
Sowerby, _Eng. Fung._, t. 12.

Rather rare on fallen stems of herbaceous plants, but widely
distributed, New England to Oregon and Washington.


11. DIDERMA SAUTERI (_Rost._) _Macbr._

  1875. _Chondrioderma sauteri_ Rost., _Mon._, p. 181.
  1891. _Chondrioderma aculeatum_ Rex, _Proc. Phil. Acad._, p. 390.

Sporangia scattered, gregarious, sessile, lenticular or hemispherical,
flattened above and sometimes concave or umbilicate below, dusky or
yellowish white, the outer peridium papyraceous, thin, occasionally
wrinkled, rupturing irregularly, remote from the inner, which is thin,
delicate, semi-transparent, grayish, rarely iridescent; hypothallus
none; columella irregular, sometimes small and hardly evident, rugose,
with spine-like processes, the persisting bases of the capillitial
threads, reddish brown; capillitium scanty, white, or colorless, simple
or sparingly branched; spores dark violaceous, spinulose, 12-13 µ.

This is _Chondrioderma aculeatum_ Rex, _Proc. Acad. Nat. Sci. Phil._,
1891, p. 390. After careful comparison of specimens and various
descriptions, especially that of Rostafinski with the type specimens of
Dr. Rex, I am constrained to concur with Lister in adopting
Rostafinski's name. The sporangia in the type specimens (Rex) are on
moss, borne at the extreme tips of acuminate or aculeate leaves, so that
at first sight they appear stipitate.

Apparently rare. Maine, New York.


12. DIDERMA COR-RUBRUM _Macbr. n. s._

PLATE XVIII., Fig. 2

Sporangia gregarious clustered, small .5-.7 mm., sessile
corrugate-plicate, especially above, snow-white, the outer peridium
cartilaginous polished without and within, the inner delicate,
evanescent; columella well developed, globose or clavate, anchored by
several stout transverse trabeculæ to the peridial wall, papillate,
deep-red as is the peridium especially below; capillitium very delicate,
sparingly branching, colorless; spores verruculose, fuliginous tinged
with red, about 12 µ.

This curious but elegant little species is represented by a single
colony collected by Professor Morton Peck in Iowa. It resembles _D.
sauteri_ but is distinguished by the plicate white wall, the stout
columella with its lateral extensions, as by the more delicate spores.
On rotten wood.


13. DIDERMA OCHRACEUM _Hoffm._

  1795. _Diderma ochraceum_ Hoffm., _Deutsch. Fl. Tab._ 9, 2, b.
  1911. _Diderma ochraceum_ Hoffm., List., _Mycetozoa, 2nd ed._, p. 109.

Sporangia gregarious or clustered, .7-1 mm., sessile, globose or
sometimes plasmodiocarpous, ochraceous yellow; outer wall cartilaginous
with yellow deposits of lime, the inner also yellow, adherent or free;
columella not distinct; capillitium simple or branching, purple-brown,
hyaline at base; spores spinulose, purplish-grey, 9-11 µ.

Mr. Lister reports this species from Massachusetts.


14. DIDERMA ROANENSE (_Rex_) _Macbr._

  1893. _Chondrioderma roanense_ Rex, _Proc. Phil. Acad._, p. 368.

Sporangia scattered, discoidal, thin, flattened or slightly convex
above, plane or plano-concave below, umber-brown, stipitate, the outer
peridium smooth, brittle, rupturing irregularly, the basal fragments
somewhat persistent, concrete with the inner peridium, which is pure
white, except near the columella, and punctate; stipe short, variable,
longitudinally ridged, jet-black; hypothallus none; columella flat,
discoidal, pale ochraceous; capillitium sparse, white or colorless,
composed of simple, rarely forked, sinuous threads occasionally joined
by lateral branches; spores dark violaceous, distinctly warted, 12-14 µ.

This species is readily distinguished by its color. The sporangia, found
on rotten wood, are large, 1 mm., brown, and have thick, persistent
walls. Dr. Rex considered that the species differs from other related
forms not only in color, but in the well-marked discoidal columella and
the jet-black irregular stipe. It is perhaps most nearly related to the
following species.

Tennessee.


15. DIDERMA RADIATUM (_Linn._) _Morg._

PLATE XVIII., Fig. 8

  1753. _Lycoperdon radiatum_ Linn. (?) _Sp. Pl._, 1654.
  1797. _Didymium stellare_ Schrad., _Nov. Gen. Pl._, p. 21.
  1801. _Diderma stellare_ (Schrad.) Persoon, _Syn._, p. 164.
  1875. _Chondrioderma radiatum_ (Linn.) Rost., _Mon._, p. 182.
  1894. _Diderma radiatum_ (Linn.) Morg., _Jour. Cin. Soc._, p. 66.
  1899. _Diderma stellare_ Schrad., Macbr., _N. A. S._, p 104.
  1911. _Diderma radiatum_ List., _Mycetozoa, 2nd ed._, p. 112.

Sporangia scattered, depressed-globose, sometimes also flattened below,
stipitate, smooth or slightly corrugate, ashen or brownish, about 1 mm.
in diameter, the peridium dehiscing irregularly or somewhat radiately
from above downwards, the segments reflexed, the inner layer not
distinguishable, or inseparable; stipe short, stout, brownish, sometimes
almost lacking; hypothallus not conspicuous, but sometimes sufficient to
connect the bases of adjacent stipes; columella large, hemispherical or
globose, pallid or yellowish; capillitium abundant, of slender generally
simple, colored threads, paler at the furcate tips; spores dark
violaceous, minutely roughened, 8-11 µ.

Rare on rotten logs in the forests; September. Easily recognized by the
short-stiped, ashen sporangia which before dehiscence indicate by
delicate tracings the lines which subsequent cleavage is to follow. In
texture the peridium resembles that of _D. floriforme_.

Pennsylvania, Ohio, Iowa, Virginia, Colorado, Washington, Oregon; Europe
generally.

The Linnæan description on which to base the specific name _D. radiatum_
is wholly inadequate. It appears also by the testimony of Linné _fils_,
that _L. radiatum_ Linné is a lichen! and the name is so applied by
Persoon. But in the Linnæan herbarium preserved at London, _teste_
Lister, the original type of _Lycoperdon radiatum_ L. may yet be seen!
to the confusion of _fils_, Persoon, and other followers of Schrader
all, and our stellar species becomes radiate now, let us hope for long!


16. DIDERMA TREVELYANI (_Grev._) _Fr._

  1825. _Leangium trevelyani_ Grev., _Scot., Cr. Fl._, Tab. 132.
  1829. _Diderma trevelyani_ (Grev.) Fr., _Syst. Myc._, III., p. 105.
  1875. _Chondrioderma trevelyani_ (Grev.) Rost., _Mon._, p. 182.
  1877. _Diderma geasteroides_ Phill., _Grev._, V., p. 113.
  1877. _Diderma laciniatum_ Phill., _Grev._, V., p. 113.

Sporangia scattered, globose or nearly so, smooth or verruculose,
reddish-brown or rufescent, sessile or short-stipitate, the outer
peridium firm, splitting more or less regularly into unequal, revolute,
petal-like lobes which are white within, the inner not distinguishable
as such; stipe, when present, equal, furrowed, concolorous; columella
small or none; capillitium abundant, the threads rather rigid, purple or
purplish brown, branching and anastomosing, more or less beaded; spores
dark, violaceous brown, spinulose, 10-13 µ.

In 1876, Harkness and Moore collected in the Sierra Nevada Mountains of
California, forms of _Diderma_ which are described by Phillips, _Grev._,
V., p. 113, as _D. geasteroides_ and _D. laciniatum_. English
authorities who have examined the material agree that the forms
described constitute but a single species, and Lister makes them
identical with _D. trevelyani_ (Grev.) Fr. Rostafinski's figures, 161,
162, are a curious reproduction, evidently, of Fried. Nees von
Esenbeck's, Plate IX., Fig. 4. Massee describes a columella; Lister
says there is none. What may occasion such divergence of statement none
may say; such forms as come in so far from our western mountains have no
columella.


17. DIDERMA ASTEROIDES _List._

PLATE XVIII., Figs. 3, 3 _a_

  1902. _Diderma asteroides_ List., _Jour. Bot._, XL, p. 209.
  1911. _Diderma asteroides_ List., _Mycetozoa, 2nd ed._, p. 113.

Sporangia globose or ovoid-globose, the apex more or less acuminate,
sessile, sometimes narrowed at the base to a short, thick stalk, brown
or chocolate tinted, marked at the apex by radiant lines, and at length
dehiscent by many reflexing lobes revealing the snow-white adherent
inner peridium on the exposed or upper side; columella also white,
globose or depressed-globose; capillitium generally colorless, somewhat
branched, especially above; spores dark violaceous, verruculose, 10-12
µ.

Oregon, the Three Sisters Mountains; Colorado; California.

A very beautiful species, recognizable at sight; when unopened, by the
peculiar chocolate brown, the sporangia smaller than in _D. radiatum_.
When opened, the snow-white flower-like figure, flat against the
substratum, is definitive. Very near number 16 preceding; the dehiscence
more regular.


18. DIDERMA FLORIFORME (_Bull._) _Pers._

PLATE VIII., Figs. 1, 1 _a_, 1 _b_.

  1791. _Sphaerocarpus floriformis_ Bulliard, _Champ._, p. 142, t. 371.
  1794. _Diderma floriforme_ (Bull.) Persoon, _Röm. N. Mag. Bot._,
           p. 89.

Sporangia crowded, generally in dense colonies, globose, smooth,
ochraceous-white, stipitate, the peridium thick, cartilaginous,
splitting from above into several petal-like lobes, which become
speedily reflexed exposing the swarthy spore-mass, the inner peridium
not discoverable, inseparable; stipe concolorous, about equal to the
sporangium; hypothallus, generally well developed, but thin,
membranaceous, common to all the sporangia; columella prominent, globose
or cylindric, often constricted below, and prolonged upward almost to
the top of the spore-case; capillitium of slender, delicate, sparingly
branched threads; spores dark violaceous-brown, studded with scattered
warts, 10-11 µ.

Not uncommon, especially on rotten oak logs. Easily recognized by the
peculiar form of the fruit, spherical before dehiscence, floriform
after. Unlike most species, this form often fruits in dark places, in
the interior of a log, even in the ground.

New England, Ontario to Iowa and Nebraska, and south.


19. DIDERMA RUGOSUM (_Rex_) _Macbr._

PLATE XVIII., Fig. 10.

  1893. _Chondrioderma rugosum_ Rex, _Proc. Phil. Acad._, p. 369.

Sporangia gregarious, scattered, white or ashen, rugulose over the whole
surface, the ridges marking the lines of subsequent rupture or
dehiscence, the peridium thin papyraceous, stipitate; stipe well
developed about equal to the sporangium, subulate, almost black;
hypothallus none; columella distinct, generally white, sometimes small,
globose, sometimes penetrating the sporangium, to one-half the height;
capillitium white or colorless, the filaments freely forked and combined
by lateral branches into a loose network attached to the columella and
basal wall below and the upper sporangial wall above; spores
violaceous-brown, warted, 8-10 µ.

This species is well designated _rugosum_, and is recognizable at sight
by its wrinkled, areolate surface. Related to _D. radiatum_ in the
prefigured dehiscence, but otherwise very distinct. Liable to be
overlooked as a prematurely dried physarum. Rare. Plasmodium gray.

North Carolina, Iowa.


=4. Lepidoderma= _DeBary_

  1858. _Lepidoderma_ DeBy., MS. Rost., _Versuch_, p. 13.

Sporangia stalked or sessile; peridium cartilaginous, adorned without
with large calcareous scales, superficial or shut in lenticular
cavities; capillitium non-calcareous.[33]


=Key to Species of Lepidoderma=

  _A._ Sporangia stipitate, stipe brown                 1. _L. tigrinum_

  _B._ Sporangia sessile, plasmodiocarpous,
         spores 10-12 µ                              2. _L. carestianum_

  _C._ Sporangia plasmodiocarpous, spores 8-10 µ      3. _L. chailletii_


1. LEPIDODERMA TIGRINUM (_Schrad._) _Rost._

PLATE XIV., Fig. 7.

  1797. _Didymium tigrinum_ Schrad., _Nov. Gen. Plantarum_, p. 22.
  1873. _Lepidoderma tigrinum_ (Schrad.) Rost., _Versuch_, p. 13.

Sporangia scattered, rather large, hemispherical-depressed, stipitate,
umbilicate beneath, the peridium shining, olivaceous or purplish, tough,
covered more or less abundantly with angular scales; the stipe stout,
furrowed, dark brown, but containing calcareous deposits withal,
tapering upward, and continued within the peridium as a pronounced more
or less calcareous columella; hypothallus more or less prominent,
yellowish or brownish; capillitium dark, purplish-brown, of sparingly
branching threads radiating from the columella; spores dull
purplish-brown, minutely roughened, 10-12 µ.

A singular species, rare, but easily recognized by its peculiar, placoid
scales, large and firmly embedded in the peridial wall. The internal
structure is essentially that of _Diderma_ or _Didymium_. The species
occurs in hilly or mountainous regions, on moss-covered logs. The
plasmodium pale yellow, some part of it not infrequently remains as a
venulose hypothallus connecting such sporangia as are near together.

New England to Washington and Oregon; Vancouver Island.


2. LEPIDODERMA CARESTIANUM (_Rabenh._) _Rost._

  1862. _Reticularia carestiana_ Rabenh., _MS. Fung. Eur. exsic._,
           No. 436.
  1875. _Lepidoderma carestianum_ (Rabenh.) Rost., _Mon._, p. 188.
  1891. _Amaurochaete minor_ Sacc. & Ell., _Mich._, II., p. 566.

Fructification in the form of flat, pulvinate plasmodiocarps, or, anon,
sporangiate, the sporangia sessile, sub-globose, ellipsoidal, elongate,
irregular, confluent, yellowish-grey, the peridium covered more or less
completely with dull white, crystals or crystal-like scales; columella,
where visible, yellowish-brown, calcareous; capillitium, coarse, rigid,
more or less branched and united, or colorless, delicate, forming a
definite net; spores distinctly warted, purple 10-12 µ.

This is a most remarkable species. The sporangiate forms little resemble
those distinctly plasmodiocarpal. In the former the calcic scales and
crystals are distinct and quite as in _L. tigrinum_; in the latter they
are cuboid, irregular. The wall of the peridium in the plasmodiocarps at
hand is black, and the covering accordingly shows white; in the
sporangial forms the wall is brown, and the scales have a yellow tinge
as if tinged with iron. In the sporangial presentation the capillitium
is intricate delicate; in the plasmodiocarp, rigid, dark-colored, etc.
This looks like a didymium and in so far justifies the opinion of
earlier students. Fries, of course, includes all these things with the
didymiums, and _D. squamulosum_ probably often sheltered them under
extended wing.

_Didymium granuliferum_ Phill., _Grev._, V., p. 114, from California is
by European authors referred here. The capillitium carries calcareous
crystalline deposits in special vesicles and the spores show remarkable
variation in unusual size--15-30 µ.[1]

Should probably be entered _Lepidoderma granuliferum_ (Phill.) Fr.,
spores 15-18 µ.[34]

Utah,--Harkness.


3. LEPIDODERMA CHAILLETII _Rost._

PLATE XVIII., Figs. 6, 6 _a_, 6 _b_.

Sporangia distinct, coalescent or plasmodiocarpous, large, when isolated
1-1.5 mm., dull drab in color, very sparsely sprinkled with white
tetrahedral or irregular scales; the peridium thin, more or less
translucent, rugulose, dull brown, persistent; columella none;
capillitium abundant, under the lens purple-brown, sparingly branched,
even, stout, rigid, no calcareous deposits nor vesicles; spores 8-10 µ,
minutely warted, fuliginous.

Yosemite Cañon, California, _Prof. B. Shimek._

This is, no doubt, similar to _L. carestianum_ but differs in the size
and habit of the sporangia, and in the fact that the capillitium is
uniform throughout, whatever the style of fructification, and in the
size, color, and surface characters of the spore.

Evidently not _Didymium granuliferum_ Phill. Both will, no doubt, be
again collected, and we shall then have much needed light.

Nor is this quite Rostafinski's species as cited. The spores are much
smaller; Rostafinski says 10-12 or more, and calls for a distinctly
netted capillitium, the surface strongly marked by abundant calcareous
crystals. Ours may be a different thing.


=5. Colloderma= _G. Lister_

  1910. _Colloderma, Jour. of Botany_, XLVIII., p. 312.

Peridium double; the outer gelatinous, the inner membranaceous;
capillitium intricate, limeless.


COLLODERMA OCULATUM (_Lipp._) _G. Lister._

  1894. _Didymium oculatum_ Lipp., _Verh. Zo-Bot. Ges. Wien_, XLIV.,
           p. 74.
  1910. _Colloderma oculatum_ (Lipp.) G. List., _Jour. Bot._, XLVIII.,
           p. 312.

Sporangia gregarious, globose, or sub-globose, sessile or
short-stipitate, olivaceous or purplish-brown, smooth and shining, the
outer peridium gelatinous, thickened by moisture, hyaline; stipe dark
brown; columella none; capillitium as in _Didymium_ purplish-brown,
colorless at the tips; spores spinulose, fuscous, about 12 µ.

New Hampshire, Europe.

Our specimens from the late Dr. W. G. Farlow who collected it in New
Hampshire. Swollen by immersion in water the sporangia take on an
eye-like appearance, oculate, etc.


=EXTRA-LIMITAL=

PHYSARINA _von Höhnel._

  1909. _Physarina_ von Höhnel, _Akad. Wiss. Wien; Math-nat. KL._,
           CXVIII., p. 431.

Sporangium wall rough with blunt spine-like processes, otherwise as
_Diderma_.

One species, _op. cit._, p. 432, _P. echinocephala_ v. Höhn.

Java. Might as well be called _Diderma echinocephalum_, one would think.
Structure is that of _Leangium_. The striking character is a surface
modification of the outer peridium, according to the description.


ORDER II

=STEMONITALES=

Capillitium present, thread-like, arising in typical cases from a
well-developed columella; spores in mass, black or violet-brown, more
rarely ferruginous.


=Key to the Families of Stemonitales=

  _A._ Fructification æthalioid, capillitium poorly
         defined; columella rudimentary or none           AMAUROCHÆTACEÆ

  _B._ Fructification of distinct sporangia, capillitium
         well defined; the columella generally prominent,
         long and abundantly branched throughout            STEMONITACEÆ

  _C._ Sporangia distinct; capillitium developed chiefly
         or only, from the summit of the columella        LAMPRODERMACEÆ


_A._ AMAUROCHÆTACEÆ

Fructification æthalioid, an inch or two in diameter, in form varying
with the habitat and place; capillitium dendroid, consisting of rather
stout branches which rise irregularly more or less vertically from the
hypothallus, branch repeatedly, often anastomose to form a network,
especially toward the periphery; spores black.

A single genus--


=1. Amaurochæte= _Rostafinski_

  1873. _Amaurochaete_ Rost., _Versuch._, p. 8.

The genus _Amaurochaete_ as defined by Rostafinski and the genus
_Reticularia_ as represented by _R. lycoperdon_ Bull. stand, the
expression, perhaps, of not dissimilar histories. Whether in regressive
or progressive series, each to-day presents a case of arrested
development. Each in æthalioid fructification, reveals a mass of
involved individual (?) sporangia, so imperfectly developed that their
outlines can be inferred rather than anywhere, with absolute
definiteness, certainly ascertained. Perhaps, because similar sporangia
in the group to which either belongs, do come under other circumstances,
to more perfect individual form and function--perhaps for this reason we
may look upon these æthalia as exhibiting a suspended performance; the
sporangia have failed to go forward to what was evidently a possible,
though apparently not an essential destiny in form and figure. For the
care and dispersal of the spores, achievement must surely be somewhat
impaired. Whatever the measure of such inefficiency, among the
_Stemonitales Amaurochaete_ shows the acme, as _Reticularia_ among the
brown-spored forms.

In _Amaurochaete_ the individuality of anything like separate sporangia
is less clear. The view afforded, however, by a good vertical section of
a well-developed colony or cushion is interestingly arborescent. Ragged,
dendroid stems arise, dissipated above into a network most intricate, a
"pleached arbor" if you please. The resemblance of the overhead net to
that presented by a stemonitis or comatricha is very striking.


=Key to the Species of Amaurochæte=

  _A._ Capillitium rigid, irregular spores rough      1. _A. fuliginosa_
  _B._ Capillitium soft, woolly, cincinnate,
         spores as in _A_                               2. _A. tubulina_

1. AMAUROCHÆTE FULIGINOSA (_Sowerby_) _Macbr._

PLATE V., Figs. 8, 8 _a_.

  1803. _Lycoperdon fuliginosum_ Sow., _Eng. Fung._, t. 257.
  1805. _Lycogala atrum_, Alb. & Schw., _Consp. Fung._, p. 83.
  1875. _Amaurochaete atra_ (Alb. & Schw.) Rost., _Mon._, p. 211.

Fructification aethalioid, varying in form and size, if on the upper
side of the substratum, pulvinate, if below pendent and almost
stipitate, covered with a delicate cortex, at first shining, soon dull,
black, fragile, and early dissipated; hypothallus long-persisting,
supporting the capillitium, which is extremely variable, irregular, and
for its perfection dependent upon the form assumed by the æthalium, and
the conditions of weather, etc., under which it matures, sometimes,
especially when prostrate, in a very much depressed æthalium, spreading
into long fibrous threads, again under better conditions rising in
columella-like forms, supporting a peripheral net; spores dark brown or
black, irregularly globose, spinulose, 12.5-15 µ.

Common in Europe, and probably not uncommon in this country wherever
pine forests occur. Specimens before us are from New England and New
York, Ohio, Carolina, Colorado. Canada.

Sowerby, in his comment on plate 257, _Eng. Fungi_, says: "It appears to
consist of branching threads affixed to the deal and holding a dense
mass of sooty powder. Over the whole is a thin, deciduous pellicle."
This description seems to be applicable to nothing else. The figure
amounts to little. Fries recognizes the English description, as does
Rostafinski, but both authors adopt the later name given by Albertini
and Schweinitz, simply because of the excellent detailed description
found in the _Conspectus_.


2. AMAUROCHÆTE TUBULINA (_Alb. & Schw._) _Macbr._

PLATE XX., 6 and 6 _a_.

  1805. _Stemonitis tubulina_ (Alb. & Schw.), _Cons. Fung._, p. 102.
  1825. _Lachnobolus cribrosus_ Fr., _Syst. Orb. Veg._, p. 14.
  1912. _Amaurochaete cribrosa_ (Fr.) Macbr., _Com. in litt._
           to Herbaria, Harvard, etc.[35]
  1917. _Amaurochaete cribrosa_ (Fr.) Sturg., G. Lister, _Jour. Bot._,
           LVIII, p. 109.

Plasmodium at first transparent then white then rosy, ashen or grey
finally deepening to jet-black; the æthalium even, thin, variable in
extent from one to ten centimeters, covered by a distinct but thin
transparent cortex, papillate, extended laterally but a short distance
beyond the fructification, fragile, soon disappearing; hypothallus
long-persistent, thin, silvery, supporting the capillitium as if by
stipes, short slender columns, irregular plates, expansions, etc.; the
capillitium an intricate network, very abundant, elastic, on fall of the
peridium appearing like tiny tufts of wool, the meshes large, but formed
as in _Stemonitis_, persistent, dull black; spores, under the lens, dull
olivaceous black, minutely roughened, 12-14 µ.

This species differs from the preceding, already well known, especially
in the capillitial characters. In the older species the capillitial
branches fray out, and are only sparingly united into a net extremely
lax. In the present form the net is the thing, common to all sporangia.
The total effect is to lend to the blown-out æthalium a woolly
appearance, entirely unlike that of its congener under the same
conditions. But until fructification is quite mature, the presence of
the collaborating sporangia below is indicated, suggested, by the
papillose upper surface.

The amaurochetes are remarkable in that they appear upon coniferous
wood, logs or lumber, to all appearance undecayed. The species just
described developed abundantly in August on the recently decorticated
logs of _Pinus ponderosa_, on the south-western slopes of Mt. Rainier,
Washington. In logging operations in the locality referred to, the trees
are felled often at considerable distance from the mill. They are not
infrequently large, 75-120 cm. in diameter. The logs are dragged along
the ground, the transportation facilitated by removal of the bark from
the new fallen trunk. In a few weeks' time, affected by alternate rain
and sun, the whole surface becomes marked with hundreds of minute,
almost invisible cracks, and it is in the larger of these that the
plasmodium of the present species has its habitat. Hardly any mycologic
phenomenon is more surprising than to see plasmodia rising to
fructification, scores at a time, upon a surface, new and white, showing
otherwise no evidence of any decomposition. Doubtless the persisting
cambium, the unused starches, sugars, the wood of the season yet
unlignified, afford easily accessible nutrition.

When this form was first examined in the laboratory its distinctness was
immediately seen. It was without doubt Fries' cribrose reticularia;
nobody questions that. Under this name, citing Fries' description,
specimens were sent out to herbaria as Harvard. Further study of the
records, however, soon convinces one familiar with the ontogeny of the
case that we are here face to face with the species, described by Alb. &
Schw. in their fine _Conspectus_. Their account of the form, evidently
often taken and now described with great care, is entirely clear when
read in presence of the facts. It is here submitted, as less easy of
access but essential, if the reader would appreciate the present
disposal of the species.


"S. Tubulina NOBIS

"_S. magna pulvinata subhemisphaerica, stylidiis gregariis
circinantibus, capillitiis elongatis cylindraceis in massam pulveraceam
fuscam connatis, apicibus obtusis, prominulis, lucidis nigris._

"The size indeed, the circumscribed form, the capillitiums conjoined
into a single body--indue this (form) with an appearance peculiar to a
degree; however, should anyone prefer to call it a very remarkable
variety of the preceding (_S. fasciculata_), we shall not strenuously
refuse. At first glance it looks like a tubulina. After the fashion of
its kind, the beginning is soft and milky. The diameter generally an
inch and a half to two inches, the height four to six lines; the form
perfectly round, or more rarely somewhat oblong. The hypothallus, stout,
pellucid silvery, betimes iridescent, when turned to the light, easily
separable from the substratum, bears the columellae, dusky, thin,
hair-like, aggregate and yet entirely free, and everywhere circinately
convergent, depressed by the superimposed burden, hence decumbent: ...
the capillitium loosely interwoven, coalesces to a common mass whose
smooth and shining surface shows above, regularly disposed minute
papillae, the apices of individual sporangia.

"Far from infrequent, on decorticate pine, of _Lycogala atrum_ a
constant companion"!

It goes of course without saying, that for the authors quoted, _Lycogala
atrum_ is _Amaurochaete atra_ Rost. _A. fuliginosa_ (Sow.) of more
recent students, described and perfectly figured in the volume cited.

It is surprising that they did not enter the present species also as a
lycogala. But the stemonitis relationship this time impressed them
rather than the æthalial; besides they were misled by the _S.
fasciculata_ of Gmelin and Persoon, a composite which the genius of
Fries hardly availed to disentangle twenty-five years later.

The last named author, as we see, wrote first _Lachnobolus_, then
_Reticularia_. He calls the interwoven capillitium--_lachne_, wool, a
"_pilam tactu eximie elasticam_," etc. He read the description in the
_Conspectus_, but carried away the stemonitis suggestion dominant there,
as we have seen, put _S. tubulina_ A. & S. as an undeveloped phase of
_S. fusca_, which, of course, it is not. It needed not the authority of
Rostafinski, _Mon._, p. 197, to assure us this. The earlier authors
describe the species in course of development to complete maturity, and
clinch the story by declaring the form a constant companion of the
commonly recognized amaurochete, so fixing the relationship for us by
habitat also.

These men made a mistake, of course, in placing their species among the
stemonites at all. They did much better however than Fries who called it
a reticularia. It was also a mistake to cite _S. fasciculata_,--the
small fasciculate tufts of _S. fusca_ and _S. axifera_ offering by the
aggregate habit only faint resemblance,--a possible refuge for those who
would prefer another disposition of their species distinct (_aliena_)
though it is.

Since Fries' day the species has been overlooked although the genus has
received more than once attention. Zukal _Hedwigia_, XXXV., p. 335,
describes _A. speciosa_ as a new species. This Saccardo writes down,
Syll. Fung., VII., p. 399, _S. tubulina_ A. & S., admitting, however, at
the same time, that as fine an authority as Raciborsky refuses to call
Zukal's species either a stemonite or an amaurochete, thinks it
deserving generic appellation of its own.

However, _A. speciosa_ Zuk. need not here concern us. Neither in his
description nor figures does Zukal at all approach the form we study.
His species is not an amaurochete; the size of the spores suggest that,
to say nothing of the capillitial structure.

In the same volume VII., the distinguished author introduces another
amaurochete, _A. minor_ Sacc. & Ellis, _Mich._ II., p. 566. This is
American; sent from Utah by our famous pioneer collector Harkness. A
specimen is before us: it is a lepidoderma! in shining, scaly armor
dressed; vid. under _L. carestianum_.

Since the distribution of Washington material, as mentioned, our species
reappears at various points in western Europe, points in England, etc.,
and will no doubt now share, hereafter as a century ago, the habitat so
long conceded to the long familiar older type.


_B._ STEMONITACEÆ

Capillitium abundant, springing usually as dissipating branches from all
parts of the columella; the sporangia generally definite and distinct,
though sometimes closely placed and generally rising from a common
hypothallus.


=Key to the Genera of the Stemonitaceæ=

  _A._ Fructification æthalioid; capillitium charged
         with vesicles                                    1. _Brefeldia_

  _B._ Sporangia distinct, or nearly so.

     _a._ Stipe and columella jet-black.

          1. Capillitium so united as to form a surface
               net                                       2. _Stemonitis_

          2. Capillitial branch-tips free                3. _Comatricha_

     _b._ Stipe and columella whitish; calcareous          4. _Diachaea_

=1. Brefeldia= _Rostafinski_

  1873. _Brefeldia_ Rost., _Versuch_, p. 8.

Sporangia occupying in the æthalium several layers, those of the median,
and especially of the lowest layers, furnished with columellæ which
blend beneath; capillitium threads in the lowest layers arising from the
columella, in the upper extending radiately between the individual
sporangia, and united at the sporangial limits by means of rather large
inflated sacs.

The genus _Brefeldia_ is, like some others, difficult to dispose of in
any scheme of classification where linear sequence must be followed.
Rostafinski placed it in an order by itself. Its relationships are on
the one hand with _Amaurochaete_ and _Reticularia_, and on the other
with the _Stemonitales_, though easily distinguished from either. It is
intermediate to _Amaurochaete_ and _Stemonitis_, and withal, as it
appears to us, a little nearer the latter, as the limits of the
individual sporangia are in _Brefeldia_ pretty well defined.


1. BREFELDIA MAXIMA (_Fr._) _Rost._

PLATE V., Figs. 7, 7 _a_, 7 _b_, and PLATES XXI., XXII.

  1825. _Reticularia maxima_ Fries, _Syst. Orb. Veg._, I., p. 147.
  1875. _Brefeldia maxima_ (Fr.) Rost., _Versuch._, p. 8.

Æthalium large, four to twenty cm, papillate above, violet-black at
first, then purple or purple-brown, developed upon a widespread,
silver-shining hypothallus; sporangia in favorable cases distinct,
indicated above by the papillæ; columellæ obscure, black; capillitium
abundant, the threads uniting by multifid ends to surround as with a net
the peculiar vesicles; spore-mass dark violet-black, the individual
spores paler by transmitted light, distinctly papillose, 12-15 µ.

A very remarkable species and one of the largest, rivalled by _Fuligo_
only. To be compared with _Reticularia_, which it resembles somewhat
externally, and with some of the larger specimens of _Enteridium_. The
plasmodium at first white with a bluish tinge is developed abundantly in
rotten wood, preferably a large oak stump, and changes color as maturity
comes on, much in the fashion of _Stemonitis splendens_, leaving a
widespread hypothallic film to extend far around the perfected
fruit-mass. In well-matured æthalia, "_Jove favente_," the sporangia
stand out perfectly distinct, particularly above and around the margins.
Closely and compactly crowded, they become prismatic by mutual pressure,
and attain sometimes the height of half an inch or more. In the centre
of the fructification, next the hypothallus, the sporangia are very
imperfectly differentiated. Many are here horizontally placed, and
perhaps supplied with an imperfectly formed peridium,--if so are to be
interpreted the lowest parts of the capillitial structure, the long,
branching, ribbon-like strands which lie along the hypothallus. Some of
these branch repeatedly with flat anastomosing branchlets, ultimately
fray out into lengthened threads, and perish after all the
superstructure has been blown away. From every part of the structure so
described, but more especially from the margins, are given off in
profusion the strange cystiferous threads, so characteristic of this
genus. These are exceeding delicate filaments, attached at one end, it
may be, to a principal branch, at the other free or united to a second
which again joins a third, and so looping and branching, dividing, they
form a more or less extended network, a capillitium in which are
entangled the myriad spores. Each filament bears at its middle point (or
is it the meeting point of two?) a peculiar plexus which embraces
several large cysts or vesicles whose function or further homology does
not readily appear.

From the base of the fructification rise also ascending branches which
are black, terete, and not infrequently branched as if to form the
capillitium of a stemonitis. These ascending branches are in many cases,
probably in all, real, though as yet imperfectly developed, columellæ.
They rise, at least in many cases, directly from the hypothallus, each
is central to an individual sporangium, rises to about two-thirds its
height, but never attains the summit. The sporangia are so crowded that
many are choked off below, never reach the top of the æthalium. In such
cases the columella may cease at the sporangium-top. The columella bears
cystiferous threads sparingly, if at all; nevertheless these abound in
the peripheral portions of the sporangium all the way up, and are
especially noticeable beyond the level of the top of the columella. Many
are so arranged that the plexus with its vesicles occupies a place in
the plane separating adjacent sporangia, suggesting the possibility that
we have here to do with an imperfectly developed surface-net and
peridium. In this view the cysts would represent the meeting-point of
two opposite radial capillitial threads rather than the middle of one.
This accords with Rostafinski's observations and drawings. The cysts,
then, belong morphologically to the peridium or sporangium wall. It is a
stemonitis whose sporangia have never been perfectly differentiated, a
case of arrested development. See further under _Stemonitis confluens_.

Rostafinski really offers the first definitive description. Fries
probably distinguished it, but his description would not indicate the
fact except for the added note wherein appears the reason for discarding
an apparently older name, viz., that given by Link. But neither Link nor
Sowerby distinguished by description or figure _Brefeldia_ from
_Amaurochaete_.

Throughout the northern forest; Maine to Vancouver Island: not common.


=2. Stemonitis= (_Gleditsch_) _Rost._

  1753. _Stemonitis_ Gleditsch, in part, _Meth. Fung._, p. 140.
  1873. _Stemonitis_ (Gleditsch) Rost., _Versuch_, p. 7.

Sporangia distinct, though often closely aggregate, cylindric,
stipitate; columella prominent; capillitium well developed by repeated
lateral and apical branching of the columella, at length assuming at the
surface the form of a distinct net which supports an evanescent
peridium.

The genus is marked by its surface-net supported at the tips of the
dichotomously branched divisions of the columella. Over the net is
spread, theoretically at least, the peridial film supported by very
short points projecting from the net,--the peridial processes; the
peridium, however, is seldom seen; in some cases, certainly, is never
developed. Rostafinski first defined the genus as employed by recent
writers. Gleditsch simply renamed Micheli's _Clathroidastrum_; all
writers subsequent included species of other genera.

The taxonomy of this genus is of the most difficult. Macroscopic,
defining characters are few, and even these sometimes uncertain.
Microscopic distinctions also tend to be illusive, variable in such
fashion that often at the critical point the most exact description
fails. All that may be done at present is to recognize two or three
definite types and then cautiously differentiate among these with the
light we have, until more general study of the group brings to service a
wider range of observation with more comprehensive record on which
judgment may better be sustained.

We have before us many and beautiful forms of this genus yet unstudied.
Some of these doubtless have already found place in our growing
taxonomic literature; some apparently undescribed; all to wait wider
leisure or perhaps a younger hand.

The entire life-history of every form is none too much if we would set
out with any hope of accuracy the genetic relationships for which
taxonomy stands. Recently European students are making the color of the
plasmodium a basis for species-discrimination, which is good so far. But
plasmodic characters are at present unserviceable generally, for two
reasons; they vary in the same species; and unfortunately, when most
needed, they are unknown and inaccessible. The student is generally
confronted by forms mature, the plasmodic stage already past.


=Key to the Species of Stemonitis=

  _A._ Sporangia connately united.

     _a._ Spores verruculose                           1. _S. confluens_

     _b._ Spores reticulate                          2. _S. trechispora_

  _B._ Sporangia at maturity distinct.

     _a._ Spore-mass grayish black.

          1. Larger, 8-12 mm. spores distinctly
               reticulate or warted, but sometimes
               nearly smooth        3. _S. fusca_

          2. Spores reticulate and spinulose.

             i. Spores adherent, clustered               4. _S. uvifera_

            ii. Sporangia very tall, 15-20 mm.,
                  rigid                              5. _S. dictyospora_

           iii. Sporangia short, jet- or
                  violet-black                        6. _S. nigrescens_

     _b._ Spore-mass rich brown.

          1. Columella central.

             i. Sporangia shorter, 5-6 mm., spores
                  banded                            7. _S. virginiensis_

            ii. Sporangia 8-10 mm.; spores
                  verruculose                            8. _S. webberi_

           iii. Sporangia tall, 15-20 mm. or more      9. _S. splendens_

          2. Columella eccentric, sporangium in
               cross-section, angular                10. _S. fenestrata_

     _c._ Spore-mass ferruginous; sporangia in
            tufts.

          1. Spores smooth or nearly so.

             i. Sporangia pale, small, 3-5 mm.,
                  crowded, stipe unpolished             11. _S. smithii_

            ii. Sporangia ferruginous; columella
                  regular                               12. _S. axifera_

           iii. Sporangia ferruginous; columella
                  proliferate just below the apex   13. _S. flavogenita_

            iv. Sporangia, spore-mass,
                  dusky-purplish or brown.

                 O On dead wood.

                    o Scattered, apex blunt             14. _S. pallida_

                   oo Clustered, acuminate         15. _S. carolinensis_

                OO On living leaves, preferably,
                     spore-mass brown                 16. _S. herbatica_


1. STEMONITIS CONFLUENS _Cooke & Ellis._

PLATE XI., Figs. 4, 4 _a_, 5.

  1876. _Stemonitis confluens_ Cke. & Ell., _Grev._, V., p. 51.
  1894. _Stemonitis splendens var. confluens_ Lister, _Mycet._, p. 112.
  1899. _Stemonitis confluens_ Cke. & Ell., Macbr., _N. A. S._, p. 114.
  1911. _Stemonitis confluens_ Cke. & Ellis, List., _Mycet., 2nd ed._,
           p. 147.

"Sporangia fasciculate, confluent on a persistent hypothallus, dark
fuscous; peridia very fugacious; stipes united at the base, erect,
furcate; spores large, brown, globose. On oak bark.

"The stems are branched in a furcate manner and confluent at the base,
forming a compact tuft. The capillitium is membranaceous at the angles;
spores very large compared with allied species, being 12 µ. The
specimens were too fully matured for more satisfactory description."

Such is the original description of this unique and interesting species.
The sporangia occur in close-set tufts or clusters, are distinct,
separate at their tips and bases only; perhaps not always at base. The
capillitium rises by branching from the columella, rather more prolific
than usual, and combines to form a distinct superficial net of large
even meshes. From the outer arcs of the bounding net spring rather long
acute processes which should support the peridium. This, however, is
altogether rudimentary. In most places there is no sign of peridium at
all, but here and there between contiguous sporangia opposite processes
unite and at their point of union a tiny circular disk of the peridial
membrane appears. At intervals, therefore, over the entire sporangium
are seen these small brown disks, each about equalling in diameter the
size of the average mesh. At other points the sporangia do not seem at
all coalescent, but where the opposing processes do meet the union is
perfect and the little disk seen edgewise looks like some delicate
counter strung upon a wire.

The interest attaching to this in view of what has been said about
_Amaurochaete_ and _Brefeldia_ is obvious.

Under the lens the spores and capillitium are concolorous, dark fuscous,
the spores distinctly verruculose, about 12.5 µ.

The original gathering here described was from New Jersey; twenty years
later Mr. Ellis was so fortunate as to find again fine specimens all on
oak bark. The sporangia are quite small, only 3 mm. high, when blown out
concolorous with the habitat.


2. STEMONITIS TRECHISPORA (_Berk._) _Torr._

PLATE XX., Figs. 11, 11 _a_, 11 _b_, 11 _c_.

  1909. _Stemonitis fusca_ (Roth) Rost. var. _trechispora_ (Berk.),
          _Fl. Myxom._, Torrend, p. 141.
  1911. _Stemonitis fusca var. trechispora_ Torr., List., _Mycetozoa,
           2nd ed._, p. 144.

Fructification in form of aggregations of more or less coalescent,
small, dark-brown or dull black, sessile sporangia; hypothallus
continuous, well-developed; columella black, gently tapering to a point
beneath the apex, the capillitial branches, irregular, few, but passing
into an open rather evenly-meshed net, the mesh several times the
spore-diameter, free-ending branch-tips not lacking; the spores by
transmitted light distinctly brown, the epispore a beautiful
reticulation, a dozen or more cells to the hemisphere, 10-12 µ.

This is entered sometimes as a variety of _S. fusca_ to which species
relationship would seem remote. The differences lie in form, color and
structure. The spores alone are distinctive; there are none such, so
far, none just like them, elsewhere in the genus. Torrend and Lister
both enter the form as varietal; why not set it out, and save questions?
The habitat approaches that of _Amaurochaete_, but the sporangia are
distinct.

For our specimens we are indebted to the kindness of Dr. Roland Thaxter.
The specimens were taken in a half-dry marsh, near Cambridge.

Material from Toronto sent by Professor Faull is also provisionally here
referred. The form has netted spores, but they are not quite the same.
The structure besides is more that of an amaurochaete; it has the
peculiar basal webs and band-like stipes at base, stipes that never rise
from horizontal to perpendicular and characterize _Reticularia_ and
especially _Brefeldia_ as well as the usual amaurochaete. See Plate XX.,
Figs. 9, 9_a_, 9_b_.


3. STEMONITIS FUSCA (_Roth_) _Rost._

PLATE VI., Figs. 4, 4 _a_, 4 _b_

  1787. _Stemonitis fusca_ Roth, _Röm. Mag. Bot._, I., p. 26.
  1875. _Stemonitis fusca_ (Roth) Rost., _Mon._, p. 193.
  1892. _Stemonitis fusca_ Rost., Massee, _Mon._, p. 72.
  1895. _Stemonitis fusca_ Roth, List., _Mycetozoa_, p. 110.
  1899. _Stemonitis fusca_ (Roth) Rost., Macbr., _N. A. S._, p. 115.
  1899. _Stemonitis maxima_ Schw., Macbr., _N. A. S._, p. 116.

Sporangia tufted, generally in small clusters 6-8 mm., the individual
sporangia slender, cylindric, blue-black or fuscous, becoming pallid as
the spores are lost, stipitate; stipe short, about one-fourth the total
height, black, shining; hypothallus scanty, but common to all the
sporangia; columella prominent, attaining almost the apex of the
sporangium, freely branching to support the capillitial net; capillitium
of slender dusky threads, which freely anastomose to form a dense
interior network, and outwardly at length combine to form a
close-meshed net; spores pale, dusky violet, usually beautifully
spinulose-reticulate, but sometimes warted or spinulose only, or nearly
smooth, 7-7.5 µ.

As here set out the description is intended to include _S. maxima_ Schw.
of the former edition. Rostafinski, Mon. _l. c._, describes _S. fusca_
Roth. as having "spores smooth." Since most American gatherings have
reticulated spores, and since Schweinitz described a black American
species, his specific name seemed appropriate for all except
smooth-spored forms.

In the meantime two things have happened; Mr. Lister has examined the
specimens remaining in the Strasburg herbarium and finds them with
reticulate spores. The statement quoted from the _Monograph_ evidently
does not apply to _all_ of Rostafinski's material; but under the
circumstances the name _fusca_ may easily take the field, especially
since another discovery makes for the same conclusion. The evidence is
good that _S. maxima_ Schw. was indeed the largest, i. e. perhaps, the
_tallest_ stemonitis he ever saw! probably, as his scanty
herbarium-remnant shows, _S. fenestrata_ Rex!


4. STEMONITIS UVIFERA _n. s._

PLATE XX., Figs. 8, 8 _a_, 8 _b_, 8 _c_.

Sporangia tufted, generally in medium-sized clusters much as in _S.
fusca_. The individual sporangium 7-9 mm. high, dark, slender, brown,
becoming dull black or pallid as the spores are lost, stipitate, the
stipe about one-fourth to one-third the total height, black polished
shining; hypothallus distinct, common to all sporangia, purple-brown,
shining; columella distinct, attaining almost the summit of the
sporangium but inclined to waver a little at last, in other words,
flexuose toward the top, freely branching, the branches rather stout,
anastomosing to support the capillitial net; the meshes larger, several
times the spore-diameter, the spores sooty-brown, distinctly warted or
spinulescent, about 7-8 µ, clustered in groups of four or more.

Mt. Rainier, Washington,--1914.


5. STEMONITIS DICTYOSPORA _Rost._

  1873. _Stemonitis dictyospora_ Rost., _Mon._, p. 195; _Myc. Fen._,
           pp. 114, 122.
  1879. _Stemonitis dictyospora_ Rost., Mass., _Mon._, p. 83(?).
  1888. _Stemonitis dictyospora_ Rost., _Sacc. Syl. Fung._, Vol. VII.,
           p. 397.
  1893. _Stemonitis castillensis_ Macbr., _Nat. Hist. Bull._, Vol. 11,
           p. 381.

PLATE X., Figs. 5, 5 _a_, 5 _b_.

Sporangia crowded in colonies of unusual size, 4-8 cm., tall, rigid
18-25 mm., slender, erect, stipitate, black throughout; the columella
prominent, reaching nearly to the apex, abundantly branched, the
branches forming an intricate dark brown capillitium; the net
large-meshed several times the spore-diameter; the spores reticulate,
spinulose, clear violet, 7-8 µ.

We here recover as is believed one of Rostafinski's best-described
species. Our material is from Nicaragua, by kindness of Professor
Shimek. Its relationship is with _S. fusca_ where Rostafinski placed it.
The phrase describing spore-color is his.


6. STEMONITIS NIGRESCENS _Rex._

  1891. _Stemonitis nigrescens_ Rex, _Proc. Phil. Acad._, p. 392.
  1911. _Stemonitis fusca_ Roth, Lister, _Mycetozoa, 2nd ed._, p. 143.

Sporangia gregarious, upon a common hypothallus, erect, small,
cylindric, stipitate; stipe black, extremely short, about half a
millimetre; columella reaching the apex; capillitium violet-black,
darker near the surface, forming a complete superficial net at the lower
part of the sporangium only, elsewhere irregular or vanishing;
spore-mass nearly black; single spores violet-black under the lens, the
epispore spinulose and reticulate, about 8 µ.

The author of this species remarks: "This species is noteworthy for its
comparatively short stipes, its very spinulose spores, and its black or
nearly black color, the slight violet tint being only apparent on close
inspection, especially in fresh moist specimens."

It is a small but very beautiful form, at first sight to be mistaken for
a short _S. fusca_, though much more intensely black. The capillitium is
concolorous, the inner network of rather few open meshes, the outer of
large hexagonal openings, the arcuate threads of which are remarkable
for the size, and especially the number, of the peridial processes, as
many as five or six sometimes appearing along one side of a single mesh.
The stipe is very short, and the columella runs as a straight, gradually
diminishing axis to the very apex of the sporangium. Total height 3-5
mm.

The English _Monograph_ includes this with _S. fusca_; but it seems
quite distinct in size, habit, color, etc., and has been found in the
mountainous regions of Virginia and North Carolina, as well as about
Philadelphia.


7. STEMONITIS VIRGINIENSIS _Rex._

  1891. _Stemonitis virginiensis_ Rex, _Proc. Phil. Acad._, p. 391.
  1899. _Stemonitis virginiensis_ Rex, Macbr., _N. A. S._, p. 130.
  1911. _Comatricha typhoides_ Rost., List., _Mycetozoa, 2nd ed._,
           p. 158.

Sporangia erect, gregarious, from a common hypothallus, generally
clustered, cylindric or elongate-ovate, stipitate; stipe black, shining;
columella reaching the apex, where it blends with the capillitium;
capillitium delicate, the meshes of the net small, scarcely greater than
the diameter of the spores; spore-mass umber brown; epispores
reticulated, with ten or twelve meshes to the hemisphere, 5-7 µ.

This is a beautiful, and, as it seems to us, a very distinct, species.
The markings on the epispore are sufficient to identify it. These are
conspicuously banded somewhat as the spores of _Trichia favoginea_, for
example. In habit, size of the sporangia, and capillitial branching,
this species recalls _Comatricha typhoides_ (Bull.) Rost. All the
sporangia examined are, however, plainly stemonitis in type, possessing
the characteristic superficial net.

Until further light this may stand as offered in the first edition. Miss
Lister prefers to enter it, banded spores and all, with the comatrichas,
on account of color, size and occasional default (?) of surface net.

Virginia, _Dr. Rex._


8. STEMONITIS WEBBERI _Rex._

PLATE XI., Figs. 6, 7, 8.

  1891. _Stemonitis webberi_ Rex, _Proc. Phil. Acad._, p. 390.

Sporangia clustered, usually in small tufts 1 cm. wide, rusty brown in
color, 8-10 mm., including the stipe, which is jet black, shining, and
much expanded at the base; hypothallus continuous, well-developed, a
thin, transparent pellicle; columella black, tapering upward, giving off
at intervals the capillitial branches, and becoming dissipated just
below the obtuse apex; inner capillitial network very open, the branches
far apart, anastomosing but a few times before breaking into the surface
net to form large, irregular meshes, 50-125 µ; spores minutely
roughened, fuscous, 8-9 µ.

These three forms, 8, 9, 10, are sometimes entered as varieties of a
single species. Dr. Rex himself was inclined to take that view. There is
no doubt of close similarity; it is a question of clearness in our
dealing with the subject.

All three forms occur abundantly in the Mississippi Valley, but are
generally,--always, as it seems to the writer,--distinguishable by the
hand-lens. If we take No. 9 as type, 10 has an eccentric columella; 8 is
shorter, about 1 cm., of a different tint, Dr. Rex even says "spores
ferruginous in mass". To the west and southwest, the capillitium becomes
coarser, more decidedly brown. In short, however similar in presentation
the phases may sometimes appear, it would seem that each at its best is
distinct enough for immediate recognition.

West of the Mississippi River chiefly: Iowa, South Dakota, Nebraska,
Kansas, Oklahoma, New Mexico, etc.


9. STEMONITIS SPLENDENS _Rost._

PLATE VI., Figs. 6, 6 _a_, 6 _c_, 7, 7 _a_.

  1875. _Stemonitis splendens_ Rost., _Mon._, p. 195.
  1880. _Stemonitis morgani_ Peck, _Bot. Gaz._, V., p. 33.
  1893. _Stemonitis splendens_ Rost., Macbr., _Bull. Lab. Nat. Hist._,
           Vol. II, p. 381.
  1894. _Stemonitis splendens_ Rost., List., _Mycetozoa_, p. 112, in
           part.
  1899. _Stemonitis morgani_ Peck, Macbr., _N. A. S._, p. 118.
  1911. _Stemonitis splendens_ Rost., List., _Mycetozoa, 2nd ed._,
           p. 145.

Sporangia clustered irregularly, sometimes forming patches 6-10
centimetres or more in extent, rich purple-brown in mass, cylindric,
long, 15-18 mm., stipitate; stipe black, polished, shining, rising from
a common hypothallus, which extends as a thin silvery film beneath the
entire colony, but does not usually transcend its limits; columella
black, percurrent, sparingly branched; capillitium of fuscous threads,
within forming a network very open, the branches scarcely anastomosing
until they reach the surface where they form the usual net of small
meshes, pretty uniform in size, and presenting very few small,
inconspicuous peridial processes; spores brown, very minutely warted,
about 8 µ.

This elegant species occurs not rarely on rotten wood, usually in
protected situations, although sometimes on the exposed surfaces of its
habitat. The sporangia attain with us unusual height, sometimes 2 cm.;
plasmodia, 6-8 cm., in diameter. The clear brown tufts appear in the
autumn, marvels of graceful elegance and beauty; at sight easily
recognizable by the large size and rich color. In Iowa it is almost
universally present on fallen stems of _Acer saccharinum_ Linn., and it
appears to be widely distributed, by far the most beautiful of all this
beautiful series.

New England to Iowa, South Dakota, Washington, and British Columbia.
Professor Shimek brings a _dusky_ phase from Nicaragua!--the type?

The plasmodium is white on maple stems, more creamy on stems of linden,
on which wood it is more rarely found: occasionally on ash-stumps; even
on the fallen bark of trees preferred.

In 1875 in his famous _Monograph_, Rostafinski set out three species
with "dusky violet spores". These are his Nos. 94, 95 and 96.

The first one of these he calls _S. fusca_, "spore-mass, etc.,
violet-black, individual spore clear violet, smooth, 7-9 u."

The second species he writes down _S. dictyospora_, "hypothallus, stalk,
columella, capillitium and spore-mass, violet-black, spore netted and
fringed, clear-violet, 7-9 µ."

The third species is _S. splendens_, "hypothallus stalk, columella and
spore-mass violet-black, spore smooth, clear-violet, 7-8 µ."

It will be observed that in color down to color of the spore by
transmitted light, the three species are exactly the same; constitute a
suite, so to say. It has since turned out, as noted under our No. 3,
that the spores of _S. fusca_ are netted. Error in description here is
not surprising; the reticulations are sometimes faint. In _S.
dictyospora_ they are admittedly strong, and the inference was that the
'_gladkie_' spores of the third species might be netted also. This is no
criticism: lenses were fifty years since not nearly so good for such
discoveries as the oil-immersion is now.

However; Rostafinski made his specific diagnosis turn largely upon the
mesh-width in the superficial net. This comes out in the '_opis_'
following the description, and upon _this_ the European decision in
Rostafinski's favor as against _S. morgani_ largely turns. Tropical
gatherings are probably always darker, and evidently from such, from the
north coast of South America, the original description was drawn.
Specimens before us from the same latitude are dusky indeed; no clear
brown at all, but purplish withal.

For the sake of harmony we may therefore now substitute the earlier name
"with reservations"! but our description remains as before, presenting
the really splendid, shining things that adorn our northern fields. Dr.
Rostafinski called the large open meshes of the net '_oka_', eyes;
_lumina_ let us say! quite uniform they are in 9 and 10, much less so in
8.


10. STEMONITIS FENESTRATA _Rex._

  1890. _Stemonitis splendens_ R. _f. fenestrata_ Rex, _Proc. Phil.
           Acad._, p. 36.

Sporangia aggregated, in tufts 2 cm. or more in diameter, rich purple
brown, on a common hypothallus, more or less erect, stipitate, tall,
about 2 cm., slender, triangular in section; stipe black, about
one-third the total height, passing into a slender columella which is
lateral in position, not central, but little branched, continued almost
to the apex; the capillitium consisting almost entirely of the
peripheral net, which presents meshes of unusual uniformity of size and
shape; spores in mass brown, colorless by transmitted light, nearly
smooth, 6-7.5 µ.

The remarkable shape of the sporangium and the peculiar regularity of
the surface net, the lateral columella, all combine here to warrant the
erection of a distinct species. Dr. Rex referred this to _S. bäuerlinii_
Mass. At that time he had not the author's description, and had seen
only a very poor fragment received with notes in a letter. Mr. Massee's
description makes it immediately evident that whatever other
affiliations _S. bäuerlinii_ may have, by description it has at least
none with _S. fenestrata_ nor with our northern form of _S. splendens_.
Massee's species is described as having the "mass of spores black", the
capillitium with "branches springing from the columella; the main
branches more and more numerous, thicker and irregular towards the apex
of the sporangium, and often form irregular flattened expansions":--etc.
This suggests some form of _S. dictyospora_ Rost.: see under our No. 5.
Possibly for such reasons Lister referred it to _S. splendens_ Rost.,
which as we have just seen, was undoubtedly regarded by the author as a
form of the _fuscous_ group.

The long, slender, simple columella is not only lateral, but occupies
indeed the sharp vertical angle of the triangular, prismatic sporangium.
Furthermore, the sporangium is at maturity strangely twisted, so that
the columella in its ascent accomplishes one or more spiral turns. In
forms collected by Dr. Rex, which seemed to him most nearly to agree
with Massee's species, the inner capillitium is somewhat abundant, but
the character of the columella just the same.

Pennsylvania, Ohio, Kansas, Colorado, Iowa; India!


11. STEMONITIS SMITHII _Macbr._

  1893. _Stemonitis smithii_ Macbr., _Bull. Lab. Nat. Hist. Ia._, II.,
           p. 381.
  1894. _Stemonitis microspora_ List., Morg., _Jour. Cin. Soc._, p. 54.
  1911. _Stemonitis ferruginea_ var. _smithii_ Lister, _Mycetozoa,
           2nd ed._, p. 150.

Sporangia in small clusters, close-packed and erect, not spreading,
bright ferruginous prior to spore dispersal, cylindric, stipitate, of
varying height; stipe jet-black, shining, about one-third the total
height; hypothallus generally well developed; columella black, gradually
tapering, at length dissolving in capillitial threads and net some
distance below the diminished plumose apex; capillitium of fuscous
threads, the inner network of abundant, sparingly united branches
uniformly thickened, the surface net very delicate, composed of small,
regular, polygonal meshes, the peridial processes few; spore-mass bright
ferruginous, spores by transmitted light pale, almost colorless, smooth,
4-5 µ.

The species as thus constituted includes forms varying in size from
2.5-3 mm. only. The common form heretofore known everywhere in America
as _S. ferruginea_ is from 10-15 mm. high. The _type_ to which the
specific name _S. smithii_ was originally applied is 2.5 mm. high and
rejoices in smooth, almost colorless spores, 4-5 µ.

The plasmodium in the case of the species now considered is as concerns
the _type_, of course, unknown. In one or two gatherings referred here
the color of the plasmodium was noted greenish-yellow. This has the look
of _S. flavogenita_; but small spores and delicate make-up take it the
other way. Miss Lister makes it varietal to No. 12, next following.


12. STEMONITIS AXIFERA (_Bull._) _Macbr._

PLATE VI., 5, 5 _a_, and 5 _b_.

  1791. _Trichia axifera ferruginea_ Bull., _Champ. de la Fr._, p. 118,
           tab. 477.
  1818. _Stemonitis ferruginea_ Ehr., _Syl. Myc. Berol._, p. 20;
           et auct. Europ. ex parte; Americ., non.
  1894. _Stemonitis ferruginea_ Ehr., List., _Mycetozoa_, p. 115,
           in part.
  1899. _Stemonitis axifera_ (Bull.) Macbr., _N. A. S._, p. 120,
           in part.
  1911. _Stemonitis ferruginea_ Ehr., Lister, _Mycetozoa, 2nd ed._

Sporangia terete, acuminate, fasciculate small in dense clusters,
distinctly ferruginous in color, stipitate, from 10-15 mm. in height;
the stipe black one-third to one-half the total height, not shining or
polished; columella evenly branching, dissipated before reaching the
acuminate apex; capillitium-branches clear brown anastomosing and
dividing more or less to bear the superficial fine-meshed net; spores
pallid, faintly ferruginous, smooth or nearly so, 5-6 µ.

This would seem to be the common _ferruginous_ species of the world.
Doubtless Micheli had the thing before him when he drew Tab. 94,
_clathroidastrum_, Hoffman and Jacquin seem to have recognized the form.
To be sure, under the present plasmodic limitations we cannot be quite
certain about these references. Not until 1791 does anyone write down a
particular species as marked by a white plasmodium, and distinguish it
from other similar fructifications having similar origin. Bulliard, _l.
c._, does this, discriminating between _T. axifera ferruginea_ and _C.
typhoides_; see under the last-named species. Youthful Ehrenberg, in his
doctor's thesis, nearly thirty years later, draws a similar parallel but
ignores the great French author, writing _S. ferruginea_ Ehr. as though
the thing had never been seen before! By this name it has been called
until very lately; Fries accepting it, but noting that the plasmodium,
for him at least, was _yellow_!

In 1904 Dr. E. Jahn, following Fries' suggestion, established the fact
that Ehrenberg's white-plasmodic species had small spores, that Fries
had in mind a form with larger spores, having indeed yellow plasmodium;
but see number 13 below.

It is for the present assumed that the plasmodium of our American _S.
axifera_ is white. So far, there are few or no observations which
establish the fact. The color, the small smooth spores, the fine-meshed
capillitial net and the general dimensions determine the reference.


13. STEMONITIS FLAVOGENITA _Jahn._

PLATE XX., Figs. 10, 10 _a_, 10 _b_.

  1829. _Stemonitis ferruginea_ Ehr., Fries, _Myc._ III., p. 158,
           Syn. excl.
  1899. _Stemonitis axifera_ (Bull.) Macbr., _N. A. S._, p. 120,
           in part.
  1904. _Stemonitis flavogenita_ Jahn, _Abh. Bot. Ver. Brandenb._,
           XLV, p. 265.
  1911. _Stemonitis flavogenita_ Jahn, List., _Mycetozoa, 2nd ed._,
           p. 149.

Sporangia cylindric, obtuse, closely fasciculate, "cinnamon brown,"
stipitate, 5-7 µ; stipe short, black, columella ceasing abruptly below
the apex; capillitium a loose net-work with many broad expansions; the
peridial net very delicate, the meshes small but uneven, 6-15 µ, with
many projecting points; spores pale ferruginous, verruculose, 7-9 µ.

This is _S. ferruginea_ Ehr. of Fries with its plasmodium yellow. Fries
says "flavicat," _becomes_ yellow, if one may follow the analogy of
corresponding Latin verbs of color, so that the record of color-changes
in the present species is yet to be recorded.

Until further experience may advise to the contrary, we may assume that
all stemonites cinnamon-brown in color, with widened columella-tip, and
pale yellowish spores 7-9 µ in diameter, have at some time in their
history a yellow plasmodium, and accordingly represent in America the
new-found species.

The larger spores, and, the strange proliferate development of the
columella-tip, to which Miss Lister has happily called attention,
constitute the essential diagnostic features here.

Our only specimens so far are from Oregon.


14. STEMONITIS PALLIDA _Wingate._

PLATE XIII., Fig. 3

  1897. _Stemonitis pallida_ Wing., _N. A. F._, Ell. and Ev., No. 3498.
  1899. _Stemonitis pallida_ Wing., Macbr., _N. A. S._, p. 123.
  1911. _Stemonitis pallida_ Wing., List., _Mycetozoa, 2nd ed._, p. 149.

Sporangia gregarious, or somewhat clustered, erect, cylindric obtuse,
short, blackish brown, rubescent, becoming pallid, stipitate; stipe
short, black, polished, rising from a thin, brown, or iridescent
hypothallus; columella percurrent, ceasing abruptly at the apex;
capillitium filling the interior with abundant branches which form at
the surface a close-meshed net, little developed above, making the apex
very blunt; spores in mass, dark brown, by transmitted light dusky,
nearly smooth, 7.5 µ.

This species is well recognized at sight, among the fuscous forms, by
its scattered, erect habit. In color it is not unlike _S. fusca_, but
has an added reddish tinge. In form it is peculiar by virtue of the
blunt rounded apex which seems to be a constant character. The spores
under moderate lens are perfectly smooth, under the 1-12 they present
very delicate low scattered papillæ.

Rare; eastern part of United States.


15. STEMONITIS CAROLINENSIS _Macbr._

PLATE XIII., Fig. 5.

  1894. _Stemonitis tenerrima_ Berk. & C., Morg., _Jour. Cin. Soc._,
           p. 53.
  1899. _Stemonitis carolinensis_ Macbr., _nom. nov._, _N. A. S._,
           p. 152.
  1911. _Stemonitis pallida_ Wing., Lister, _Mycetozoa, 2nd ed._,
           p. 149.

Sporangia tufted in scattered clusters, small, slender, cylindric but
tapering from the apex, at first ferruginous then ashen or purplish,
stipitate; the stipe short, black and shining, one-fourth the total
height or less, even; hypothallus well developed, black or very dark
brown; columella black, gradually diminishing, at length dissipated some
distance below the clavate or acuminate apex of the sporangium;
capillitium dense, the inner of many, scarcely expanded, pallid, freely
anastomosing branches, the outer a net of very small meshes, often less
than the spores, 3-15 µ, peridial processes imperceptible; spore-mass
pale ferruginous, spores by transmitted light pale violaceous brown,
smooth, 6-7 µ.

Very closely related to the preceding, but recognizable by its
proportionately much more slender, taller, acuminate sporangia, paler,
and denser capillitium and the remarkably close-meshed net.

Not uncommon south: Kentucky, Alabama.


16. STEMONITIS HERBATICA Pk.

PLATE XVI., Figs. 14, 14 _a_, 14 _b_.

  1874. _Stemonitis herbatica_ Peck, _Rep. N. Y. Mus._, XXVI., p. 75.
  1899. _Stemonitis axifera_ (Bull.) Macbr., _N. A. S._, p. 120,
           in part.
  1911. _Stemonitis herbatica_ Pk., Lister, _Mycetozoa_, p. 148.

Sporangia clustered, in scattered tufts, cylindric, obtuse, pallid
ferruginous, stipitate or sometimes nearly sessile; stipe fuscous or
jet-black, only slightly expanded below, much shorter than the
columella; hypothallus scanty or none; columella lessening upward,
sometimes attaining the apex of the sporangium, sometimes dissolved in
capillitial threads some distance below; capillitium of rich brown
threads forming the usual inner network of medium density, with many
wide expanded nodes, the surface net made up of delicate, almost
colorless threads surrounding small polygonal meshes; spore-mass
ferruginous, spores by transmitted light very pale, brownish, minutely
warted, 7-9 µ.

The plasmodium of this species is variously cited from white to yellow.
Probably each report is true, dependent on the relative time of the
observation.

The low tufts of brown sporangia with short black stipes, borne often as
Dr. Peck found them, assembled on living leaves, distinguish this little
species. In the former edition this form was tentatively enrolled under
_S. axifera_ (Bull.); but see further under that species.

Probably widely distributed, but confused with short forms of other
species; sometimes also on rotten wood or other substratum; so reported.

New York to Iowa; Washington and Oregon. Reported also from Europe.


=3. Comatricha= (_Preuss_) _Rost._

  1851. _Comatricha Preuss_, _Linnaea_, XXIV., p. 140.
  1873. _Comatricha_ Rostafinski, _Versuch_, p. 7.

Sporangia cylindric or globose, stipitate; stipe prolonged upward to
form a more or less extended and tapering columella bearing branches on
every side, which by repeated divisions and reunions form the
capillitium; ultimate branch-tips free, not supporting a surface net
parallel to the peridial wall; peridium evanescent, perhaps sometimes
not developed at all.

The genus _Comatricha_ was set off from _Stemonitis_ by the joint effort
of Preuss (1851) and Rostafinski (1873-5). Preuss included in his genus,
_Comatricha_, alien forms, and besides failed to give an accurate
definition; included, however, in his list some species which have since
been known by his generic name.

The distinction between the two genera is almost an artificial one, and
species are sometimes arbitrarily assigned to one genus or the other.
The diagnosis in any case turns upon the presence or absence of a
surface net, formed, in _Stemonitis_, by the anastomosing of the
ultimate divisions of the capillitial branches. In _Comatricha_ the
anastomosing is general, from the columella out, and is not specialized
at the surface.

Recent attempts to reunite the genera here compared seem to result in no
apparent advantage. The genera come very near together, but their
separation along the line suggested by Rostafinski remains convenient.


=Key to the Species of Comatricha=

  _A._ Sporangia closely clustered.

     _a._ Obovate or short cylindric.

          1. Spores verruculose                       1. _C. caespitosa_

          2. Spores reticulate                        2. _C. cylindrica_

     _b._ Elongate, reddish-brown, tufts extended       3. _C. flaccida_

  _B._ Sporangia scattered more or less widely.

     _a._ Capillitium lax, open.

          i. Sporangia long, 10-12 mm.                     4. _C. longa_

         ii. Sporangia shorter, capillitium
               irregular                             5. _C. irregularis_

     _b._ Capillitium dense.

          i. Sporangia large, to 10 mm., spore-mass
               black                                  7. _C. suksdorfii_

         ii. Sporangia smaller--6 mm.

              O Spore-mass brown, spherical,
                  conoidal, etc., generally with
                  more or less lengthened stipe            8. _C. nigra_

             OO Spore-mass violaceous or purplish       9. _C. aequalis_

        iii. Sporangia ovate or cylindric, minute,
               to 3.5 mm.

              O Cylindric, spore with few,
                  scattered warts                     10. _C. typhoides_

             OO Smaller, capillitium irregular,
                  loose                                     6. _C. laxa_

            OOO Total height to 2 mm. or much less.

                 + Columella digitately divided         11. _C. elegans_

                ++ Columella lamprodermoid, and on
                     leaves                              12. _C. rubens_

               +++ Columella stemonitoid              13. _C. pulchella_

              ++++ Columella furcate at tip             14. _C. ellisii_

             +++++ Columella almost percurrent.   15. _C. subcaespitosa_


1. COMATRICHA CÆSPITOSA _Sturgis._

PLATE XI., Figs. 12, 13, 14.

  1893. _Comatricha caespitosa_ Sturg., _Bot. Gaz._, XVIII., p. 186.
  1894. _Diachaea thomasii_ Rex, var., List., _Mycetozoa_, p. 92.
  1899. _Comatricha caespitosa_ Sturg., Macbr., _N. A. S._, p. 124.
  1911. _Diachaea caespitosa_ Lister, _Mycetozoa, 2nd ed._, p. 121.

Sporangia densely crowded or cespitose, sub-sessile or short stipitate,
clavate, 1-1.5 mm. high, the peridium gray, iridescent with blue tints,
comparatively permanent but finally disappearing; columella attaining
two-thirds to three-fourths the height of the sporangium, giving rise
throughout its length to the dense blackish capillitium; hypothallus
delicate, inconspicuous; capillitium, the main branches thick at the
point of origin, frequently anastomosing, and becoming gradually thinner
toward the surface of the sporangium, the tips pointed, free, forming
the network; spores blackish-violet in mass, by transmitted light pale
brownish-violet, rough, 9.5-13 µ.

A very distinct and curious species. The sporangia are densely crowded,
though by the nature of habitat somewhat tufted. The shape of the
individual sporangium is quite uniformly clavate or obovate, decidedly
truncate above. The spores are uniformly verruculose and plainly
unequal.

This species, as indicated, was by its author described as a comatricha.
To transfer it to another genus seems idle, especially when long
established generic boundaries must be seriously disturbed expressly to
admit the new arrival.

New England, North Carolina, on moss and lichens.--_Dr. Sturgis._


2. COMATRICHA CYLINDRICA (_Bilgram_) _Macbr._

  1905. _Diachaea cylindrica_ Bilgram, _Proc. Acad. Nat. Sci. Philad._,
           524.
  1911. _Diachaea cylindrica_ Bilgram, List., _Mycetozoa, 2nd ed._,
           p. 121.

Sporangia cylindrical with obtuse apex, sessile, gregarious,
iridescent, steel-gray or bronze, 1 to 1.7 mm. high, .5 to .65 mm.
thick; hypothallus whitish, rugose; sporangium-wall membranous, hyaline,
not adhering to the capillitium; columella arising from the hypothallus
and extending nearly to the apex, brown, very light and semi-translucent
near the base, irregular, flexuous, limeless throughout; capillitium
brown, radiating from the columella to the periphery, repeatedly
branching and anastomosing; spores warted, the warts connected by ridges
forming a more or less perfect, coarse reticulation, violaceous, pale,
10-12 µ.

This is a very interesting species closely related to the preceding from
which it differs chiefly in the reticulation and generally more uniform
character of the spores. The author hesitated about the generic
reference, finally referring it to _Diachaea_ despite the lack of
calcium, because it was sessile and had a peridium rather more
persistent than is usual in comatrichas. But the presence of lime in
stipe and columella is an essential element in the diagnosis of
_Diachaea_, while length of stem is everywhere variable in stipitate
forms of every genus, and the persistence of the peridium is also an
uncertain factor; hangs on long in _C. typhoides_, _e. g._

On dead twigs, etc.--Philadelphia,--_Mr. Bilgram_; New Hampshire.


3. COMATRICHA FLACCIDA _List._

  1894. _Comatricha flaccida_ List., Morg., _Jour. Cin. Soc._, p. 51.
  1894. _Stemonitis splendens_, var. _flaccida_ List., _Mycetozoa_,
           p. 112.
  1894. _Comatricha flaccida_ (List.) Morg., Macbr., _N. A. S._, p. 133.
  1911. _Stemonitis splendens_, var. _flaccida_ List., _Mycetozoa,
           2nd ed._, p. 146.

Sporangia semi-erect, close crowded in tufts two inches in diameter,
ferruginous, from a dark brown hypothallus, sessile or short stipitate;
columella weak, crooked, percurrent, generally enlarged irregularly at
the apex; capillitium of few, slender, brown branches which anastomose
sparsely and irregularly as in _C. irregularis_, and present when freed
from spores the same chenille-like appearance; spore-mass ferruginous
brown; spores by transmitted light bright reddish brown, minutely
warted, 8-10 µ.

"Growing on old wood and bark of Oak, Willow, etc. The component
sporangia 5-10 mm. in length. The early appearance is much like that of
a species of _Stemonitis_, but the mature stage is a great mass of
spores with scanty capillitium, as in _Reticularia_; the columellas,
however, are genuine and not adjacent portions of wall grown
together."--_Professor Morgan._

Professor Morgan's herbarium material is at hand for study. It meets his
description, needless to say, very generally. In what remains of the
type the membranous connections are obscure; in fact the relation of
such peridial (?) fragments to the capillitium in any way, is no longer
evident. But in any event the colony does not impress one as something
prematurely or improperly developed, a stemonitis gone begging;--nothing
of that kind; it is clearly a comatricha, easily identifiable with no
trace of a surface net but, with long free tips in plenty.

Misled no doubt, by the peridial fragments referred to, Mr. Lister in
_Mycetozoa, l. c._, associated this with _S. confluens_ Cke. & Ell., but
entered it as a variety of _S. splendens_ Rost., just the same. In the
second edition of the _Monograph_, Ellis' species is set out, but
Morgan's retains the old position.

In light of present knowledge, the relationship suggested would be
difficult of proof. If _C. flaccida_ Morgan be related to the
_splendens_ group at all, it must be with the form known as _S. webberi_
Rex., but it differs from this in almost every particular. It has no
net, with meshes uniform or diverse; it is clear brown in color, with a
tinge of red, beneath the lens; the spores are smaller, distinctly
warted and with the reddish tinge of the capillitium; and in short, it
seems to be a comatricha and not a stemonitis.

Specimens from western Washington differ in some particulars but are
apparently the same thing.

Ohio, Kentucky, Washington, California; not common.


4. COMATRICHA LONGA _Peck._

PLATE VI., Figs. 2, 2 _a_, 2 _b_.

  1890. _Comatricha longa_ Peck, _Rep. N. Y. Mus._, XLIII., p. 24.

Sporangia crowded in depressed masses or tufts, black, long, cylindric,
even, stipitate; stipe black, shining, generally very short;
hypothallus well developed, black; columella black, slender, weak,
generally dissipated some distance below the apex; capillitium of
slender brown or dusky threads anastomosing to form an open network next
the columella, but extended outwardly in form of long free slender
branchlets, now and then dichotomously forked; spore-mass blue-black,
spores by transmitted light dark brown, globose, spinulose, some of them
faintly reticulate, about 9 µ.

A very remarkable species. Rare in the west, more common, as it appears,
in the eastern states. The sporangia occur in tufts about 1 or 2 cm.
wide, springing generally from crevices in the bark of decaying logs,
especially willow and elm, in swampy places. The sporangia are
remarkable for their great length. Generally about 20-25 mm., specimens
occasionally reach 50 mm.! The capillitial branches are so remote that
the spores are scarcely retained by the capillitium at all. Well
described and figured by the author of the species, _Forty-third Rep. N.
Y. State Museum_, p. 24, Pl. 3.

New York, Pennsylvania, Ohio, Iowa.


5. COMATRICHA IRREGULARIS _Rex._

  1891. _Comatricha irregularis_ Rex, _Proc. Phil. Acad._, p. 393.

Sporangia crowded in flocculent tufts, very dark brown or black,
semi-erect or drooping, 4-5 mm. in height, irregularly cylindric,
variable, stipitate; stipe black, distinct, often one-half the total
height; hypothallus well developed, brown, shining; columella central,
slender, flexuous, reaching the apex, where it blends, by branching,
with the capillitium; capillitium loose, open, composed of arcuate
threads which radiate from the columella, and are joined together,
forming a central, irregular reticulation of large meshes, brown, paler
toward the surface, where the free ends are sometimes colorless;
spore-mass black, spores by transmitted light brown, minutely warted,
7-8 µ.

Related, no doubt, to _C. longa_, but differing in habit, stature, as in
texture and structure of the capillitium. In _C. longa_ the inner net is
extremely simple,--a row or two of meshes at most, and the radiating
branches are long and straight; in the species before us the inner
network is well developed, and the radiating branches proportionately
shorter and abundantly branching, with pale or white free tips.

Generally, though not always, found growing in the crevices of the bark
on fallen logs of various deciduous trees. September. Not common.

This is thought to be _C. crypta_ Schw., _N. A. F._, 2351; but the
description under that number does not make clear what form Schweinitz
had before him, the present species or _C. longa_, and the herbarium
specimen of Schweinitz is "utterly lost"; the later specific name is
accordingly adopted.

New England west to the Cascade Mountains; south to Kansas and Texas.


6. COMATRICHA LAXA _Rostafinski._

PLATE V., Figs. 5, 5 _a_.

  1875. _Comatricha laxa_ Rost., _Mon._, p. 201.
  1877. _Lamproderma ellisiana_ Cooke, _Myx. U. S._, p. 397.
  1891. _Comatricha ellisiana_ (Cooke) Ell. & Ev., _N. A. F._, 2696.

Sporangia scattered, gregarious, sub-globose or short cylindric, and
obtuse, dusky stipitate; stipe short, black, tapering rapidly upward
from an expanded base; hypothallus scant or none; columella erect,
rigid, sometimes reaching nearly to the apex of the sporangium,
sometimes dichotomously branched a little below the summit, before
blending into the common capillitium; capillitium lax, of slender,
horizontal branches, anastomosing at infrequent intervals and ending in
short, free tips; spores pallid, nearly smooth, 7-9.5 µ.

A very minute, delicate little species, about 1½ mm. high; the stipe
half the total height. In general appearance the shorter forms of the
species resemble slightly _C. nigra_, but are distinguished by a much
shorter stipe and much more open capillitium. The sporangia of _C.
nigra_ mounted on long capillary stipes always droops more or less; the
sporangia of the present species stand rigidly erect. The sporangia vary
in form and in the branching of the columella. In the more globose
phases, the columella almost always shows a peculiar dichotomy near the
apex; in the cylindric types, this peculiar division fails.[36] In fact,
the shape is determined chiefly by the mode of branching as affects the
columella. Rostafinski's figure, on Tab. XIII, does not present the
type usually seen in this country, nor even in Europe if we may judge
from later illustrations.

The species with us has received various names, but so far as can be
determined, all apply to the same thing, and comparison of specimens
from Mr. Ellis with those from Europe show the correctness of the
nomenclature here adopted.

Rare, but widely distributed; across the continent.


7. STEMONITIS SUKSDORFII _Ell. & Everh._

PLATE XI., Figs. 9, 10, 11.

  1882. _Stemonitis suksdorfii_ Ell. & Everh., _Bull. Washb. Coll._,
           Vol. I., p. 5.
  1892. _Stemonitis suksdorfii_ Ell. & Everh., Mass., _Mon._, p. 76.

Sporangia scattered in small tufts or gregarious, cylindric, obtuse at
both ends, sometimes widened above, black, 2-6 mm., stipitate; stipe
jet-black, shining, even, about one-half the total height; hypothallus
not continuous, dark brown; columella black, rather slender, terminating
in two or more large branches just below the apex; capillitium
exceedingly dense, dark fuscous or black, the flexuous threads
anastomosing in a close network, with abundant free pallid extremities;
spores in mass, blue-black, by transmitted light fuscous or dark
violaceous-brown, minutely warted, 10-12 µ.

Easily recognizable at sight by its sooty color. Entirely unlike any of
the preceding. The type of the capillitium is that of _C. pulchella_,
but it is very much more dense and entirely different in color. The
sporangia are often widened above, and fairly truncate; the total height
about 6 mm. Found on the bark of fallen twigs of _Abies, Larix_, etc.
Distributed by Ell. & Everh. under this name as an _exsiccata_. The
evanescent peridium is colorless; when free, white or silvery.


8. COMATRICHA NIGRA (_Pers._) _Schroeter._

PLATE XI., Figs. 1, 2, 3.

  1791. _Stemonitis nigra_ Pers., Gmel., _Syst. Nat._, p. 1467.
  1801. _Stemonitis ovata_, var. _nigra_ Pers., _Syn._, p. 189.
  1863. _Stemonitis friesiana_ DeBy., _Rab. Eur. Fung._, No. 568.
  1875. _Comatricha friesiana_ (DeBy.) Rost., _Mon._, p. 200.
  1889. _Comatricha nigra_ (Pers.) Schroeter, _Pilz. Krypt. Fl.
           v. Schles._, I., p. 118.
  1894. _Comatricha obtusata_ Fr., Lister, _Mycetozoa_, p. 117.
  1899. _Comatricha nigra_ (Pers.) Schroeter, Macbr., _N. A. S._,
           p. 128.

Sporangia scattered, ferruginous or dark brown, globose or ovoid,
stipitate; stipe long, hair-like, tapering upward, black; hypothallus
none; columella rapidly diminished toward the top, at length dissipated;
capillitium of slender flexuous threads, radiating horizontally,
repeatedly branching and anastomosing to form an intricate dense
network, from the surface of which project a few short hook-like
peridial processes; spore-mass black, spores by transmitted light dark
violaceous, smooth or nearly so, 7-10 µ.

This species, when typical, is easily recognized by its almost globose
sporangia mounted on long slender stocks. These are 2 or 3 mm. high and
generally persist, as Persoon noticed, a long time after the sporangium
has fallen. The sporangia are at first black; after spore disposal pale
ferruginous. In shape they vary from ovate to spherical. Sometimes they
are umbilicate below, so that a vertical section would be obcordate.
Care must be taken to distinguish the present species from blown-out
forms of _Lamproderma_.

This most common species seems to be also the center of widest
differentiation. In a valuable paper on the Myxomycetes of Dr. C. H.
Peck's Herbarium Dr. Sturgis points out the varying relationships of a
group of surrounding forms. According to account _C. nigra_ verges on
one side to _C. laxa_, on the other to _aequalis_ which the Listers
enter as varietal here. However, in the former the more rigid, direct
and simple branching from the columella is usually determinative; in the
latter the color, form, and generally more delicate structure, and a
tendency to grow in tufts will serve to distinguish.

In this discussion we have assumed as typical the globose sporangium,
with the variations in the direction of ovate, obovate, ellipsoidal,
etc., the capillitium flexuous and more richly anastomosing near the
columella. On the drier slopes in the mountains of Colorado specimens
are especially abundant, in proper season covering apparently the lower
surface of every barkless twig or fallen stem or _tree entire_! In such
a field one might imagine every possible variation open to observation.
Probably such is the case; but as a matter of fact a single small
plasmodium at lower levels will sometimes show greater range of
variation than were noted on the mountain-side. The cylindric forms were
for some reason few, and when noted were short, though often surmounting
stems of double the usual length.

Rostafinski calls this _C. friesiana_, a name suggested by De Bary. By
this name the species was commonly known for many years. More recently
some writers prefer _C. obtusata_ Preuss; but _C. obtusata_ Preuss, as
figured by that author (Sturm's _Deutsch. Fl._, Pl. 70), is surely more
likely _Enerthenema papillata_, and the author says in his description
"capillitio vertice soli innato." Persoon certainly recognized the
species, and his description, though brief, is yet applicable to no
other European species. There seems no reason why the name he gave
should not be permanently adopted. Rostafinski's figure, Tab. XIII.,
shows an ellipsoidal sporangium, not cylindric.

On the lower levels of the Mississippi valley, the species is not
common. Possibly overlooked by reason of its minuteness.

Massachusetts, Pennsylvania, Ohio, Iowa, Colorado, North Carolina,
Missouri.


9. COMATRICHA ÆQUALIS _Peck._

PLATE VI., Figs. 3, 3 _a_, 3 _b_, 3 _c_, 3 _d_; and PLATE XVIII., Figs.
13, 13 _a_, 13 _b_.

  1890. _Comatricha equalis_ Peck., _Rep. N. Y. Mus._, XXXI., p. 42.

Sporangia gregarious, seldom erect, usually inclined, curved or nodding,
dark brown, becoming violet, cylindric, acuminate-obtuse, stipitate;
stipe about half the total height, 2-2½ mm., black, polished, even;
hypothallus well developed, brown, continuous; columella black, tapering
gradually, and attaining almost the summit of the sporangium;
capillitium dense, of flexuous tawny threads which, by repeated
branching, form an intricate network, the free extremities numerous,
short, and pale; spores dark violaceous, distinctly warted, 7.5-8 µ.

A very graceful, elegant species, related to _C. pulchella_ and _C.
persoonii_, but distinct by its much greater size and smaller spores.
The specimens before show us the perfection of beauty in this genus;
the polished stipe, the symmetrical capillitium, the soft purple-brown
tints, are remarkable, and enable one to recognize the form at sight.

Specimens from Oregon are unusually fine; larger than usual, reach 7 mm.
total height, and when blown out present the tints of violet in unusual
clearness; var. _C. pacifica_. Plate XVIII., Figs. 13, 13_a_, and 13_b_.

New York, Pennsylvania, Ohio, Illinois; Oregon, _Professor Peck._


10. COMATRICHA TYPHOIDES (_Bull._) _Rost._

PLATE VI., Figs. 1, 1 _a_, 1 _b_.

  1772. _Mucor stemonitis_ Scopoli, _Fl. Carn._, II., pp. 493-494 (?).
  1774. _Mucor stemonitis_ Schaeffer, _Icones. Tab._, CCXCVII (?).
  1780. _Stemonitis typhina_ Wiggers, _Prim. Fl. Hols._, p. 116 (?).
  1791. _Trichia typhoides_ Bulliard, _Champ. de la France_, p. 119,
           t. 477, II.
  1796. _Stemonitis typhina_ Persoon, _Myc. Obs._, I., p. 57, in part.
  1805. _Stemonitis typhoides_ (Bull.) D. C., _Fl. Fr._, p. 257.
  1829. _Stemonitis typhoides_ (Bull.) Fr., _Syst. Myc._, III., p. 158.
  1873. _Comatricha typhoides_ (Bull.) Rost., _Vers._, p. 7.
  1875. _Comatricha typhina_ (Pers.) Rost., _Mon._, p. 197.
  1895. _Comatricha stemonitis_ (Scop.) Sheldon, _Minn. Bot. Stud._,
           p. 473.
  1899. _Comatricha stemonitis_ (Scop.) Sheld., Macbr., _N. A. S._,
           p. 130.
  1911. _Comatricha typhoides_ Rost., List., _Mycetozoa, 2nd ed._,
           p. 157.

Sporangia gregarious, scattered, cylindric, erect, sometimes arcuate,
obtuse, 2-3 mm. high, at first silvery, then brown, as the peridium
vanishes, stipitate; stipe black, about one-half the total height or
less; hypothallus distinct, more or less continuous, reddish-brown;
columella tapering upward, black, attaining more or less completely the
apex of the sporangium; capillitium, arising as rather stout branches of
the capillitium, soon taking the form of slender, flexuous, brownish
threads, which by repeated anastomosing form at length a close network,
almost as in _Stemonitis_, the free, ultimate branches very delicate and
short; spore-mass dark brown; spores by transmitted light, pale, almost
smooth, except for the presence of a few scattered but very prominent
umbo-like warts, of which four or five may be seen at one time, 5-7.5 µ.

This is our most common North American species. It occurs everywhere on
decaying wood, sometimes in remarkable quantity, thousands of sporangia
at a time. The plasmodium, watery white in color, infests preferably
very rotten logs of _Quercus_, on which in June the sporangia rise as
white or pallid columns. The peridium is exceedingly delicate, less
seldom seen here than in some other species, but likely to be overlooked
entirely. The spores when fresh have a distinct violet or bluish tinge;
in old specimens they are almost colorless. In any case they are well
marked by the large papillæ already referred to.

_C. typhina_, var. _heterospora_ Rex, differs from the type in several
particulars: the sporangia manifest a closer habit; the capillitium is
made up of more slender threads and forms a yet denser network; the
spores between the large papillæ are marked by a more or less perfectly
formed reticulation.[37]

As to nomenclature, this is our old friend _C. typhina_ (Pers.) Rost. It
should be, more properly, called _C. typhina_ Rost., for it is not
Persoon's species exactly. But Scopoli, _l. c._, by citing Hall,
Gleditsch, and Micheli, so describes our form as to leave small doubt
that he had before him our common species. Schaeffer's figures also come
to the rescue, which, though by no means satisfactory, yet can probably
refer to no other species. However, Bulliard gives the first good
account and figure, and in concord with the decision of our English
colleagues, the name afforded by the famous _Champignons_ is here
adopted.

Widely distributed. Maine to California, and from British America to
Nicaragua.


11. COMATRICHA ELEGANS (_Racib._) _List._

PLATE XVI., Fig. 12.

  1884. _Rostafinskia elegans_ Racib., _Rozpr. Akad. Krak._, XII., 77.
  1888. _Raciborskia elegans_ Berl., _Sacc. Syl._, VII., p. 400.
  1894. _Raciborskia elegans_ Berl., List., _Mycet._, p. 133.
  1909. _Comatricha elegans_ List., _Br. Mus. Guide to Mycet._, p. 31.

Sporangia loosely gregarious, globose, purplish-brown, small, 1-1.5 mm.
in total height, stipitate; stipe black, subulate, to 1 mm,; columella
at first divided into a few main branches, from which by repeated
subdivision the delicate, anastomosing, flexuose capillitial threads
take origin; spores pale brownish-violaceous, spinulescent, 8-10 µ.

South Carolina. Colorado:--_Dr. Sturgis._


12. COMATRICHA RUBENS _Lister._

  1894. _Comatricha rubens_ List., _Mycet._, p. 123.

Sporangia gregarious, globoid or ellipsoidal, 1-1.5 mm., pink-brown,
stipitate; peridium persistent below; stipe .5-1 mm., black, shining;
columella to more than half the sporangium, giving off on all sides the
brownish-violaceous, flexuose threads of the capillitium, somewhat
thickened and broadly attached to the persisting peridial cup; spores
lilac-brown, spinulescent, 7-8 µ.

Another border species, looking to the lamprodermas. Philadelphia, by
courtesy _Mr. Bilgram_.


13. COMATRICHA PULCHELLA (_Bab._) _Rost._

PLATE XIII., Fig. 4, and PLATE XII., Figs. 16 and 16 _a_.

  1837. _Stemonitis pulchella_ Bab., _Trans. Lin. Soc._, p. 32.
  1841. _Comatricha pulchella_ Bab., Berk., _Ann. Mag. Nat. Hist._,
           I. vi., p. 431, Pl. XII., 11. _a._ _b._
  1848. _Stemonitis tenerrima_ Curtis, _Am. Jour._, VI., p. 352.
  1873. _Stemonitis tenerrima_ Berk. & C., _Grev._, II., p. 69.
  1876. _Comatricha pulchella_ (Bab.) Rost., _Mon. App._, p. 27.
  1875. _Comatricha persoonii_ Rost., _Mon._, p. 201.
  1894. _Comatricha persoonii_ Rost., List., _Mycet._, p. 122.
  1899. _Comatricha pulchella_ (Bab.) Rost., Macbr., _N. A. S._, p. 129.
  1899. _Comatricha persoonii_ Rost., Macbr., _N. A. S._, p. 132,
          _excl. syn._
  1911. _Comatricha pulchella_ Rost., List., _Mycet., 2nd ed._, p. 156.
  1911. _Comatricha pulchella_ var. _gracilis_ Wing., List., _Mycet.,
           2nd ed._, p. 156.

Sporangia very minute, 1 mm. high, scattered, ovate or ovate-cylindric
acuminate, pale brown or ferruginous, stipitate; stipe short, black,
nearly even; hypothallus none, or merely a circular base to the tiny
stem; columella straight, gradually tapering, reaching almost if not
quite to the apex of the sporangium; capillitium dense, a network of
flexuous brown threads, rather broad within, ending in slender tips
without; spore-mass brown, spores by transmitted light pale "lilac
brown," or pale ferruginous, minutely but uniformly warted, 6-8 µ.

Probably widely distributed but rarely collected. Pennsylvania, Iowa;
_Okoboji_. Toronto,--_Miss Currie._


14. COMATRICHA ELLISII _Morg._

PLATE XII., Figs. 15 and 15 _a_.

  1894. _Comatricha ellisii_ Morg., _Jour. Cin. Soc._, p. 49.
  1899. _Comatricha laxa_ Rost., Macbr., _N. A. S._, p. 127.
  1911. _Comatricha nigra_ Schroet., List., _Mycet., 2nd ed._, p. 152.

Sporangia short, erect, oval or ovoid to oblong. Stipe and columella
erect, brown and smooth, rising from a thin pallid hypothallus, tapering
upward and vanishing into the capillitium toward the apex of the
sporangium, the stipe usually longer than the columella. Capillitium of
slender pale brown threads; these branch several times with lateral
anastomosing branchlets, forming a rather open network of small meshes,
ending with very short free extremities. Spores globose, even, pale
ochraceous, 6-7 mic. in diameter.

Growing on old pine wood. Sporangium .3-.6 mm. in height by .3-.5 mm. in
width, the stipe usually a little longer than the sporangium.

On the strength of the clear descriptions and beautiful drawings of
Celakowsky, _Myxomyceten Böhmens_, p. 52; Taf. 2, Figs. 7 and 8, this
elegant little species as described by my colleague Professor Morgan
was, in the former edition, referred to _C. laxa_ Rost. It was then
reported from New Jersey only. Since then we have specimens from Ohio
and from southern Missouri, all true to form, almost identical. It seems
wise accordingly, while recognizing the relationship of the form to both
_C. laxa_, and to _C. nigra_ as well, to give it here an individual
place again. It is very small; but once studied may thereafter be easily
recognized by a hand-lens. The form is definite, clean-cut, and the
spores are pronouncedly smaller than in either of the two related
species.


15. COMATRICHA SUBCAESPITOSA _Peck._

PLATE XII., Figs. 17, 17 _a_.

  1890. _Comatricha subcaespitosa_ Peck, _N. Y. Mus. Rep._ 43, p. 25.

Sporangia scattered or sometimes in loose clusters, cylindric, obtuse,
about 1.5-2 mm., dark brown, stipitate; stipe short, one-fifth total
height; hypothallus minute; capillitium regular, the branching quite
uniform parallel, flexuous, brown with a tinge of violet, not dense;
columella well-defined, almost percurrent; spores brown in mass, under
lens dusky, nearly smooth, 9-10 µ.

The larger spores, regular, erect form, and clustered habit separate
this form from others with which it will be naturally associated. See
page 283 under _Addenda_.


=4. Diachæa= _Fries_

  1825. _Diachaea_ Fries, _Syst. Orb. Veg._, I., p. 143.[38]

Sporangia distinct, globose or cylindric, the peridium thin, iridescent,
stipitate; the stipe and columella surcharged with lime, white or
yellowish, rigid, thick, tapering upward; capillitium of delicate
threads free from lime, radiating from various points on the columella,
branching and anastomosing as in _Comatricha_ to form a more or less
intricate network, the ultimate branchlets supporting the peridial wall.

Rostafinski placed this genus near the _Didymieae_ on account of the
calcareous columella and the non-calcareous capillitium. On the other
hand the structure of the capillitium and the iridescent simple peridium
ally _Diachaea_ to _Lamproderma_ and the _Stemoniteae_; the only
distinction being the calcareous stem. It is simply an intermediate
genus to be placed here more conveniently than anywhere else in what is
of necessity a linear arrangement.


=Key to the Species of Diachæa=

  _A._ Stipe and columella white.

     _a._ Sporangium cylindric                        1. _D. leucopodia_

     _b._ Sporangium globose.

          i. Evidently stalked                         2. _D. splendens_

         ii. Stalk very short, 5 mm., conic.

              O Spores warted                         3. _D. bulbillosa_

             OO Spores faintly netted                4. _D. subsessilis_

  _B._ Stipe yellowish or orange                        5. _D. thomasii_


1. DIACHAEA LEUCOPODIA (_Bull._) _Rost._

  1791. _Trichia leucopodia_ Bull., _Champ. de la France_, Pl. 502,
           Fig. 2.
  1825. _Diachaea elegans_ Fries, _Syst. Orb. Veg._, I., p. 143.
  1875. _Diachaea leucopoda_ (Bull.) Rost., _Mon._, p. 190.

Sporangia rather closely gregarious, metallic blue or purple iridescent,
cylindric or ellipsoidal, obtuse, sub-umbilicate below, stipitate; stipe
short, much less than one-half the total height, snow-white, tapering
upward; hypothallus white, venulose, occurring from stipe to stipe to
form an open network over the substratum; columella thick, cylindric,
tapering, blunt, terminating below the apex, white; capillitium
springing from every part of the columella, of slender threads, brown,
flexuous, branching and anastomosing to form an intricate net; spores in
mass nearly black, by transmitted light dull violaceous, minutely
roughened, 7-9 µ.

A very beautiful species; not uncommon in the eastern states; rare west
of the Mississippi. Easily recognized, amid related forms, by its
snow-white stem, a feature which did not escape the notice of Bulliard
and suggested the accepted specific name. Fries adopted the specific
name proposed by Trentepohl and wrote _D. elegans_, simply because to
him the peridium was "admodum elegans."

The peridium is exceedingly thin and early deciduous; the stipe long
persistent. The plasmodium, dull white, was observed by Fries at the
beginning of the century; "morphoseos clavem inter myxogastres hoc genus
primum mihi subministravit."

This species, as the diachæas generally, affects fallen sticks and
leaves in orchards and forests and even spreads boldly over the foliage
and stems of living plants.

New England, New York, Pennsylvania, Maryland, Virginia, South Carolina,
Ohio, Iowa, California, Canada.


2. DIACHAEA SPLENDENS _Peck._

PLATE VII., Figs. 1, 1 _a_, 1 _b_, 1 _c_.

  1877. _Diachaea splendens_ Peck, _Rep. N. Y. Mus._, XXX., p. 50.

Sporangia gregarious, metallic blue with brilliant iridescence, globose,
stipitate; stipe white, short, tapering upward; hypothallus white,
venulose, a network supporting the snowy stipes; columella white,
cylindric, passing the centre, obtuse; capillitium lax, of slender,
anastomosing, brown, translucent threads; spores in mass black, by
transmitted light dark-violaceous, very coarsely warted, 7-10 µ.

This is perhaps the most showy species of the list. The globose
brilliantly iridescent sporangia are lifted above the substratum on
snow-white columnar stalks; these are again joined one to another by the
pure white vein-like cords of the reticulate hypothallus. The plasmodium
may spread very widely over all sorts of objects that come in the way,
dry forest leaves and sticks, or the fruit and foliage of living plants.
Closely resembling the preceding, but differing in the globose
sporangia, it may be instantly recognized under the lenses by its
coarsely papillate spores.

Not common. New York, Pennsylvania, Ontario, Ohio, Iowa, Nebraska.


3. DIACHAEA SUBSESSILIS _Pk._

  1879. _Diachaea subsessilis_ Pk., _Rep. N. Y. Mus. Nat. History_,
           XXXI., p. 41.
  1894. _Diachaea subsessilis_ Pk., Lister, _Mycetozoa_, p. 92.

Sporangia gregarious or closely crowded, small, about .5 mm., dull
iridescent-blue, greenish-gray, etc., globose or depressed-globose,
short-stalked or nearly sessile; stipe generally very short, reduced
sometimes to a mere persistent cone, white; columella obsolescent or
reduced to white conical intrusion of the stipe; capillitium radiating
from the stipe, brown, consisting of branching, anastomosing threads,
paler at the tips; hypothallus very scanty or none; spores minutely
warted, the papillæ arranged in an irregular, loose net-work,
violet-brown, paler under the lens, 10-12 µ.

This species is easily recognizable by its diminutive size and generally
defective structure; i. e. it has the appearance of a degenerate or
depauperate representative of some finer form. Besides the type, yet to
be seen in Albany, Dr. Sturgis reports the species from Connecticut and
from the Isle of Wight! A small gathering is before me from Colorado.
Every sporangium is borne upon a calcareous pedicel, very short indeed,
but real. The _var. globosa_ referred to in the English text under _D.
leucopodia_ has not appeared so far as reported, on this side the sea,
but even such variety could scarcely in the hands of a collector take
the place of the form now under consideration.

Specimens of _D. subsessilis_ from Europe correspond remarkably with
those described by Drs. Peck and Sturgis. Mr. Lister would have our
species a synonym for _Lamproderma fuckelianum cracovense_ (Rost.) Cel.

Rare; from Connecticut to Colorado.


4. DIACHÆA BULBILLOSA (_Berk. & Br._) _List._

  1873. _Didymium bulbillosum_ Berk. & Br., _Jour. Linn. Soc._, XIV.,
           p. 84.
  1898. _Diachaea bulbillosa_ Lister, _Jour. Bot._, XXXVI., p. 165.
  1911. _Diachaea bulbillosa_ Lister, _Mycetozoa, 2nd ed._, p. 119.

Sporangia gregarious, globose, small, iridescent purple, stipitate;
stipe conical, white, sometimes brown, half-a-mm., half the total
height; columella clavate, white or brown; capillitium of purple-brown
threads united to form a lax net; spores violet-grey, marked with
scattered warts "6-8 in a row across the hemisphere", 7-9 µ.

Java, _Berkeley & Broome, op. c._ Toronto, Canada; cited here by
courtesy of Miss Currie who gives the spores 7.8 µ.


5. DIACHAEA THOMASII _Rex._

PLATE V., Fig. 6, 6 _a_.

  1892. _Diachaea thomasii_ Rex, _Proc. Phil. Acad._, p. 329.

Sporangia gregarious, more or less crowded, purple and bronze,
iridescent, globose sessile or short stipitate; stipe, when present,
very short, thick, tapering rapidly upward, orange; hypothallus orange,
prominent venulose, continuous; columella ochre yellow, rough,
cylindric, tapering upward to one-half the height of the sporangium,
obtuse; capillitium lax, of slender brown rigid threads, radiating from
the columella in every direction, anastomosing to form a loose,
large-meshed network; spore-mass brown; spores by transmitted light
violaceous, minutely, unevenly warted, 10-12 µ.

The peculiar orange color of the calcareous deposits in stipe and
columella easily distinguish this species. The capillitium is also
distinctive, rigid, simple, and comparatively scant, lamprodermoid. Rex
calls attention to the fact that under low magnification the spores
appear spotted; but the spots are occasioned simply by the closer
aggregation, at particular points, of the ordinary papillæ.

A southern species. All the specimens so far reported are from the
mountains of North Carolina.

The specimens referred to under this name by Lister, _Mon._, p. 92, as
coming from "Kittery, U. S. A." (Kittery, Maine?), are, no doubt,
according to Mr. Lister's figures, _Comatricha caespitosa_ Sturgis. See
under that species.


_C._ LAMPRODERMACEÆ

Sporangia distinct, generally gregarious, more or less spherical;
capillitium developed chiefly or solely from the summit of the
columella.


=Key to the Genera of the Lamprodermaceæ=

  _A._ Columella percurrent; capillitium from a disk
         at the apex                                      1. ENERTHENEMA

  _B._ Columella scarce reaching the centre of the
         sporangium.

     _a._ Capillitium not forming a net                   2. CLASTODERMA

     _b._ Capillitium forming an intricate net            3. LAMPRODERMA

     _c._ Minute, capillitium rudimentary               4. ECHINOSTELIUM

=1. Enerthenema= _Bowman_

  1828. _Enerthenema_ Bowman, _Trans. Linn. Soc._, XVI., p. 152.

Sporangia stipitate, the stipe extended as a columella, which entirely
traverses the sporangium and forms at the apex an expanded disk; from
this depends the capillitium.


=Key to the Species of Enerthenema=

  _A._ Spores free                                    1. _E. papillatum_

  _B._ Spores in clusters                           2. _E. berkeleyanum_


1. ENERTHENEMA PAPILLATUM (_Pers._) _Rost._

PLATE V., Fig. 3.

  1801. _Stemonitis papillata_ Pers., _Syn._, p. 188.
  1828. _Enerthenema elegans_ Bowm., _Trans. Linn. Soc._, XVI., p. 152.
  1862. _Comatricha obtusata_ Preuss, Sturm, _Deutschl. Flora_, Pl. LXX.
  1876. _Enerthenema papillatum_ (Pers.) Rost., _Mon. App._, p. 28.

Sporangia scattered or crowded, stipitate, spheroidal, naked, black
fuscous, above, shining, adorned with a minute, black papilla; stipe
black, opaque, conical or attenuate upward, about equal to the peridium;
columella at the apex expanded into a shining disk; capillitium
springing from the lower side of the disk or from its edge, made up of
scarcely forked threads which are free below; spores violaceous or
fuscous black, minutely warted, 10-12 µ.

Rare. Wisconsin, Ohio, South Carolina, Illinois, Pennsylvania, Iowa,
Colorado.

This is one of the few species so well marked that Persoon's
description, _l. c._, is definitive: "Stylidio toto penetrante.
Capillitium exacte globosum, sub-compactum, in eius apice stylidium
papillæ in modum prominet." For this reason Bowman's specific name
_elegans_ is discarded.


2. ENERTHENEMA BERKELEYANUM _Rost._

  1876. _Enerthenema berkeleyanum_ Rost., _Mon. App._, p. 29.
  1913. _Enerthenema syncarpon_ Sturgis, _Myxo. Col._, II., p. 448.

This species corresponds to the preceding in all respects except in the
fact that the spores are clustered in groups of four to twelve and are a
little larger, 11-13 µ, strongly spinulose on the exposed surface.

Dr. Sturgis reports this from Colorado, _l. c._, but discards
Rostafinski's specific name on the ground that the type has disappeared;
only the spores of some fungus hyphæ remain in the place and these may
have been mistaken by Berkeley. This seems hardly possible since such
supposition would not account for the generic reference either by
Berkeley (and Broome) or by Rostafinski. The description in the
_Monograph_ is minute as that of one who had the form under his lenses.
Rostafinski _saw_ Berkeley's specimens.

For a similar case, see under _Prototrichia metallica, Mycetozoa 2nd
ed._, p. 261.

South Carolina, type; Colorado.


=2. Clastoderma= _Blytt_

  1880. _Clastoderma_ Blytt, _Bot. Zeit._, XXXVIII., p. 343.

Sporangium globose, distinct, stipitate; the columella short or
obsolete; the capillitium of few sparsely branched threads, which bear
at their tops the persistent fragments of the peridium, but are not
otherwise united.

Distinguished from _Lamproderma_ by the peculiar manner in which the
peridium is ruptured, and by the simplicity of the scanty capillitium.
So far there appears to be but a single species.


1. CLASTODERMA DEBARYANUM _Blytt._

PLATE XIII., Fig. 6, and PLATE XVI., Fig. 13.

  1880. _Clastoderma debaryanum_ Blytt, _Bot. Zeit._, XXXVIII., p. 343.
  1886. _Orthotrichia microcephala_ Wing., _Jour. Myc._, II., p. 126.

Sporangia scattered or gregarious, very minute, 1-12 to ¼ mm. in
diameter, the peridium fugacious, except the minute patches that adhere
to the capillitial branchlets, and the slight annulus at the base of the
columella; stipe long, unequal, dark below, above paler; columella
almost none, giving early rise to the comparatively few slender threads
which by their repeated forking make up the capillitium; spores globose,
even, violaceous, 8-9 µ.

Reported in the United States so far from Maine, Pennsylvania, Ohio, and
Illinois.

The sporangia are very small, but beautiful, delicate little structures,
found on the bark of living red oak in this country; in Norway it seems
to have been seen first on a dead polyporus. Its minuteness doubtless
causes it to be generally overlooked, _N. A. F._, 2498.


=3. Lamproderma= _Rostafinski_

  1873. _Lamproderma_ Rostafinski, _Versuch_, p. 7.

Sporangia stipitate, globose, or ellipsoid; columella cylindric or
inflated or clavate at the apex, scarcely attaining half the height of
the peridium; peridium shining with metallic tints, deciduous, except
where, at the base of the columella, it forms a ring around the stipe;
capillitium rising in tufts or by simple branches from the columella,
the threads regularly forked, generally united into a net.

The lamprodermas are distinguished from the comatrichas, to which they
are most nearly allied, by the arrangement of the capillitium, its
development from the apex only of the columella, the continuation of the
stipe within the peridium. In other words, the peridium leaves the stipe
some distance below the point where the lowest capillitial branches take
origin. In mature specimens the peridium has often entirely disappeared,
its only trace, a collar, more or less distinct, around the stipe,
marking the beginning of the columella. Nevertheless the peridium is far
more persistent than in any comatricha, and shows in yet greater
brilliancy the wondrous metallic tints and iridescence of _Comatricha_
and _Diachaea_. Older authors, so far as can be seen, distributed the
species between _Physarum_ and _Stemonitis_.


=Key to the Species of Lamproderma=

  _A._ Peridium metallic blue.

    _a._ Stipe short, stout.

      1. Capillitium tips colorless                    5. _L. violaceum_

    _b._ Stipe long, slender.

      1. Capillitium of dark, tapering, oft-united
           threads                                    3. _L. columbinum_

      2. Capillitial threads rigid, dark brown,
           seldom united                             4. _L. scintillans_

  _B._ Peridium not blue, silvery.

    _a._ Stipe long, slender.

      1. Capillitium very intricate, forming a
           compact net                               6. _L. arcyrionema_

      2. Capillitium of rigid dark brown threads     1. _L. physaroides_

    _b._ Stipe short, heads large, 1 mm. or more        2. _L. robustum_


1. LAMPRODERMA PHYSAROIDES (_Alb. & Schw._) _Rost._

  1805. _Physarum physaroides_ Alb. & Schw., _Consp. Fung._, p, 103.
  1875. _Lamproderma physaroides_ (Alb. & Schw.) Rost., _Mon._, p. 202.

Sporangia gregarious, wide-spreading, globose, the peridium persistent
with a silver metallic, sometimes brassy, lustre; stipe long, brown or
black, tapering upward; hypothallus well developed, brown or purple,
usually not continuous; columella swollen, obtuse, short at best, hardly
attaining the centre of the sporangium; capillitium very rigid, of
simple or sparingly branched, dark-brown threads radiating from the
clavate apex of the columella and only here and there anastomosing
toward the surface, the ultimate divisions distinctly rough; spores
lilac brown, rough, 10-12.5 µ.

This species is well described and illustrated in Rostafinski's
_Monograph_. It is well marked by its clavate columella and peculiarly
simple, dark rigid capillitium, the branches of which rise in great
numbers immediately from the columella, and maintain their primitive
thickness during the greater part of their length. The transverse
vincula are often at right angles to the principal branches, and the
meshes, where formed, are often long and rectangular. Externally, it
resembles _L. arcyrionema_, but is by its spores and capillitium
instantly distinguished. Rostafinski gives the spores 12.5-14.2 µ. Large
spores are less common in the specimens before us. Lister figures a
sessile variety.

In our first edition this species was entered from lists published for
New England, New York, and Ohio. The intervening years, however, have
brought no confirmation. Specimens from Maine and Ohio, with large
spores, represent _L. columbinum_, and those cited for New York are
forms of _L. violaceum_. It is accordingly doubtful that _L.
physaroides_ (A. & S.) Rost. occurs in North America. That it is to be
found in Europe there seems no doubt. The figure and description by
Schweinitz, _l. c._, may indeed be inconclusive, but Rostafinski's
citation and abundant description leave no doubt as to his opinion;
while numerous localities named would indicate adequate material. What
Rostafinski described will no doubt obtain wider recognition some day.


2. LAMPRODERMA ROBUSTUM _Ell. & Evh._

  1892. _Lamproderma robustum_ Ell. & Evh., Mass., _Mon._, p. 99.
  1894. _Lamproderma violaceum_ var. _sauteri_ Rost., List.,
          _Mycetozoa_, p. 129.
  1899. _Lamproderma sauteri_ Rost., Macbr., _N. A. S._, p. 140.

Sporangia gregarious, globose, dull black, the peridium when present
silvery, shining, or simply smooth, transparent and without
iridescence, stipitate; stipe short, black, tapering rapidly upward,
annulate with the persisting base of the peridium; columella short,
thick, truncate, and widened at the top; hypothallus well developed,
brown or purple; capillitium dense, made up of dark brown branches,
numerous and rather slender, repeatedly branched and anastomosing toward
the surface to form a slight delicate network with abundant free ends;
spores dark purple brown, rough, 14-16 µ.

This species in outward appearance resembles _L. physaroides_, from
which it is easily distinguished by the much greater diameter of the
globose sporangium, 1 mm. or more. The persistent base of the peridium
is also characteristic, very prominent sometimes, and visible to the
naked eye. The capillitium is also unlike that of _L. physaroides_;
resembles more nearly that of _L. violaceum_. From the latter species
_L. robustum_ is distinguished by the color of the peridium, and by the
larger, darker spores and generally different capillitium. In our former
edition this is called _L. sauteri_ Rost. That much-quoted author
distinguished _L. violaceum_ and _L. sauteri_; the English authors make
the last named a variety only of the former. This our American species
is _not_.

It is, as presented in our western mountains, clear-cut, well defined,
not a variety of anything. The original name is therefore restored.

_Lamproderma arcyrioides_ (Somm.) Morgan is probably a form of _L.
columbinum_. The original _L. arcyrioides_ has not yet been certainly
identified in North America; see following species.

Colorado, Oregon, Washington, California.


3. LAMPRODERMA COLUMBINUM (_Pers._) _Rost._

  1796. _Physarum columbinum_ Pers., _Obs. Myc._, I., p. 5.
  1875. _Lamproderma columbinum_ Rost., _Mon._, p. 203.

Sporangia scattered, gregarious; rich violet or purple with metallic
iridescence, globose, stipitate; the stipe long, three-fourths the total
height, slender, subulate, black; hypothallus scant, purplish or brown;
columella small, one-third the height or less, tapering or acute, black;
the capillitium brown throughout, not dense, arising from nearly all
parts of the columella, freely branching and anastomosing to an open,
large-meshed network; spore-mass black, spores by transmitted light dark
brown, rough, 10-12 µ.

Rostafinski distinguished this beautiful species by the color of the
peridium and the conic columella. According to Mr. Lister, Rostafinski
was not specially careful in labelling his material, different forms
having been included under this specific name. Nevertheless, the
description is well drawn, and excludes _L. physaroides_ completely. At
all events our American specimens correspond so well with the
description of _L. columbinum_ (Pers.) Rost. that there seems no doubt
that we have here what the Polish author figured and described, whether
or not he was always consistent in applying his labels. The color
distinguishes at sight the present species from _L. physaroides_, and
the capillitium and large rough brown spores distinguish it from _L.
violaceum_. The capillitium of the minute _L. scintillans_ is much
denser and more rigid, and the spores smaller. The stipe when dry is
ciliate.

This is the common species of our western mountains, especially on the
Pacific slope. In the Cascades every dark ravine is certain to show it
in later summer and autumn, far extended colonies covering the moist
surfaces of every mouldering log; the myriad globoid sporangia giving
back when brought to the sunlight the most extravagant blues and greens
with all the splendor of metallic sheen, their brilliant beauty never
fails to quicken the attention of even the most insensate tourist.

Abundant in the western forests, in the east extremely rare; Maine,
Pennsylvania, South Carolina, Washington, Oregon; Vancouver, Canada.


4. LAMPRODERMA SCINTILLANS (_Berk. & Br._) _Morg._

PLATE V., Figs. 2, 2 _a_.

  1877. _Stemonitis scintillans_ Berk. & Br., _Jour. Linn. Soc._, XV.,
           p. 2.
  1877. _Lamproderma arcyrioides_, var. _iridea_ Cke., _Myx. G. B._,
           p. 50.
  1892. _Lamproderma irideum_ (Cke.) Mass., _Mon._, p. 95.
  1894. _Lamproderma scintillans_ (Berk. & Br.) Morg., _Jour. Cin.
           Soc._, p. 47.

Sporangia gregarious, scattered, globose or depressed-globose, rich
metallic blue or purple, iridescent, stipitate; the stipe long, slender,
even, inclined and nodding or sometimes erect; hypothallus small,
circular; columella cylindric, small, not reaching the centre, black;
capillitium dense, of rigid, straight, sparingly branched or
anastomosing, brown threads, which are sometimes white or colorless just
as they leave the columella; spores globose, rough, violaceous brown, 8
µ.

This is _L. irideum_ of Cooke and of Massee's _Monograph_. Its
capillitium is remarkable, and constitutes an easy diagnostic mark. The
threads appear at first sight entirely simple, but are really several
times furcate, and not infrequently anastomose. The spores are covered
with sparsely sown large papillæ, easily seen under moderate
magnification.

This is one of our earliest species. To be sought in May on beds of
decaying oak leaves in the woods, especially in wet places, near
streams, etc.

Rare. New England, Pennsylvania, Ohio, Iowa.


5. LAMPRODERMA VIOLACEUM (_Fries_) _Rost._

  1829. _Stemonitis violacea_ Fries, _Syst. Myc._, III., p. 162.
  1875. _Lamproderma violaceum_ (Fries) _Rost., Mon._, p. 204.

Sporangia closely gregarious or scattered, depressed-globose, more or
less umbilicate below, metallic blue or purple, sessile or short
stipitate; stipe stout, dark brown or black, even; hypothallus, when the
sporangia are crowded, a thin, continuous, purplish membrane; when the
sporangia are scattered, the hypothallus discoidal; columella cylindric
or tapering slightly upward, the apex obtuse, black, attaining the
centre of the sporangium; capillitium lax and flaccid, made up of
flexuous threads branching and anastomosing to form a network, open in
the interior, more dense without, the threads at first pale brown as
they leave the columella, becoming paler outward to the colorless tips;
spores minutely warted, violaceous gray, 9-11 µ.

This is our most common species; found on decaying sticks and logs late
in the fall. Its pale capillitium will usually distinguish it,
especially where the sporangia are empty; then the pallid free
extremities of the capillitial branches give to the little spheres under
the lens a white or hoary appearance not seen in any other species.

The plasmodium is at first almost transparent, then amber tinted,
sending up tiny semi-transparent spheres on shining brownish stalks. As
the changes approach maturity, the sporangia become jet-black, and only
at last when the spores are ready for dispersal does the peridium assume
its rich metallic purple tints. Colonies a meter in length, two or three
decimeters in width, are sometimes seen!

New England, New York, Pennsylvania, Ohio, Indiana, Illinois, Iowa,
South Dakota; Toronto. Common.


6. LAMPRODERMA ARCYRIONEMA _Rost._

PLATE V., Figs. 1, 1 _a_.

  1875. _Lamproderma arcyrionema_ Rost., _Mon._, p. 208.

Sporangia gregarious, scattered, globose, silvery gray or bronze,
iridescent, erect, stipitate; stipe black, long, two-thirds to
three-fourths the total height, slender, rigid; columella slender,
cylindric, attaining about one-third the height of the sporangium when
it breaks into the primary branches of the capillitium; capillitium
exceedingly intricate, made up of slender, flexuous brown threads which
frequently branch and anastomose to form an elegant round-meshed network
resembling that of _Arcyria_, free ultimate branchlets not numerous;
spores in mass jet-black, by transmitted light violaceous, smooth, or
only faintly warted, 6-8 µ.

In outward appearance this species resembles _L. physaroides_, but is
easily recognizable by its very peculiar capillitium. This, in its
primary branching, resembles a comatricha. In typical forms, the
columella branches at the apex only, generally into two strong divisions
which then break up irregularly and anastomose in every direction. This
seems to have been the form present to Rostafinski when he wrote
"columella truncate." In Central American and some North American
specimens, the branching is very different; the twigs leave the
columella at various points almost down to the annulus, and the entire
effect is dendroid. The columella is lost almost at once. A small form
of this species was formerly distributed in the United States as
_Comatricha friesiana_ DeBy. This circumstance led the present author to
describe Central American forms as _C. shimekiana_. Judging from a
remark by Massee (_Mon._, p. 97), a similar confusion seems to have
prevailed in Europe. As a matter of fact, the resemblance between _C.
friesiana_, i. e. _C. nigra_, and the present species is sufficiently
remote.

_Lamproderma minutum_ Rostafinski seems to be a small form of this
species. Rostafinski bases his diagnosis upon the branching of the
columella, which is, as we have seen, inconstant, and upon the colorless
capillitium. This feature in specimens examined is also inconstant.

Occurring in large colonies on barkless decaying logs of various
species; the plasmodium almost colorless.

New England, Pennsylvania, Ohio, Louisiana, Texas, Mexico, Nicaragua;
Vancouver's Island; Ontario, Toronto,--_Miss Currie._


=4. Echinostelium= _DeBary_

  1873. _Echinostelium_ DeBary, Rost., _Versuch_, p. 7.

Sporangia distinct, globose, minute, the structure limited to a few
imperfect rib-like, loosely joined branches developed from the short
columella or stem-top, sustaining the spores.

A single species:--


1. ECHINOSTELIUM MINUTUM _DeBy_.

  1873. _Echinostelium minutum_ DeBy., Rost., _Versuch_, p. 7.

PLATE XIX., Figs. 11 and 11 _a_

Sporangia distinct, scattered, globose, very minute, 40-50 µ, stipitate;
the stipe, hair-like subulate, granular but hyaline; columella minute or
none; capillitium consisting of a few arcuate spinose threads loosely
united supporting the uncovered spores, spores globose, colorless,
smooth, 7-8 µ.--_Rostafinski._

This very singular and diminutive form, the least of all slime-moulds,
is probably widely distributed but the accident of discovery is rare.
DeBary found it once only, at Frankfurt am Main.

Miss Lister reports its occurrence in England and Austria. In the United
States it has been seen but once on certain laboratory material from
Massachusetts, studied by Dr. Thaxter.

Our drawing is after Rostafinski, IV., 68; Miss Lister follows No. 54,
and so finds a bit of peridium below the two spores shown in the figure,
one on each side of a microscopic _columella_.

This is almost the only taxonomic suggestion;--a mere suggestion; this
microscopic bit of anxious life is but a shadow,--a shade, a shadow of a
lamproderma!


ORDER III

CRIBRARIALES

Fructification plasmodiocarpous or æthalioid, or consisting of distinct
sporangia; peridia membranaceous at maturity, more or less evanescent,
opening irregularly or by means of a delicate network, which involves at
least the upper part of the sporangium; capillitium usually none; spores
of some shade of brown, umbrine, rarely purplish.

This order is distinguished--except in a single case--by the entire
absence of true capillitium, the pallid or brown spores, the gradual
evolution of distinct sporangia in which provision for spore-dispersal
is made by peridial modification especially at the sporangium-top.


=Key to the Families of the Cribrariales=

  _A._ Fructification plasmodiocarpous scattered as
         if made up of the segments of the
         plasmodial net                                          LICEACÆ

  _B._ Fructification of distinct and separate
         sporangia, long stipitate, opening by a
         delicate operculum at the top                      ORCADELLACEÆ

  _C._ Fructification æthalioid, the sporangia
         generally more or less tubular, often
         prismatic by mutual pressure; opening by
         rupture of the apex, the lateral walls entire       TUBIFERACEÆ

  _D._ Fructification æthalioid, the sporangia ill
         defined, their walls more or less
         perforate, frayed, or dissipated, forming
         a pseudo-capillitium,                            RETICULARIACEÆ

  _E._ Fructification of distinct and separate
         sporangia, the walls more or less
         reticulately perforate especially above            CRIBRARIACEÆ


_A._ LICEACEÆ

A single genus,--


=1. Licea= (_Schrader_) _Rost._

  1797. _Licea_ Schrader, _Nov. Gen. Plant._, p. 16, in part.
  1875. _Licea_ (Schrader) Rost., _Mon._, p. 218.

Sporangia plasmodiocarpous, looped, irregular, or distinct, sessile,
and regularly rounded or elliptical; the peridium simple, rather firm,
ruptured irregularly or by simple fissure; hypothallus none.

This genus is distinguished from other similar plasmodiocarpous forms by
the extreme simplicity of its structure. There is absolutely no
capillitium nor anything like it, simply a mass of spores surrounded by
thin membranous walls. The spores range from pale olive, colorless under
the lens, through various shades of brown to dusky almost black in _L.
pusilla_. Schrader included the _Tubifera_ species.


=Key to the Species of Licea=

  _A._ Plainly plasmodiocarpous                       1. _L. variabilis_

  _B._ Opening by regular segments.

       1. Segments two only                              2. _L. biforis_

       2. Segments several.

          i. Spores brown                                 3. _L. minima_

         ii. Spores dusky olive                          4. _L. pusilla_


1. LICEA VARIABILIS _Schrader._

PLATE XII., Figs. 7 and 8.

  1797. _Licea variabilis_ Schrader, _Nov. Gen._, p. 18, Pl. VI.,
           Figs. 5 and 6.
  1801. _Licea variabilis_ Schr., Pers., _Syn. Meth._, p. 197.
  1801. _Licea flexuosa_ Pers., _Syn. Meth._, p. 197.
  1911. _Licea flexuosa_ Pers., List., _Mycetozoa, 2nd ed._, p. 189.

Fructification plasmodiocarpous, elongate, hamate, annulate or
irregularly repent, very dark brown, rough, the peridium of two layers,
the outer closely adhering, dark brown, thick, opaque, the inner
delicate, membranous, very thin, transparent, iridescent, rugulose,
rupturing irregularly; hypothallus none; spores in mass pale yellow with
a greenish tinge, by transmitted light nearly colorless, large, globose,
minutely spinulose, 12.5 µ.

This is the largest species of the genus as represented in this country,
the plasmodiocarps of various lengths and from .5-.7 µ wide. Somewhat
resembling some species of _Ophiotheca_, but of much darker color. The
outer peridium is deciduous, and the inner slowly ruptures, by irregular
fissures discharging the spores. The plasmodium, according to Schrader,
is white. Rare. Probably overlooked.

Any good reason for changing the name given to this form so well
illustrated and described by Schrader does not appear. Persoon quotes
his predecessor's species and adds _L. flexuosa_ on his own account;
strangely enough, since Schrader expressly describes _L. variabilis_,
"in uno eodemque enim loco peridium hemisphericum, ovatum, oblongum
_flexuosum_ vel aliter formatum diversi est diametri."

New York, Pennsylvania, Ohio, Iowa.

_Licea flexuosa_ Pers. is by Schweinitz reported from Pennsylvania. It
is described as having brown spores, 10-15 µ, spinulose.


2. LICEA BIFORIS _Morgan._

PLATE XII., Fig. 10.

  1893. _Licea biforis_ Morgan, _Jour. Cin. Soc._, p. 5.

Sporangia regular, compressed, sessile on a narrow base, gregarious; the
wall firm, thin, smooth, yellow brown in color and nearly opaque, with
minute, scattered granules on the inner surface, at maturity opening
into two equal parts, which remain persistent by the base; spores
yellow-brown in mass, globose or oval, even, 9-12 u.

Minute but perfectly regular, almost uniform, corneous-looking sporangia
are thickly strewn over the inner surface of decaying bark. Each, at
first elongate, pointed at each end, opens at length by fissure along
the upper side setting free the minute yellowish spores. Unlike anything
else; reminding one, at first sight, of some species of _Glonium_.

Inside bark of _Liriodendron_. Ohio, Canada.


3. LICEA MINIMA _Fries_.

  1829. _Licea minima_ Fries, _Syst. Myc._, III., p. 199.

Sporangia gregarious, umber-brown, spherical or hemispherical, sessile;
the peridium opaque, brown, opening along prefigured lines, forming
segments with dotted margins, ultimately widely reflexed; spores in mass
dark brown, by transmitted light paler with olive tints, minutely
roughened, 10-11 µ.

The very minute sporangia, 3 mm., of this species cause it to be
overlooked generally by collectors. Nevertheless, it may be found on
decaying soft woods, in August, probably around the world. The number
of sporangia produced by one plasmodium is in Iowa also small. The
larger specimens might be mistaken for species of _Perichaena_, but are
easily distinguished by the regular and lobate dehiscence. The
plasmodium is yellow.

Dr. George Rex, in almost the last paper from his hand, gives an
interesting account of this diminutive species. Among various gatherings
studied he found a black variety, a melanistic phase, so to say, and was
able to follow the evolution of the sporangia from the yellow
plasmodium. The sutures by which the peridium opens, first show signs of
differentiation by change of color from yellow through garnet to black.
Later the entire wall undergoes similar color changes, beginning next
the completed sutural delimitations. Of the open peridia, the reflexed
segments remind one of certain didermas, as _D. radiatum_. See _Bot.
Gaz._, Vol. XIX., p. 399.

New England, New York, Pennsylvania, Iowa.


4. LICEA PUSILLA _Schrader._

  1797. _Licea pusilla_ Schrad., _Nov. Gen. Pl._, p. 19, tab. VI.,
           f. 4.
  1829. _Physarum licea_ Fries, _Syst. Myc._, III., p. 143.
  1875. _Protoderma pusilla_ (Schrader) Rost., _Mon._, p 90.

Sporangia scattered, gregarious, depressed-globose, sessile on a
flattened base, dark brown, shining, .5-1 mm.; peridium thin, dark
colored, translucent, dehiscent above by regular segments; spore-mass
almost black, spores by transmitted light olivaceous brown, smooth, or
nearly so, 15-17 µ.

Fries, _l. c._, makes this a physarum, and argues the case at length,
evidently with such efficiency that he greatly impressed Rostafinski,
who did not make it a physarum indeed, but actually gave it generic
place and station of its own; a physarum may do without calcium in the
capillitium perhaps, but not be entirely non-calcareous; so he writes
_Protoderma_ (first cover) and places the species number 1 on the long
list of endosporous forms. Even in his '_Dodatek_', or supplement, as we
should say, he refers to the thing again, but only to correct the
inflexional ending of the specific name; he writes _Protoderma pusillum_
(Schrader) Rost!

Schweinitz reports the species for America and Morgan cites Schweinitz
and reports it for Ohio, but we find it in no American collections.


_B._ ORCADELLACEÆ;

Sporangia distinct, minute, long stipitate, opening above by a distinct
lid.

A single genus,--


=Orcadella= _Wingate_

  1889. _Orcadella_ Wingate, _Proc. Phil. Acad._, p. 280.

Sporangia furnished with rigid, unpolished stipes, blending above with
the substance of the thick unpolished walls; the operculum thin,
delicate, membranaceous.

A single species,--


1. ORCADELLA OPERCULATA _Wingate._

PLATE XII., Fig. 11.

  1889. _Orcadella operculata_ Wingate, _Proc. Phil. Acad._, p. 280.

Sporangia scattered, gregarious, ellipsoidal, ovoid, obconical or nearly
globose, dull brown or blackish, the wall simple, thick, coarse, at the
top replaced by a delicate, thin, yellowish, iridescent, lustrous or
vernicose membrane which forms a circular, smooth, or wrinkled lid, soon
deciduous; stipe of varying height, rough from deposit of plasmodic
refuse; spores, in mass yellowish, globose, smooth, 8-11 µ.

This curious little species, well described by its discoverer, appears
to be very rare. At least it is seldom collected; overlooked by reason
of its minuteness. It is a stipitate licea, or a lid-covered cribraria;
perhaps nearer the former. It affects the bark of species of _Quercus_,
and seems to be associated there with _Clastoderma debaryanum. N. A.
F._, 2497.

Pennsylvania, Maine.


_C._ TUBIFERACEÆ

Fructification æthalioid or of distinct sporangia; sporangia well
defined, tubular, often prismatic by mutual pressure, seated on a
common, well-marked hypothallus, at length dehiscent by the irregular
rupture of the peridium, in typical cases at the apex, its walls
remaining then otherwise entire; capillitial threads in No. 3, only.


=Key to the Genera of the Tubiferaceæ=

  _A._ Spores olivaceous; sporangia in one or several
         series,                                           1. LINDBLADIA

  _B._ Spores umber; sporangia in a single series            2. TUBIFERA

  _C._ Sporangia stipitate; capillitium of tubular threads    3. ALWISIA


=1. Lindbladia= _Fries_

  1849. _Lindbladia_ Fries, _Sum. Veg. Scand._, p. 449.

Fructification æthalioid; the sporangia short, tubular, sometimes
superimposed, sometimes forming a simple stratum, in the latter case
generally sessile, but sometimes short-stipitate, the peridium at first
entire, at length opening irregularly either at the sides or apex, beset
with granules; spores olivaceous.

This genus was established by Fries in 1849 to accommodate a single
species of wide distribution and somewhat varying habit, which is
neither a tubifera nor yet a cribraria and offers points of resemblance
to each. It is distinct in that the sporangia, while often in single
series, are yet often superimposed. It resembles _Tubifera_ in its
simple sporangia, opening without the aid of a net; it is like
_Cribraria_ in the smooth ochraceous-olivaceous spores and granuliferous
peridium.


1. LINDBLADIA EFFUSA (_Ehr._) _Rost._

PLATE I., Figs. 3, 3 _a_, PLATE XII., Figs. 1, 2.

  1818. _Licea effusa_ Ehr., _Sylv. Myc. Ber._, p. 26.
  1875. _Lindbladia effusa_ (Ehr.) Rost., _Mon._, p. 223.
  1879. _Perichaena caespitosa_ Peck, _Rep. N. Y. Mus._, XXXI., p. 57.

Sporangia minute, either closely combined and superimposed, so as to
form a pulvinate æthalium, or crowded together in a single layer,
sessile, or short-stipitate; the peridia thin, membranous, marked by
scattered plasmodic granules, often lustrous, sometimes dull
lead-colored or blackish, especially above; stipe, when present, very
short but distinct, brown, rugulose; hypothallus well developed,
membranous, or more or less spongiose in structure; spore-mass
ochraceous, under the lens, nearly smooth, almost colorless, 6-7.5 µ.

This very variable species has been well studied by Dr. Rex. See _Bot.
Gaz._, XVII., p. 201. In its simpler phases it presents but a single
layer of sporangia generally closely crowded together, sometimes free
and even short stipitate! In the more complex phase the sporangia are
heaped together in a pulvinate mass in which the peridia appear as
boundaries of minute cells. In this case the outermost sporangia are
often consolidated to form a cortex more or less dense and shining. In
any case the hypothallus is a prominent feature; generally laminated and
of two or three layers, it is in the more hemispheric æthalia very much
more complex, sponge-like. When thin this structure is remarkable for
its wide extent, 40-50 cm.! The simpler forms approach very near to
_Cribraria_ through _C. argillacea_. The most complex remind us of
_Enteridium_.

This is _Perichaena caespitosa_ Peck. In this country it has, however,
been generally distributed as _L. effusa_ Ehr. This author throws some
doubt on the species he describes by suggesting that the plasmodium may
be _red_. The description, however, and figures are otherwise good and
are established by the usage of Rostafinski. The plasmodium has much the
same color as the mature fruit.

Widely distributed. New England to the Black Hills and Colorado, south
to Arkansas. California, about Monterey.


=2. Tubifera= _Gmelin_

  1791. _Tubifera_ Gmelin, _Syst. Nat._, II., p. 1472.

Sporangia tubular, by mutual pressure more or less prismatic, connate,
pale ferruginous-brown, iridescent, the walls thin, slightly granular,
long-persistent; dehiscence apical; hypothallus thick, spongiose, white
or whitish; spore-mass ferruginous.

This genus is easily recognized by the tubular sporangia, destitute of
capillitial threads, seated upon a strongly developed hypothallus. The
synonymy of the case is somewhat difficult. It is possible that
Mueller's _Tubulifera ceratum, Fl. Dan._, Ellevte Haefte, 1775, p. 8,
may belong here, but neither the text nor the figures make it certain.
Neither he nor OEder, who gives us _T. cremor_ in the same work, had
any accurate idea of the objects described. Gmelin's description of
_Tubifera_, II., 2, 1472, is, however, ample, and his citations of
Bulliard's plates leave no doubt as to the forms he included. Gmelin
writes: "Thecæ (membranæ expansæ superimpositæ) inter se connatæ
seminibus nudiusculis repletæ."

Why, in face of so good a description, Persoon changed the name to that
since current, _Tubulina_, is not clear.

Fries thinks Mueller had an immature _Arcyria_ before him, _Syst. Myc._,
III., p. 196. _Tubulifera arachnoidea_ Jacq., 1778, is also an uncertain
quantity, insufficiently described.


=Key to the Species of Tubifera=

  _A._ Hypothallus well developed, but not conspicuous.

     _a._ Pseudo-columellæ none                      1. _T. ferruginosa_

     _b._ Pseudo-columellæ present at least in many
            of the tubules                              2. _T. casparyi_

  _B._ Hypothallus prominent, columnar                 3. _T. stipitata_


1. TUBIFERA FERRUGINOSA (_Batsch_) _Macbr._

PLATE I., Fig. 4; PLATE VII., Fig. 8; PLATE XII., Fig. 14.

  1786. _Stemonitis ferruginosa_ Batsch, _Elench._, p. 261, Fig. 175.
  1791. _Sphaerocarpus cylindricus_ Bull., _Champ._, p. 140, t. 470,
           III.
  1791. _Tubifera ferruginosa_ Gmelin, _Syst. Nat._, 1472 (_ex parte_).
  1805. _Tubulina cylindrica_ (Bull.) DC., _Fl. Fr._, 671.
  1875. _Tubulina cylindrica_ (Bull.) Rost., _Mon._, p. 220.
  1894. _Tubulina fragiformis_ (Pers.) Lister, _Mycetozoa_, p. 153.

Sporangia crowded, cylindric or prismatic, elongate, connate, more or
less distinct above, pale umber-brown, generally simple though
occasionally branched above, the peridia thin, sometimes fragile, but
generally persistent, transparent, iridescent; hypothallus strongly
developed, spongiose, white, often projecting beyond the æthalioid mass
of sporangia; spore-mass umber-brown or ferruginous; spores by
transmitted light almost colorless, plainly reticulate over
three-fourths of the surface, 6-7 µ.

Not rare on old logs, mosses, etc., from Maine to Alaska. Apparently
more common north than south. Easily known by its long, tubular
sporangia packed with rusty spores and destitute of any trace of
columella or capillitium, the hypothallus explanate, rather thick, but
not columnar. A single plasmodium may give rise to one or several
colonies, at first watery or white, then red, of somewhat varying
shades, then finally umber-brown. These colors were noticed by all the
older authors, but very inaccurately; thus a white plasmodium is the
basis for _Tubifera cylindrica_ (Bull.) Gmel., a roseate plasmodium for
_Tubifera fragiformis_ (Bull.) Gmel., and the mature fructification for
_Tubifera ferruginosa_ (Batsch) Gmel. Rostafinski adopted a specific
name given by Bulliard, but Batsch has clear priority.

The peridia are sometimes accuminate, and widely separate above. This is
Persoon's _T. fragiformis_. In most cases, however, the peridia are
connate throughout, and sometimes present above a membranous common
covering. This is _T. fallax_ of Persoon; _Licea cylindrica_ (Bull.)
Fries. In forms with thicker peridia, the walls often show the granular
markings characteristic of the entire _Anemeae_.


2. TUBIFERA STIPITATA (_Berk. & Rav._) _Macbr._

  1858. _Licea stipitata_ Berk. & Rav., _Am. Acad._, IV., p. 125.[39]
  1868. _Licea stipitata_ Berk. & Rav., _Jour. Linn. Soc._, X., p. 350.
  1875. _Tubulina stipitata_ (Berk. & Rav.) Rost., p. 223.

Sporangia crowded in a globose or more or less hemispheric, expanded
head, borne upon a spongy, stem-like, sulcate hypothallus 3-4 mm. high,
their apices rounded, their walls very thin, evanescent; spores in mass
umber-brown, small, about 5 µ, the epispore reticulate as in the
preceding species.

This differs from number 1 chiefly in the cushion-like receptacle on
which the crowded sporangia are borne, and in the smaller spores. The
species originates in a plasmodium at first colorless, then white,
followed by salmon or buff tints, which pass gradually into the dark
brown of maturity. This peculiar succession of colors is perhaps more
diagnostic than the difference in habit. The spores are, however,
constantly smaller in all the specimens we have examined, and the
stipitate habit very marked.

New England, New York, south to South Carolina, and west to South
Dakota; our finest specimens are from Missouri.


3. TUBIFERA CASPARYI (_Rost._) _Macbr._

PLATE XII., Fig. 9.

  1876. _Siphoptychium casparyi_ Rost., _Mon. App._, p. 32.

Sporangia closely crowded, tubular, cylindric or prismatic by mutual
pressure, connate, the apices rounded, convex, covered by a continuous
membrane, umber-brown; the peridia firm, persistent, minutely granular,
iridescent; hypothallus well developed, thin, brown, explanate;
pseudo-columellæ erect, rigid, traversing many of the sporangia, and in
some instances bound back to the peridial walls by slender, membranous
bands or threads, a pseudo-capillitium; spore-mass dark brown or umber,
spores by transmitted light pale, globose, reticulate, 7.5-9 µ.

This is _Siphoptychium casparyi_ Rost. In _Bot. Gaz._, XV., p. 319, Dr.
Rex shows that the relationships of the species are with _Tubifera_;
that the so-called columella is probably an abortive sporangium, the
so-called capillitial threads having no homology with the capillitial
threads of the true columelliferous forms. It is a good species of
_Tubifera_, nothing more. The tubules are shorter than in either of the
preceding species; the spores are darker, larger, and more thoroughly
reticulate.

The plasmodium is given by Dr. Rex, _l. c._, as white, then "dull gray
tinged with sienna color," then various tones of sienna-brown, to the
dark umber of the mature æthalium.

New York, Adirondack Mountains; Allamakee Co., Iowa.


=3. Alwisia= _Berk. & Br._

PLATE XIX., Figs. 5 and 5 _a_.

  1873. _Alwisia_ Berk. & Br., _Jour. Linn. Soc._, Vol. XIV., p. 86.

Sporangia ellipsoidal, clustered, stipitate; dehiscence by the falling
away of the upper part of the peridium disclosing a persisting pencil of
capillitial threads. A single species:--


1. ALWISIA BOMBARDA _Berk. & Br._

  1873. _Alwisia bombarda_ Berk. & Br., _Jour. Linn. Soc._, XIV., p. 86.

Sporangia gathered in clusters of four to eight, surmounting coalescent,
or sometimes divergent stalks, rusty-brown, or pallid, the peridium
evanescent above; the coalescing stalks forming, especially below, a
clustered column, 2 mm. in height, equalling the sporangia, dull
reddish-brown in color; capillitium of rigid, tubular, generally simple
threads, attaching above by delicate tips, below by a broader sometimes
branching base, sometimes conjoined near the peridial wall, now and then
at irregular intervals inflated slightly or anon bulbose, roughened by
projecting spinules, one-third the diameter, brownish or yellow; spores
reddish-brown, faintly marked by reticulating bands over large part of
the surface, 5-5.5 µ.

This peculiar species looks at first very little like a myxomycete. The
stiff projecting hairs of the capillitium are hyphal in appearance and
under the lens recall the phycomycetes; but the spores and withal the
general structure seem to claim recognition here. Rostafinski was
inclined to make a trichia of it, because of the hair-like capillitium,
and markings on the threads, Massee found indistinct spiral markings
even, enough to suit at least the prototrichias. Mr. Lister would put it
near the tubifers. Father Torrend thinks of the dianemas, margaritas,
etc., because of simple capillitium attached above and below!
Spore-characters are probably the index most reliable, and the partial
reticulation suggests association with _Tubifera_ and for the present it
may find station there, as in the English monograph.

Rare. Collected three times: twice in Ceylon, once in Jamaica. By the
courtesy of Dr. Farlow, late lamented, we record the western specimens.


_D._ RETICULARIACEÆ

Fructification æthalioid; the sporangia sometimes poorly defined,
intricately associated, borne on a common hypothallus and covered above
by a common cortex; the lateral walls variously perforate and
incomplete, form a pseudo-capillitium; spores umber or ochraceous.


=Key to the Genera of the Reticulariaceæ=

  _A._ Spores umber.

    _a._ Sporangia wholly indeterminate, their walls much
           consolidated below, fraying out above into
           long, slender threads,                         1. RETICULARIA

    _b._ Sporangia bounded, more or less distinctly, by
           broad perforate plates throughout               2. ENTERIDIUM

  _B._ Spores ochraceous                              3. DICTYDIÆTHALIUM

=1. Reticularia= (_Bull._) _Rost._

  1791. _Reticularia_ Bulliard, _Champ. de la France_, p. 95, in part.
  1873. _Reticularia_ (Bulliard) Rost., _Versuch_, p. 6.

Plasmodium at first white, then pink, 'ashes of roses,' etc. Sporangia
wholly indeterminate or undefined, their walls represented (?) by a
spongy mass of so-called capillitium, consisting of membranous plates,
branching, anastomosing, vanishing without order or symmetry, generally
giving rise at the sides, and especially above, to long slender flexuous
threads; outer cortex silvery white; hypothallus distinct, white;
spore-mass and threads umber or rusty brown.

A single species,--


1. RETICULARIA LYCOPERDON (_Bull._) _Rost._

PLATE X., Figs. 7, 7 _a_; PLATE XII., Fig. 3.

  1791. _Reticularia lycoperdon_ Bull., _Champ. de la France_, p. 95.

Æthalium pulvinate, 2-8 cm. broad, at first silvery white, later less
lustrous, the cortex irregularly and slowly deciduous; hypothallus at
first conspicuous as a white margin extending round the entire
aethalium, evanescent without, but persisting as a firm membrane beneath
the spore-mass, pseudo-capillitium abundant, tending to form erect
central masses which persist long after the greater part of the fruit
has been scattered by the winds; spore-mass umber, spores by transmitted
light pale, reticulate over about two-thirds of the surface, the
remainder slightly warted, 8-9 µ.

Not common. Often confused with the following, the spores of the two
forms being very much alike; the internal structure, entirely different,
and once compared, the two are thereafter easily distinguished at sight
by external characters. The sporangial make-up is indifferent, confused.
It represents a phase in development whence might issue columellæ with
capillitium-branches or distinct tubular sporangia with persisting
walls; or are such structures here but reminiscent only? Compare
_Amaurochaete atra_, where similar conditions prevail. There
differentiation goes on to the formation of a structure of which
_Stemonitis_ is type; here the sporangium-wall becomes dominant; suffers
modification for spore-disposal, an idea reaching fair expression in
_Cribraria_ and _Dictydium_.

The plasmodium is white, noted Bulliard. Fries cites with approval the
words of Schweinitz,--"color corticis ab initio argenteus sericeo
nitore insignis; sed deinde sordescit e griseo in subfuscum vergens."
Sometimes the surface does indeed shine as silver!

The fructification appears to be isolated in each case; the entire
plasmodium consumed in a single plasmodiocarp.

Widely distributed. Maine to California, and south.


=2. Enteridium= _Ehrenberg_

  1818. _Enteridium_ Ehrenberg, Link and Spreng., _Jahrb., Bd._ II.,
           p. 55.

Fructification æthalioid; the confluent sporangia inextricably
interwoven, the walls perforate by large openings, the resultant network
of broad plates and bands widening at the points of intersection.

The genus _Enteridium_ is distinguished from _Reticularia_ chiefly by
the more perfectly developed sporangial walls. These are everywhere
membranous and do not show the abundant filiform dissipation so
characteristic of _Reticularia_. The resultant structure in
_Reticularia_ is a mass of more or less lengthened and anastomosing
threads; in _Enteridium_, an exceedingly delicate but sufficiently
persistent sponge. The "net-like, three-winged skeleton" referred to by
Rostafinski results from the union at one point of three adjoining
sporangia. Compare the section of the adjoining cells of a honeycomb.

Of this genus there are but two or three species, all so far occurring
in our territory.

=Key to the Species of Enteridium=

  _A._ Fructification umber brown                      1. _E. splendens_

  _B._ Fructification olivaceous                       2. _E. olivaceum_

  _C._ Fructification minute, 1-2 mm.                    3. _E. minutum_


1. ENTERIDIUM SPLENDENS _Morg._

PLATE I., Figs. 1, 1 _a_, 1 _b_; PLATE XII., Figs. 4, 5.

  1876. _Reticularia_ (?) _rozeanum_ Rost., _Mon. App._, p. 33.
  1889. _Enteridium rozeanum_ (Rost.) Wing., _Proc. Phil. Acad._,
           p. 156.
  1892. _Enteridium rozeanum_ Wingate, Macbr., _Bull. Lab. Nat. Hist.
           Iowa_, II., p. 117.
  1893. _Reticularia splendens_ Morg., _Jour. Cin. Soc._, p. 11.
  1899. _Enteridium splendens_ Morg., Morg. _in litt._

Æthalium pulvinate, even, or somewhat irregular, unevenly swollen or
inflated, lobate or compound, covered by an exceedingly thin, generally
smooth, shining, but never white, pellicle or cortex, brown, from 1-6
cm. in diameter; hypothallus white, often wide extending; capillitium
none; the sporangial walls thin and brown forming a network as above
described; spore-mass umber, spores by transmitted light pale, about
two-thirds of the surface reticulate, the rest nearly smooth, 7-9 µ.

Very common, especially west, on decaying logs and stumps of every
description. Easily distinguished by its brown color and smooth,
shining, though uneven surface. The plasmodium as it emerges to form
fruit is pale pink or flesh color, slowly deepening to brown as maturity
advances. The first emergence is a watery white.

New England, Canada, to Minnesota and Nebraska, South Dakota.

In 1876 Rostafinski provisionally referred to the genus _Reticularia_
certain specimens received from M. Roze of Paris. Thirteen years later
in correspondence with M. Roze, Mr. Wingate satisfied himself that the
specimens discovered by Roze were the same as our common enteridium. He
therefore, _l. c._, applied to our American forms the name they have
widely borne, _E. rozeanum_. Mr. Lister, _Jour. of Botany_, Sept. '91,
applied the Rostafinskian name to certain English specimens. Thereafter
to be known as _Reticularia lobata_ Rost. and so fixed the status of
that species. From all the literature before us it appears that Mr.
Lister was right. _R. lobata_ List. (now _Liceopsis lobata_ List.)
Torr., occurs in various parts of Europe, while our American species of
_Enteridium_ is yet to be discovered on that side of the sea!

Were the latter native to the old world at all, it had surely been seen
long ago. It is large and fine, and could not have escaped the famous
collectors of the last two hundred years. Although it has been sent by
students from this side of the ocean to Europe for more than thirty
years, it has not even adventitiously appeared.

It therefore appears that our American species is known to Europe
through Mr. Wingate's reference only.

Twenty years ago in correspondence with Mr. Wingate it was learned that
the material received by him from M. Roze was but a small fragment,
crushed flat, and even this was at that time no longer in evidence. This
specimen was itself _not part of the gathering submitted to
Rostafinski_; but only the fragment of something _appearing in 1890 in
the same locality_!

    ... "something not the same,
    But only like its forecast in men's dreams."

When we further reflect that the spores of species of several of the
forms now in review, _Tubifera_, _Reticularia_, _Enteridium_, are not
without difficulty distinguished, it is easy to see that Mr. Wingate's
specific reference has narrow foundations to say the least. It seems now
likely that Father Torrend's _Liceopsis_, _Reticulara lobata_ R., M.
Roze's aftermath, and all, are but the depauperate forms of some
tubifera!

_E. rozeanum Wing._, is therefore the synonym for an ill-defined
something in Western Europe and need not further here concern us as far
material reference goes.

In any case, what induced Mr. Wingate to pull Rostafinski's uncertain
description of a problematic form across the sea, to attach it to our
clearly defined and well known American species, changing the Polish
description the while to make it fit, is hard to understand; especially
in view of the fact, by Wingate admitted, that Rex had in his letters to
Morgan already named the American type _Enteridium umbrinum_. The two
students differed as to generic reference, and later on Morgan published
_Reticularia splendens_ Morg.; rather than _R. umbrina_ (Rex) Morg.
because he was using _R. umbrina_ Fr. for what is generally known as _R.
lycoperdon_ (_Bull._)

It would then appear that when Wingate sought to impose the
Rostafinskian specific name upon our American form by changing (fixing!)
Rostafinski's generic reference, and by re-writing the specific
description from the pages of the _Monograph_ in order to claim
identity, he was entirely without justification, especially since he
knew the species appropriately named by his colleague, Dr. Rex, and had
the name as used in the Rex and Morgan correspondence.

In brief; Mr. Wingate proceeded to re-describe Rostafinski's rozean
specimen and referred a long-known American form (very different) to the
European specimen as type. Wingate's description is right; he had the
American material before him; but his cited type is worthless, an
entirely different thing.

Does the reader care to see what the European _type_ of our common form,
Wingate _teste_, really looks like, let him consult the _Jour. of
Botany_, Vol. XXIX., p. 263, 1891.


2. ENTERIDIUM OLIVACEUM _Ehr._

  1818. _Enteridium olivaceum_ Ehr.

Æthalium depressed flat, oval or elongate, .3 cm. in extent, .6 mm.
thick when fresh, glossy, smooth, greenish-olivaceous-brown; within a
spongy net-work representing sporangial walls which are thin, pale
olivaceous, perforate by circular openings, meshes surrounded by wide
plates; spores in clusters, six or more together, ovoid, distinctly
warted at the wider end, pale olivaceous, 9-11 µ.

This, the type of the genus, is a very distinct species of this by its
structure readily distinguished form. Fries thought the species might
represent a less perfectly-developed reticularia, and therefore wrote
_Reticularia olivacea_ noting, however, the clustered spores and the
lack of hypothallus.

Common, as would appear, in Europe and in S. America; rare with us.
Reported from N. Hampshire and we have one specimen from Colorado.


3. ENTERIDIUM MINUTUM _Sturg._

  1917. _Enteridium minutum_ Sturg., _Mycologia_, IX, p. 328.

Æthalia rounded or elongate, pulvinate, pale umber in color, seated on a
broad membranous base, 1.5-2 mm. in diameter; wall wrinkled and usually
marked with small scattered pits, pale-yellow, membranous; walls of
component sporangia, membranous, minutely roughened, perforated with
round openings, the margins of which show many free threads; or reduced
to irregular, anastomosing strands arising from the base of the
æthalium, with membranous or net-like expansions at the angles and with
many delicate, free, pointed ends. Spores pale-yellow, usually united in
twos or threes, and ovoid or flattened on one side; when free, globose,
very minutely spinulose, 9.5-10.5.

Colorado: _Dr. Sturgis._


=3. Dictydiæthalium= _Rostafinski_

  1873. _Dictydiaethalium_ Rost., _Versuch_, p. 5.
  1875. _Clathroptychium_ Rost., _Mon._, p. 224.

Æthalium depressed, flat; the sporangia erect, regular, prismatic by
mutual pressure, the peridia convex above, wanting at the sides and
within the æthalium represented by vertical threads marking the angles
and passing from base to summit.

This genus is readily recognized by the internal structure of the
æthalium. The lateral wall-openings, which, as we have seen,
characterize the sporangia of the preceding genus, here become extreme,
occupying to such extent the lateral wall-space of each sporangium that
only threads remain to mark the vertical angles.

In 1873 Rostafinski applied the generic name here adopted, because he
thought he discovered close relationships with _Dictydium_. In 1875,
believing his first impressions erroneous, and desirous that the
nomenclature might not at once mislead the student and perpetuate the
memory of his own mistake, the same author proposed the name by which
the genus has generally ever since been known--_Clathroptychium_.
However sensible the latter conclusion reached by our Polish author, it
is plainly contrary to all rules of priority.

Our region shows but a single widely distributed species,--


1. DICTYDIAETHALIUM PLUMBEUM (_Schum._) _Rost._

PLATE I., Figs. 2, 2 _a_, 2 _b_.

  1803. _Fuligo plumbea_ Schum., _Enum. Saell._, No. 1410.
  1833. _Licea rugulosa_ Wall., _Cr. Fl. Ger._, IV., p. 345.
  1873. _Dictydiaethalium plumbeum_ (Schum.) Rost., _Versuch_, p. 5.
  1875. _Clathroptychium rugulosum_ (Wallr.) Rost., _Mon._, p. 225.
  1894. _Dictydiaethalium plumbeum_ Rost., List., _Mycetozoa_, p. 157.

Æthalium thin, very flat, olivaceous or ochraceous, smooth, under the
lens punctate, in section showing the columnar or prismatic sporangia,
which are normally six-sided, having at the edges six simple threads,
the remains of peridium, extending from base to apex, where the peridium
remains intact, arcuate; hypothallus prominent, radiating far around the
æthalium, silvery white; spores in mass, ochraceous, or dull brownish
yellow, by transmitted light almost colorless, rough 9-10 µ.

Not rare, on decaying logs, especially of _Tilla americana_, where in
the same place successive fructifications follow each other sometimes
for weeks together in the latter part of summer and early fall. The
æthalium is generally elliptical or elongate, 2-3 cm. in extent,
sometimes irregular or branched, varying in color according to degree of
maturity, weathering, etc. Plasmodium at first watery, then pink, or
flesh-colored.

Eastern United States; common. Toronto;--_Miss Currie._


_E._ CRIBRARIACEÆ

Sporangia distinct, more or less closely gregarious, stipitate, the
peridium opening, especially above, by a well-defined network formed
from thickenings in the original sporangial wall.

=Key to the Genera of the Cribrariaceæ=

  _A._ Peridial thickenings in form of an apical net
         with definite thickenings at the intersections
         of the component threads                           1. CRIBRARIA

  _B._ Peridial thickenings in form of parallel
         meridional ribs connected by delicate
         transverse threads                                 2. DICTYDIUM


=Cribraria= (_Pers_) _Schrader._

  1794. _Cribraria_ Persoon, Römer, _N. Bot. Mag._, I., p. 91, in part.
  1797. _Cribraria_ Schrader, _Nov. Gen. Plant._, p. 1, in part.
  1875. _Cribraria_ Rostafinski, _Mon._, p. 229.

Sporangia distinct, gregarious or closely crowded, globose or obovoid,
stipitate; the stipe of very varying length; the peridium simple, marked
within by distinct and peculiar, granular, thickenings, which below take
the form of radiating ribs, supporting the persisting cup, _calyculus_,
and above, by extremely delicate anastomosing branches, unite to weave a
more or less regular net with open polygonal meshes; spores various,
more often yellowish or ochraceous, sometimes brown, reddish, or
purple.

The genus _Cribraria_, as limited by Persoon, included all forms in
which the peridium is thin, evanescent half-way down, or entirely, and
in which capillitium, as Persoon regarded the case, is formed of a
network of reticulate threads surrounding the spores. Schrader redefined
the genus; opposed Persoon's view as to the capillitial nature of the
net, and separated the genus _Dictydium_, but by imperfect
limitations,--in fact, chiefly because of the more completely evanescent
peridium. Fries follows Schrader. Rostafinski first clearly separated
the two genera, and his classification is here adopted. Nevertheless,
after reviewing the subject entire one is more and more inclined to
appreciate the commendation of Fries; "Auctor Schrader, qui insuper
plurimas species detexit, et hoc et sequens genus ita proposuit ut
sequentes vix aliquid addere valuerint."

As to the habitat of the cribrarias, the remark of Schrader is still
pertinent--"in vetustissimis plenariæ destructionis proximis arborum
truncis"--for all the species. Rotten, coniferous wood seems to be
preferred, but the decayed logs of trees of other orders are by no means
refused. Rotten oak forms a very common habitat.


=Key to the Species of Cribraria=

  _A._ Sporangia with spores ochraceous or brownish.

     _a._ Sporangia larger, .5 mm. or more.

          1. Net poorly developed, sometimes merely
               indicated                              1. _C. argillacea_

          2. Net conspicuous, nodes expanded, not swollen.

             i. Calyculus reticulately thickened,
                  ill-defined above                   2. _C. macrocarpa_

            ii. Calyculus with radiant lines or ribs;
                  net small-meshed; free ends none    6. _C. aurantiaca_

           iii. Net wide-meshed, calyx rufous               4. _C. rufa_

            iv. Calyx replaced by ribs                 5. _C. splendens_

          3. Net conspicuous, nodules swollen.

             i. Net-threads simple; free ends many  7. _C. dictydioides_

            ii. Net-threads often parallel in twos
                  or threes                            8. _C. intricata_

     _b._ Sporangia small, less than .5 mm.

          1. Nodes not expanded                      3. _C. minutissima_

          2. Nodes well shown.

             i. Calyculus distinctly marked by
                  radiant lines, nodes round            10. _C. tenella_

            ii. Calyculus minute or none;
                  nodes prominent                    11. _C. microcarpa_

  _B._ Sporangia more or less marked with purple or violet tints.

     _a._ Purple or violet throughout.

          1. Net poorly developed                      12. _C. violacea_

          2. Net well developed.

             i. Meshes regular and the nodes
                  distinct                              14. _C. elegans_

            ii. Meshes and nodules irregular           13. _C. purpurea_

     _b._ Purple tints confined chiefly to plasmodic
            granules on the calyculus and stipe.

             Net with nodes well expanded.

             i. Stipe short, not more than double the
                  sporangium; net and calyculus both
                  well developed                      9. _C. piriformis_

            ii. Stipe many times the sporangium,
                  weak                              15. _C. languescens_

           iii. Stipe slender, sporangium
                  copper-colored                         16. _C. cuprea_


1. CRIBRARIA ARGILLACEA _Pers._

PLATE XII., Figs. 12, 13; PLATE XVII., Fig. 1.

  1791. _Stemonitis argillacea_ (Pers.) Gmel., _Syst. Nat._, II., 1469.
  1796. _Cribraria argillacea_ Pers., _Obs. Myc._, I., p. 90.

Sporangia dull ochraceous-olivaceous, globose, nearly 1 mm. in diameter,
sessile or short stipitate, closely gregarious or crowded, the peridial
walls at maturity smooth, shining, except above, long persistent,
obscurely reticulate, with irregular thickenings which at the apex at
length present the appearance of an irregular, coarsely meshed net
without nodal thickenings; stipe very short, stout, erect, reddish
brown, spore-mass ochraceous, spores by transmitted light pale,
spinulose, 5-6 µ.

This species stands just on the border-line between the tubiferas and
the genus now before us. While on the one hand it possesses many
characters such as the habit, form of sporangium, which are distinctly
tubuline, on the other it shows in the upper peridial wall definite
reticulations which suggest _Cribraria_. In freshly formed sporangia the
reticulations are barely visible in the crown; later on they are more
manifest, until, as spore-dispersal proceeds; the cribraria characters
come out with sufficient distinctness, and in empty sporangia the
reticulations may be seen to affect the entire peridial wall. The nodes
are not expanded. The spores are pale by transmitted light, spinulose,
about 6 µ. Plasmodium lead-colored. Found sometimes in large patches on
rotten logs of various species. Not uncommon. Cf. _Lindbladia effusa_.

New England, New York, Pennsylvania, South Carolina, Ohio, Illinois,
Iowa, Washington; Canada.


2. CRIBRARIA MACROCARPA _Schrader._

PLATE XVII., Fig. 2.

  1797. _Cribraria macrocarpa_ Schrad., _Nov. Gen. Plant._, p. 8.

Sporangia more or less closely gregarious, yellowish brown, pear-shaped
or obovate, large, .8-1 mm. in diameter, stipitate; stipe brown
furrowed, erect or often nodding, about equal to the sporangium or
longer; calyculus distinct, marked by numerous dark brown radiating
ribs, iridescent, perforate above, deeply dentate, and merging gradually
into the elegant network, of which the dark nodes are more distinctly
expanded about half way up, less so at the apex and below, the filaments
exceedingly delicate, simple, with occasional free ends projecting into
the small meshes; spore-mass yellowish, spores by transmitted light
almost colorless, minutely roughened, 5-6 µ.

Perhaps the most striking characteristic of the present species, aside
from its large size, is the peculiarly perforated cup or calyculus.
Schrader's artist failed him here completely. The structure is
exceedingly delicate, the peridium between the ribs and reticulations
reduced to the last degree of tenuity, with the iridescence of the
soap-bubble, here and there lapsed entirely. Withal the structure seems
firm enough and persists until all the spores are dissipated by the
wind.

Easily distinguished from the preceding, its only rival in size, by the
obovate or turbinate, netted sporangium, its much longer stem, and flat,
perfectly formed nodes.

Rare. New York, North Carolina, South Carolina, Oregon; Toronto,
Canada.


3. CRIBRARIA MINUTISSIMA _Schweinitz._

PLATE XVII., Figs. 6, 6 _a_.

  1832. _Cribraria minutissima_ Schw., _N. A. F._, No. 2362.

Sporangia scattered, orange or nut-brown, very minute, .1-.3 mm. or
less, globose or ellipsoidal, stipitate, erect or nodding; hypothallus
none; stipe short, 1-3 times the sporangium, filiform, tapering upward,
brown; the calyculus variable, sometimes well marked and separated from
the net when fully mature, by a shallow constriction, more commonly
small or entirely wanting, especially in the spherical sporangia; net
simple, large meshed, without nodal expansions, the threads flattened;
spore-mass yellow, spores by transmitted light, pale, nearly smooth, 5-6
µ.

A most beautiful tiny species. Generally in all the specimens before us,
a perfect, spherical net, firm enough to retain its place and structure
after all the spores have been scattered. When mature the spore-mass
seems to roll about as a ball, freely within the net, the spores being
thus gradually dispersed. The calyculus when present is without veins.
_C. minima_ Berk. & C., and _C. microscopica_ Berk. & C. are doubtless
the same thing. _Grev._, II., p. 67, 1823. See also _Bot. Gaz._, XIX.,
397.

Rare. Pennsylvania, South Carolina, Missouri, Iowa; Black Hills, South
Dakota.


4. CRIBRARIA RUFA (_Roth_) _Rost._

PLATE XIX., Fig. 8.

  1788. _Stemonitis rufa_ Roth, _Fl. Germ._, I., p. 548.
  1794. _Cribraria rufescens_ Pers., Roemer, _N. Mag. Bot._, I.,
           p. 91.
  1797. _Cribraria fulva_ Schrad., _Nov. Gen. Pl._, p. 5.

Sporangia scattered, sub-globose or turbinate, dark or reddish orange,
.5-.7 mm. in diameter, erect, stipitate; stipe about equalling the
height of the sporangium or longer, dark brown or black; calyculus
one-third to one-half the sporangium, the margin toothed, the wall
ribbed and continuous with the open wide-meshed net; the network deep
yellow or orange, the threads flattened; the nodes not thickened, little
differentiated; spores concolorous, by transmitted light, pale yellow,
verruculose, 5-7 µ.

Similar to the preceding, but generally much larger and not so much
inclined to brown. The size, however, is extremely variable in sporangia
from the same plasmodium (reported white), some no larger than those of
the species reckoned most minute.

Oregon. _Professor Morton Peck._


5. CRIBRARIA SPLENDENS (_Schrader_) _Rost._

PLATE XIX., Fig. 10.

  1797. _Dictydium splendens_ Schrad., _Nov. Gen._, p. 14.
  1801. _Cribraria splendens_ (Schrad.) Pers., _Syn. Fung._, p. 191.

Sporangia gregarious, globose, dusky yellow when filled with spores,
dull or dusky brown when these are discharged, stipitate; stipe long,
3-4 times the sporangium, subulate, erect-nodding, brown; hypothallus
none; network brown, with large meshes, imperfectly defined nodes and
flattened threads; calyculus none, its place supplied by nine or ten
distinct, firm ribs which radiate from the stipe and support the net,
branching to blend with its reticulations; spore-mass yellow, spores by
transmitted light, colorless, smooth or nearly so, 6-7.5 µ.

Of this species two specimens only are before us, one from Muscatine
County, Iowa, and one from Washington (state). The species seems thus to
have wide range, but to be exceedingly rare. It differs from all other
American forms, so far described, in the peculiar development of the
calyculus. Rostafinski emphasizes the persistence of the peridial wall
and the peculiar gleaming of the metallic tints, displayed by all the
structures. These particulars we have not been able to verify. Such
characters may be incident to age or conditions of development. At all
events, in forms which in all other respects seem to agree exactly with
Rostafinski's descriptions, the colors are dull and without any
noticeable iridescence. The spores in our specimens are also a little
larger than quoted. Rostafinski gives 5-6 µ; Massee, 5-7 µ.


6. CRIBRARIA AURANTIACA _Schrader._

PLATE XVII., Fig. 3, and XIX., Fig. 7.

  1797. _Cribraria aurantiaca_ Schrad., _Nov. Gen. Pl._, p. 5.

Sporangia gregarious, spherical, dusky or yellowish stipitate, nodding;
the calyculus variable, generally prominent, more or less distinctly
marked by fine, delicate radiating venules, the margin denticulate, the
teeth numerous and slender, supporting the well-defined globose net;
network made up of very tenuous threads, forming rather small irregular
brownish nodules and showing only here and there a free extremity; stipe
generally short, two or three times the diameter of the sporangium,
sometimes longer, tapering upward, brown, slender, arcuate above;
spore-mass yellow or ochraceous, spores by transmitted light, colorless,
5-6 µ, almost smooth.

This widely distributed and very variable species is generally
recognized by the large sporangia, .5-.9 mm., comparatively short stipe,
simple net, and more or less orange color. The color is an uncertain
thing even in the sporangia, which rise from one plasmodium. Schrader,
however, made this feature so far diagnostic that he placed the more
pronouncedly yellow forms in the species _C. aurantiaca_ and set off as
_C. vulgaris_ forms in which more dusky tints prevail. The dark-colored
forms have also usually longer stipes, but so much is dependent upon the
climatic conditions prevalent at the time of fruiting, that this feature
also is indeterminate. Rostafinski's figures, 21 and 26, Tab. II., show
the characteristic nodules and the typical net structure. It is to be
observed that Fig. 21 represents higher magnification; otherwise the two
figures are very much alike.

New England, New York, Pennsylvania, Maryland and South, Ohio,
Washington, California; Canada, Toronto.


7. CRIBRARIA DICTYDIOIDES _Cke. & Balf._

PLATE I., Figs. 5, 5 _a_, 5 _b_, and XIX., 6, 6 _a_, 6 _b_.

  1881. _Cribraria dictydioides_ Cke. & Balf., _Rav. Fung. Am._, 475.

Sporangia gregarious, of medium size, globose, cernuous, stipitate; the
stipe long, slender, tapering upwards, dull brown in color; hypothallus
none; the calyculus variable, sometimes well developed, as in _C.
aurantiaca_, sometimes rudimentary or represented only by irregular,
node-like ribs; the network delicate, the meshes small, few-sided; the
nodules large, prominent, brown, irregular, with several radiating,
free, projecting threads, beside the single continuous filaments which
pass from node to node; spore-mass pale, ochraceous; spores nearly
smooth, colorless, 5-7 µ.

This seems to be the most common _Cribraria_ in the Mississippi valley.
It is generally distinguished by the scant calyculus and the beautiful
richness of its clear delicate net. The stellate nodules especially
above, emit filamental rays in all directions, but are, notwithstanding,
united by single, unpaired threads only. The calyculus is often entirely
absent, and this has been supposed the typical condition; but, on the
contrary, there often may present itself a cup as distinct as in _C.
aurantiaca_. See, for this variation, _Bot. Gaz._ XIX., p. 398. The
rather large sporangia, .6-.7 mm., the nodes joined by single threads,
the remaining radiant threads, many or few, but very short--these seem
to be the most distinctly diagnostic characters, and these are
sufficiently constant to separate this species easily from _C.
intricata_ on the one hand and _C. tenella_ on the other. Mr. Lister
considers this merely a form of the next species.

Abundant on rotten logs of every sort, especially oak; common on the
lower side of rotting pine planks in wooden walks along the streets
everywhere. N. A. F., 2095, seems to belong here.

Pennsylvania, Ohio, North Carolina, Missouri, Illinois, Iowa, Nebraska.


8. CRIBRARIA INTRICATA (_Schrad._) _Rost._

  1797. _Cribraria intricata_ Schrad., _Nov. Gen. Pl._, p. 7.

Sporangia gregarious, globose, large, .7-1 mm. in diameter, nut-brown or
olivaceous, erect, stipitate; stipe long, slender, purplish brown,
flexuous; calyculus variable, sometimes occupying one-third of the
sphere, when it is delicately costate, concolorous with the stipe, and
passes over to the net by a distinctly toothed or serrulate margin,
sometimes represented by irregular ribs or costæ only; net well
differentiated, the threads delicate, transparent, yellow, connecting
large black nodules, running from one to the other in pairs or sometimes
three together, free ends not numerous, the meshes few-sided, often
triangular; spores in mass, dull olivaceous, under the lens pallid,
nearly smooth, 6-7 µ.

A very rare species, if indeed it occur in this country. At least the
form figured by Rostafinski, Tab. II., Fig. 27, and Massee, Pl. 1, Fig.
11, has not come to our notice. The parallelism of the net threads is a
touch added by Rostafinski; Schrader does not mention it. Lister makes
this species include the preceding. The form described in _Bull. Lab.
Nat. Hist. Ia._ II., p. 119, is _C. dictydioides_.

Reported from New York, New England and Pennsylvania.

In the English _Monograph_ we are repeatedly assured that this species
is common in the United States. The statement is made possible only by
the inclusion of the form originally described from America and truly
abundant east of the Rocky Mountains, _C. dictydioides_ Cke. & Balf.;
_C. intricata_, by all accounts, just as preeminently the species of
Europe. It is true that Schrader did not emphasize the parallel
connecting threads by which later authorities distinguish the form; he
had little occasion so to do, even did his figures intend accuracy in
each detail, which they did not, and Rostafinski's, though his drawing
is a diagram, certainly knew what he was doing. Cooke, in his list for
Great Britain, quotes the Polish text without dissent, and Massee
follows and illustrates; so that there can be no doubt as to what the
European species is.

In any cribraria the presence or relative obsolesence, of the calyculus
is of little taxonomic import since that structure is variable in every
species. In the latest edition of Mr. Lister's work, the American form
is entered as a variety in "hot-houses"; apparently adventitious; it is
indeed related to the European form but is a geographic species.


9. CRIBRARIA PIRIFORMIS _Schrader._

PLATE XVII., Fig. 9; PLATE XIX., Fig. 9.

  1797. _Cribraria piriformis_ Schrad., _Nov. Gen. Pl._, p. 4.

Sporangia gregarious, small, .3-.5 mm., turbinate or globose, erect,
purplish brown, stipitate; stipe comparatively short, tapering upward,
longitudinally furrowed, purple or brown; calyculus very well defined,
about one-third the sporangium, not ribbed, flattened or even umbilicate
below, the margin plainly denticulate, dusky brown; the net simple, the
meshes large, triangular, with few free ends; the nodules small,
globose or undifferentiated, slightly convex or flat; spore mass dull,
yellowish brown; spores by transmitted light pale ochraceous or
salmon-tinted, nearly smooth, 5-6 µ.

Schrader defined this beautiful form chiefly by its shape. This, though
variable, is yet generally so far pyriform as to show distinct
contraction toward the stipe. The well-defined calyculus is narrowed
below and eroded or denticulate above. The cyanic tints due to the
presence on the calyculus of radiating lines of purplish granules about
one-half the size of the spores, the net open, uniform, the stipe rather
stout, short, and distinctly furrowed, rising often from a small
hypothallus--these are marks of this species. The net suggests _C.
tenella_, but the latter species is much smaller, has a different stem,
much longer and unfurrowed. The cup here is more nearly that of some
form of _C. intricata_, but is better defined, passing into the net very
abruptly by the simple intervention of projecting teeth.

Apparently rare. Our specimens are from New York, through the courtesy
of Dr. Rex, Virginia, North Carolina, Iowa, Oregon, Colorado, and
represent, as usual a modification of the European type, _C. notabilis_
Rex. Miss Lister, _Mon., 2nd ed._, writes var. _notabilis_.

Colorado forms are remarkable for dense brown coloration.


10. CRIBRARIA TENELLA _Schrader._

PLATE XVII., Fig. 5.

  1797. _Cribraria tenella_ Schrad., _Nov. Gen. Pl._, p. 6.

Sporangia gregarious, small, .3-.5 mm. in diameter or smaller,
olivaceous or ochraceous, long-stipitate, nodding; stipe slender, dark
brown or blackish, very long, reaching 6 mm., weak and flexuous;
calyculus variable, sometimes well defined, brown, costate, sometimes
represented by the costæ only connected by a thin, transparent membrane;
net well differentiated, the meshes small, irregular, the nodes small,
black, more or less globular, prominent, connected by transparent
threads with occasional or a few free ends; spores in mass,
olivaceous-ochraceous, under the lens pallid, globose, smooth, 5-7 µ.

Very common eastward and south, on the weathered surface of rotten wood.
Generally easily recognized by its very long stipe, small, globose
sporangium dotted with numerous small roundish nodules projecting
plainly above the general surface. The obconic calyculus is always
represented in the outline if not in definite structure.

New England, New York, Pennsylvania, Ohio, Tennessee, Illinois,
Missouri, Iowa, Canada; Toronto,--_Miss Currie._


11. CRIBRARIA MICROCARPA (_Schrad._) _Persoon._

PLATE XVII., Fig. 4.

  1797. _Dictydium microcarpum_ Schrad., _Nov. Gen. Pl._, p. 13.
  1801. _Cribraria microcarpa_ Schrad., Pers., _Syn._, p. 190.
  1875. _Cribraria microcarpa_ (Schrad.) Rost., _Mon._, p. 235.
  1892. _Cribraria microcarpa_ Schrad., Massee, _Mon._, p. 63.
  1893. _Cribraria microcarpa_ Schrad., Morg., _Myx. Mi. Vall._, p. 15.
  1899. _Cribraria microcarpa_ Schrad., Macbr., _N. A. S._, p. 168.
  1911. _Cribraria microcarpa_ Pers., Lister, _Mycetozoa, 2nd ed._,
           p. 183 (?).

Sporangia loosely gregarious, very small, .2-.3 mm. in diameter, yellow
ochraceous, stipitate, nodding; stipe comparatively stout, dark brown or
blackish, tapering upward, often twisted at the apex as in _D.
cancellatum_; calyculus none, represented by simple ribs which give off
at intervals free or floating branchlets before blending into the common
net; net well developed, the meshes large, the nodes small, irregular,
though often rounded and prominent, black, connected by delicate
transparent threads, with free ends few or none; spore-mass yellow,
fading to ochraceous; spores pale, smooth, globose, 6-7 µ.

This species resembles at first sight the preceding, and has been often
mistaken for it. As a matter of fact, the distinctions are generally
very sharp. In the first place, the sporangia, when carefully measured,
are seen to be not more than half as great in diameter; the meshes of
the net, on the other hand, are much wider, the whole structure more
compact. The nodules are like those of _tenella_, but are much fewer.
The stipe is shorter, the cup wanting, and the costæ are few and simple.
The color suggests _C. aurantiaca_. The habitat and distribution as _C.
tenella_.

To anyone who will read the account of the species as given by the
English _Mon., 2nd ed._, p. 183, it is immediately apparent that the
author has in mind a different form from that seen and described in our
territory and previously noted by the authors of Europe. These from
Schrader down, agree in portraying a brunescent form with yellow spores;
Mr. Lister enters it with the cyanic series and so describes and figures
it throughout. Schrader figures a nut-brown species; Rostafinski uses
that descriptive term in connection with the general appearance when
fresh, but gives the spore-mass yellow; only in the stipe does he find
another tint, nut-brown-purple. The figure, 145 in the _Monograph_ now
before us portrays, except in color, our _C. tenella_ exactly. Dr. Rex,
_Bot. Gaz._, XIX., 398, compares the present species with _C.
minutissima_, and _C. tenella_ with _C. dictydioides_; which is correct
for the American presentation of the species named. _C. dictydioides_ is
certainly our presentation of _C. intricata_, a geographic species at
the least; but if _C. microcarpa_ is purple we have of it no
representation; our forms under that name are closely related to _C.
tenella_, a yellow-spored species, and might perhaps be there referred;
have, however, somewhat larger spores.


12. CRIBRARIA VIOLACEA _Rex._

PLATE XVII., Fig. 8.

  1891. _Cribraria violacea_ Rex, _Proc. Phil. Acad._, p. 393.

Sporangia scattered or gregarious, very small, .2 mm. in diameter,
violet tinted, erect, stipitate short, about one-half the total height,
concolorous, slender, tapering upward; calyculus crateriform,
persistent, or marked with minute plasmodic granules; the net
rudimentary or poorly developed, the meshes large, irregular, the
nodules also large triangular, violaceous; spores pale violet in mass,
by transmitted light reddish, 7-8 µ, minutely warted.

A very minute but well-marked species discovered by Dr. Rex in
Wissahickon Park, near Philadelphia, otherwise very rare. Lister,
however, reports it from England. In minuteness to be compared with _C.
minutissima_, from which its color instantly distinguishes it. Dr. Rex
reports the plasmodium as "violet black." All our specimens are on very
rotten wood, basswood, _Tilia americana_.

Pennsylvania, Illinois, Iowa.


13. CRIBRARIA PURPUREA _Schrad._

  1797. _Cribraria purpurea_ Schrad., _Nov. Gen. Pl._, p. 8.

Sporangia gregarious, large, 1 mm. in diameter, dark purple, erect,
stipitate, depressed-globose; stipe concolorous, furrowed, about twice
the diameter of the sporangium in length, with a distinct hypothallus;
calyculus persistent, less than half the sporangium, obscurely ribbed,
marked by concentric plications, the margin toothed; the net poorly
differentiated, the meshes irregular in form and size, as are also the
flat, unthickened nodes, the threads pale, free ends short and not
numerous; spore-mass purple; spores by transmitted light, pale or
colorless, 5-6 µ, smooth.

Rare. Found on rotten coniferous wood in deep forests. Easily recognized
by its large size and uniform purple color. To the next species it
offers a general resemblance, but has larger sporangia and an entirely
different net. The plasmodium just before the formation of the fruit is
scarlet.

Maine, New York, Pennsylvania, Ontario, Oregon, Colorado.


14. CRIBRARIA ELEGANS _Berk. & C._

  1873. _Cribraria elegans_ Berk. & Curt., _Grev._, II., p. 67.

Sporangia gregarious, erect or nodding, small, .4-.5 mm., bright purple,
stipitate; stipe long, slender, tapering upward, almost black, arising
from a scanty hypothallus; calyculus about half the sporangium, finely
ribbed, covered especially above with small purple granules, the margin
toothed or perforate; net well developed, the meshes small, polygonal,
the threads delicate, colorless, with many free ends, the nodules
dark-colored, numerous and somewhat prominent; spore-mass pale purple;
spores by transmitted light pale violaceous, smooth, 6-6.5 µ.

To be compared with the preceding. The small-meshed net with
well-defined, dark-colored nodules is distinctive, aside from the fact
of the much smaller sporangia. The stipe is also different, more
slender, smooth, and dark-colored. The habitat of the two species
appears to be the same. The present species is much more common, ranges
farther west, and is to be looked for on the Pacific coast.

New York, Pennsylvania, South Carolina, Missouri, Iowa; Black Hills,
South Dakota.


15. CRIBRARIA LANGUESCENS _Rex._

  1891. _Cribraria languescens_ Rex, _Proc. Phil. Acad._, p. 394.

Sporangia scattered, very minute, .25-.35 mm., spherical,
long-stipitate, drooping; stipe 2.5-3 mm., slender, flexuous, subulate,
rugulose; calyculus about one-third the sporangium, reddish brown,
shining, minutely striate with granular lines, the margin more or less
regularly serrate; net reddish brown, the meshes triangular and the
threads simple, the nodes large, polygonal, flat, but well
differentiated; the spores when fresh dull red in mass, paling with age;
by transmitted light colorless, 6 µ, smooth.

A very singular species, easily recognizable by its long, slender
stipes, terminating in exceedingly small spherical sporangia. The colors
are obscure, but the striations on the calyculus are violet-tinted, and
the reds perhaps predominate elsewhere. "In its scattered and solitary
growth, its tall, slender stipes, and relaxed habit it resembles _C.
microcarpa_, in its network it approaches _C. tenella_, and its spores
have the color of the paler form of _C. purpurea_." So Dr. Rex, _l. c._
Western forms of the first-named species have much shorter stipes; the
network in the specimens before us is unlike that of _C. tenella_, but
resembles that of _C. purpurea_.

Rare, on very rotten wood, in the forest. New York, Ohio, South
Carolina, Ontario.


16. CRIBRARIA CUPREA _Morgan._

PLATE XVII., Fig. 7.

  1893. _Cribraria cuprea_ Morg., _Jour. Cin. Soc_., p. 16.

Sporangium very small, .33 mm., oval or somewhat obvoid, copper-colored,
stipitate, nodding; stipe concolorous or darker below, subulate, curved
at the apex, 2-4 times the sporangium; calyculus about one-half the
sporangium, finely ribbed and granulose within, the margin nearly even;
the net rather rudimentary, the meshes large, triangular or
quadrilateral, the nodules also large, flat, concolorous, the threads
slender, transparent, with free ends few; spores in mass copper-colored,
by transmitted light colorless, smooth, 6-7 µ.

Recognizable by its small size and peculiar color, that of bright
copper, although this fades somewhat with age, and the metallic tints
are then lacking. Related to the preceding and in specimens having
globular sporangia closely resembling it; but the ground color in _C.
languescens_ is always darker, and the stipe proportionally much longer.
In habit the sporangia are widely scattered, much more than is common in
the species of this genus. Miss Lister, _2nd ed._ regards this as a var.
of No. 15.

Comparatively rare. Before us is one very small colony of sporangia from
Iowa, one from Ohio, and a large number from Missouri. If one may judge
from the material at hand, the favorite habitat is very rotten basswood,
_Tilia americana_.


=2. Dictydium= (_Schrad._) _Rost._

Sporangia distinct, gregarious, globose or depressed-globose, stipitate,
cernuous; the peridium very delicate, evanescent, thickened on the
inside by numerous meridional costæ which are joined at frequent
intervals by fine transverse threads more or less parallel to each
other, forming a persistent network of rectangular meshes.

The ribs or costæ of the spore-case radiate from the top of the stipe
and unite again at the top of the sporangium in a feeble, irregular net.
Schrader, _Nov. Gen. Pl._, p. 11, 1797, applied the name _Dictydium_ to
all _Cribraria_-like species in which the calyculus was wanting. Fries
follows this, _Syst. Myc._, III., p. 164. Rostafinski, _Versuch_, p. 5,
_Mon._, p. 229, first correctly limits the genus and separates it from
_Cribraria_. 1873-75.

A single species is widely distributed throughout the world,--


1. DICTYDIUM CANCELLATUM (_Batsch_) _Macbr._

PLATE I., Figs. 6, 6 _a_ and PLATE XIX., Figs. 1, 1 _a_, 1 _b_, 1 _c_,
2, 3.

  1789. _Mucor cancellatus_ Batsch, _Elench. Fung._, II., p. 131.
  1797. _Dictydium umbilicatum_ Schrad., _Nov. Gen. Pl._, p. 11.
  1801. _Cribraria cernua_ Pers., _Syn._, p. 189.
  1816. _Dictydium cernuum_ Nees, _Syst. d. Pilz._, p. 117.
  1875. _Dictydium cernuum_ (Pers.) Rost., _Mon._, p. 229.
  1893. _Dictydium longipes_ Morg., _Cin. Soc. Jour._, p. 17, in part.

Sporangia gregarious, depressed globose, nodding, the apex at length
umbilicate, stipitate, in color brown, or brownish purple; the stipe
varying much in length from two to ten times the diameter of the
sporangium, attaining 5-6 mm., generally erect, more or less twisted and
pallid at the apex, below dark brown, with hypothallus small or none;
calyculus often wanting, when present a mere film connecting the ribs of
the net; the net made up chiefly of meridional ribs connected at
intervals by transverse parallel threads, above an open _Cribraria_-like
network closing the apex and more or less rudimentary; the spores
varying in color through all shades of brown and purple when seen in
mass, by transmitted light reddish, 5-7 µ, smooth or nearly so.

This species in the United States is one of the most variable in the
whole group. The extremes of such variation might easily constitute
types for several distinct species were it not that in all directions
the varieties shade into each other so completely as to defy definition.
We have before us specimens purple throughout and short-stemmed; purple
with stem long, pale and twisted at apex; brown, with the same
variations; short-stemmed, with the apex of the stem pallid, and
long-stemmed, with and without the same peculiarity. Morgan (_Cin. Soc.
Nat. Hist. Jour._, 1893) would set off the purple, long-stemmed forms as
_D. longipes_, "stipe three to five times the sporangium," but here are
forms in which the stem is ten times the diameter of the sporangium,
which yet possess in all other particulars the characters of the
short-stemmed forms. European forms also vary. Massee figures one type;
Lister, one or two others; Rostafinski's figure indicates a taller form;
Fries says, "Stipes elongatus, peridio quinquies et ultra longior." It
seems reasonable to suppose that the variation is largely due to
atmospheric conditions at the time of fruiting. The purple forms may be
cases of arrested development, since the plasmodium appears to be in all
cases purple, or at least they seem to represent those plasmodia which
have failed of normal ripening. We may recognize two or three general
types, distinguished primarily by color:--

a. _D. cancellatum cancellatum._--Sporangia clear brown or with only a
purplish tinge, the stipe tapering upward, and in extreme cases
perfectly white at the twisted apex. The stipe in length ranges from
three to ten times the diameter of the sporangium. The reticulations of
the net are generally small and the ribs numerous. This is the most
highly differentiated, finished type of the species.

b. _D. cancellatum purpureum._--Sporangium dark, the purple tints
predominating, the stipe tapering upward, more or less twisted at the
paler, sometimes almost colorless, apex. The stipe ranges a little
shorter than in the preceding variety, three to seven times the
sporangium. The reticulations of the net are often coarse, the ribs
being fewer; the whole structure weak and showing signs of imperfect
development.

The figures, 1, 1 _a_, 1 _b_, 1 _c, l. c._, illustrate the ideal
accomplishment in form (a). The color is a clear definite brown with no
suggestion of purple anywhere. The stipes are three or four times the
diameter of the sporangium, brown below, white above, and twisted to
allow the sporangium to hang inverted. This is complete in every part; a
definite bell-shaped calyx, widening into the cancellate receptacle, the
margin constricted, and closed at last by the apical net, _cribrum_,
sign of the order.

In form (b), the structure is similar but by no means so symmetrical and
complete. The calyx often fails, or is present by obscure indications
only. The cancellation is coarser, the number of ribs fewer, the whole
sporangium more or less globose; ferruginous or purple, the prevailing
tint. Figs. on Pl. 1. are from the ferruginous type.

Figure 3 represents a beautiful thing; cup-less, ellipsoidal, delicate,
of average size and in every way well-proportioned, clear rosy brown in
color.

This may stand for a third variety; (c) _D. cancellatum prolatum_.

Common everywhere. The fruit appears in June on decaying logs and stumps
of various species of deciduous trees, conifers, etc., the finest, and
greatest variety, are from southern Missouri.


ORDER IV

=LYCOGALALES=

Fructification æthalioid; peridium membranaceous, tough, simple, without
vesiculose with protoplasmic masses, within gelatinous; the capillitium
of cortical origin, consisting of irregular lobate or branching tubules,
varying much in width, and marked by numerous corrugations, irregular
warts or bands; spores minute, ashen or pallid.

This order includes but a single genus,--


=Lycogala= _Micheli._

  1729. _Lycogala_ Micheli, _Nov. Plant. Gen._, pp. 216, 217.
  1753. _Lycoperdon_ Linn. _Syst. Nat._, in part.
  1794. _Lycogala_ Persoon, Römer, _N. Bot. Mag._, p. 87.

Micheli's description and figures, _Nov. Plant. Gen._, pp. 216, 217,
Tab. 95, leave no doubt but that this illustrious man had species of
_Lycogala_ before him when he described the genus. His figure 1. no
doubt portrays the second species in our present list. More recent
writers, from Persoon down, have used Micheli's designation, but
differed in regard to the limits to which the name should be applied. It
is here used substantially as in 1729. Fries and, after him, Rostafinski
make a mistake in quoting Retzius as writing _Lycogala_ (1769). Retzius
wrote _Lycoperdon sessile; Kongl. Vetenskaps Acad. Handling, för Ar._
1769, p. 254.


=Key to the Species of Lycogala=

  _A._ Æthalia irregularly globose.

     _a._ Cortex minutely roughened or warted; about
            12 mm. in diameter                        1. _L. epidendrum_

     _b._ Cortex smooth, size large                 2. _L. flavo-fuscum_

     _c._ Cortex rough; diameter 6 mm. or less           3. _L. exiguum_

  _B._ Æthalia conical                                   4. _L. conicum_



1. LYCOGALA EPIDENDRUM (_Buxb._) _Fries._

  1721. _Lycoperdon epidendron_, etc., Buxb., _En. Pl. Hal._, p. 203.
  1753. _Lycoperdon epidendrum_ Linn., _Sp. Pl._, p. 1184.
  1829. _Lycogala epidendrum_ (Buxb.) Fries, _Syst. Myc._ III., p. 80.

Æthalia solitary or clustered, depressed spherical, or, when crowded,
irregular, olivaceous or blackish, minutely warted, 3-10 mm. in
diameter, dehiscing irregularly, but more often near the apex; peridium
thin, but tough and persistent, made up of numerous agglutinated tubules
enclosing in their mashes peculiar cell-like vesicles; capillitium
parietal, consisting of long, branching, and anastomosing flattened
tubules extended inwardly among the spores, everywhere marked by
transverse wrinkles, ridges, and warts, the free ends of the ultimate
branchlets rounded, concolorous with the spores; spore-mass, when fresh,
rosy, or ashen with a rosaceous or purplish tinge, becoming with age
sordid or ochraceous, spores by transmitted light colorless, minutely
roughened or reticulate, 5-6 µ.

This is not only a cosmopolitan species, but is no doubt, the most
common slime-mould in the world. Found everywhere on decaying wood of
all sorts, more particularly on that of deciduous trees. It has likewise
been long the subject of observation. It is doubtless the "_Fungus
coccineus_" of Ray, 1690, and the type of Micheli's genus as here, 1729.
The different colors assumed, from the rich scarlet of the emerging
plasmodium to the glistening bronze of the newly formed æthalium, have
suggested various descriptive names,--as _L. miniata_ Pers., _L.
chalybeum_ of Batsch, and _L. plumbea_ Schum. The peridium is by authors
described as double. This is for description only. In structure the
outer and inner peridium completely blend. The outer is predominately
vesiculose, the inner more gelatinous. For discussion of the microscopic
structure see under the next species.

Common. New England, west to Nebraska, South Dakota, Colorado,
Washington, Oregon, California; Alberta to Nicaragua.

_Lycogala terrestre_ Fr., _Syst. Myc._, III., 83, appears to be a
variety of the present species. In spores and capillitial thread the
forms are indistinguishable; the difference is a matter of size, and to
some extent, of the color of the wall. The specimens are a little
larger, depressed and angular. The peridium is paler, smoother, though
sometimes almost black, thin, ruptured irregularly. But the form and
color of the peridium in the sporocarps of the older species vary much
in response to external conditions; on a substratum affording scant
nutrition the forms of fructification are minute; and in all cases, if
maturity be hastened, the peridium responds in darker colors. Under more
favorable conditions the wall is smoother and brighter.


2. LYCOGALA FLAVO-FUSCUM (_Ehr._) _Rost._

  1818. _Diphtherium flavo-fuscum_ Ehr., _Syl. Myc. Berol._, p. 27.
  1829. _Reticularia flavo-fusca_ (Ehr.) Fries, _Syst. Myc._, III.,
           p. 88.
  1873. _Lycogala flavo-fuscum_ (Ehr.) Rost., _Versuch_, p. 3.

Æthalia solitary or sometimes two or three together, large 2-4 cm. in
diameter, spherical or spheroidal, purplish-gray or brown, smooth,
shining; the peridium thick, simple but in microscopic section showing
two or three successive layers; capillitium of abundantly branching,
irregular, transparent tubules, marked by numberless warts and
transverse rings or wrinkles, spores in mass yellowish gray, by
transmitted light, colorless, smooth or only faintly reticulate or
roughened, 5-6 µ.

This, one of the largest and most striking of the slime-moulds, is by
students generally mistaken for a puff-ball. It occurs on stumps and
rotten logs of various sorts in the Mississippi valley, more often
affecting stumps of _Acer saccharinum_ L. The fructification, when
solitary, about the size of a walnut, though sometimes larger; when
clustered, the individuals are smaller. The form depends largely upon
the place in which the fruit is formed. The plasmodic mass is so large
that its form is determined by gravity. Thus on the lower surface of a
log raised a little distance from the earth the æthalium is often
pyriform. This fact did not escape Micheli. See _Nov. Plant. Gen._, Tab.
95. The plasmodium is pale pink, soon becomes buff when exposed in
fruiting, finally pallid or somewhat livid, and is outwardly changed
into the stout, tough peridium. This consists of an intricate network of
irregular gelatinous tubules enclosing within the meshes protoplasmic
masses of pretty uniform size, 60-100 µ. Outwardly the protoplasmic
vesicles predominate; inwardly the gelatinous tubules, which are, in
some instances at least, continued toward the centre of fructification
to form the capillitium. The protoplasmic masses referred to respond to
ordinary stains, are often broken into numberless small cells
corresponding in size and appearance to ordinary spores.

Not common. New England, Ohio, Iowa. Perhaps more abundant in the
Mississippi valley; Canada.


3. LYCOGALA EXIGUUM _Morg._

  1893. _Lycogala exiguum_ Morg., _Jour. Cin. Soc._, p. 8.

Æthalia small, 2-5 mm. in diameter, gregarious, globose, dark brown or
black, sessile, minutely scaly, irregularly dehiscent; the peridium
thin, the vesicles comparatively few, in irregular patches which are
more or less confluent; capillitium as in preceding species, the tubules
slender and branching; spore-mass pale, ochraceous, spores by
transmitted light colorless, almost smooth, 5-6 µ.

Found in the same situations as No. 1, and at the same season.
Recognizable by its _gregarious_ habit, not crowded nor superimposed,
small size, and dusky color. The little spheres occur a dozen or more in
a place, dark lead-colored, shading to black, opening rather regularly
at the top. It looks like a depauperate _L. epidendrum_, but seems to be
constantly collected.

Our specimens are from Ohio, Iowa, Missouri, Canada.


4. LYCOGALA CONICUM _Pers._

  1801. _Lycogala conica_ Pers., _Syn. Fung._, p. 159.
  1875. _Dermodium conicum_ (Pers.) Rost., _Mon._, p. 284.

Æthalia scattered, sometimes two or three together, small 2-4 mm. high,
conical, sessile, pallid, grayish brown, marked by obscure black
reticulations, opening regularly at the somewhat acuminate tip; peridium
thin in structure, as in _L. epidendrum_, but more delicate; capillitium
made up of abundant, slender, uniform threads almost smooth, simple, the
free ends obtuse, taking origin in the cortex much as in the preceding
species; spores in mass ochraceous, by transmitted light colorless,
minutely warted or faintly reticulate, about 5 µ.

A very distinct and rare little species. Well described by Persoon, who
also appears to have observed the plasmodium "_primo rubra_." The color
of the mature form varies with age; at first somewhat purplish. Dr. Rex
collected it in Pennsylvania; Mr. Morgan has it from Ohio; our specimens
are from southeastern Missouri.


ORDER V

=TRICHIALES=

Fructification sporangial, rarely plasmodiocarpous, the sporangia
stalked or sessile, gregarious or closely crowded, limeless throughout;
the capillitium of definite threads, free or attached to the sporangial
wall, isolated or combined into a net; spores generally some shade of
yellow, never purple or black.

The distinguishing feature in this order is found in the peculiar
sculpture of the capillitial threads. This is suggested by the tubules
of _Lycogala_, though probably the resemblance is superficial only. The
individual threads, as in _Trichia_, are called elaters, from their
probable efficiency in spore-dispersal.

As here limited, the order is coextensive with the _Calonemeae_ of
Rostafinski, except that that includes in addition the genera
_Prototrichia_ and _Dianema_. The course of differentiation may be
assumed to start with _Dianema_, through the _Perichaenaceae_ to the
_Arcyriaceae_ and again from the same starting-point through
_Prototrichia_ to the _Trichiaceae_.


=Key to the Families of the Trichiales=

  _A._ Capillitial threads transverse to the sporangial
         cavity, attached usually at each end, plain or
         only slightly roughened                           _Dianemaceae_

  _B._ Capillitium plain, papillose, or spinulose, often
         scanty, not netted, the threads sometimes
         attached by one end to the sporangium wall     _Perichaenaceae_

  _C._ Capillitium a distinct net, usually attached
         below to the sporangial wall; sculpture
         various, not continuous spiral bands              _Arcyriaceae_

  _D._ Capillitial threads transverse, fascicled,
         attached at both ends, but sculptured by well
         defined spiral bands                         _Prototrichiaceae_

  _E._ Capillitial threads typically free, sometimes
         more or less branched, forming a loose net
         attached below, characterized by definite
         spiral bands, or sometimes by scattered rings     _Trichiaceae_


_A._ DIANEMACEÆ

=Key to the Genera of the Dianemaceæ=

  _A._ Capillitial threads attached at one end, or free     1. MARGARITA

  _B._ Capillitial threads attached at each end               2. DIANEMA


=1. Margarita= _List._

  1894. _Margarita_ Lister, _Mycet._, p. 203.

Sporangia sessile, the capillitium simple, hair-like, coiled.


1. MARGARITA METALLICA (_Berk. & Br._) _List._

PLATE XVII., Figs. 1, 1 _a_, 1 _b_.

  1838. _Physarum metallicum_ Berk. & Br., _Mag. Zool. & Bot._, I.,
           p. 49.

Sporangia scattered or clustered, globose, or somewhat plasmodiocarpous,
.5-1 mm., sessile, coppery iridescent, the peridium thin, opening above
irregularly; capillitium of long flexuous, coiling, simple or little
dividing threads, nearly smooth, with infrequent attachments to the
peridial wall; spores in mass yellowish, transparent under the lens,
delicately verruculose, 10-12 µ.

One of the handsomer species of the present group. So far a Pacific
coast form. California, Oregon, Washington; reported from Chile.


=Dianema= _Rex_

  1891. _Dianema harveyi_ Rex, _Proc. Phil. Acad._, p. 397.

Sporangia simple or plasmodiocarpous; capillitium composed of threads
without characteristic thickenings running entirely across the
sporangium attached both to the base and to the opposite wall, not
joined to form a network.


=Key to Species of Dianema=

  _A._ Sporangia distinct, iridescent                    1. _D. harveyi_

  _B._ Fructification more or less plasmodiocarpous,
         dull brown                                   2. _D. corticatum_

  _C._ Sporangia, some of them stipitate               3. _D. andersoni_


1. DIANEMA HARVEYI _Rex._

PLATE XVI., Figs. 5 and 5 _b_.

  1891. _Dianema harveyi_ Rex, _Proc. Phil. Acad._, p. 397.

Sporangia gregarious, generally rounded or cushion-shaped, depressed,
sessile, iridescent bronze, 1 mm. in diameter; peridium thin,
translucent, opening irregularly; capillitium of simple threads, not
netted, but often forked two or three times, taut, running from base to
top; spores yellow, by transmitted light pale yellowish, minutely
roughened, 8-10 µ.

This interesting species was collected in Orono, Maine, in 1889, by
Professor F. L. Harvey, and so far as can be learned has not been taken
since. Mr. Lister records two species from England which he refers to
this genus. As to its systematic place, Dr. Rex says, _l. c._ "It stands
as a single representative of a new and separate family adjoining the
_Perichaenacae_ in the order _Calonemeae_ of Rostafinski."

Rare. Maine.


2. DIANEMA CORTICATUM _List._

PLATE XVI., Figs. 5 _a_, 5 _c_.

  1894. _Dianema corticatum_ List., _Mycetozoa_, p. 205.

"Plasmodium pink"; sporangia sometimes flat-hemispheric, more often
ill-defined, united in irregular, depressed, netted plasmodiocarps,
generally dull brown; peridium opaque, didermatous, capillitium of
simple or rarely branching filaments, variously beaded or marked with
spiral bands, lightly attached at either end, occasionally twisted
together; spore-mass dull brown, the spores in clusters of four or more,
colorless by transmitted light, more or less verruculose, ellipsoidal,
about 8-10 µ.

Our specimens are from the mountains of Alberta.

A curious, flat plasmodiocarp, an inch or more in length. It suggests
_Hemitrichia serpula_ prematurely dry.


3. DIANEMA ANDERSONI, _Morg._

_Dianema andersoni_, _Morg._ MS., _non. pub._

Sporangium globose, sessile or sub-stipitate, seated on a thin brownish
hypothallus; the wall a thin smooth pinkish membrane, when dry rugulose
and iridescent, the inner surface somewhat thickened below and brownish
at the base. Capillitium arising out of the thickened base, the threads
hyaline or pinkish, ascending, flexuous, simple, or branched a time or
two, the extremities attached on all sides to the wall of the
sporangium. Spores globose, very minutely warted, pale, pinkish, 10-11
µ, in diameter, free.

Growing on old wood and bark of _Alnus_; British Columbia, _W. B.
Anderson_.

Sporangium spherical, 6-8 mm. in diameter, sessile or on a very short
stipe. This species differs from D. harveyi Rex in the _uniform pinkish_
color of the wall and of the spores; the dividing threads are furnished
remotely with minute roundish tubercles as in _Didymium_; the spores are
somewhat larger than in _D. harveyi_.


_B._ PERICHÆNACEÆ

=Key to the Genera of the Perichænaceæ=

  _A._ Sporangia more or less plasmodiocarpous in type,
         terete; dehiscence irregular                      1. OPHIOTHECA

  _B._ Sporangia more or less polygonal in outline, or
         round, depressed; dehiscence circumscissile        2. PERICHÆNA


=1. Ophiotheca= _Currey_.

  1869. _Ophiotheca pallida_ Berk. & C., _Jour. Linn. Soc._, X., p. 350.

Fructification generally plasmodiocarpous, terete, bent or flexuous,
often annular or cornuate, rarely globose, opening irregularly, peridium
thin, not polished, covered more or less strongly with a distinct layer
of scales or granules; capillitium of slender, loosely branching
filaments, the surface rough to strongly spinulose; spores yellow.

As a generic name _Ophiotheca_ plainly has priority. _Cornuvia_ as
understood by Rostafinski has no representative so far in our region.


=Key to the Species of Ophiotheca=

  _A._ Plasmodiocarp usually upon herbaceous stems,
         slender                                    1. _O. vermicularis_

  _B._ Plasmodiocarp on rotting bark, logs, etc,

     _a._ Pale brownish or yellowish                2. _O. chrysosperma_

     _b._ Chestnut brown or blackish                    3. _O. wrightii_


1. OPHIOTHECA VERMICULARIS (_Schw._) _Macbr._

  1834. _Physarum vermicularis_ Schw., _N. A. F._, No. 2296.
  1869. _Ophiotheca pallida_ Berk. & C., _Jour. Lin. Soc._, X., p. 350.
  1873. _Ophiotheca umbrina_ Berk. & C. Grev., II., p. 88.
  1876. _Perichaena pallida_ (Schw.) Rost., _Mon. App._, p. 34.

Plasmodiocarp very slender, terete, elongate, flexuous or reticulate,
annular, etc., of dull gray or neutral tint; the peridium thin,
translucent, but with a delicate granular outer coating; capillitium of
slender threads, frequently branched, warted and usually minutely
spinulose; spore-mass ochraceous yellow; spores by transmitted light
pale yellow, minutely roughened, 10 µ.

Perhaps common, but seldom collected, probably overlooked on account of
protective coloration; the color is about that of the habitat, the
weathered surface of dead herbaceous stems and roots. On dead corn
stalks not infrequent. Differs from other species of the genus in having
smoother capillitium, for which reason Rostafinski calls the present
species _Perichaena vermicularis_. _O. pallida_ Berk. & C. seems to us
to be the same thing, _N. A. F._, 726.

New England, New Jersey, South Carolina, Ontario, Ohio, Iowa.


2. OPHIOTHECA CHRYSOSPERMA _Currey_.

  1854. _Ophiotheca chrysosperma_ Currey, _Quart. Mic. Jour._, II.,
           p. 240.
  1875. _Cornuvia circumscissa_ (Wallr.) Rost., _Mon._, p. 290.
  1911. _Perichaena chrysosperma_ Lister, _Mycetozoa, 2nd ed._, in
           part, p. 248.

Plasmodiocarp elongate, bent and curved in various ways, spherical, more
rarely annular or even reticulate, yellowish or ochraceous brown,
opening irregularly; peridium thin, with yellowish outer layer;
capillitium rather abundant, of threads slender, sparingly branched and
minutely but distinctly spinulose; spore-mass yellow, spores by
transmitted light pale, almost smooth, about 8 µ.

Occurs on the inner bark of deciduous trees, especially of oak. Not
common.

This is possibly _Cornuvia circumscissa_ (_Wallr._) of Rostafinski's
monograph; but it is doubtful to what Wallroth referred. Rostafinski's
other citations are equally uncertain. Currey's figures and description
alone merit recognition.

Ohio, Iowa, Tennessee; Canada.


3. OPHIOTHECA WRIGHTII _Berk._

PLATE II., Figs. 7, 7 _a_, 7 _b_.

  1868. _Ophiotheca wrightii_ Berk. & C., _Jour. Linn. Soc._, X.,
           p. 349.
  1876. _Cornuvia wrightii_ (Berk. & C.) Rost., _Mon. App._, p. 36.
  1892. _Cornuvia wrightii_ (Berk. & C.) Macbr., _Bull. Lab. Nat.
           Hist. Ia._, II., p. 122.
  1911. _Perichaena chrysosperma_ Lister, _Mycetozoa, 2nd ed._,
           p. 248.

Plasmodiocarp bent or short-flexuous, often arcuate or completely
annular, dark chestnut brown or black, opening irregularly; peridium
thin, brittle, translucent, covered without by a rather dense layer of
brownish or black brown scales; capillitium of long, sparingly branched
threads furnished with projecting spinules remarkable for their length,
about twice the diameter of the thread; spores yellow, minutely but
distinctly warted, about 12 µ.

This is the common species everywhere on the inner side of the bark of
fallen trees, _Ulmus_, etc. It is readily distinguished at sight by the
peculiar annular, looped, and U-shaped plasmodiocarps, with their dark
umbrine or blackened surface. From the preceding it is especially
distinguished by the spinulose capillitium and larger spores.

Not rare. New England, New York, Pennsylvania, Ohio.


=2. Perichæna= _Fries_

  1817. _Perichaena_ Fries, _Symb. Gast._, p. 11.

Sporangia flattened, sometimes small and roundish, more often larger,
polygonal by mutual interference, or irregular, the peridium thickened
outwardly by a dense reddish or brownish layer of scales; dehiscing by
circumscission or by a lid; capillitium often scant, of slender, warted,
yellowish threads, attached betimes to the upper wall; spores yellow,
oval or spherical.


=Key to the Species of Perichæna=

  _A._ Sporangia plainly flattened.

     _a._ Very flat, sporangia 1mm. or more in width    1. _P. depressa_

     _b._ Depressed; sporangia smaller                  2. _P. quadrata_

  _B._ Sporangia more or less spherical

     _a._ Chestnut brown                              3. _P. corticalis_

     _b._ Gray or canescent                            4. _P. marginata_


1. PERICHAENA DEPRESSA _Libert._

PLATE XVII., Fig. 10.

  1837. _Perichaena depressa_ Lib., _Fl. Crypt. Ard._, IV., No., 378.

Sporangia sessile, applanate, crowded, polygonal by mutual contact,
fuscous or chestnut brown, shining, opening by a definite lid;
spore-mass and capillitium yellow, the capillitium well developed, of
slender yellow threads of various widths, almost smooth; spores minutely
warted, 10-12 µ.

Easily recognized by the peculiar, polygonal, depressed-flattened
sporangia and consequent shallow spore-cases in which lie the yellow
spores and scanty capillitium. Rostafinski refers here _P. vaporaria_
Schw., No. 2311, but the meagre description seems rather to apply to the
next species. The original material is no longer accessible.

In the crevices and on the inside of bark of fallen logs of various
sorts, walnut, maple, etc.

Not commonly collected. Specimens are before us from New England,
Illinois, Iowa, Missouri, Florida, Mexico, Nicaragua. Probably over the
whole wooded region of the continent.


2. PERICHAENA QUADRATA _Macbr._

  1893. _Perichaena irregularis_ Berk. & C., Morgan, _Jour. Cin. Soc._,
           p. 20.

Sporangia very small, less than ½ mm., crowded, polygonal or
quadrangular, depressed, but not flattened, smooth, bright rufous or
brown; the peridium rather thick, yellow within, the dehiscence
circumscissile; capillitium scanty, of slender, sparingly branched
filaments, the surface minutely roughened, warted or spinulose;
spore-mass yellow; by transmitted light pale yellow, 9-11 µ.

Differs from the preceding by the much smaller size of the sporangia,
different color and habit. The sporangia, while depressed, still
maintain considerable rotundity; they are occasionally quite spherical,
and then of very uneven size, hardly in contact. In some cases the
plasmodium before maturing seems to assume the form of a plasmodiocarp,
which, by transverse fission at intervals, forms the curious four-sided
conceptacles. At other times the plasmodium assumes the shape of a flat
cushion or plate, which then subdivides into minute polygonal segments.
This form has been known some years to collectors, and, if named at all,
has been called _P. irregularis_. Lister, _l. c._, assures us that
Berkeley's type "is typical _P. depressa_."

Not common. Pennsylvania, Ohio, Illinois, Missouri.


3. PERICHAENA CORTICALIS (_Batsch_) _Rost._

PLATE II., Figs. 1, 1 _a_, 1 _b_.

  1783. _Lycoperdon corticale_ Batsch, _Elench. Fung._, p. 155.
  1875. _Perichaena corticalis_ (Batsch) Rost., _Mon._, p. 293.
  1817. _Perichaena populina_ Fries, _Symb. Gast._, p. 12.

Sporangia sessile, gregarious, flattened, hemispherical; peridia simple,
opening by a lid; dehiscence circumscissile, the upper part chestnut
brown, the lower almost black; capillitium feebly developed, smooth,
attached to the lid and usually coming away with it, bringing the
brilliantly yellow spore-mass, and leaving a delicate, shining cupule
adherent to the substratum; spores yellow, nearly smooth, 10-12 µ. On
and under the bark of dead elms of various species.

A very handsome little species occuring rarely with us, or perhaps
overlooked by virtue of its protective coloration. Found sometimes on
the inner side of the bark where the latter has separated, but not yet
wholly parted company with the wood. In such situations the tiny
sporangia are so nearly quite the color of the moist substratum as to
escape all but the closest scrutiny. The dehiscence is very remarkable,
characteristic, beautiful. Black, brown, chestnut, and gold are
harmoniously blended, in the opening coffers. Prior to maturity the
future line of fission is plainly indicated by the difference in color.

This is clearly the species found by Batsch "ligni demortui putridi in
interiore corticis pagina." Bulliard has also described and figured the
species, _Sphaerocarpus sessilis_ t. 417, Fig. V.

The capillitium is nearly smooth; the spores are only slightly roughened
by minute warts.

Apparently not common. Iowa, Missouri; Black Hills, South Dakota;
Canada;--_Miss Currie._


4. PERICHAENA MARGINATA _Schweinitz._

  1831. _Perichaena marginata_ Schw., _N. A. F._, No. 2319, p. 258.

Sporangia depressed, globose, polygonal as they become approximate or
crowded, hoary canescent, sessile; peridium rather thick, persistent,
circumscissile in dehiscence, covered without by minute whitish
calcareous (?) scales, within punctate by the imprint of the spores;
hypothallus distinct, white; capillitium scant or none! Spores in mass
dull yellow, by transmitted light pale, nearly smooth, 14-15 µ.

Lister, following Rostafinski, includes this form with the preceding.
The differences between the two forms are, it seems to us, sufficient to
make convenient their separation as by Schweinitz. Apart from the
peculiar incrustation in the present species, the larger spores, and
especially the peculiar white hypothallus, are distinctive. The method
of dehiscence is also different. In _P. corticalis_ the line of cleavage
before spore dispersal is indicated by a definite band surrounding the
sporangium. Nothing similar appears in the gray specimens of the present
form, although the dehiscence is quite as certainly circumscissile. The
habitat in American specimens is the _outer_ surface of the bark, which
causes the species generally, by protective coloration, to be
overlooked.

Not common. Pennsylvania, Ohio, Missouri.


_C._ ARCYRIACEÆ

=Key to the Genera of the Arcyriaceæ=

  _A._ Peridium becoming fragmentary, but persisting;
         capillitium non-elastic                          1. LACHNOBOLUS

  _B._ Peridium evanescent above, persistent below;
         capillitium elastic                                  2. ARCYRIA

  _C._ Capillitium elastic, bearing hamate branches     3. HETEROTRICHIA


=1. Lachnobolus= _Fries_.

  1829. _Lachnobolus_ Fries, _Syst. Myc._, III., p. 177.

Sporangia distinct, sessile or nearly so, globose or cylindric, often
distorted, scattered or densely crowded, the peridium extremely thin,
ruptured irregularly, and persistent in fragments; capillitium attached
at numerous points to the sporangial wall, forming a dense net, the
threads warted or spinulose, non-elastic.

Species of this genus are easily distinguished from those of the next by
the peculiar fragile peridium and the inelastic capillitium.


=Key to the Species of Lachnobolus=

  _A._ Sporangia pale yellow, on fallen flowers and
         fruit-burs of Castanea                         1. _L. globosus_

  _B._ Sporangia rosy or copper-colored, at length
         ochraceous                                 2. _L. occidentalis_


1. LACHNOBOLUS GLOBOSUS (_Schw._) _Rost._

  1822. _Arcyria globosa_ Schw., _Syn. Fung. Carol._, No. 400.
  1875. Lachnobolus globosus (Schw.) _Rost., Mon._, p. 283.
  1894. _Arcyria albida_ Pers. (in part) Lister, _Mycetozoa_, p. 186.

Sporangia on the spines of fallen chestnut burs, scattered, pale yellow
or whitish, small, globose, the peridium early evanescent above, more
persistent below, stipitate; stipe small, tapering upward, from a small
hypothallus; capillitium a dense but not expanding network attached
chiefly to the lower portion of the sporangial wall, minutely waited or
roughened, with few expansions or inflations; spores in mass pale
yellow, under the lens colorless, almost smooth, 7-8 µ.

This singular little species is remarkable chiefly in the habitat it
affects,--fallen chestnut burs. On these almost universal, but on
nothing else, except on the fallen catkins of the same species. Regarded
by Mr. Lister as _A. cinerea_, from which it differs constantly in form,
in capillitium more open and with larger threads, 4-5 µ in diameter as
well as in its unique habitat, and yellowish color.

Distribution coterminous with that of _Castanea dentata_
Borkhausen,--eastern half of the United States.


2. LACHNOBOLUS OCCIDENTALIS _Macbr._

PLATE II., Figs. 2, 2 _a_, 2 _b_; 4 and 4 _a_.

  1885. _Lachnobolus incarnatus_ (Alb. & Schw.) Macbr., _Bull. Lab.
           Nat. Hist. Iowa_, II., p. 126.

Sporangia scattered or crowded upon a hypothallus more or less distinct,
globose or ellipsoidal, short-stipitate, varying somewhat in color, at
first rosy or flesh-colored, later brownish or ochraceous; the peridium
exceedingly thin, pellucid, mealy, evanescent above, persisting as a
shallow cup below; capillitium inelastic, rather closely netted of
threads variable in thickness, marked by frequent thickenings or
expansions, everywhere warted, attached to the peridial walls, spores in
mass flesh-colored, under the lens colorless, smooth, globose, 7.5-9 µ.

This delicate and elegant little species appears to be not uncommon, but
is probably generally passed over as an _Arcyria_, which it
superficially resembles. When newly formed, the sporangia have a
peculiar rosy or flesh-colored metallic tint, which is all their own.
Within a short time this color passes, and most of the material comes
from the field brownish or ochraceous in color. Typical sporangia are
spherical on distinct short stipes; when crowded, the shape is of course
less definite. The capillitium never expands as in _Arcyria_, but,
exposed by the vanishing upper wall, remains a spherical mass resting
upon the shallow cup-like base of the peridium.

This species has been in the United States generally distributed as _L.
incarnatus_ (Alb. & Schw.) Schroet. A careful study of all descriptions
of European forms and comparison of many specimens leads us to believe
that we have here to do with a type presenting constant peculiarities.
We have in America nothing to correspond with the figures of Schweinitz,
Berkeley, or Lister. In the American gatherings the sporangia are
uniformly regular, globose, very generally short-stipitate, more or less
closely gregarious, never superimposed, or heaped as shown in Berkeley's
figure, for instance, _Ann. and Mag. Nat. Hist._, IV., xvii., Pl. ix.,
Fig. 2. The plasmodium of our species is white; as it approaches
maturity a rosy metallic tinge supervenes, quickly changing to dull
yellow or alutaceous. The graphic description given by Fries of
_Perichaena incarnata_, _Syst. Myc._, III., p. 193, presents scarcely a
character attributable to the form before us. _L. congesta_ Berk. & Br.,
evidently the form figured and described by Lister, _Mycetozoa_, p. 194,
Pl. lxx., B., resembles our species in color and capillitium, but is
entirely different in habit.

Not uncommon. Maine, Iowa, Missouri, Nebraska.


=2. Arcyria= (_Hill_) _Pers._

  1751. _Arcyria_ Sir John Hill, _Gen. Nat. Hist._, II., p. 47.
  1801. _Arcyria_ Pers., _Syn. Fung._, p. 182.

Sporangia ovoid or cylindric or even globose, stipitate; the peridium
thin, evanescent to near the base, the lower part persisting as a
calyculus; the stipe variable, packed with free cell-like vesicles,
resembling spores, but larger; capillitium attached below, to the
interior of the stipe or to the calyculus, in form an elastic network,
the tubules adorned with warts, spinules, half-rings, etc., but without
spiral bands or free extremities.

Micheli, of course, discovered the arcyrias, put them in two genera and
several species, which we may only dimly recognize. Persoon first saw
distinctly the outlines of the genus as now understood and adopted the
name given by Hill in his curiously prolix description of certain
species, probably partly of the genus _Arcyria_, partly _Stemonitis_.


=Key to the Species of Arcyria=

  _A._ Mature capillitium loosely adhering to the calyculus.

     _a._ Mature capillitium far-expanded, drooping.

          i. Dusky.

              O Long, 12 mm. or more                       1. _A. magna_

             OO Shorter, about 6 mm.                  2. _A. oerstedtii_

         ii. Yellow                                       3. _A. nutans_

     _b._ Mature capillitium short, not drooping, though
            sometimes procumbent.

          i. Capillitium greenish yellow              4. _A. versicolor_

         ii. Capillitium reddish, flesh-colored, at
               length sordid, etc.

              O Capillitium marked by transverse
                  half-rings, cogs, etc.               5. _A. incarnata_

             OO Capillitium marked by sharp-edged
                  transverse plates and by numerous
                  nodes                                 6. _A. nodulosa_

            OOO Capillitium marked by close
                  reticulations                       7. _A. ferruginea_

  _B._ Capillitium persistently attached to the calyculus.

     _a._ Sporangia reddish brown, etc.                 8. _A. denudata_

     _b._ Sporangia gray or ashen

          i. Simple                                      9. _A. cinerea_

         ii. Clustered                                 10. _A. digitata_

     _c._ Sporangia yellow                           11. _A. pomiformis_

     _d._ Sporangia rose-colored, .5-1.5 mm.           12. _A. insignis_


1. ARCYRIA MAGNA _Rex._

  1893. _Arcyria magna_ Rex, _Proc. Phil. Acad._, p. 364.

Sporangia densely aggregated, forming clusters of greater or less
extent, sometimes reaching several centimetres in either direction,
tawny gray or ashen, cylindric, tapering a little above, when expanded
reaching a length of half a centimetre or more, stipitate; peridium
evanescent except the small shallow cup-like base, the calyculus; stipe
long (1 mm.), weak, pale brown or reddish, tubular, the channel filled
with plasmodic masses; capillitium gray or drab-colored, very slightly
attached to the bottom of the calyculus, far expanded, forming a
loose-meshed net, the threads regular, cylindric, coarsely sculptured
with rings, half-rings, cogs, spines, etc.; spores in mass dull gray,
drab, under the lens colorless, papillate, with few papillæ, 7-8 µ.

This magnificent form resembles in habit and general appearance, save
color, _A. nutans_. The capillitium is, however, very different both in
the sculpture and in the more delicate markings of the threads. Dr. Rex,
_l. c._, has pointed out the lack of reticulation on the capillitium and
calyculus. The color is also diagnostic. A roseate variety seems to
occur with the present form. This is _A. magna rosea_ Rex, and appears
to agree with the type in all respects save color. The relationship here
must be determined by future inquiry. The capillitial threads are
remarkable for their graceful slenderness, regularity, and symmetry.


2. ARCYRIA OERSTEDTII _Rost._

  1875. _Arcyria oerstedtii_ Rost., _Mon._, p. 278, Fig. 196.

Sporangia cylindric, arcuate, 1.5 mm. high when unexpanded, closely
clustered, dull crimson, stipitate; peridium evanescent except here and
there a persistent patch, the calyculus shallow, plicate, papillose
within; stipe short, weak, concolorous; hypothallus distinct,
membranous, concolorous; capillitium a loose, far-expanding, elastic
net, the meshes uneven, often small, the threads characterized by much
irregularity and many bulbose thickenings, especially at the nodes,
strongly spinulose throughout; spore-mass crimson or reddish brown,
dull; spores by transmitted light colorless, nearly smooth, sub-globose,
9-10 µ.

This well-marked species is certainly rare within our limits. We have
specimens from New England and from Pennsylvania. The Iowa material
referred to this species, _Bull. Lab. Nat. Hist. Ia._, II., p. 125, is
_A. magna_ Rex. Rostafinski's figure is excellent in the present case,
and gives the idea of what we regard the typical marking of the
capillitium in _A. oerstedtii_. Externally the species resembles
somewhat _A. nodulosa_, and the network of the capillitium is also
suggestive of that form; the spiny capillitium is unique.

Rare. Adirondacks, New York--_Dr. Rex._


3. ARCYRIA NUTANS (_Bull._) _Grev._

PLATE II., Figs. 6, 6 _a_, 6 _b_.

  1791. _Trichia nutans_ Bulliard, _Champ._, p. 122, t. 502, III.
  1794. _Arcyria flava_ Pers., _Römer N. Mag. Bot._, I., p. 90.
  1824. _Arcyria nutans_ Grev., _Fl. Edin._, p. 455.

Sporangia crowded, cylindric, about 2 mm. high when unexpanded, pale
yellow or buff, short-stipitate or sessile by an acute base; peridium
wholly evanescent, except at the base, where persists the shallow,
colorless, often inwardly spinulose, plicatulate calyculus; stipe very
short or wanting; hypothallus thin but usually in evidence; capillitium
expanding to great length, forming an extremely flexile, plumose,
pendulose open network of pale ochraceous tint, the threads 3-4 µ in
thickness, adorned with spinules, sharp edged transverse plates
sometimes rings, the surface especially marked by an indistinct
reticulation; spore-mass buff or ochraceous, spores by transmitted light
colorless, smooth or nearly so, 7-8 µ.

This elegant species is not rare in undisturbed woods, especially on
fallen willows. The expanded capillitia are very soft and plume-like,
waving and nodding, very lightly attached below to the centre of the
peridial cup. The capillitium threads are rough, with irregular spines
and sharp-edged transverse plates, occasionally extending to form rings.
Resembles the first species somewhat in habit, size, and the spinescent
capillitium, but the resemblance is superficial only. The color is at
once diagnostic, and the capillitium is after all entirely different.
Not uncommon; Canada to Mexico; Maine to California; probably
cosmopolitan.

Bulliard's figure determines the synonymy. Persoon called the form _A.
flava_, because Bulliard had missed the genus.


4. ARCYRIA VERSICOLOR _Phillips._

  1877. _Arcyria versicolor_ Phillips, _Grev._, V., p. 115.
  1877. _Arcyria vitellina_ Phillips, _Grev._, V., p. 115.

Sporangia gregarious or more or less crowded, pyriform or clavate,
dingy, olivaceous yellow, becoming reddish, stipitate; peridium
membranous, largely persistent below, where it gives rise to the deep,
goblet-shaped calyculus; stipe strand-like, weak, sometimes wanting,
concolorous with the peridium; hypothallus prominent or venulose;
capillitium only slowly expanded, bright golden yellow or orange, the
threads rather broad, about 4 µ in diameter, regular, even, elegantly
branching, adorned with abundant short spines or warts, very small and
evenly distributed, the whole net anchored in the bottom of the vasiform
calyculus; spore-mass yellow, by transmitted light pale or nearly
colorless, smooth, about 10 µ.

This beautiful species is easily known by its comparatively large size,
peculiar, obovate shape, its brilliant color, and unusually persistent
membranous calyculus. It is peculiar to the western part of North
America, South Dakota west to the Pacific Ocean.

South Dakota, Colorado, California, Washington.

In the thin-covered mountains of Colorado, or hidden by the still drier
thickets and woods of Southern California, the fruit of this species is
small, somewhat as the clavate hemitrichia, pure, deep yellow, golden or
vitelline as Phillips says; but at loftier altitudes in the ever cool
forests on the high mountain flanks, beginning away up where the glacier
first starts to crack and slide between the 'cleavers', and forests of
stunted white-stemmed pine or wooly-fruited fir throw down their twigs
and foliage undisturbed through centuries,--on down to where the plowing
ice forgets its thrust, and melts to gentle floods amid spruce and
hemlock-groves,--all the way the beautiful versicolor spreads and
fruits, in August and September in all the richness of color which its
name implies, which Phillips saw, tints of red, and yellow, and olive,
and green, not brilliant, but in all the softer shades the artists love,
weaving, in far-spread strands of tufted cylinders and cones upturned,
fair as flowers, dusky garlands, by sunlight long forgot! Did not the
old-time botanists liken these things once and again, to flowers!


5. ARCYRIA INCARNATA _Persoon._

  1786. _Clathrus adnatus_ Batsch, _Elench. Fung._, 141. (?)
  1791. _Arcyria incarnata_ Pers., Gmel., _Syst. Nat._, II., 1467.

Sporangia closely crowded, cylindric, 1-1.5 mm. high, rosy or
flesh-colored, stipitate or almost sessile; stipe generally short,
sometimes barely a conical point beneath the calyculus; hypothallus
none; peridium wholly evanescent, except the shallow, saucer-like,
inwardly roughened calyculus; capillitium loose, broad, pale reddish,
attached to the cup at the centre only by strands which enter the hollow
stem, the threads adorned with transverse plates, cogs, ridges, etc.,
arranged in an open spiral; spore-mass rosy, spores by transmitted light
colorless, nearly smooth, 7-8 µ.

This common species is well marked both by its color and by the
delicate attachment of the capillitium to the calyculus. This is so
frail that the slightest breath ofttimes suffices to effect a
separation, and the empty calyculi are not infrequently the only
evidence of the fructification. This peculiarity did not escape the
attention of Persoon, and is well shown in his figure (_Obs. Myc._, I.,
p. 58, pl. V. Figs. 4 and 5) referred to by Gmelin, _l. c._ Batsch
simply named and described Micheli's figure (Tab. XCIV., Fig. 2), and
accordingly his claim to priority is no better than Micheli's figure,
which may possibly concern the present species, but is in no sense
determinative. It is impossible to say what Retzius meant by his
_Clathrus ramosus_, cited by Fries as a synonym here.

Common, especially in the Mississippi valley and south; more rare in the
west; Black Hills, South Dakota; Toronto to New Mexico.


6. ARCYRIA NODULOSA _Macbr._

PLATE III., Fig. 8.

Sporangia small, about 1 mm. high when unexpanded, crowded in clusters
of varying size, dull red or brownish, stipitate; the peridium
evanescent except the cup; stipe very short, concolorous, plicate as the
cup, or both smooth and unmarked; capillitium centrally attached, slowly
expanded, open-meshed, dense, the threads even, 5-6 µ wide, expanded in
globose, spinulose, or papillate-reticulate nodules, especially at
points of intersection, marked everywhere by close-set, transverse,
sharp-edged ridges, which encircle the thread and show no trace of
spiral arrangement; spore-mass brown or red brown; spores by transmitted
light pale yellow or colorless, minutely but distinctly roughened,
globose, 10-12 µ.

This variety is not distantly related to the preceding, as shown by the
centrally attached capillitial mass, but differs in several definite
particulars; the sporangia are much smaller of an entirely different
color with longer stipes, larger, rougher spores; the capillitium is
also peculiar, the threads unusually wide and densely corrugated
transversely, expanding at frequent intervals into globose nodules which
are sometimes double the width of the thread. In color suggests _A.
affinis_ Rost., but corresponds to no other particular.


7. ARCYRIA FERRUGINEA _Sauter._

PLATE XII., Figs. 6, 6 _a_, 6 _b_.

  1841. _Arcyria ferruginea_ Saut., _Flora_, XXIV., p. 316.
  1881. _Arcyria macrospora_ Peck, _Rep. N. Y. Mus._, XXXIV., p. 43.
  1883. _Arcyria aurantiaca_ Raunier, _Myx. Dan._, p. (44).

Sporangia ovoid or short cylindric, crowded or gregarious, dull red or
brownish, stipitate; stipe about equal to the sporangium, dark brown or
black; hypothallus well developed, membranous, yellowish brown
continuous; calyculus large, wide and shallow, smooth; capillitium
centrally attached, when fresh, brick-red in color, fading on exposure,
the threads of uneven size, those above 6-7 µ, below 3 µ, abundantly
branching, marked by conspicuous reticulations formed by the
intersection of numerous vertical plates or ridges; spore-mass reddish,
spores by transmitted light pale ochraceous, distinctly warted, 10-12 µ.

This species is distinguishable at sight by the peculiar color and form
of the sporangia. Mr. Durand in _Bot. Gaz._, XIX., pp 89, 90, gives a
careful study of the form. The same author declares the dehiscence
circumscissile. We cannot distinguish _A. aurantiaca_ Raun. from the
present form.

Rare. Maine, New York; Monterey, California.


8. ARCYRIA DENUDATA (_Linn._) _Sheldon._

PLATE II., Figs. 5, 5 _a_.

  1753. _Clathrus denudatus_ Linn., _Syst. Nat._, 1179.
  1794. _Arcyria punicea_ Pers., _Röm. N. Mag. Bot._, I., p. 90.
  1895. _Arcyria denudata_ (Linn.) Sheld., _Minn. Bot. Studies_,
           No. 9, p. 470.

Sporangia crowded or gregarious, ovoid or short cylindrical, tapering
upward, red-brown, stipitate; peridium evanescent except the plicate
calyculus; stipe about equal to the expanded capillitium, concolorous,
plicate or striate, ascending from a small hypothallus; capillitium
attached to the whole inner surface of the calyculus and connate with
it; hence not deciduous, bright red or carmine when fresh, turning brown
or paler with age, the threads even, about 3 µ adorned with a series of
rather distant cogs or half rings, which form around the thread a
lengthened spiral; spore-mass red or reddish brown, spores by
transmitted light colorless, nearly smooth, 6-8 µ.

This species is easily distinguished from all other of similar tints by
the attachment of the capillitium. In this respect it corresponds with
the following species. In the adornment of the threads it is like _A.
incarnata_. It is by far the commonest species of the genus, and
probably enjoys a world-wide distribution. To be found at all seasons on
the lower side of fallen sticks, _Populus_, _Tilia_, etc.

Micheli, Pl. XCIV., shows that he had the present species. The
description given by Linné is worthless, but helped out by Micheli, and
several other authors of the eighteenth century, who take the trouble to
describe the species, but still give the Linnean binomial as a synonym;
we may give Linné here the credit. As a matter of fact, Batsch under
_Embolus crocatus_ first presents an unmistakable description and
figure.

Maine to the Black Hills and Colorado, and north and west; Alaska to
Nicaragua.


9. ARCYRIA CINEREA (_Bull._) _Pers._

PLATE II., Figs. 3, 3 _a_.

  1791. _Trichia cinerea_ Bull., _Champ. de France_, p. 120, Tab. 477,
           Fig. iii.
  1801. _Arcyria cinerea_ (Bull.) Pers., _Syn. Fung._, p. 184.

Sporangia scattered or gregarious, ovoid or cylindrical, generally
tapering upward, about 2-3 mm. high, ashen gray, sometimes with a
yellowish tinge, stipitate; calyculus very small, thin; stipe about half
the total height, rising from a small hypothallus, thin, gray or
blackish, densely crowded with spore-like cells; capillitium dense,
freely branching, ashen, or yellowish, little wider below, minutely
spinulose; spore-mass concolorous, spores by transmitted light
colorless, smooth, 6-7 µ.

A very common little species, easily recognized by its color and habit.
The capillitium is more dense than in any other species and expands
less. The stipe is about equal to the expanded capillitium, unusually
long. The plasmodium occurs in rotten wood, especially species of
_Tilia_, is gray and, judging from the number of sporangia found in one
place, scanty.

Bulliard, _l. c._, gives the first account of the species by which it
can with any certainty be identified. By some authors _Clathrus
recutitus_ Linn. is cited as a synonym. We fail to distinguish _A.
cookei_ Mass. from the old type.

Widely distributed; Maine to Alaska, and south to Mexico and Nicaragua.


10. ARCYRIA DIGITATA (_Schw._) _Rost._

  1831. _Stemonitis digitata_ Schw., _N. A. F._, p. 260, No. 2350.
  1868. _Arcyria bicolor_ Berk. & C., _Jour. Linn. Soc._, X., p. 349.
  1875. _Arcyria digitata_ (Schw.) Rost., _Mon._, p. 274.

Sporangia compound, that is gathered in tufts, number 3-12 or more on a
single stipe, the clusters themselves scattered; individual sporangia
elongate cylindric, about 3-4 mm. long, ashen gray or nearly white,
stipitate; stipe as long or longer than the sporangium, stout, sometimes
showing traces of consolidation of several, sometimes none, dark brown
or black; capillitium looser and more expanded than in the last, the
threads more strongly spinulose; spore-mass concolorous, spores under
the lens colorless, smooth, globose, 7.5-8 µ

Closely related to the preceding, but different in habit and on the
whole larger and more robust throughout. The stipes in some cases are
completely merged in one; in others traces of coalescence remain. The
number of united sporangia varies. There are some clusters before us
containing 16 and 18 in a single fascicle!

Not very common. On rotten wood of deciduous trees, especially south.

New England, Pennsylvania, Ohio; Black Hills, South Dakota, and south to
Nicaragua.

_Arcyria bicolor_ Berk. & C. seems to refer to the fact that the
sporangia have sometimes an ochraceous tint. Berkeley's specimens are
from Cuba. Our latest specimens are from Nicaragua; the form seems not
to be reported from the old world.


11. ARCYRIA POMIFORMIS (_Leers_) _Rost._

  1775. _Mucor pomiformis_ Leers, _Flor. Herb._, p. 218.
  1875. _Arcyria pomiformis_ Rost., _Mon._, p. 271.

Sporangia scattered, gregarious, globose, bright yellow, very minute,
.5 mm. high, .3 mm. in diameter, stipitate; stipe short, one-third the
total height, pale brown or yellow; hypothallus none; capillitium loose,
freely expanding, not deciduous, honey-yellow, the threads generally
wide, 4-5 µ, toward the periphery more narrow, 2.5 µ warted, marked with
blunt spinules, which not infrequently pass into distinct transverse,
narrow plates or half-rings, free ends clavate and numerous; spore-mass
yellow, spores by transmitted light smooth, granular, globose, 7-9 µ.

This species as represented by the material before us seems constant in
size, color, and microscopic characters, in all which it differs from
all species here listed. It resembles somewhat _Lachnobolus globosus_
Schw., but differs in habit, habitat, color, the capillitium, its
attachment and in the mode of dehiscence. In the present species the
wall is evanescent almost _in toto_; in _L. globosus_ is it remarkably
persistent, and the capillitium is adherent.

Probably rare. Its smallness removes it from sight of all but the most
exact collectors. Maine, New York, South Carolina, Alabama, Missouri,
Iowa; Black Hills, South Dakota; Ontario;--_Miss Currie._

While usually remotely gregarious a collection from southern California
shows that on occasion the entire plasmodium may pass to fruit with
narrowest limits, forming a stipitate, compact, globose mass of crowded,
superimposed sporangia as in _Oligonema nitens_. Set Plate XX., Fig. 12.


12. ARCYRIA INSIGNIS _Kalkbr. & Cke._

  1882. _Arcyria insignis_ Kalkbr. & Cke., _Grev._, X., p. 143.
  1911. _Arcyria insignis_ Kalkbr. & Cke., List., _Mycet., 2nd ed._,
           p. 240.

Sporangia gregarious or clustered, pale or bright rose-colored, .5-1.5
mm. in height, stipitate, ovate or cylindric; stipe short, .2-.4 mm.
red, with spore-like cells; capillitium a close net-work of delicate
threads with a few bulbous free ends, with faint transverse bands or
short spinules, or nearly smooth, colorless beneath the lens; spores
colorless, nearly smooth, 6-8 µ.

Reported from Mass. by Miss Lister. Should follow No. 8: apparently a
very delicate form of the common species, _A. denudata_.


=3. Heterotrichia= _Mass._

  1892. _Heterotrichia_ Mass., _Mon._, p. 139.

Sporangia distinct, stipitate; the peridium simple evanescent above as
in _Arcyria_; capillitium centrally attached, freely branched, the
threads within very slender, without broad, anastomosing to form a dense
peripheral network, and everywhere extended to form short, free, often
hamate tips. A single species,--


1. HETEROTRICHIA GABRIELLAE (_Rav._) _Mass._

PLATE XIII., Figs. 1, 1 _a._

  1850. _Arcyria gabriellae_ Rav. _in litt. ad Cooke_.
  1892. _Heterotrichia gabriellae_ Mass., _Mon._, p. 140.
  1911. _Arcyria ferruginea_ Saut., var. _heterotrichia_ List., _Mycet.,
           2nd ed._, p. 234.

Sporangia crowded or gregarious, oblong cylindric, ovoid, at first red,
becoming yellowish brown, stipitate; the peridium evanscent except the
calyculus, which is small and thin, polished; stipe shorter than the
expanded capillitium, pale reddish brown; capillitium centrally
attached, showing threads of two sorts, those within freely branching,
slender, 1-1.5 µ, marked with half-rings or ridges, those on the
periphery very different, yellow, broad, 5-6 µ, forming rather dense
reticulations, with abundant free tips, acute and often curved, the
whole surface here minutely and densely warted; spore-mass reddish
yellow, spores by transmitted light colorless, globose, 7-8 µ.

The peculiar double capillitium seems to separate this form from the
true arcyrias. Some difference in the diameter of the capillitial
threads in different regions is not infrequent in the several species of
_Arcyria_, but that difference is here emphasized and rendered yet more
striking by the peculiar free tips. The present forms bear only the most
superficial resemblance to _A. ferruginea_ Saut., with which species it
is in some quarters sought to unite it.

Very rare. Collected, as noted, nearly fifty years ago in South Carolina
by Ravenel, it was more recently (1896) again collected in Maine by the
late Professor Harvey.


_D._ PROTOTRICHIACÆ

A single genus,--


=Prototrichia= _Rost._

  1876. _Prototrichia_ Rost., _Mon. App._, p. 38.

A single species,--


1. PROTOTRICHIA METALLICA (_Berk._) _Mass._

PLATE XVIII., Figs. 12, 12 _a_, 12 _b_.

  1860. _Trichia metallica_ Berk. Hook., _Fl. Tasm._, 2, p. 168.
  1866. _Trichia flagellifera_ Berk. & Br., _Ann. Mag. Nat. Hist._, 3,
           XVII., p. 56.
  1876. _Prototrichia flagellifera_ (Berk.) Rost. _Mon. App._, p. 38.
  1894. _Prototrichia flagellifera_ Rost., List., _Mycet. 2nd ed._,
           p. 206.
  1899. _Prototrichia flagellifera_ (Berk. & Br.) Rost., Macbr.,
          _N. A. S._, p. 199.
  1892. _Prototrichia metallica_ Mass., _Mon._, p. 127.
  1911. _Prototrichia metallica_ Mass., List., _Mycet., 2nd ed._,
           p. 260.

Sporangia sessile, scattered or sometimes crowded, brown, sometimes with
a rosy tinge, about 1 mm. in diameter; peridium a thin, transparent,
iridescent membrane, bearing in its inner surface the distal attachments
of the capillitial threads; capillitium of numerous brown, spirally
banded threads, which take origin in the base of the sporangium, become
subdivided as they ascend, and are at length attached by their tips to
the sporangium wall; spore-mass brown, spores by transmitted light pale,
minutely roughened.

This curious form, with its spirally sculptured capillitial threads
attached at both ends, stands intermediate between _Dianema_ and
_Hemitrichia_ and _Trichia_. Berkeley called it a trichia, ignoring the
attachment of the threads. Cooke notes this as sufficient to exclude the
form from the genus. But it remained for Rostafinski to make the
transfer by setting up for its reception the genus now adopted. He
preferred the later (1866) specific name as more descriptive. Miss
Lister reverts to the earlier name with the remark; "Little now remains
of the type _Prototrichia metallica_ Berk. from Tasmania; but the
specimen is referred to _Prototrichia flagellifera_ by Rostafinski who
saw it in good condition."

Not uncommon in the abietine forests of the West. Alberta, Oregon,
Washington, California, Nevada, Montana, Idaho, Colorado.


_E._ TRICHIACEÆ

Capillitium marked by spiral bands, sometimes scattered rings, etc., the
threads entirely free, or at least loosely branched, and with free tips
more or less numerous.

=Key to the Genera of the Trichiaceæ=

  _A._ Capillitium threads long, generally united to
         form a loose net, centrally attached.

     _a._ Sculpture spiral                            1. _Hemitrichia_

     _b._ Sculpture reticulate                           2. _Calonema_

  _B._ Capillitial threads shorter, entirely free,
         though sometimes branched.

     _a._ Threads, elaters, marked by spiral bands        3. _Trichia_

     _b._ Sculpture irregular or wanting                4. _Oligonema_


=1. Hemitrichia= _Rost._

  1829. _Hemiarcyria_ Fries, _Syst. Myc._, III., p. 183 in part.
  1873. _Hemitrichia_ Rost., _Versuch_, p. 14.

Capillitium a tangled net of more or less branching and anastomosing
fibres centrally attached; the sculpture regular, of conspicuous
spirally winding bands or ridges; habit and color various.

The species here associated are intermediate between _Arcyria_ and
_Trichia_, resembling the former in the capillitial net and the latter
in thread-sculpture. Fries applied the name _Hemiarcyrieae_ to a group
of trichias so-called, citing _H. rubiformis_ as the first. In his
_Versuch_ Rostafinski wrote _Hemitrichia_ and afterward _Hemiarcyria_ in
the _Monograph_. Massee combines the genera _Arcyria_ and _Hemiarcyria_
under the former name.

=Key to the Species of Hemitrichia=

  _A._ Plasmodiocarpous

     _a._ Plasmodiocarp net-like, yellow                 1. _H. serpula_

     _b._ Imperfectly plasmodiocarpous, brown          2. _H. karstenii_

  _B._ Sporangia all distinct.

     _a._ Sessile; very short stalked

          i. Peridium hyaline, iridescent                  3. _H. ovata_

         ii. Peridium opaque                            10. _H. montana_

     _b._ Stipitate, generally distinctly so; sometimes
            nearly sessile.

          i. Yellow or ochraceous.

              O Stalk hollow.

                 + Small, ½ mm., iridescent           6. _H. leiocarpa_

                ++ Larger, 1 mm., smooth but not iridescent

                   1. Free ends more or less abundant    8. _H. clavata_

                   2. Free ends none                   9. _H. stipitata_

             OO Stalk solid                              7. _H. intorta_

         ii. Not yellow.

              O Ruby red                               4. _H. vesparium_

             OO Copper-colored                           5. _H. stipata_


1. HEMITRICHIA SERPULA (_Scop._) _Rost._

PLATE III., Figs. 4, 4 _a_, 4 _b_.

  1772. _Mucor serpula_ Scop., _Fl. Carn_, II., p. 493.
  1794. _Trichia serpula_ (Scop.) Pers., _Röm. N. Bot. Mag._, I., p. 90
  1875. _Hemiarcyria serpula_ (Scop.) Rost., _Mon._, p. 266.

Fructification plasmodiocarpous, often covering several square
centimetres, terete, branching freely and usually everywhere reticulate,
rusty, tawny, or bright yellow; the peridium thin, transparent, with
irregular dehiscence; hypothallus none; capillitium variable, a tangle
of long yellow threads, sparingly branched, free everywhere, except
below, spinulose, the free tips spinose, acuminate, spiral ridges three
or four, with traces of longitudinal striæ; spore-mass golden yellow,
spores beneath the lens pale yellow, globose, delicately reticulate,
about 10 µ.

Very common, recognized by its bright yellow color and conspicuous
reticulate habit. The plasmodium is yellow, at least upon emergence, and
passes almost without change to fruit. Found on rotten logs of every
description, on the _lower_ surface. In the Mississippi valley, the
lower surface of planks used in the construction of sidewalks appears to
be a favorite habitat.

Common west to the Rocky Mountains, south to Mexico and Nicaragua.


2. HEMITRICHIA KARSTENII (_Rost._) _List._

  1876. _Hemiarcyria karstenii_ Rost., _Mon., App._, p. 41.
  1891. _Hemiarcyria obscura_ Rex, _Proc. Phil. Acad._, p. 395.
  1894. _Hemitrichia karstenii_ Lister, _Mycetozoa_, p. 178.

Fructification plasmodiocarpous, with a tendency to form distinct
sessile, globose sporangia, color brownish red; capillitium a sparingly
branched network, with free ends few, the thread marked by seven or
eight faint spirals, the interspaces narrow, dull red in color, and 2.5
µ in diameter; spores yellow, delicately warted, 10-10.5 µ.

This is doubtless a very rare species. In the description we have
followed Dr. Rex, _l. c._, as being more to the point for American
forms. It is not improbable that the American material may after all be
distinct, as discrepancies, if one may judge by descriptions, are not
few. Lister, who had a slide from Dr. Rex, considers the European and
American forms the same.

In outward appearing, plasmodiocarpous phases of this species very
closely resemble forms of _Licea_ or _Ophiotheca_, and are in
consequence often wrongly labeled.

Toronto; Montana--_Anderson_. To be looked for north and west.


3. HEMITRICHIA OVATA (_Pers._) _Macbr._

  1796. _Trichia ovata_ Pers., _Obs. Myc._, I., p. 61, and II., p. 35.
  1863. _Trichia abietina_ Wigand, _Pringsh. Jahr._, III., p. 33,
           Tab. ii., Fig. 11.
  1875. _Hemiarcyria wigandii_ Rost., _Mon._, p. 167.

Sporangia crowded or sometimes closely gregarious, sub-globose or
turbinate, shining yellow, sessile, the peridium thin, iridescent;
capillitium a tangle of sparingly branched yellow or ochraceous-yellow
threads, rather slender, 3-5 µ, marked by one or two prominent spiral
bands forming a loose somewhat irregular spiral, the free ends
not infrequent, inflated and rounded; spore-mass yellow or
yellow-ochraceous, spores by transmitted light pale yellow,
distinctly and sharply spinulose, but not netted, 10-11 µ.

A rare and beautiful species, distinguished well by the small size,
about .5 mm., by the thin iridescent peridium, as by the microscopic
characters of the capillitial threads.

There is no doubt that this is Persoon's _Trichia ovata_. His
description is accurate in all that pertains to external features, and
Rostafinski, _App._, p. 41, explicitly says that he _saw_ in Persoon's
herbarium specimens of the species bearing the name cited. Just why
Rostafinski did not here adopt the older name is not clear, nor is there
excuse for abandoning Wigand's name were Persoon's invalid. According to
Lister, _Trichia nana_ Mass., from Maine, is the same thing. Persoon,
_l. c._, gives a synonymy which, in the nature of case, is unverifiable,
the specific characters being microscopic.

Fries, _Syst. Myc._, III., p. 187, confirms Persoon and takes pains to
say that the color separates it from _T. chrysosperma_ with which it is
sometimes compared.

Rare. Maine, Massachusetts, New York, Ohio, Toronto.


4. HEMITRICHIA VESPARIUM (_Batsch_) _Macbr._

PLATE III., Figs. 2 and 2 _a_.

  1786. _Lycoperdon vesparium_ Batsch, _Elench. Fung._, pp. 255, 256,
           Fig. 172.
  1794. _Trichia rubiformis_ Pers., _Röm. N. Bot. Mag._, I., p. 88.
  1875. _Hemiarcyria rubiformis_ (Pers.) _Rost., Mon._, p. 262.

Sporangia clustered or crowded, rarely single, clavate or subcylindric
stipitate or sessile, dark wine-red or red-black in color, the peridium
in perfect specimens glossy or shining metallic, opaque; stipes solid,
usually blent together, concolorous; capillitium of intertwisted slender
threads, sparingly branched, marked by three or four spiral ridges,
abundantly spinulose, the free tips also acuminate, terminating in a
spine, the whole mass dull red. Spore-mass brownish-red, spores by
transmitted light reddish-orange, very distinctly warted, sub-globose,
10-12 µ.

A most common species, on rotten wood everywhere, especially in forests.
Recognized generally at sight by its color and fasciculate habit. The
peridium shows a tendency, often, to circumscissile dehiscence, and
persists long after the contents have been dissipated, in this condition
suggesting the name applied by Batsch, _vesparium_, wasp-nest. The
capillitium is remarkably spinescent, the branching of the threads,
rare. Rostafinski describes the spores as smooth; they seem to be
uniformly distinctly warted. The plasmodium is deep red, and a
plasmodiocarpous fructification occasionally appears.

Throughout the whole range, New England to Washington and Oregon, south
to Nicaragua; Toronto.


5. HEMITRICHIA STIPATA (_Schw._) _Macbr._

PLATE I., Figs. 8, 8 _a_, 8 _b_.

  1834. _Leangium stipatum_ Schw., _N. A. F._, p. 258, No. 2304.
  1876. _Hemiarcyria stipata_ (Schw.) _Rost., Mon. App._, pp. 41, 42.
  1894. _Arcyria stipata_ (Schw.) Lister, _Mon. Mycetozoa_, p. 189.

Sporangia distinct, crowded, cylindric or irregular, overlying one
another, rich copper-colored, metallic, shining, becoming brown,
stipitate; peridium thin, the upper portion early evanescent, the base
persistent as a cup, as in _Arcyria_; capillitium concolorous, the
thread abundantly branched to form a loose net, with many free and
bulbous ends, pale under the lens, marked by three or four somewhat
obscure spiral bands and a few wart-like or plate-like thickenings;
stipe very short; spore-mass reddish, spores by transmitted light pale,
nearly or quite smooth, 6-8 µ.

This species is known at sight by its peculiarly beautiful tint when
fresh, as by the crowded prolix habit of the singular overlying
sporangia. The netted capillitium and the evanescent peridium suggests
_Arcyria_, but there are abundant free tips, and the threads are
unmistakably spirally wound, especially in the large, handsome sporangia
characteristic of the Mississippi valley. It is a boundary form
unquestionably. The stipe is generally very short, about one-tenth the
total height; sometimes, when the peridium is more globose, the stipe is
proportionally longer. Specimens from Iowa show fructifications several
centimetres long and wide.

Not rare. New England to the Black Hills and south.


6. HEMITRICHIA LEIOCARPA (_Cke._) _Macbr._

  1877. _Hemiarcyria leiocarpa_ Cke., _Ann. Lyc. Nat. Hist. N. Y._,
           XI., p. 405.
  1891. _Hemiarcyria varneyi_ Rex, _Proc. Phil. Acad._, p. 396.

Sporangia simple, obovate or pyriform, rarely almost globose, pallid,
with a stem of the same color, as long as the diameter of the
sporangium; spore-mass and capillitium concolorous, or with slight
ochraceous tint; capillitium forming a loose net, the tubes branching in
a reticulate manner; spirals three, thin, prominent, along the convex
sides of the tubes mixed with a few obtuse spines; spores globose, with
a thin membrane, 12-14 µ.

Such is the original description of this distinctly American species.
_H. varneyi_ Rex should differ in having spirals seven or eight, and
spore only 6.25 µ. Mr. Lister, who has compared types of both species,
declares them the same! The present writer has been unable to secure
authentic specimens.

Pennsylvania.


7. HEMITRICHIA INTORTA _List._

  1891. _Hemiarcyria intorta_ Lister, _Jour. Bot._, p. 268.
  1891. _Hemiarcyria longifila_ Rex, _Proc. Phil. Acad._, p. 396.
  1894. _Hemitrichia_ intorta List., _Mycetozoa_, p. 176.

Sporangia gregarious, globose-turbinate or pyriform, golden-yellow,
stipitate; peridium thin, translucent, shining, opening at the summit
irregularly, leaving a funnel-shaped receptacle below; stipe dark red
brown, solid, rugulose; capillitium of threads sparingly branched, but
looped and doubled upon themselves and constantly intertwisted,
orange-yellow, 3-4 µ in diameter, with spirals four, sparingly
spinulose, even and regular, the longitudinal striæ conspicuous; spores
in mass concolorous, under the lens yellow, delicately warted, globose,
9-10 µ.

Concerning this species, Dr. Rex says: "Externally this species
resembles _H. clavata_ Pers., and has probably often been mistaken for
it. The capillitium, however, in its structural details and habit of
growth, is widely different. The partial untwisting of the loops of the
capillitium by drying, after the rupture of the sporangium, causes it to
be projected and elongated sometimes two or three times the length of
the sporangium." Outwardly the open sporangium, by the projecting free
tips, reminds one of a trichia. The capillitium is like that of _H.
vesparium_, but less rough, and, of course, different in color.

Rare. Fairmount Park, Philadelphia; Ohio, Iowa.


8. HEMITRICHIA CLAVATA (_Pers._) _Rost._

PLATE III., Figs. 1, 1 _b_.

  1794. _Trichia clavata_ Pers., _Röm. N. Bot. Mag._, I., p. 90.
  1873. _Hemitrichia clavata_ Pers., Rost., _Versuch_, p. 14.
  1875. _Hemiarcyria clavata_ (Pers.) Rost., _Mon._, p. 264.
  1893. _Hemiarcyria ablata_ Morg., _Jour. Cin. Soc._, p. 30.
  1893. _Hemiarcyria funalis_ Morg., _Jour. Cin. Soc._, p. 32.

Sporangia clavate or turbinate, gregarious, scattered or crowded,
yellow, olivaceous or brownish, stipitate; the peridium generally thin,
evanescent above, breaking away so as to leave a more or less definite
cup beneath; stipe about one-half the total height, reddish,
reddish-brown, or blackish, hollow about half-way down; capillitium
various, yellow or ochraceous, made up of slender threads more or less
freely branched and netted, bearing four or five regular, even, spiral
plates which project sharply and are generally smooth, the free
extremities numerous or almost none, swollen, or simply obtuse;
spore-mass concolorous, spores by transmitted light pale yellow,
globose, minutely but distinctly warted, 8-9 µ.

This cosmopolitan species is generally one of the first brought in by
the collector, its color and comparatively large size, 2-3 mm. high,
making it conspicuous. Nevertheless, we are not able to recognize it in
the descriptions of the older authors. Rostafinski quotes Schmiedel,
_Icones_, 1776, as affording the earliest account of the species, but
neither his description nor figure is definitive. Even Bulliard fails us
here, and is differently interpreted by different authors. Persoon's
description is none too good, but is reënforced by Fries and
Rostafinski. The capillitium is variable both in the degree of
smoothness presented, and the number of free ends, and the amount of
branching. The spores in all specimens we have examined are remarkably
constant in size and surface. In typical specimens free ends are easily
discoverable, the branching forms a definite net, and the perfectly
formed capillitial thread is smooth. In some American forms--developed
under less favorable circumstances?--the net is less determined, the
free ends are many, and the spirals minutely rough. Here may be placed
_H. funalis_ Morgan, _l. c._

Widely distributed. New England to Colorado, south to Mexico.


9. HEMITRICHIA STIPITATA (_Mass._) _Macbr._

  1889. _Hemiarcyria stipitata_ Mass., _Jour. Mic. Soc._, p. 354.
  1893. _Hemiarcyria plumosa_, Morg., _Jour. Cin. Soc._, p. 29.

Sporangia scattered, seldom crowded, obovoid or turbinate, olivaceous
yellow, stipitate; the peridium smooth without, granulose within,
evanescent above, persisting as a funnel-shaped cup below; the stipe
long, reddish or blackish, rising from a small hypothallus; capillitium
of threads 5-6 µ thick, very much branched, forming a dense net, free
ends none, or not evident; the sculpture as in _H. clavata_, smooth and
regular; spore-mass yellow; spores by transmitted light yellow, minutely
warted, 7-8 µ.

This form corresponds in nearly every respect with _H. clavata_, except
in the structure of the capillitium. The color is rather ochraceous,
dirty yellow, and the stipe is proportionally longer and darker, but the
form of the net is positive and gives to the species a decidedly
striking and unique appearance, so that it may be recognized by the
naked eye. It looks like an arcyria and for this reason Professor Morgan
said _H. plumosa_. Lister regards it as the same as our number 8.

Common. Ohio, Illinois, Missouri, Iowa, and west; south to Mexico.


10. HEMITRICHIA MONTANA _Morgan._

Sporangia scattered or gregarious more or less closely, globose,
whitish, sessile or very short stipitate; the peridium opaque, dull
white, persistent below; capillitium deep yellow, the threads abundantly
branched, forming a compact network, 7 µ wide, bearing spirals five or
six, uneven and irregular, or anon interrupted, conspicuously spinulose
or warted, free tips not lacking, generally inflated; spore-mass yellow,
spores by transmitted light pale, nearly colorless, distinctly warted,
10 µ.

Recognizable by its peculiar pallid, sessile sporangia, as by the
internal structure. Perhaps related to _Hemiarcyria bucknalli_ Mass. Our
specimens are from Mr. Morgan, of Ohio, with the statement that they
were collected in the San Bernardino Mountains, California, by Mr. S. B.
Parrish; collected later from Monterey south.

Common throughout south-western states to lower California.

=2. Calonema= _Morgan._

  1893. _Calonema_ Morgan, _Jour. Cin. Soc._, p. 33.

Sporangia sub-globose, crowded or superimposed, irregular sessile;
hypothallus none; capillitium of slender tubules, arising from the
sporangium base, branched, marked with branching veins in an irregular
reticulation, and terminating in free extremities. Spores yellow.


1. CALONEMA AUREUM _Morgan._

PLATE XIII., Figs. 2, 2 _a_, 2 _b_, 2 _c_.

  1893. _Calonema aureum_ Morgan, _l. c._

Sporangia crowded or heaped in scattered clusters; peridium thin, golden
yellow, adorned with intricate radiating veinlets capillitium of threads
more or less branched, attached below, free above, the surface to the
very tips venulose, interrupted with rings or fragmentary spirals, the
apices bulbous and obtusely conical; spore-mass yellow, spores by
transmitted light bright yellow, covered by a network of interlocking
plates, as in _T. favoginea_, globose, 14-16 µ.

A curious form, related to _Hemitrichia_, much as _Oligonema_ is to
_Trichia_. Related to both the genera first named, but distinct, in the
peculiar sculpture, from _Hemitrichia_, and from _Oligonema_ in that the
threads are not entirely free. Professor Morgan's original
determination, founded on Ohio materials is confirmed by material sent
us by Professor Underwood from Alabama.


=3. Trichia= (_Haller_) _Rost._

  1768. _Trichia_ Haller, _Hist. Stirp. Helv._, III., p. 114, in part.
  1875. _Trichia_ (Haller) Rost., _Mon._, p. 243.

Sporangia distinct, sessile or stipitate; capillitium of distinct
elastic threads, free acuminate at each end, yellow or more rarely
reddish or brown; spores generally yellow.

The trichias are easily recognized among their kind by their beautiful
spirally wound, elastic capillitial threads, the _elaters_; these are
entirely free, about 3-4 mm. in length, simple or only rarely branched,
and generally acute at each extremity. The spiral bands, sometimes
called _taeniae_, are generally very uniform in thickness, distance from
each other, and pitch, and in many species are further reënforced by
minute longitudinal plications running from one spiral to the next.
Furthermore, the spirals may be smooth or spinulose the elater uniform
throughout or enlarged betimes by nodes and swellings. Taken altogether,
the trichias with the species of the genus next following exhibit the
highest degree of differentiation attained by the Myxomycetes.

Most of the earlier authors, including Haller, used the generic name
_Trichia_ to cover a variety of forms. It is here used with the limits
sketched by De Bary in 1859 and 1864 (_Die Myxomyceten_), and followed
more exactly ten years later by his pupil, Rostafinski.


=Key to the Species of Trichia=

  _A._ Sporangia, in typical cases at least, wholly sessile.

     _a._ Gregarious; hypothallus none.

          i. Peridium brown or reddish brown.

              O Elaters smooth.

             OO Spirals even, regular                1. _T. inconspicua_

                 + Spirals irregular                    2. _T. contorta_

                ++ Elaters rough, spinescent            3. _T. iowensis_

         ii. Peridium olivaceous or yellow.

              O Elaters smooth                             4. _T. varia_

     _b._ Hypothallus distinct; sporangia crowded;
            spores reticulate, banded, or netted.

          i. Spore-bands pitted                       6. _T. persimilis_

         ii. Spore-bands, narrow, plain                7. _T. favoginea_

        iii. Spores covered by a delicate net             5. _T. scabra_

  _B._ Sporangia stipitate.

     _a._ Hypothallus distinct                         8. _T. verrucosa_

     _b._ Hypothallus none; peridium checkered with
            pale reticulations.

          i. Brownish red or black                     10. _T. botrytis_

         ii. Olivaceous.

              O Elaters smooth                         11. _T. subfusca_

             OO Elaters rough                            12. _T. erecta_

     _c._ Peridium plain, shining                     13. _T. decipiens_

     _d._ Peridium plain, dull black                  14. _T. lateritia_


1. TRICHIA INCONSPICUA _Rostafinski._

PLATE III., Figs. 5, 5 _a_, 5 _b_.

  1875. _Trichia inconspicua_ Rost., _Mon._, p. 259.

Sporangia gregarious or crowded, small, spherical, ellipsoidal or
arcuate, brown or reddish brown, sessile; hypothallus none; capillitium
dull, dark, ochraceous, the elaters long, slender, even, about 3 µ wide,
the spirals three or four rather closely wound, the apices attenuate,
acute, sometimes turned to one side; spore-mass concolorous, spores pale
ochraceous, minutely but distinctly warted, 10-12 µ.

One of the smallest of the _Trichiae_, not uncommon in the Mississippi
valley on decaying fallen stems of _Populus_--sp. Distinguished at sight
from all except No. 3 following, by its small size and brown color.
Under the lens the long, delicate, finely sculptured capillitial
threads, with fine tapering threads are distinctive.

New England, New York, Pennsylvania, Illinois, Iowa, Missouri, Nebraska;
Black Hills, South Dakota; Toronto.


2. TRICHIA CONTORTA (_Ditmar_) _Rost._

PLATE XIII., Figs. 7, 7 _a_.

  1811. _Lycogala contortum_ Ditmar, Sturm, _Deutsch. Fl._, III.,
           Tab. 5.
  1872. _Trichia reniformis_ Peck, _Rep. N. Y. Mus._, XXVI., p. 74.
  1875. _Trichia contorta_ Rost., _Mon._, p. 259.

Sporangia gregarious, or crowded, small, ellipsoid or reniform, arcuate,
dark red brown, sessile; hypothallus none; capillitial mass ochraceous
or dull yellow, the elaters few, irregular, the spirals uneven,
irregular, often projecting and thin, though generally flat or obscure,
the apices more or less swollen, ending in a curved tip; spore-mass
concolorous, spores beneath the lens bright yellow, papillose, 10-12 µ.

This species resembles the preceding in color, but is of less aggregate
habit, and the sporangia are more plasmodiocarpous, reniform, arcuate,
etc. The capillitium is also distinctive, the sculpture irregular,
uneven with general lack of symmetry. Our description is made up from
specimens of _T. reniformis_ Peck, which appears to be the American form
of Rostafinski's species.

Rare. New York, Montana?


3. TRICHIA IOWENSIS _Macbr._

PLATE III., Figs. 3, 3 _a_, 3 _b_; PLATE X., Fig. 5.

  1892. _Trichia iowensis_ Macbr., I_a., Bull. Lab. Nat. Hist._, II.,
           p. 133.

Sporangia sessile, gregarious, spherical or reniform, with no
hypothallus, purple brown; spores and spore-mass yellow; elaters with
three or four spiral bands unevenly distributed, and with occasional
inflations, sparingly branched, spinulose, especially where inflated,
spinules long, 3-6 µ, recurved, often bifid or trifid, especially at or
near the acuminate tip; spores delicately warted, 9-11 µ.

This species occurs not rarely and is found on the bark of _Populus_, so
far, exclusively. The sporangia are inconspicuous until opening by
fissure they display the yellow spores and capillitial threads. The
species is immediately recognized by its elaters, whose numerous and
lengthened spinules are unlike those of any cognate form, reminding one
of the capillitium of _Ophiotheca_. Related to the two preceding, but
distinct by its spinulose capillitium.

Iowa, Missouri; Black Hills, South Dakota.

_Trichia andersoni_ Rex carefully described by Morgan, _Myx. Mi. Val._,
p. 38, belongs with this first group, four small species, the
inconspicuous. To the present writer in each the structure seems
distinct. In the herbarium a small bit of Anderson's material has rested
long; but it must not be lost to sight. The species is sure to be taken
again in the cool mountains, somewhere abundant; as these stretch from
Alberta to far Alaska. The capillitium is very even the taeniae closely
wound, the elater-ends often furcate.


4. TRICHIA VARIA (_Pers._) _Rost._

PLATE IV., Figs. 3, 3 _a_, 3 _b_.

  1791. _Stemonitis varia_ Pers., Gmel., _Syst. Nat._, II., 1470.
  1794. _Trichia varia_ Pers., _Röm. Neu. Mag. Bot._, I., p. 90.
  1829. _Trichia varia_ (Pers.) Fries, _Syst. Myc._, III., p. 188.
  1875. _Trichia varia_ (Pers.) Rost., _Mon._, p. 251.

Sporangia gregarious or sometimes closely crowded, globose, obovoid, or
irregularly globoid, yellowish or ochraceous, shining, sessile, or with
a short black stipe; hypothallus none; capillitium of rather long,
simple, or more rarely branched elaters, 4-5 µ, wide, marked by
irregular spirals generally only two, prominent and narrow and in places
remote, the apices acute, about twice the elater diameter; spore-mass
yellow, spores by transmitted light dull yellow, 12-14 µ, delicately
verruculose, guttulate.

A very common species, very variable in form, stipitate forms occuring
anon beside those which are irregular and sessile. According to
Rostafinski the stipitate phase constitutes the _T. nigripes_ of Persoon
and other authors. The capillitium is, however, characteristic
throughout. The two spiral bands wind loosely and irregularly and
present an elater unlike anything else in the group except the same
structure in _T. contorta_, but here the elater is narrow and the
sculpture obscure. Since the specific distinctions are purely
microscopic, the synonymy beyond Rostafinski is mainly conjectural. It
is possible that Fries properly applied the name.

Common. Maine to Oregon and California, and south to Arkansas and
Alabama.


5. TRICHIA SCABRA _Rost._

PLATE IV., Figs. 4, 4 _a_, 4 _b_.

  1875. _Trichia scabra_ Rost., _Mon._, p. 258.

Sporangia closely crowded upon a well-developed hypothallus, regular,
globose or turbinate-globose, orange or golden brown, smooth, shining;
capillitial mass clear, golden yellow, or sometimes rusty orange, the
elaters simple, long, 4-5 µ in width, the spirals three or four, closely
wound, spinulose, even and regular, the apices short, acuminate;
spore-mass concolorous, under the lens spores yellow, covered by a
delicate fine-meshed network, or simply spinulose under low power, 10-12
µ.

Generally a well-marked species, easily recognized by its regular but
roughened capillitial threads. Under a 1-12 objective the spores are
also diagnostic. To the unaided eye it resembles the next species in
both color and habit. Fructifications two inches or more in length and
half as wide are not infrequent on the lower side of fallen stems in
forests of deciduous trees. The plasmodium is white.

Not uncommon. Maine to Washington, Oregon, Alaska, and south to Missouri
and Arkansas.


6. TRICHIA PERSIMILIS _Karst._

PLATE IV., Figs. 1, 1 _a_, 1 _b_, 1 _c_; 6, 6 _a_, 6 _b_, 6 _c_, 6 _d_.

  1868. _Trichia persimilis_ Karst., _Not. Saellsk. Fenn. Förh._ IX.,
           p. 353.
  1869. _Trichia affinis_ De Bary, _Fuckel, Sym. Myc._, p. 336.
  1875. _Trichia jackii_ Rost., _Mon._, p. 258.
  1877. _Trichia abrupta_ Cke., _Myxom. U. S._ p. 404.
  1878. _Trichia proximella_ Karst., _Myc. Fenn._, IV., p. 139.

Sporangia globose or obovoid or irregularly spherical, shining, golden
yellow to tawny, anon iridescent with metallic lustre, sessile;
hypothallus thin, but usually very distinct; capillitial mass ochraceous
or tawny yellow, the elaters long, even, about 4 µ wide, the spirals
four, more or less spinulose, generally joined by longitudinal ridges,
the apices short, tapering regularly, anon bifurcate; spore-mass
concolorous, spores by transmitted light bright yellow, marked by an
irregular or fragmentary banded reticulation, the bands broad, flat, and
pitted, 10-12 µ. Plasmodium said to be white.

This species, common throughout the northern world, is distinguished
from its congener, the following, not only by the episporic character,
but generally by its different peridium and more sombre colors. It never
shows at maturity the brilliant golden yellow fluff that hangs in masses
about the open and empty vases of _T. favoginea_, a fact not unnoted by
Batsch, and rendering his figure and description so far determinable.

The episporic network shows all degrees of perfection or imperfection,
and the elater also varies somewhat both in the apices and distinctness
of longitudinal striæ. The several synonyms listed seem to have taken
origin in a recognition of some of the more pronounced variations. In
any event the American form _T. abrupta_ Cke., with bifid apices,
belongs here, and European specimens seem to show the identity of forms
described by Karsten and De Bary.

Not rare. New England, Canada, New York, Pennsylvania, Ohio, Alabama,
Missouri, and west.


7. TRICHIA FAVOGINEA (_Batsch_) _Pers._

PLATE IV., Figs. 5, 5 _a_, 5 _b_.

  1786. _Lycoperdon favogineum_ Batsch, _Elench. Fung._, p. 257,
           Fig 173, _a_, _b_.
  1791. _Sphaerocarpus chrysospermus_ Bull., _Cham. de Fr._, Tab. 417,
           Fig. 4.
  1794. _Trichia favoginea_ (Batsch) Pers., _Röm. N. Mag. Bot._, I.,
           p. 90.
  1875. _Trichia chrysosperma_ (Bull.) Rost., _Mon._, p. 255.

Sporangia closely crowded, cylindric or prismatic by mutual pressure,
obovoid, sessile, olivaceous yellow, smooth and shining; the peridium
thin, opening above somewhat stellately, persistent; capillitium golden
yellow, escaping entirely from the peridia, and forming woolly masses
above them, the threads long, even, beautifully sculptured, bearing
spirals about four, usually smooth and connected by light longitudinal
ridges, the apices short tapering, about equal to the width of the
elater, 6-7 µ; spores concolorous, by transmitted light paler, but still
bright yellow, the episporic net conspicuous, the bands narrow and high,
not pitted nor fragmentary, in form irregularly globose, 12-14 µ.
Plasmodium yellow.

A common and beautiful species recognizable at sight, after the peridia
break, by the aggregate capillitium constantly in evidence above the
abandoned vasiform peridia. The figures of Bulliard are unsatisfactory,
although the description he gives and the name he suggests, still
current, may lead us to concede that he had our species before him. The
spores are larger than in _T. persimilis_, and the episporic net
different, the "border" wider. The plasmodium in the latitude of Iowa
not uncommon in woods in June, after emerging passes into fruit in the
laboratory in about forty-eight hours, and the rupture of the peridia
follows presently. The hypothallus is quite distinct, extra-marginal,
and in substance like to the peridial wall.

Not rare. Throughout the northern forests, Maine to Washington and
Oregon, south to Alabama, Louisiana, Mexico.


8. TRICHIA VERRUCOSA _Berk._

  1860. _Trichia verrucosa, Fl. Tasm._, II., p. 269.

Sporangia pyriform, or obovoid, shining, ochraceous from the color of
the contents, stipitate, more or less botryoid or connate; stipe twice
the height of the spore-case, reddish brown, simple or consolidated with
others, weak, inclined, or procumbent; hypothallus distinct; spore-mass
ochraceous yellow, the elaters simple, with smooth tapering points, with
spirals three or four, the spores beautifully and strongly reticulate,
after the manner of the spores in the species preceding, with the meshes
generally complete and always large, quite variable in size 12-16 µ.

Rostafinski quotes the species (_teste_ Lister) from Chile. Specimens in
the herbarium of the State University of Iowa are from Jalapa, Mexico,
collected by Mr. C. L. Smith. The species may be therefore expected in
the southern United States. Berkeley described it from Tasmania. _T.
superba_ Mass, from description would seen to be the same thing.


9. TRICHIA PULCHELLA _Rex._

  1893. _Trichia pulchella_ Rex, _Proc. Phil. Acad._, p. 366.

Sporangia solitary or in groups of four or five, bright vitelline
yellow, sessile; the peridium thin, transparent, opening irregularly
above; hypothallus none; capillitium bright yellow, not emergent, the
threads narrow, 3-4 µ, wound with spirals three or four, more or less
irregular, smooth, longitudinal ridges wanting, the apices rather long,
acuminate, about twice the diameter of the elater, or anon clavate or
even globose, bulbose at the tip and furnished with several stout
spines; spore-mass concolorous; under the lens spores colorless, marked
by a very feebly developed reticulation of _T. persimilis_ type, but the
bands narrow and, as shown by the narrow "border," low, meshes few and
often imperfect, globose or sub-globose, about 12 µ.

The episporic characters of this species ally it to _T. persimilis_ most
nearly. The reticulations are possibly not more divergent from the
typical form of that species than are the same features in some other
forms there included. But in the present case, added to the episporic
sculpture, we must reckon the peculiar capillitial thread, unlike that
seen in either of the chrysospermatous forms, and the gregarious habit
without hypothallus. These peculiarities seemed to Dr. Rex distinctive,
and as they appear constant they may be left to separate the species.


10. TRICHIA BOTRYTIS _Persoon._

PLATE XIII., Figs. 8, 8 _a_.

  1791. _Stemonitis botrytis_ Pers., Gmel., _Syst. Nat._, II., 1468.
  1794. _Trichia botrytis_ Pers., _Röm. N. Mag. Bot._, I., p. 89.
  1803. _Sphaerocarpus fragilis_ Sowerby, _Eng. Fung._, I., p. 279.
  1829. _Trichia pyriformis_ Fries, _Syst. Myc._, III., p. 184.
  1875. _Trichia fragilis_ (Sow.) Rost., _Mon._, p. 246.

Sporangia gregarious, scattered, sometimes combined in clusters,
pyriform or turbinate, stipitate, red-purple or, ochraceous-brown the
peridium breaking up irregularly, the dehiscence sometimes prefigured by
pale reticulations on the surface; stipe solid, single, or united in
clusters of five or more together, dark-colored, red or purple-brown,
opaque; capillitium orange, ochraceous yellow, or even reddish brown,
the threads simple or rarely branched, long-fusiform, about 4 µ thick at
the centre, tapering gradually to the long accuminate, apiculate tips,
spirals three or four, even, smooth, rather closely wound and traceable
almost to the apex; spores concolorous in mass, under the lens pale,
globose, more or less closely minutely warted but not reticulate, 10-12
µ.

A species remarkable for its variations in color. More commonly the
unopened sporangia are opaque brown, by reason of a dense outer wall,
and more frequently simple, or if compound, show but two or three
united. The reddish variety, vinous or scarlet-black in color, is
remarkably fasciate. Some clusters show twenty or more stipitate,
globose sporangia, conjoined by their distinct but coherent stems. In
such fruitings the sporangia are small, .5 mm. In the brown sporangia
the dehiscence, as stated, is often definitely prefigured; in the
multiple, red, obscurely, if at all. As presented in collections from
the eastern United States, the two forms might well be disjoined.
Persoon, however, discussed both together and so they remain.

Saccardo includes _Craterium floriforme_ Schw. here.

By the descriptions of the earlier authors it is impossible to
distinguish this from _H. vesparium_ on the one hand, and _T. decipiens_
on the other. _T. botrytis_ Pers., _l. c._, gives us first secure
foothold. Fries discards Persoon's appellation as unsuitable and
improperly applied, and takes up what he deems an older specific
designation, _T. pyriformis_ Leers. But Rostafinski is certain Leers had
_A. punicea_ in mind, and that other early names are equally
ill-applied. Rostafinski rejects Persoon's names simply as not pertinent
in every case. Massee examined the specimens of Léveillé, and finds them
belonging here; but see our No. 14, _seq._

Not common, but with wide range. Maine, Massachusetts, New York,
Pennsylvania, Ohio, Colorado; Toronto.


11. TRICHIA SUBFUSCA _Rex._

  1890. _Trichia subfusca_ Rex, _Proc. Phil. Acad._, p. 192.

Sporangia gregarious, scattered, dull tawny brown, shading to dark brown
below, about ½ mm. in diameter, globose, stipitate; stipe short, about
equal to the sporangium, stout, brown or brownish black, rugulose,
solid; capillitial mass bright straw color; the elaters long
cylindrical, 3-4 µ wide, adorned with spirals four, which wind unevenly,
are perfectly smooth, and terminate in abrupt tips about twice the
diameter of the elater; spores yellow, under the lens yellow, minutely
and closely warted, globose, 12 µ.

The spores of this species resemble closely those of the preceding, but
the sporangium is at sight different in appearance and proportions and
the capillitium not the same at all. The elaters are never fusiform, the
apices always abrupt in their acumination, and the sculpture irregular
and uneven. In form the elater resembles that of _T. scabra_. The
description is drawn from specimens, _N. A. F._, 2495, with which,
however, specimens received from Dr. Rex and later collected exactly
correspond.

The elaters of uniform diameter, the apices abruptly narrowed to a blunt
point, turned to one side, will serve to distinguish this species from
the whole _T. botrytis_ group, some forms of which it outwardly
resembles.

We have beautiful specimens from the shores of Puget Sound.

New York.


12. TRICHIA ERECTA _Rex._

  1890. _Trichia erecta_ Rex, _Proc. Phil. Acad._, p. 193.

Sporangia gregarious, often in clusters of two or three together, but
generally single, nut-brown, checkered with broad, conspicuous yellow
dehiscence bands, globose, ½ mm. wide, stipitate, stipe double the
sporangium, dark brown, solid; capillitial mass bright yellow, the
elaters cylindric, 3-4 µ wide, terminating in apices short and smooth,
adorned with spirals, four, coarsely spinulose, winding unevenly or even
branching and so united to one another! spore-mass yellow, spores by
transmitted light pale, globose, minutely warted, 12 µ.

Distinguished at sight by the peculiarly mottled peridium. _T. botrytis_
in its ochraceous forms sometimes shows tendency to the same thing, but
the checkered surface is here conspicuous. The elaters resemble those of
the preceding form, but are remarkably rough.

Rare. Adirondacks, New York.


13. TRICHIA DECIPIENS (_Pers._) _Macbr._

PLATE IV., Figs. 2, 2 _a_, 2 _b_.

  1793. _Lycoperdon pusillum_ Hedwig, _Abh._, I., p. 35, Tab. iii.,
           Fig. 2.
  1795. _Arcyria decipiens_ Pers., _Ust. Ann. Bot._, XV., p. 35.
  1796. _Trichia fallax_ Pers., _Obs. Myc._, I., p. 59, etc.

Sporangia gregarious, sometimes closely so, sometimes scattered,
turbinate, shining olive or olivaceous brown, stipitate; stipe generally
elongate, concolorous above, dark brown below, hollow, _i. e._ filled
with spore-like cells; capillitial mass yellowish or olivaceous yellow,
the elaters perfectly smooth, long fusiform, tapering gradually to the
long, slender taeniate apices, simple or often branched, adorned with
spirals three, which wind evenly but somewhat distantly; spore-mass
olivaceous or ochraceous, spores under the lens, pale, minutely
delicately reticulate, 10-12 µ.

One of our largest and most common species, in form and size resembling
_H. clavata_, but immediately distinguished by its color. The
capillitium is like that of _T. botrytis_, but differs in the more open
sculpture and the longer and smoother unwound tips. The episporic net is
a constant character in all the specimens examined. This feature reminds
of _T. scabra_.

This is, of course, our familiar _T. fallax_ of all authors from Persoon
down. The earliest unmistakable reference to this species is Hedwig, _l.
c._ But Batsch, in 1789, had used the same combination to describe a
real puff-ball, so that Hedwig's name was already a synonym. The
specific name here adopted is next in point of priority, although
Persoon discarded it the year following, substituting _fallax_, because
he had mistaken the genus.

Not rare. New England, Toronto; west to the Black Hills and Washington,
Oregon, California, south to the Carolinas and Kansas; Jalapa, Mexico.


14. TRICHIA LATERITIA _Lév._

  1846. _Trichia lateritia_ Lév., _Ann. Sci. Nat. Bot._, 3 V., p. 167.
  1875. _Trichia lateritia_ Lév., Rost., _Mon._, p. 250.
  1892. _Trichia fragilis_ (Sow.) Rost., Mass., _Mon._, p. 176.
  1894. _Trichia botrytis_ Pers. var. _lateritia_ (Lév.) List., _Mon._,
           p. 171.
  1899. _Trichia botrytis_ Pers., Macbr., _N. A. S._, p. 216.
  1911. _Trichia botrytis_ Pers. var. _lateritia_ (Lév.) List.,
          _Mycetozoa, 2nd ed._, p. 217.

Sporangia more or less closely gregarious, (_a_) simple
globose-turbinate, dull black when dry, when moist generally with a
vinous tinge, 1 mm. in diameter, stipitate. The stipe concolorous,
rigid, erect, simple even, 2-6 mm., or (_b_) multiple, several
sporangia united by their pale brown or reddish-brown, striate, weak,
closely adherent or united stems; hypothallus small or none;
capillitial-mass bright brick-red cut-off from the stem-cavity, such as
may be, and enclosed by a thick, firm opaque peridium, which opens above
in fragmental or petaloid lobes, leaving a craterium-like cup below, to
persist in flower-like fashion long after the contents have blown away;
elaters fusiform, extremely long, to 50 µ; about 5 µ in width at the
widest (middle) point, long acuminate, adorned with usually four
clean-cut even, regular, taeniae, uniformly spaced and carried forward
on the progressive acumination, almost to the smooth, straight
spine-like point; spores in mass brick-red, by transmitted light,
orange-brown almost smooth, 10-12 µ.

This showy and remarkable species is set out from _T. botrytis_ Pers.
with which it has been more or less closely associated, for several
reasons. In the first place, it is easily recognized in the field, by
its size, color, and structure. Often simple throughout a colony entire,
nevertheless where the vegetative development has been stronger, simple
and multiple fructifications may stand side by side, but the odd
fasciation is generally limited to few sporangia, perhaps three or four,
or at most, half a dozen. These fasciate forms generally shorter, or
less erect. The elaters, so far as our observation goes, are the longest
in the genus notable for their beautiful symmetry. The spores are larger
than in the red forms of _T. botrytis_ as usually presented, smoother
and of different color.

We have also a geographic limitation. Taken to Paris first from southern
Chile, it promises to be a Pacific coast species, found as it now has
been in North America from San Diego, to Vancouver. In a deep forest
near Monterey, California, a half-buried log showed one colony a meter
in length and from six to twelve centimetres in width, hundreds of
sporangia, each by gentlest explosion opening to display its tuft of
bright-tinted wool, a patch of color visible from far.


=4. Oligonema.=

  1875. _Oligonema_ Rost., _Mon._, p. 291.

Sporangia distinct, small, generally crowded together and superimposed;
hypothallus none; capillitium scanty, the sculpture rudimentary and
imperfect, scattered rings or mere roughenings, sometimes imperfect or
faint spirals; spores yellow.

The oligonemas are simply degenerate _Trichiae_, and show the vagaries
usually to be noted in a passing type. They are difficult to define, and
the species are indeed variable. Those here listed seem to offer
constant features throughout our range.


=Key to Species of Oligonema=

  _A._ Spores reticulate.

     _a._ Sporangia in broad effused patches          2. _O. brevifilum_

     _b._ Sporangia in small heaped clusters.

          i. Elaters roughened, no distinct rings
               or spirals                               1. _O. flavidum_

         ii. Elaters with scattered rings; sometimes
               faint spirals                              3. _O. nitens_

  B. Spores warted                                        4. _O. fulvum_


1. OLIGONEMA FLAVIDUM (_Peck_) _Mass._

  1874. _Perichaena flavida_ Peck, _Rep. N. Y. Mus._, p. 76.
  1892. _Oligonema flavidum_ (Peck) Mass., _Mon._, p. 171.

Sporangia crowded and superimposed, sessile in small masses or clusters
1 cm. or less, bright yellow, shining, the peridium thin but opaque,
yellow; capillitium of long, slender tubules usually simple, anon
branched, even, or with an occasional inflation, the sculpture confined
to warts or small, distinct spinules, roughening more or less
conspicuously the entire surface, the apices generally obtuse, anon
apiculate; spore-mass yellow, spores under the lens pale yellow,
irregularly globose, beautifully reticulate, the meshes large and few,
as in _Trichia favoginea_, 12-14 µ.

This species is marked by its capillitium, which is abundant for the
present genus. The threads are longer than in any other species, and not
infrequently branched, smooth, or more commonly, very distinctly
minutely spinulose throughout, no trace of rings or relief sculpture of
any sort, the spirals, that are to be expected, very imperfect, if
discernible at all. In habit the species resembles _O. nitens_, but the
colonies are much larger, and the sporangia higher and larger, attaining
1 mm.

New England to Iowa and Nebraska; south to Alabama and Louisiana.
Toronto; _Miss Currie._


2. OLIGONEMA BREVIFILUM _Peck._

PLATE XX., Figs. 5, 5 _a_.

  1878. _Oligonema brevifila_ Peck, _Rep. N. Y, Mus._, p. 42.

Sporangia small, cylindric, dull ochraceous-yellow, sessile closely
crowded, sometimes superimposed, forming large, effused patches several
centimetres in extent; capillitium exceedingly scant, consisting of
nothing more than a few minute threads, very short, only three or four
times the diameter of the spore, smooth, or without any definable
sculpture, ochraceous; spore-mass dark ochraceous, under the lens the
spores are brighter, marked with reticulations much as in other species
of the genus, 10-12 µ.

Probably a variety of our No. 1, but constantly collected.

Separate, however, from the following also in color and habit. To the
naked eye the fructification suggests _Trichia persimilis_; the color
much the same, and the sporangia similarly congested. The peculiarly
rudimentary condition of the capillitium is apparently also constant.
Iowa specimens accord perfectly with those from New York.

Rare. New York, Ohio, Pennsylvania, North Carolina, Iowa, Missouri,
Oregon, Washington, California; Vancouver Island.


3. OLIGONEMA NITENS (_Lib._) _Rost._

PLATE II., Figs. 8, 8 _a_, 8 _b_.

  1834. _Trichia nitens_ Lib. _Pl. Cr. Ard._, III., No. 227.
  1875. _Oligonema nitens_ (Lib.) Rost., _Mon._, p. 291.
  1883. _Trichia pusilla_ Schroet., _Kr. Fl. Schl._, III., p. 114.

Sporangia gathered in small, heaped clusters, irregularly spherical,
bright straw-color, or yellow, sessile, superimposed, the peridium thin,
smooth, shining; capillitium of short elaters, simple or branched,
smooth, adorned with an occasional projecting ring, often with faint
spiral sculpture spreading especially toward the apices, which are blunt
or anon acute, the point sometimes flexed or bent to one side, never
very long; spore-mass bright yellow, spores globose, beautifully
reticulate, 12-14 µ.

Readily recognized at sight by its heaped, shining, or glistening
sporangia. The capillitial threads are further definitive, and serve to
distinguish it from everything else.

The range is wide, probably coextensive with the forests of the country.
Specimens are before us from New England, Canada, Montana, and all
intervening regions, and south to the Gulf of Mexico; California,
Nevada,--_Prof. Bethel._ Yosemite, shores of Mirror Lake!


4. OLIGONEMA FULVUM _Morgan._

  1893. _Oligonema fulvum_ Morgan, _Jour. Cin. Soc._, p. 42.

Sporangia large, sub-globose, sessile, or crowded, more or less regular;
the peridium tawny yellow, or olivaceous, very thin and fragile,
iridescent; mass of capillitium and spores tawny-yellow, elaters simple
or sometimes branched, very short, sometimes with thicker swollen
portions, the surface marked with low smooth spirals, in places faint
and obsolete, the extremities rounded and obtuse, usually with a minute
apiculus; spores globose, minutely warted, 10-13 µ.

This species may be recognized by its tawny, irregular, more or less
crowded sporangia. Under the lens the warted, not reticulate, spores are
diagnostic. The elaters are quite constantly marked by imperfect
spirals.

Our specimens are from the author of the species, and so far there are
none reported from outside Ohio.

FOOTNOTES:

[15] For other crucifers, see _Bull. Torr. Bot. Club_, xxi, pp. 76-8.

[16] See in reference to this whole matter, _Myxomycetenstudien_ by E.
Jahn, No. 7, _Ceratiomyxa_, 1908. See also Olive, _Trans. Wis. Acad. of
Sci. Arts and Letters_, Vol. xv, pl. II, p. 771.

[17] See Jahn, _Myxomyceten Studien_ No. 8, Berlin 1911.

[18] In discussing these species the reader may be referred to Professor
Harper's study of cytology, _Bot. Gazette_, vol. XXX., p. 217. It is
probable that in all these æthalioid forms the effect of disturbance,
transfer to laboratory, is likely to be quite pronounced. Giant spores
are often seen, doubtless due to arrested cleavage in the procedure
described by Dr. Harper: a giant spore is penultimate or antepenultimate
in series; should, on this theory, occasionally, at least, show more
than one nucleus.

[19] Prior to Persoon the physarums were variously referred:
_Lycoperdon_, _Sphaerocarpus_, _Trichia_, etc. It seems unnecessary to
quote the synonymy further here.

[20] Persoon's first-named species is _P. aureum_; see _Römer Neu. Mag.
f. d. Bot._, I., p. 88. 1794.

[21] Fries (_Sum. Veg. Scand._, p. 454) described the new genus in the
following words: Tilmadoche. Fr. Physari spec. S. M. Peridium simplex,
tenerrimum (_Angioridii_) irregulariter rumpens. Capillitium
intertexto-compactum, a peridio solutum liberum, sporisque inspersis
fuscis. Columella o.

  1. T. leucophæa. Fr.

  2. T. soluta. (Schum.)

  3. T. cernua. (Schum.)

[22] See also _Inaug. Diss._, H. Rönn, _Schr. d. Naturw. Ver. f. Schl.
Holst._, XV., Hpt. I., p. 55, 1911.

[23] Inasmuch as there has been decided difference of opinion in
reference to this particular species,--all judges readers of the same
original description,--it has seemed wise to submit an English
translation from the celebrated _Monograph loc. cit._

"24. Physarum diderma _Rfski._

"Sporangia sessile, globose, adnate by a narrow base, white. Peridium
double; the outer thick, strongly calcareous, very distinctly set off
from the thin inner one by an air-filled space; the calcareous nodules
many, angular, loosely developed within to form a pseudo-columella;
spores dark violet, spinescent, 9.2-10 in diameter.

"_Opis._ This physarum looks extremely like a diderma.

"The sporangia stand either aggregated or bunched together in heaps of
five to twelve, adnate to the hypothallus by a narrow base, etc."

Massee, _Mon._, p. 304, translated this description, but misunderstood
what is said of the columella and is inclined to think the author did
not know a diderma when he saw one; which is pretentious, to say the
least!

[24] See also, after all our trouble, _Jour. Bot._, LVII., p. 106.

[25] See Fries, _Syst. Myc._, Vol. III., pp. 130, 137, Rost., _Mon._, p.
127, and _Rep. N. Y. State Mus._, XXXI., p. 55.

[26] It would seem that M. Massee would have written _T. reniformis_,
were this authentic.

[27] For further synonymy, see under _P. auriscalpium_, No. 49.

[28] Robt. E. Fries, _Ofvers. K. Vetens. Akad. Forh._, 1899, No. 3, p.
225.

[29] The Polish author wrote Tilmadoche instead of Physarum in each case
cited.

[30] Forms cited are chiefly those likely to be found in our neighboring
tropics, West Indies, etc.

[31] These little structures have a fairly architectural appearance and
may be called trabecules,--trabeculæ, little beams.

[32] Dr. Cooke, who used the microscope, applied the _Monograph_
description to British forms occurring on leaves; proceeded further and
found the same situation in New York. Mr. Massee gives the species wide
range with spores 8-10 µ; average 9 µ; only a fraction too large;
evidently none 12-15 µ.

[33] If a sporangium of _L. tigrinum_ be mounted in water and treated to
weak solution of hydro-chloric acid we may easily discover that the
crystals, which so wonderfully adorn the outer wall in this and other
species, consist, in part at least, of calcium carbonate. We may also
discover that in the case before us the crystal or scale lies indeed
enclosed in a filmy sac of organic origin, and that could we have seen
the outer peridium as it came to form, we might probably have found it
made up largely of an ectosarcous foam in whose cavities the excreted
calcium found place for tabulate crystallization. In other species
listed, conditions are different, and the crystals assume a different
shape. The phrase "bicarbonate of lime" quoted in this connection in the
former edition of this work from Mr. Massee's _Monograph_, etc., is not
clear.

[34] Doubtless immature; _v. Mitteil. Naturwiss. Gesell. Wintert._, VI.,
p. 64, Lister quoted by Schinz.

[35] Vid. _Mycologia_, N. Y., Vol. IX., p. 328.

[36] See _Addenda, d_, p. 282 following.

[37] In the _Mycetozoa_, 2nd ed., p. 158, is cited _Stemonitis
virginiensis_ Rex as a synonym of this variety. By reference to p. 163
of the present volume the Virginian stemonitis is left as Rex assigned
it, and if the present variety be synonymous, it should be quoted there.
The treatment of the species _C. nigra_ in the second edition does not
establish such fact, nor with three varieties make for any increasing
clearness.

[38] It had seemed less necessary to retain the classic orthography in
this instance since De Bary and Rostafinski both use _Diachea_. But
modern scholarship is nothing if not meticulous; it is the fashion in
Latin still to keep the digraph, even to the vexation of all men. In the
same way when Bulliard wrote _leucopodia_, 'white stockings', he
doubtless meant to be exact.

[39] For this citation we are indebted to _Mr. Hugo Bilgram_.




ADDENDA


a. This volume is as we see, a descriptive list of the various forms of
the Myxomycetes in so far as these have come to the personal notice of
the writer.

Each form is designated, as is usual in discussing objects of the sort,
by a particular binomial name, followed, in abbreviated form, by the
name of the student or author who in describing the form in question
used the combination. Thus _Stemonitis splendens_ was first described by
Rostafinski, and the name he thus used is applicable to the form he
described, wherever found, and to _nothing else_.

The proper naming of any specimen would thus appear to be a very simple
matter. Such, however, is often not the case, particularly where we are
concerned with species long familiar to science. Such often have
received, at different times, and at the hands of the same author, or
certainly of different authors, different names, given for various
reasons; so that one who would refer to, or discuss, a single specimen
to-day finds himself often in great uncertainty, confronted by a
multitude of binomial combinations all thought to refer to the same
particular thing.

By general consent, of course, we strive to ascertain the oldest name on
the list; the first that is really and clearly applicable, and we write
all other names down as synonyms. In this volume a list of synonyms
often accompanies the description; precedes it, showing, year by year,
the history of the case; an abstract in fact of the title, as at last
approved. The preparation of such an abstract is very troublesome, but
is believed to be worth the trouble; must be made, indeed, if we are
ever in our discussions to be sure that when we speak or write in
America, we are dealing with the same thing intended by the man who
speaks or writes in England, or elsewhere.

The space occupied in synonymy, is therefore by no means wasted. By and
by, if we succeed in establishing a nomenclature on which competent
judges can agree, a thing not at all improbable, almost now attained,
the lists may gradually disappear as having historical value only.

b. Taxonomy, in any field, is of necessity concerned with history. For
his own sake, no student can ignore the thought and work of his
predecessors. No man ever sees nature in completeness, nor even the
small part of the world to which he devotes attention. He needs every
possible assistance, especially the observations of intelligent men. The
present author rejoices to acknowledge the assistance found in volumes
written in Europe during the last two hundred years. Such men as
Persoon, Bulliard, Schumacher, Schrader, Fries, are deservedly famous;
they laid the foundations of mycologic taxonomy. No student can afford
to miss _Elias Fries_; his genius, spirit and scholarship entitle him to
the recognition and sympathy of every lover of the intellectual life.

c. The considerations just mentioned may, indeed do, sometimes act as a
handicap to the American student, for the simple reason that he comes
later to the field of time. He must naturally defer to the decision of
men in Europe who are supposedly familiar with original types. An
American specimen is presumably the same as one occurring elsewhere in
similar latitude and environment. It becomes evident after while that
only in certain instances is this undoubtedly the fact. The flora of the
American continent has been sufficiently disjoined in space and time
from Europe to permit extensive differentiation even in these minor
forms, so that we have indeed in the groups we study many species, some
genera, definitely autochthonous, more it is believed than are now
suspected. An attempt to bring a specimen under the terms of a species
described in Western Europe is not seldom an error. It becomes evident,
as we go forward, that in eastern North America there are forms not only
not described in European literature, but really not, part of European
flora, not even adventitiously.

d. Many of the more minute species with which this volume has to do are
very elusive, very difficult; for one reason,--perhaps in itself
sufficient,--because of their minuteness, and consequent apparent
paucity. They may be common, but none the less seldom seen. The
comatrichas afford an illustration. There are several very small
species. _C. pulchella_, _C. laxa_, _C. ellisii_ may be mentioned. _C.
pulchella_ has been studied nearly a hundred years and has a synonymy
accordingly. In 1875 Rostafinski in the material, and among the
descriptions, thought he recognized two distinct forms, and went on to
give them names; the first in honor of Persoon, _C. persoonii_, should
show an ovate or ovate-cylindric outline with acuminate tip; the second
should be truncate and represent a type first described by Berkeley
under a name given by Babington, _C. pulchella_. Berkeley's drawing
shows a sporangium with tip acuminate! Lilac or violaceous tints
attracted attention in the spores of _C. persoonii_ only; in _C.
pulchella_ all is ferruginous. Curtis is especially commended for
noticing the fact in describing _S. tenerrima_, here included as we see.

_Comatricha gracilis_ Wing. is slender, cylindric and has small spores
hardly reaching 6 µ; should perhaps be now set out as a separate
species; it is evidently purely an American phase.

Our figures, Plate XII., 16 and 16 _a_, 18 and 18 _a_, show _C.
pulchella_ and _C. gracilis_, respectively, extremes. Plate XIII., 4,
shows an ovate form not very unusual. This and _C. gracilis_ occur on
living leaves.

_C. ellisii_ is another of this minor series, very constant in its
delicate beauty, but approaches _C. nigra_ rather than the others here
discussed.

_C. laxa_, as the name implies, shows an open construction, suggested,
perhaps, by Rostafinski's photographic print, but better brought out by
Celakowsky, _Myx. Böhm._, Tab. 2, Figs. 7 and 8.

e. It has been shown[40] that the process of cell-division in the
spore-plasm of the myxomycete is not dissimilar to that obtaining under
the same conditions in higher plants. On this supposition we have
explanation of spore-division in _Ceratiomyxa_ and can understand the
adherence of spores now and again notable. Once the latter phenomenon
was thought peculiar to the genus _Badhamia_; but the unsculptured
epispore of the spores of reticularias, tubiferas, etc., suggest the
same thing and more recently we find it in _Dianema_ and in the
_Stemoniteæ_; even _Stemonitis_ arrives with clustered spores in groups
of four, and we are in sight of a generalization wide.

It is interesting to note that something of this sort was observed by at
least one student long ago. Schumacher, _Enum. Pl. Sell._ 2, p. 215,
describes _Arcyria atra_ with the characters of an enerthenema, and says
"the capillitial threads are some of them diffuse and bear spermatic
globules"! Did he anticipate _E. berkleyanum_? See the text under that
species at p. 190, _supra_.

f. In a paper read December, 1920, before the _Mycological_ Division of
Section G., _A. A. A. S._, the present writer discussed briefly the
physical principles involved in some of the more striking peculiarities
of the slime-moulds.

It is argued in that paper that the shaping of stipitate sporangia which
is so surprising as relating to the ordinary behaviour of fluid masses,
as usually observed, is, in part at least, referable to certain well
known properties of fluids generally. For this discussion those
interested are referred to the article itself in the November number of
_Mycologia_ (N. Y.).

Sufficient to say here that it is a fact, in many cases, that in
stipitate fructification, so far as observed, the stipe is first to take
form, and, as viewed by the writer, in many cases, as it rises, becomes
more and more a most delicate but definite ectosarcate capillary tubule,
by which ascends the spore-plasm of the point concerned, to such level
as may meet the immediate conditions of pressure, of whatsoever source.

It will be interesting in this view to note the resultant shapes as
presented in the sporangia of various genera. One may examine for
illustrations Figs. 1, 3, 4, 7, Pl. XX., with the thought in mind that
the stipe in each case may have served as a capillary tubule to carry up
the spore-plasm to the position in which the spores at length are found.
In some species of _Hemitrichia_, for instance, there are spores or
spore-like cells found at maturity in the hollow stipe. In other cases
the stipe contains refuse matter.

The capillary theory may not, probably does not, play part in every
case. It would seem that a stemonitis, for example, must owe the rise of
the spore-plasm to the play of different machinery. _Brefeldia_, p. 154
above, may offer suggestion.

g. On page two of the introductory section of this volume mention is
made of the variety of colors shown in the vegetative phases of the
organisms we study. This fact is patent to all observers; but the
identity of the plasmodium making the display must be ascertained by
painstaking or prolonged and repeated observations. This for the reason
that, as I am convinced, only in comparatively few cases is the color
unchanged during the life-history of a given fructification. It may
sometimes change from hour to hour as development proceeds. The color
designated in the descriptive pages of this work is presumably, unless
as otherwise set out, that immediately preceding that of the maturing
fruit.

As suggestive, and as, it is hoped, contributory to better knowledge of
this phase of our subject a list of species is here subjoined as
presented by my colleague, Professor Morton E. Peck of Oregon, who has
given unusual attention to this particular investigation.

  SPECIES             PLASMODIUM COLORS

  _Physarum sinuosum_           light grey, nearly white, ivory white

  _Physarum serpula_            greenish-yellow; yellow

  _Physarum virescens_          pale greenish-yellow; yellow

  _Physarum cinereum_           watery grey, becoming white; pallid

  _Physarum didermoides_        watery grey, becoming white; blue-white

  _Physarum notabile_           pure white

  _Physarum globuliferum_       greenish-yellow; yellow

  _Physarum leucopus_           light grey

  _Physarum pulcherrimum_       dark red

  _Physarum flavicomum_         greenish or brownish yellow

  _Physarum viride_             clear yellow

  _Physarum wingatense_         at first grey, then pure white

  _Badhamia orbiculata_         pale yellow, passing to white

  _Physarella oblonga_          brilliant yellow

  _Mucilago spongiosa_          watery grey, then white

  _Didymium crustaceum_         white

  _Didymium squamulosum_        pale grey, watery white

  _Diderma floriforme_          grey tinged with yellow

  _Stemonitis fusca_            white passing through blue to black

  _Stemonitis smithii_          green to yellow to reddish purple

  _Comatricha longa_            white, cream-yellow, reddish purple
                                  to dusky

  _Comatricha irregularis_      white

  _Comatricha nigra_            white

  _Comatricha typhoides_        bluish white

  _Diachaea splendens_          pure white

  _Enerthenema papillatum_      colorless or greenish

  _Reticularia lycoperdon_      white

  _Dictydiaethalium plumbeum_   colorless, pink, salmon, rose, orange,
                                  chocolate brown

  _Lindbladia effusa_           brown, lead-colored

  _Tubifera ferruginosa_        watery white, scarlet, brown, almost
                                  black

  _Cribraria dictydioides_      clear dark green

  _Cribraria tenella_           watery, dark plumbeous, bronze

  _Cribraria cuprea_            red

  _Arcyria nutans_              white

  _Arcyria denudata_            watery white, then flesh-color

  _Arcyria cinerea_             grey, then white

  _Trichia varia_               colorless, then white

h. In a few instances references to illustration do not find place in
connection with the descriptive matter. One phase of _Physarum
albescens_ is figured on Pl. III.; _Mucilago_ will be found portrayed on
Pl. VII.; _Physarum viride_ on Pl. VIII.

j. The group before us has research possibilities not a few. The
question of their nutrition and its limits in respect of variety, is yet
to be solved. From present indications all that can be said is to the
effect that a pabulum similar in variety, no doubt meets the needs of
many species. Whether in artificial culture a single base as gelatin or
agar would suffice for all or several is yet to be discovered.

Whether a species brought from spore to maturity on artificial diet
would conform in any reasonable way to our dim concept of its identity
is also, it would seem, a problem. The variation in the field would seem
to make it doubtful.

From the table immediately preceding it is plain that there is place for
doubt. Color it is surmised is of itself everywhere incidental; the
structure, which maintains identity or the reverse, lies deeper,
although color may be none the less, in some way a resultant, and
therefore in so far a reliable taxonomic guide.

The treatment of our subject so far by no means exhausts the
possibilities of even the simpler phases of microscopic study. We have
endeavored to appreciate the work of those who hand us the literature of
the group, and to recognize what such keen-eyed men have seen; but in
our western and southern forests there are probably double as many
species, as species go, as we have listed.

The entire group is, as it would seem, in highest measure worthy of
investigation and comprehension, and should it at any time prove that to
such accomplishment the present volume may have been in any smallest way
contributory, the author's satisfaction will be complete indeed.

FOOTNOTES:

[40] Farr. _Cell-division in Pol. Mother-cells, Cobæa scandens, Bull.
Tor. Bot. Cl._, Vol. 47, pp. 325-38.




INDEX


NATURAL ORDERS, etc.

  CRIBRARIALES, 199

  EXOSPOREÆ, 18

  LYCOGALALES, 232

  PHYSARALES, 22

  PHYTOMYXINÆ, 17

  STEMONITALES, 148

  TRICHIALES, 236


GENERA

  ALWISIA, 208
    _Alwis_; personal.

  AMAUROCHÆTE, 148
    [Greek: amauros], dusky, and [Greek: chaitê], hair. Gr.

  ARCYRIA, 247
    [Greek: arkyon] a net. Gr.

  BADHAMIA, 313
    _C. D. Badham_; personal.

  BREFELDIA, 154
    _O. Brefeld_; personal.

  CALONNEMA, 266
    [Greek: kalos], beautiful, and [Greek: nêma], a thread. Gr.

  CERATIOMYXA, 18
    [Greek: keration], a small horn, and [Greek: myxa], mucus. Gr.

  CIENKOWSKIA, 110
    _Leon Cienkowski_; personal

  CLASTODERMA, 191
    [Greek: klastos], broken, and [Greek: derma], dermis, skin or
      covering. Gr.

  COLLODERMA, 147
    [Greek: kolla], glue, and [Greek: derma], dermis, covering.

  COMATRICHA, 171
    [Greek: komê], and [Greek: thrix], both words meaning hair. Gr.

  CRATERIUM, 103
    [Greek: kratêr], a vessel. Gr.

  CRIBRARIA, 216
    _cribrum_, a sieve. Lat.

  DIACHAEA, 185
    [Greek: diacheiu], to pour out; the application not patent. Gr.

  DIANEMA, 238
    [Greek: dia], through or across, and [Greek: nêma], thread. Gr.

  DICTYDIUM, 230
    [Greek: diktyon], a net. Gr.

  DICTYDIÆTHALIUM, 215
    Dictydium and æthalium; the latter from [Greek: aithalos], sooty.
      Gr.

  DIDERMA, 129
    [Greek: dis], twice or twofold, and [Greek: derma], as above. Gr.

  DIDYMIUM, 115
    [Greek: didymos], double. Gr.

  ECHINOSTELIUM, 198
    [Greek: echinos], a sea-urchin, and [Greek: stêlion], (?), a handle
      or stem. Gr.

  ENERTHENEMA, 189
    [Greek: enerthe], below, and [Greek: nêma], a thread.

  ENTERIDIUM, 211
    [Greek: enteron] the intestine. Gr.

  FULIGO, 23
    fuligo, soot. Lat.

  _=Hemiarcyria=_, 259
    [Greek: hêmi], half, and Arcyria.

  HEMITRICHIA, 259
    [Greek: hêmi], half, and Trichia.

  HETEROTRICHIA, 256
    [Greek: heteros], other, and Trichia.

  LACHNOBOLUS, 245
    [Greek: lachnos], woolly, and [Greek: bôlos], a lump. Gr.

  LAMPRODERMA, 191
    [Greek: lampros], shining, and [Greek: derma], as above. Gr.

  LEOCARPUS, 111
    [Greek: leios], smooth, and [Greek: karpos], fruit. Gr.

  LEPIDODERMA, 144
    [Greek: lepis], a scale, and [Greek: derma], a covering. Gr.

  LICEA, 199
    said to be Latin; _licium_, a thrum, a girdle.

  LINDBLADIA, 203
    _A. Lindblad_; personal.

  LYCOGALA, 233
    [Greek: lykos], a wolf, and [Greek: gala], milk. Gr.

  MARGARITA, 237
    [Greek: margaritês], a pearl. Gr.

  MUCILAGO, 113
    _mucilago_, musty juice. Lat.

  OLIGONEMA, 278
    [Greek: oligos], few, and [Greek: nêma], a thread. Gr.

  OPHIOTHECA, 240
    [Greek: ophis], a serpent, and [Greek: thêkê], a case. Gr.

  ORCADELLA, 203
    [Greek: orka], a cask (?). Diminutive.

  PERICHÆNA, 242
    [Greek: peri], around, and [Greek: chainein], to crack open. Gr.

  PHYSARUM, 45
    [Greek: physa], a bladder, something inflated.

  PHYSARELLA, 71
    Diminutive of _Physarum_.

  PLASMODIOPHORA, 17
    [Greek: plasma], something formed, and [Greek: phoros], that bears.
      Gr.

  PROTOTRICHIA, 257
    [Greek: prôtos], first, and _Trichia_.

  RETICULARIA, 209
    _reticulum_, a small net. Lat.

  STEMONITIS, 156
    Like a stamen.

  TILMADOCHE, 95
    [Greek: tilma], lint, and [Greek: dochê], containing. Gr.

  TRICHIA, 267
    [Greek: ophix], hair. Gr.

  TUBIFERA, 205
    _tubus_, a tube, and _fero_, I bear. Lat.


GENERA AND SPECIES

  =_Æthaliopsis,_=, 26.
    _stercoriformis_ Zopf., 27.

  =_Æthalium_=, 23.
    _flavum_ Link., 27.
    _septicum_ Fr., 27.

  ALWISIA, 208.
    bombarda _Berk. & Br._, 208.

  AMAUROCHÆTE, 148.
    _atra_ (Alb. & Schw.) Rost., 6, 149.
    _cribrosa_ (Fr.) Macbr., 150.
    fuliginosa (_Sow._) _Macbr._, 149.
    tubulina (_Alb. & Schw._) _Macbr._, 150.
    _minor_ Sacc. & Ell., 145.

  =_Angioridium_=, 52.
    _sinuosum_ Grev., 52.

  ARCYRIA, 247.
    _albida_ Pers., 245.
    _bicolor_ Berk. & C., 255.
    cinerea (_Bull._) _Pers._, 254.
    conglobosa _Macbr._, 255.
    _decipiens_ Pers., 276.
    denudata (_L._) _Sheld._, 253.
    digitata (_Schw._) _Rost._, 255.
    ferruginea _Sauter._, 253.
    _flava_ Pers., 249.
    _gabriellae_ Rav., 257.
    _globosa_ Schw., 245.
    incarnata _Pers._, 6, 251.
    insignis _Kalchbr. & Cke._, 256.
    _leucocephala_ Pers., 105.
    magna _Rex_, 248.
    nodulosa _Macbr._, 252.
    nutans (_Bull._) _Grev._, 249.
    oerstedtii _Rost._, 249.
    pomiformis (_Leers_) _Rost._, 255.
    _punicea_ Pers., 253.
    _stipata_, List., 262.
    versicolor _Phill._, 250.
    _vitellina_ Phill., 250.

  BADHAMIA, 31.
    affinis _Rost._, 35.
    capsulifera (_Bull._) _Berk._, 38, 40.
    chrysotricha _Berk. & C._, 34.
    decipiens (_Curt._) _Berk._, 34.
    _decipiens_ Berk., 49, 63.
    foliicola _G. List._, 39.
    gracilis _var. Macbr._, 37.
    _hyalina_ (Pers.) Berk., 40.
    iowensis _Macbr._, 36.
    inaurata _Currey_, 34.
    lilacina (_Fr._) _Rost._, 65.
    macrocarpa (_Ces._) _Rost._, 37.
    _macrocarpa_ Rost., 37.
    magna _Peck_, 38.
    nitens _Berk._, 34.
    _nodulosa_ Mass., 51.
    orbiculata _Rex_, 37.
    ovispora _Racib._, 33.
    panicea (_Fr._) _Rost._, 35, 51.
    papaveracea _Berk. & R._, 42.
    _penetralis_ Cke. & Ell., 177.
    populina _List._, 41.
    rubiginosa (_Chev._) _Rost._, 43.
    subaquila _Macbr._, 44.
    utricularis (_Bull._) _Berk._, 39.
    _varia_ Mass., 38.
    _verna_ Fries, 51.
    versicolor _List._, 33.

  BREFELDIA, 154.
    maxima (_Fr._) _Rost._, 154.

  =_Byssus._=
    _fruticulosa_ Fl. Dan., 19.


  CALONEMA, 266.
    aureum _Morg._, 266.

  CERATIOMYXA, 18.
    arbuscula _Berk. & Br._, 20.
    filiforma _Berk. & Br._, 20.
    fruticulosa (_Muell._) _Macbr._, 19.
    _mucida_ Schroet., 19, 21.
    porioides (_Alb. & Schw._) _Schroet._, 19, 20, 21.

  =_Ceratium_=,
    _hydnoides_ Alb. & Schw., 19.
    _porioides_ Alb. & Schw., 19, 20.

  =_Chondrioderma_=, see Diderma.
    _aculeatum_ Rex, 139.
    _calcareum_ Rost., 95.
    _crustaceum_ (Peck) Berl., 135.
    _globosum_ (Pers.) Rost., 134.
    _michelii_ (Lib.) Rost., 138.
    _niveum_ Rost., 137.
    _radiatum_ (L.) Rost., 141.
    _reticulatum_ Rost., 131.
    _roanense_ Rex, 141.
    _rugosum_ Rex, 144
    _sauteri_ Rost., 139.
    _stromateum_ (Link.) Rost., 132.
    _testaceum_ (Schrad.) Rost., 137.
    _trevelyani_ (Grev.) Rost., 142.

  CIENKOWSKIA, 110.
    reticulata (_Alb. & Schw._) _Rost._, 49, 111.

  =_Cionium_=,
    _xanthopus_ Ditm., 123.

  CLASTODERMA, 191.
    debaryanum _Blytt._, 191.

  =_Clathroptychium_=, 215.
    _rugulosum_ (Wallr.) Rost., 215.

  =_Clathrus._=
    _adnatus_ Batsch, 251.
    _denudatus_ L., 253.
    _ramosus_ Retz., 193.

  =_Clavaria_=, 19.
    _byssoides_ Bull., 19.
    _puccinia_ Batsch, 19.

  COLLODERMA, 147.
    oculatum (_Lipp._) _G. List._, 147.

  COMATRICHA, 171.
    aequalis _Peck_, 180.
    caespitosa _Sturg._, 173.
    _crypta_ Schw., 127.
    cylindrica (_Bilgr._) _Macbr._, 173.
    elegans (_Racib._) _G. List._, 182.
    _ellisiana_ (Cke.) Ell. & Ev., 177.
    ellisii _Morg._, 184.
    flaccida (_List._) _Morg._, 174.
    _friesiana_ (DBy.) Rost., 128.
    _gracilis_ Wing, 183.
    irregularis _Rex_, 176.
    laxa _Rost._, 177, 184.
    longa _Peck_, 175.
    nigra (_Pers._) _Schroet._, 178, 184.
    _obtusata_ (Preuss.) List., 179, 190.
    _persoonii_ Rost., 183.
    pulchella (_Bab._) _Rost._, 183.
    rubens _List_., 183.
    _shimekiana_ Macbr., 144.
    _stemonitis_ (Scop.) Shel., 181.
    subcaespitosa _Peck_, 132.
    suksdorfii _Ell. & Ev._, 178.
    _typhina_ (Pers.) Rost., 181.
    typhoides (_Bull._) _Rost._, 163, 181.

  =_Cornuvia_=, 240, 241.
    _circumscissa_ (Wallr.) Rost., 241.
    _wrightii_ (Berk. & C.) Rost., 241.

  =_Crateriachaea._=
    _crateriachaea mutabilis_ Rost., 99.

  CRATERIUM, 73.
    aureum (_Schum._) _Rost._, 104.
    _citrinellum_ List., 37.
    concinnum _Rex_, 107.
    _confusum_ Mass., 79.
    _convivale_ (Batsch) Morg., 105.
    _cylindricum_ Mass., 106.
    leucocephalum (_Pers._) _Ditm._, 105, 106.
    _lilacinum_ Mass., 65.
    _maydis_ Morg., 91.
    minimum _Berk. & C._, 106.
    minutum (_Leers_) _Fr._, 107, 108.
    _mutabile_ Fr., 104.
    _nodulosum_ (C. & B.) Morg., 51.
    _obovatum_ Peck, 70.
    _paraguayense_ (Speg.) List, 103.
    _pedunculatum_ Trent., 58, 107, 108.
    _rubescens_ Rex, 103.
    _rubiginosum_ Mass., 70.
    _vulgare_ Ditm., 107.

  CRIBRARIA, 216.
    argillacea Pers., 218.
    aurantiaca _Schrad._, 221.
    _cernua_ Pers., 230.
    cuprea _Morg._, 229.
    dictydioides _Cke. & Balf._, 222.
    elegans _Berk. & C._, 228.
    intricata (_Schrad._) _Rost._, 223.
    languescens _Rex_, 229.
    macrocarpa _Schrad._, 219.
    microcarpa (_Schrad._) _Pers._, 226.
    _microscopica_ _Berk. & C._, 220.
    _minima_ Berk. & C., 220.
    minutissima _Schw._, 220.
    piriformis _Schrad._, 228.
    purpurea _Schrad._, 228.
    rufa (_Roth_) _Rost._, 220.
    splendens (Schrad.) Pers., 221.
    tenella _Schrad._, 225.
    violacea _Rex_, 227.
    _vulgaris_ Schrad., 222.

  =_Cytidium._=
    _melleum_ (Berk. & Br.) Morg., 65.
    _ravenelii_ (Berk. & C.) Morg., 48.
    _rufipes_ (Alb. & Schw.) Morg., 50.


  =_Dermodium_=, 236.
    _conicum_ (Pers.) Rost., 236.

  DIACHAEA, 185.
    bulbillosa (_Berk. & Br._) _List._, 188.
    _caespitosa_ List., 173.
    _cylindrica_ (Bilgr.) List., 173.
    _elegans_ Fr., 186.
    leucopodia (_Bull._) _Rost._, 186.
    splendens _Peck_, 187.
    subsessilis _Pk._, 187.
    thomasii _Rex_, 173, 188.

  DIANEMA, 238.
    andersoni _Morg._, 239.
    corticatum _List._, 238.
    harveyi _Rex_, 238.

  DICTYDIAETHALIUM, 215.
    plumbeum (_Schum._) _List._, 215.

  DICTYDIUM, 230.
    cancellatum (_Batsch_) _Macbr._, 6, 230.
    cancellatum cancellatum _Macbr._, 231.
    cancellatum purpureum _Macbr._, 232, 173.
    cancellatum prolatum _Macbr._, 232.
    _cernuum_ Nees, 230.
    _longipes_ Morg., 231.
    _microcarpon_ Schrad., 226.
    _splendens_ Schrad., 221.
    _umbilicatum_ Schrad., 230.

  DIDERMA, 129.
    _albescens_ Phill., 137.
    asteroides _List._, 143.
    _brunneolum_ Phill., 58.
    cinereum _Morg._, 138.
    _citrinum_ Peck, 37.
    _conglomeratum_ Fr., 57.
    _contextum_ Pers., 31.
    cor-rubrum _Macbr._, 140.
    crustaceum _Peck_, 135.
    _difforme_ (Pers.) Morg., 126.
    effusum (_Schw._) _Morg._, 130.
    floriforme (_Bull._) _Pers._, 143.
    _geasteroides_ Phill., 142.
    globosum _Pers._, 134.
    _globuliferum_ Fr., 46.
    _granulatum_ (Schw.) Fr., 31.
    hemisphericum (_Bull._) _Horne._, 138.
    _laciniatum_ Phill., 142.
    lyallii _Mass._, 136.
    _mariae-wilsoni_ Clinton, 137.
    _minutum_ (Schum.) Fr., 31.
    niveum (_Rost._) _Macbr._, 137.
    _oblongum_ Fr., 40.
    ochraceum _Hoffm._, 140.
    _ochroleucum_ Berk. & C., 31.
    _persoonii_ Macbr., 126.
    radiatum (_L._) _Morg._, 141.
    _reticulatum_ Fr., 111, 130.
    reticulatum (Rost.) Morg., 131.
    roanense (_Rex_) _Macbr._, 141.
    _rufipes_ (Alb. & Schw.) Fr., 50.
    rugosum (_Rex_) _Macbr._, 144.
    sauteri (_Rost._) _Macbr._, 139.
    simplex List., 132.
    spumarioides _Fr._, 132.
    _squamulosum_ Alb. & Schw., 119.
    _stellare_ (Schrad.) Pers., 141.
    testaceum (_Schrad._) _Pers._, 137.
    trevelyani (_Grev._) Fr., 142.
    _vernicosum_ Pers., 112.

  DIDYMIUM, 115.
    anellus _Morg._, 117.
    annulatum _Macbr._, 125.
    anomalum _Sturg._, 127.
    _chrysopeplum_ Berk. & C., 47.
    _cinereum_ (Batsch) Fr., 35.
    clavus (_Alb. & Schw._) _Rabh._, 122.
    complanatum (_Batsch_) _Rost._, 116.
    _connatum_ Peck, 41.
    crustaceum _Fr._, 118.
    difforme _Duby_, 126.
    dubium _Rost._, 126.
    _effusum_ Link., 119.
    _erythrinum_ Berk., 50.
    _excelsum_ Jahn, 128.
    eximium _Peck_, 124.
    _farinaceum_ Schrad., 121.
    fulvum _Sturg._, 118.
    _glaucum_ Phill., 41.
    _gyrocephalum_ Mont., 95.
    _hemisphericum_ (Bull.) Fr., 138.
    intermedium _Schrad._, 128.
    _lateritium_ Berk. & Rav., 33.
    leoninum _Berk. & Br._, 128.
    _melanopus_ Fr., 122.
    melanospermum (_Pers._) _Macbr._, 121.
    _melleum_ Berk. & Br., 47.
    _michelii_ Lib., 138.
    _microcarpon_ (Fr.) Rost., 123.
    minus _List._, 121.
    _nigripes_ Fr., 91.
    nigripes (_Link_) _Fr._, 123.
    _obrusseum_ Berk. & C., 52.
    _oculatum_ Lipp., 147.
    _paraguayense_ Speg., 103.
    _polycephalum_ (Schw.) Fr., 95.
    _polymorphum_ Mont., 95.
    _proximum_ Berk. & C., 123.
    quitense (_Pat._) _Torr._, 127.
    _ravenelii_ Berk. & C., 48.
    _serpula_ Fr., 116.
    squamulosum (Alb. & Schw.) Fr., 119.
    _stellare_ Schrad., 141.
    _tenerrimum_ Berk. & C., 52.
    _testaceum_ Schrad., 137.
    _tigrinum_ Schrad., 145.
    trochus _List._, 125.
    wilczekii _Meylan_, 117.
    xanthopus (_Ditm._) _Fr._, 123.
    _zeylanicum_ Berk. & Br., 102.

  =_Diphtherium._=
    _flavofuscum_ Ehr., 176.


  ECHINOSTELIUM, 198.
    minutum DeBary, 198.

  ENERTHENEMA, 189.
    berkeleyanum _Rost._, 190.
    _elegans_ Bowm., 190.
    papillatum (_Pers._) _Rost._, 190.
    _syncarpon_ Sturg., 190.

  ENTERIDIUM, 211.
    _cinereum_ Schw., 26.
    minutum _Sturg._, 214.
    olivaceum _Ehr._, 214.
    _rozeanum_ (Rost.) Wing., 211.
    splendens _Morg._, 211.

  ERIONEMA, 31.
    aureum _Penz._, 31.


  FULIGO, 23.
    cinerea (_Schw._) _Morg._, 26.
    _ellipsospora_ List., 26.
    flava _Pers._, 29.
    intermedia _Macbr._, 30.
    laevis _Pers._, 29.
    megaspora _Sturg._, 30.
    muscorum _Alb. & Schw._, 25.
    _ochracea_ Peck, 25.
    ovata (_Schaeff._) _Macbr._, 6, 27.
    _plumbea_ Schum., 215.
    rufa _Pers._, 28.
    septica (_L._) _Gmel._, 27.
    _varians_ Rost., 27.
    _varians_ Sommf., 23.
    violacea _Pers._, 29.


  =_Hemiarcyria_=, see next, 259.

  HEMITRICHIA, 259.
    _ablata_ Morg., 264.
    clavata (_Pers._) _Rost._, 264.
    _funalis_ Morg., 264.
    intorta _List._, 263.
    karstenii _Rost._, 260.
    leiocarpa _Cooke_, 263.
    _longifila_ Rex, 263.
    montana Morg., 266.
    _obscura_ Rex, 260.
    ovata (_Pers._) _Macbr._, 261.
    _plumosa_ (Morg.), 265.
    _rubiformis_ (Pers.) Rost., 262.
    serpula (_Scop._) _Rost._, 260.
    stipata (_Schw._) _Rost._, 262.
    stipitata _Mass._, 265.
    _varneyi_ Rex, 263.
    vesparium (_Batsch_) _Macbr._, 262.
    _wigandii_ Rost., 261.

  HETEROTRICHIA, 256.
    gabriellae (_Rav._) _Mass._, 257.


  =_Isaria._=
    _mucida_ Pers., 19.


  LACHNOBOLUS, 245.
    _congesta_ Berk. & Br., 247.
    _cribrosus_ Fr., 150.
    globosus (_Schw._) _Rost._, 245.
    _incarnatus_ (Alb. & Schw.) Schroet., 246.
    occidentalis _Macbr._, 246.

  LAMPRODERMA, 191.
    _arcyrioides_ (Sommf.) Morg., 194.
    _arcyrioides iridea_ Cke., 195.
    arcyrionema _Rost._, 197.
    columbinum (_Pers._) _Rost._, 194.
    _ellisiana_ Cke., 177.
    _irideum_ (Cke.) Mass., 195.
    _minutum_ Rost., 144.
    physaroides (_Alb. & Schw._) _Rost._, 192.
    robustum _Ell. & Ev._, 193.
    _sauteri_ Rost., 193.
    scintillans (Berk. & Br.) List., 195.
    violaceum (_Fr._) Rost., 196.

  =_Leangium._=
    _stipatum_ Schw., 262.
    _trevelyani_ Grev., 142.

  LEOCARPUS, 111.
    fragilis (_Dicks._) _Rost._, 112.
    _fragilis_ Link., 81.
    _fulvus_ Macbr., 86.
    _vernicosum_ Link., 112.

  LEPIDODERMA, 144.
    carestianum Rost., 145.
    chailletii Rost, 146.
    _stellatum_ Mass., 61.
    tigrinum (_Schrad._) Rost., 128, 145.

  LICEA, 199.
    biforis _Morg._, 201.
    _effusa_ Ehr., 203.
    minima _Fr._, 201.
    _ochracea_ Peck, 25.
    pusilla _Schrad._, 202.
    _rugulosa_ Wallr., 215.
    _stipitata_ Berk. & R., 207.
    variabilis _Schrad._, 200.

  LINDBLADIA, 203.
    effusa (_Ehr._) _Rost._, 204.
    _tubulina_ Fr., 154.

  LYCOGALA, 233.
    _atrum_ Alb. & Schw., 149.
    conicum _Pers._, 236.
    _contortum_ Ditm., 269.
    epidendrum (_Buxb._) _Fr._, 6, 233.
    exiguum _Morg._, 236.
    flavofuscum (_Ehr._) _Rost._, 234.
    _miniata_ Pers., 234.
    _terrestre_ Fries, 234.

  =_Lycoperdon_=, 175.
    _cinereum_ Batsch, 34.
    _complanatum_ Batsch, 116.
    _corticale_ Batsch, 243.
    _epidendron_ (Buxb.) L., 233.
    _favogineum_ Batsch, 272.
    _fragile_ Dicks., 81.
    _fuliginosum_ Sow., 149.
    _pusillum_ Hedw., 276.
    _radiatum_ L., 141.
    _vesparium_ Batsch, 262.


  MARGARITA
    metallica (_Berk. & Br._) _List._, 237.

  MUCILAGO, 113.
    spongiosa (_Leyss._) _Morg._, 114.

  =_Mucor_=, 23.
    _cancellatus_ Batsch, 230.
    _ovatus_ Schaeff., 27.
    _pomiformis_ Leers, 255.
    _septicus_ L., 27.
    _serpula_ Scop., 260.
    _spongiosus_ Leyss., 83.
    _stemonitis_ Scop., 181.

  OLIGONEMA, 278.
    brevifilum _Peck_, 280.
    flavidum (_Peck_) _Mass._, 279.
    fulvum _Morg._, 281.
    nitens (_Lib._) _Rost._, 280.

  OPHIOTHECA, 240.
    chrysosperma _Currey_, 241.
    _pallida_ Berk. & C., 240.
    _umbrina_ Berk. & C., 240.
    vermicularis (_Schw._) _Macbr._, 240.
    wrightii _Berk. & C._, 241.

  ORCADELLA, 203.
    operculata _Wing._, 203.

  =_Orthotrichia_=, 191.
    _microcephala_ Wing., 191.


  PERICHAENA,
    _caespitosa_ Peck, 204.
    corticalis (_Batsch_) _Rost._, 243.
    depressa _Lib._, 6, 242.
    _flavida_ Peck, 279.
    _incarnata_ (Alb. & Schw.) Fr., 247.
    _irregularis_ Berk. & C., 243.
    marginata _Schw._, 244.
    _pallida_ (Schw.) Rost., 240.
    _populina_ Fr., 243.
    quadrata _Macbr._, 243.
    _vaporaria_ Schw., 242.

  PHYSARELLA, 108.
    _mirabilis_ Peck, 109.
    oblonga (_Berk. & C._) _Morg._, 109.

  PHYSARUM, 45.
    aeneum (_List._) _R. G. Fries_, 101.
    affine _Rost._, 80.
    albescens _Ell._, 86.
    _albicans_ Peck, 66.
    _album_ Fr., 76.
    alpinum _G. List._, 54.
    _atrorubrum_ Peck, 68.
    _atrum_ Schw., 78.
    _aurantium_ Pers., 98.
    _aureum_ Pers., 98.
    auriscalpium _Cke._, 86, 90.
    _berkeleyi_ (Rost.) List., 92, 93.
    bethelii (_Macbr._) _List._, 94.
    bitectum _List._, 53.
    _bivalve_ Pers., 52.
    bogoriense _Racib._, 54.
    brunneolum _Phill._, 58.
    _caespitosum_ Schw., 85.
    _calidris_ List., 76.
    carneum _List. & Sturg._, 85.
    _cernuum_ (Schum.) Fr., 97.
    _chrysopeplum_ Berk. & C., 65.
    _chrysotrichum_ Berk. & C., 34, 50.
    cinereum (_Batsch_) _Pers._, 51, 59, 99.
    _cinereum_ Ell. & Ev., 36.
    citrinellum _Peck_, 85.
    citrinum _Schum._, 66, 85.
    _clavus_ Alb. & Schw., 122.
    _columbinum_ Macbr., 66.
    _columbinum_ Pers., 73.
    _compactum_ List., 72.
    compressum _Alb. & Schw._, 80.
    confertum _Macbr._, 64.
    _confluens_ (Pers.) Morg., 80.
    conglomeratum (_Fr._) _Rost._, 57.
    _connatum_ Peck, 80.
    _connexum_ (Link.) Morg., 80.
    contextum _Pers._, 56.
    crateriforme _Petch._, 100.
    _cupripes_ Berk. & R., 93.
    _decipiens_ Curt., 34.
    dictyospermum _List._, 100.
    diderma _Rost._, 53, 55.
    didermoides (_Ach._) _Rost._, 6, 55, 78.
    discoidale _Macbr._, 74.
    _ditmari_ Rost., 61.
    echinosporum _List._, 101.
    _effusum_ Schw., 130.
    _ellipsosporum_ Rost., 26.
    _erythrinum_ Berk., 69.
    _farlowii_ Rost., 66.
    _flavidum_ Peck, 57.
    flavicomum _Berk._, 93.
    _flavum_ Fr., 84.
    _fulvum_ _List._, 86.
    _galbeum_ _Wing._, 92.
    _glaucum_ (Phill.) Mass., 41.
    globuliferum (_Bull._) _Pers._, 66.
    _griseum_ Link., 59.
    gulielmae _Penzig_, 101.
    gyrosum _Rost._, 49, 94, 95.
    _hyalinum_ Pers., 40.
    _inaequale_ Peck, 50.
    instratum _Macbr._, 62.
    lateritium (_Berk. & Br._) _Rost._, 50.
    leucophaeum _Fr._, 75.
    _leucophaeum_ (Fr.) Macbr., 80.
    leucopus _Link._, 79.
    lilacinum _Sturg. & Bilg._, not Fr., 67.
    _lividum_ Rost., 78.
    _luteum_ Pers., 59.
    luteo-album _List._, 71.
    _macrocarpon_ Cesati, 37; Fuckel, 102.
    maculatum _Macbr._, 77.
    _maydis_ Torr., 91.
    megalosporum _Sturg._, 63.
    _melanospermum_ Pers., 88.
    melleum (_Berk. & Br._) _Mass._, 65.
    _microcarpon_ Fr., 123.
    mortoni _Macbr._, 58.
    murinum _List._, 68.
    mutabile (_Rost._) _List._, 99.
    _nefroideum_ Rost., 80.
    newtoni _Macbr._, 73.
    nicaraguense _Macbr._, 83.
    _nigripes_ Link., 123.
    nodulosum _Cke. & Balf._, 76.
    notabile _Macbr._, 80.
    nucleatum _Rex_, 72.
    nutans _Pers._, 75, 97.
    oblatum _Macbr._, 91.
    _oblongum_ Fr., 78.
    _obrusseum_ (Berk. & C.) Rost., 92.
    _ochroleucum_ Berk. & C., 57.
    _ornatum_ Peck, 91.
    _paniceum_ Fr., 35.
    penetrale _Rex_, 70.
    _petersii_ Berk. & C, 66, 69, 92.
    _phillipsii_ Balf., 41.
    _physaroides_ Alb. & Schw., 139.
    plumbeum _Fr._, 59.
    polycephalum _Schw._, 95.
    _polymorphum_ (Mont.) Rost., 80, 92.
    _polymorphum_ Rost., 52.
    _psittacinum_ Ditm., 74.
    pulcherrimum _Berk. & Rav._, 68.
    pulcherripes _Peck_, 69.
    _pusillum_ List., 76.
    _ravenelii_ (Berk. & C.) Mass., 68.
    _reniforme_ List., 83.
    _reticulatum_ Alb. & Schw., 49, 111.
    roseum _Berk. & Br._, 100.
    _rostafinskii_ Mass., 57.
    _rubiginosum_ Chev., 62.
    _rufipes_ Alb. & Schw., 69.
    _schumacheri_ Spreng., 65.
    _scyphoides_ Cke. & Balf., 105.
    serpula _Morg._, 49.
    sinuosum (_Bull._) _Weinm._, 52.
    straminipes List., 100.
    striatum _Fries_, 59.
    _stromateum_ Link, 132.
    _sulphureum_ (Alb. & Schw.) Sturg., 84.
    _tenerum_ Rex., 77.
    tenerum _Rex_, 92.
    _testaceum_ Sturg., 55.
    _thejoteum_ Fr., 62.
    tropicale _Macbr._, 82.
    _utriculare_ (Bull.) Chev., 39.
    variabile _Rex_, 89.
    vernum _Rost._, 51.
    _vermicularis_ Schw., 240.
    viride _Pers._, 98.
    _virescens_ Ditm., 61, 62.
    wingatense _Macbr._, 72.

  PLASMODIOPHORA, 17.
    brassicae _Wor._, 18.

  =_Protoderma._=
    _pusilla_ Rost., 202.

  PROTOTRICHIA, 257.
    _flagellifera_ (Berk. & Br.) Rost., 258.
    metallica (_Berk._) _Mass._, 258.

  =_Puccinia_=, 18.
    _byssoides_ Gmel., 19.
    _ramosa_, etc., Mich., 19.

  =_Raciborskia._=
    _elegans_ Berl., 182.

  RETICULARIA, 209.
    _alba_ Bull., 114.
    _atra_ Fr., 152.
    _cribrosa_ Fr., 150.
    _flavofusca_ (Ehr.) Fr., 234.
    _hemispherica_ Bull., 138.
    lycoperdon _Bull._, 6, 210.
    _maxima_ Fr., 154.
    _rozeana_ Rost., 211.
    _sinuosa_ Bull., 52.
    _splendens_ Morg., 211.

  =_Rostafinskia_=, 182.
    _elegans_ Racib., 182.


  =_Scyphium._=
    _rubiginosum_ (Chev.) Rost., 70.

  =_Siphotychium_=, 207.
    _casparyi_ Rost., 207.

  =_Sphaerocarpus._=
    _albus_ Bull., 97.
    _aurantius_ Bull., 98.
    _capsulifer_ Bull., 40.
    _chrysospermus_ Bull., 272.
    _cylindricus_ Bull., 206.
    _floriformis_ Bull., 143.
    _fragilis_ Sowb., 274.
    _globuliferus_ Bull., 66.
    _luteus_ Bull., 98.
    _utricularis_ Bull., 67.
    _viridis_ Bull., 98.

  =_Spumaria_=, 113.
    _alba_ (Bull.) DC., 114.
    _didermoides_ (Ach.) Pers., 40.
    _granulata_ Schum., 57.
    _licheniformis_ Schw., 78.
    _minuta_ Schum., 57.
    _mucilago_ Pers., 114.

  STEMONITIS, 156.
    _alba_ (Bull.) Gmel., 97.
    _argillacea_ (Pers.) Gmel., 218.
    axifera (_Bull._) _Macbr._, 168, 169, 171.
    _bäuerlinii_ Mass. (?), 166.
    _botrytis_ (Pers.) Gmel., 274.
    carolinensis _Macbr._, 170.
    _castillensis_ Macbr., 162.
    confluens _Cke. & Ell._, 158.
    dictyspora _Rost._, 161.
    _digitata_ Schw., 255.
    fenestrata _Rex_, 166.
    _ferruginea_ Ehr., 167, 168, 169.
    _ferruginosa_ Batsch., 206.
    flavogenita _Jahn_, 169.
    _friesiana_ DBy., 178.
    fusca (_Roth._) _Rost._, 160, 162.
    herbatica _Peck_, 171.
    _leucocephala_ (Pers.) Gmel., 105.
    _maxima_ Schw. (?), 160.
    _microspora_ List., 167.
    _morgani_ Peck, 164.
    _nigra_ Pers., 178, 179.
    nigrescens _Rex_, 162.
    _ovata nigra_ Pers., 178.
    pallida _Wing._, 169, 170.
    _papillata_ Pers., 190.
    pulchella _Bab._, 183.
    _scintillans_ Berk. & Br., 142.
    smithii _Macbr._, 167.
    splendens _Rost._, 164, 174.
    _splendens_ var. _confluens_ List., 6, 158.
    _suksdorfii_ Ell. & Ev., 178.
    _tenerrima_ Berk. & C., 170, 183.
    _tenerrima_ Curt., 122, 129, 183.
    trechispora (_Berk._) _Torr._, 159.
    _tubulina_ Alb. & Schw., 150.
    _typhina_ Pers., 181.
    _typhina_ Wig., 130.
    _typhoides_ (Bull.) DC., 181.
    uvifera _Macbr._, 161.
    varia (Pers.) Gmel., 270.
    _violacea_ Fr., 196.
    virginiensis _Rex_, 163.
    _viridis_ (Bull.) Gmel., 98.
    webberi _Rex_, 163.


  TILMADOCHE, 57.
    _alba_ (Bull.) Macbr., 97.
    _bethelii_ Macbr., 94.
    _cernua_ (Schum.) Fr., 97.
    _columbina_ (Berk. & C.) Rost., 72.
    _compacta_ Wing., 72.
    _gyrocephala_ (Mont.) Rost., 95.
    _hians_ Rost., 109.
    _mutabilis_ Rost., 98.
    _nutans_ (Pers.) Rost., 97.
    _oblonga_ (Berk. & C.) Rost., 71.
    _polycephala_ (Schw.) Macbr., 95.
    _viridis_ (Bull.) Sacc., 98.

  =_Tremella_=, 19.
    _hydnoides_ Jacq., 19.

  =_Trichamphora_=, 102.
    _oblonga_ Berk. & C., 109.
    pezizoidea _Jungh._, 102.

  TRICHIA, 267.
    _abietina_ Wig., 261.
    _abrupta_ Cke., 271.
    _affinis_ DBy., 271.
    andersoni _Rex_, 211.
    _aurea_ Schum., 104.
    _axifera_ Bull., 168.
    botrytis _Pers._, 274, 277.
    _cernua_ Schum., 59, 75.
    _chrysosperma_ (Bull.) Rost., 272.
    _cinerea_ Bull., 254.
    _circumscissa_ Wallr., 241.
    _clavata_ Pers., 264.
    contorta (_Ditm._) _Rost._, 269.
    decipiens (_Pers._) _Macbr._, 276.
    erecta _Rex_, 276.
    _fallax_ Pers., 276.
    favoginea (_Batsch_) Pers., 272.
    _flagellifera_ Berk. & Br., 258.
    _fragilis_ (Sowb.) Rost., 274, 277.
    inconspicua _Rost._, 263.
    iowensis _Macbr._, 269.
    _jackii_ Rost., 271.
    lateritia _Lév._, 277.
    _leucopodia_ Bull., 186.
    _nana_ Mass., 261.
    _nigripes_ Pers., 270.
    _nitens_ Lib., 280.
    _nutans_ Bull., 249.
    _ovata_ Pers., 261.
    persimilis _Karst._, 271.
    _proximella_ Karst., 271.
    pulchella _Rex_, 273.
    _pusilla_ Schroet., 280.
    _pyriformis_ Fr., 274.
    _reniformis_ Peck, 269.
    _rubiformis_ Pers., 262.
    scabra _Rost._, 271.
    _serpula_ (Scop.) Pers., 260.
    subfusca _Rex_, 275.
    _typhoides_ Bull., 181.
    varia (_Pers._) _Rost._, 270.
    verrucosa _Berk._, 273.

  TUBIFERA, 205.
    casparyi (_Rost._) _Macbr._, 207.
    ferruginosa (Batsch) _Macbr._, 206.
    stipitata (_B. & R._) _Macbr._, 207.

  =_Tubulina_=, 155.
    _cylindrica_ (Bull.) DC., 206.
    _fragiformis_ (Pers.) List., 206.
    _stipitata_ (Berk. & Rav.) Rost., 207.




PLATES

TO ILLUSTRATE

NORTH AMERICAN SLIME-MOULDS


NOTE.--Plates I., II., IV., VI., VII., VIII., IX., X., were originally
by MISS MARY P. MACBRIDE; Plates V., XI., XII., were by MRS. HATTIE J.
DOUGLASS; Plates XIII., XIV., XV., XVI., XVII., were by the late MRS.
BERTHA E. LINDER PUMPHREY; Plate III. was the joint work of MRS.
PUMPHREY and MISS MACBRIDE. All these, except IV., have been re-drawn
for new plates; XVI., with additions, by MISS MARGARET HAYES; the
remainder by MR. W. J. CALVIN, C. E. Plate XVIII. is by MISS HAYES;
Plate XIX. by Miss A. M. HELD; Plate XX. by MISS JANE COVENTRY.


EXPLANATION OF PLATE I


_Enteridium splendens_ Morg., p. 211.

Fig. 1. Æthalium, natural size.

Fig. 1 _a_. Spore of the same species, × 1400.

Fig. 1 _b_. Capillitium of the same species, × 420.


_Dictydiæthalium plumbeum_ (Fr.) Rost., p. 215.

Fig. 2. Æthalium, natural size.

Fig. 2 _a_. Sporangia and spores, × 50 (after Schroeter).

Fig. 2 _b_. Persistent apices of the peridia.


_Lindbladia effusa_ (Ehr.) Rost., p. 204.

Fig. 3. A group of sporangia, × 30.

Fig. 3 _a_. A single spore, × 1400.


_Tubifera ferruginosa_ (Batsch) Macbr., p. 206.

Fig. 4. A group of sporangia, × 5.

See also Plate VII., Fig. 8; and Plate XII., Fig. 14.


_Cribraria dictydioides_ Cke. & Balf., p. 222.

Fig. 5. Three sporangia, × 15.

Fig. 5 _a_. A single sporangium, to show reticulate thickening, × 60.

Fig. 5 _b_. A spore, × 1400.


_Dictydium cancellatum_ (Batsch) Macbr., p. 230.

Fig. 6. Sporangium, × 30.

Fig. 6 _a_. A part of the peridial wall, seen from within, × 84.


_Ceratiomyxa fruticulosa_ (Muell.) Macbr., p. 19.

Fig. 7. Three sporiferous pillars, × about 40.

Fig. 7 _a_. Tip of a single pillar, × 84.


_Hemitrichia stipata_ (Schw.) Macbr., p. 262.

Fig. 8. Sporangia, × 6.

Fig. 8 _a_. The capillitium of the same species, × 750.

Fig. 8 _b_. A single spore, × 1000.

[Illustration: PLATE I]


EXPLANATION OF PLATE II


_Perichaena corticalis_ (Batsch) Rost., p. 243.

Fig. 1. Sporangia, × 10.

Fig. 1 _a_. A single spore, as if in section, × 900.

Fig. 1 _b_. The capillitial thread, × 750.


_Lachnobolus occidentalis_ Macbr., p. 246.

Fig. 2. The sporangia, × 8.

Fig. 2 _a_. A portion of the capillitium, × 750.

Fig. 2 _b_. Spores, × 750.

See also 4 and 4 a below.


_Arcyria cinerea_ (Bull.) Pers., p. 254.

Fig. 3. The expanded fructifications, × 5.

Fig. 3 _a_. Tip of a single capillitium mass, × 40.


_Lachnobolus occidentalis_ Macbr., p. 246.

Fig. 4. A cluster of sporangia, × 3; cylindric type.

Fig. 4 _a_. Capillitium, × 750; to show characteristic surface of the
threads.


_Arcyria denudata_ (Linn.) Pers., p. 253.

Fig. 5. Sporangia, two expanded, one still closed, × 20.

Fig. 5 _a_. A part of the capillitium of the same species, × 750.


_Arcyria nutans_ (Bull.) Grev., p. 249.

Fig. 6. Expanded capillitium, etc., × 10.

Fig. 6 _a_. Capillitium, × 750.

Fig. 6 _b_. A piece of the capillitium thread, × 1400.


_Ophiotheca wrightii_ Berk. & C., p. 241.

Fig. 7. A single sporangium, × 8.

Fig. 7 _a_. A node of the capillitial thread, × 750.

Fig. 7 _b_. A spore, × 750.


_Oligonema nitens_ (Lib.) Rost., p. 280.

Fig. 8. A single elater, × 750.

Figs. 8 _a_ and 8 _b_. Spores, × 1000.


_Badhamia macrocarpa_ Rost., p. 37.

Var. _gracilis_.

Fig. 9. Two sporangia, × 600.

[Illustration: PLATE II]


EXPLANATION OF PLATE III


_Hemitrichia clavata_ (Pers.) Rost., p. 264.

Fig. 1. Three sporangia, one closed, × 8.

Fig. 1 _b_. A single spore, × 1400.


_Hemitrichia vesparium_ (Batsch) Macbr., p. 262.

Fig. 2. Tip of the elater of capillitial thread, × 1400.

Fig. 2 _a_. A single spore, × 1400.


_Trichia iowensis_ Macbr., p. 269.

Fig. 3. A cluster of sporangia, × 5.

Fig. 3 _a_. Tip of a branching elater, × 750.

Fig. 3 _b_. A single spore, × 750.

See also Plate X., Fig. 5.


_Hemitrichia serpula_ Scop., p. 260.

Fig. 4. A plasmodiocarp, × 3.

Fig. 4 _a_. A single spore, × 1400.

Fig. 4 _b_. An elater-tip, × 1400.


_Trichia inconspicua_ Rost., p. 268.

Fig. 5. A cluster of sporangia, × 12.

Fig. 5 _a_. Tip of an elater, × 1400.

Fig. 5 _b_. A single spore, × 750.


_Physarum oblatum_ Macbr., p. 91.

Fig. 6. A single sporangium, × 20; stipe shown of unusual length.

Fig. 6 _a_. A single spore, × 1000.

See also Plate XIV., Fig. 3.


_Physarum auriscalpium_ (Cke.) Lister, p. 90.

Fig. 7. A single sporangium, × 20; a New York specimen.

Fig. 7 _a_. A single spore, × 1000.


_Arcyria nodulosa_ Macbr., p. 252.

Fig. 8. Capillitial thread, × 1200.

[Illustration: PLATE III]


EXPLANATION OF PLATE IV


_Trichia persimilis_ Karst., p. 271.

Fig. 1. Var. intermedia, × about 6.

Fig. 1 _a_. Spore of same species, × 1400.

Fig. 1 _b_. A second spore to show varying episporic network.

Fig. 1 _c_. Tip of elater, shows vertical connecting bands.


_Trichia decipiens_ (Pers.) Macbr., p. 276.

Fig. 2. Sporangia, × about 8.

Fig. 2 _a_. A spore of the same species, × 1400.

Fig. 2 _b_ and 2 _c_. Elaters of the same species, × about 225.


_Trichia varia_ (Pers.) Rost., p. 270.

Fig. 3. Sporangia, × about 8.

Fig. 3 _a_. A spore of the same species, × 1000.

Fig. 3 _b_. An elater of the same species, × 750.


_Trichia scabra_ Rost., p. 271.

Fig. 4. Sporangia, × about 8.

Fig. 4 _a_. A single spore of the same species, × 1400.

Fig. 4 _b_. An elater-tip of the same, × 1400.


_Trichia favoginea_ (Batsch) Pers., p. 272.

Fig. 5. Sporangia, × about 8.

Fig. 5 _a_. A single spore of the same, × 1400.

Fig. 5 _b_. A single elater-tip of the same, × 1400.


_Trichia persimilis_ Karst., var _abrupta_ Cke., p. 271.

Fig. 6. An elater-tip, × 1400. It will be noticed that the spirals are
connected by vertical bars.

Fig. 6 _a_. A single spore of the same variety, × 1400.

Fig. 6 _b_. A single spore, from the same sporangium as 6 _a_.

Fig. 6 _c_. Trichia persimilis, a single spore, × 1400.

Fig. 6 _d_. Tip of an elater from the same, × 1400.

[Illustration: PLATE IV]


EXPLANATION OF PLATE V


_Lamproderma arcyrionema_ Rost., p. 197.

Fig. 1. A single sporangium seen as if in section, × 40.

Fig. 1 _a_. A single spore, × 1400.


_Lamproderma scintillans_ (Berk. & Br.) List., p. 195.

Fig. 2. A single sporangium seen as in section, × 40.

Fig. 2 _a_. A single spore, × 1400.


_Enerthenema papillatum_ (Pers.) Rost., p. 190.

Fig. 3. An expanded, blown-out sporangium, × 25.


_Lamproderma robustum_ Ell. & Ev., p.

Fig. 4. A sporangium seen as in section, × 20.

Fig. 4 _a_. A single spore, × 1000.


_Comatricha laxa_ Rost., p. 177.

Fig. 5. A sporangium seen as if in section, × 40.

Fig. 5 _a_. A single spore, × 2000.


_Diachaea thomasii_ Rex, p. 188.

Fig. 6. Three sporangia magnified about 15 times.

Fig. 6 _a_. A single spore of the same species, × 800.


_Brefeldia maxima_ (Fries) Rost., p. 154.

Fig. 7. A group of sporangia, showing columellæ; × 5.

Fig. 7 _a_. Capillitial threads of the same species, × 300.

Fig. 7 _b_. Spore of the same species, × 1500.


_Amaurochæte fuliginosa_ (Sowb.) Macbr., p. 149.

Fig. 8. A bit of so-called capillitium, × 300.

Fig. 8 _a_. A single spore magnified about 1000 times.

[Illustration: PLATE V]


EXPLANATION OF PLATE VI


_Comatricha typhoides_ (Bull.) Rost., p. 181.

Fig. 1. A group of sporangia, × 5.

Fig. 1 _a_. A single spore, × 1600.

Fig. 1 _b_. Tip of the columella with its branches, × 50.


_Comatricha longa_ Peck, p. 175.

Fig. 2. A single empty sporangium, × 6.

Fig. 2 _a_. A part of the same taken near the apex, × 60.

Fig. 2 _b_. A spore, × 1400.


_Comatricha aequalis_ Peck, p. 180.

Fig. 3. A single sporangium, × 10.

Fig. 3 _a_. The columella and capillitium, × 60.

Fig. 3 _b_. A single spore, × 1600.

Figs. 3 _c_ and 3 _d_. Sporangia to which the peridium still adheres,
although in 3 _c_ in shreds.


_Stemonitis fusca_ Rost., p. 160.

Fig. 4. A group of sporangia, × 3.

Fig. 4 _a_. A part of the columella and capillitium, × 60.

Fig. 4 _b_. A single spore, × 1400.


_Stemonitis axifera_ (Bull.) Macbr., p. 168.

Fig. 5. A group of sporangia, × 3.

Fig. 5 _a_. A single spore, × 1400.

Fig. 5 _b_. A part of the capillitium with columella, × 60.


_Stemonitis splendens_, p. 164.

Fig. 6. A group of sporangia, × 3.

Figs. 6 _a_ and 6 _c_. Single spores, the latter × 1400.

Fig. 6 _b_. A part of the columella and branches, × 60.

Fig. 7. A shorter variety of the same species with coarser meshes in
capillitium, × 3.

Fig. 7 _a_. A part of the columella and net, × 60.

[Illustration: PLATE VI]


EXPLANATION OF PLATE VII


_Diachaea splendens_ Peck, p. 187.

Fig. 1. Sporangia and hypothallus, × 25.

Fig. 1 _a_. Capillitium, × 50.

Fig. 1 _b_. Spores, × 900.

Fig. 1 _c_. Portion of the capillitium, × 150.


_Didymium nigripes_ Fr., p. 123.

Fig. 2. Sporangia, × 30.

Fig. 2 _a_. A spore, × 1400.

Fig. 2 _b_. Calcareous crystals from the peridial wall, × 750.


_Didymium melanospermum_ (Pers.) Macbr., p. 121.

Fig. 3. Sporangia, × 10.

Fig. 3 _a_. A single spore, × about 1000.


_Diderma testaceum_ (Schrad.) Pers., p. 137.

Fig. 4. Sporangia; the first exhibiting the two peridial walls and the
spore-mass, × 10.

Fig. 4 _a_. Spore, × 750.

Fig. 4 _b_. Capillitial threads, × 750.


_Diderma globosum_ Pers., p. 134.

Fig. 5. Sporangia; the first with the outer peridium broken away, × 10.

Fig. 5 _a_. A single spore, × 750.


_Mucilago spongiosa_ (Leyss.) Morg., p. 114.

Fig. 6. An æthalium, borne on a grass-stem, natural size.

Fig. 6 _a_. A spore, × 750.

Fig. 6 _b_. Capillitium, with surface calcareous crystals, × 750.


_Diderma crustaceum_ Peck, p. 135.

Fig. 7. A mass of clustered sporangia, to show habit of aggregation,
natural size.


_Tubifera ferruginosa_ (Batsch) Macbr., p. 206.

Fig. 8. A single spore, × 1400.

[Illustration: PLATE VII]


EXPLANATION OF PLATE VIII


_Diderma floriforme_ (Bull.) Pers., p. 143.

Fig. 1. Sporangia of various ages, × 5.

Fig. 1 _a_. Spore of the same species, × 1000.

Fig. 1 _b_. A capillitial thread, × 1000.


_Physarum polycephalum_ Schw., p. 95.

Fig. 2. The sporangia, × 10.

Fig. 2 _a_. Spores, × 750.

Fig. 2 _b_. Capillitium, × 750.


_Leocarpus fragilis_ (Dicks.) Rost., p. 112.

Fig. 3. Sporangia, × 6.

Fig. 3 _a_. A group of sporangia, natural size, to show habit.

Fig. 3 _b_. A single spore, × 1800.


_Physarella oblonga_ (Berk. & C.) Morg., p. 109.

Fig. 4. A single sporangium, × 8.

Figs. 4 _a_ and 4 _b_. Capillitium and spore respectively, × 900.


_Craterium leucocephalum_ (Pers.) Ditmar, p. 105.

Fig. 5. Sporangia, the first closed, × 10.


_Physarum sinuosum_ (Bull.) Weinm., p. 52.

Fig. 6. Plasmodiocarp, natural size; 6 _a_, × 4; see also Plate XIX.,
Fig. 15.


_Physarum virescens_ Ditmar, p. 61.

Fig. 7. Groups of sporangia, × 3 and × 8.

Fig. 7 _a_. Spores, × 750.


_Physarum viride_ Pers., p. 98.

Fig. 8. A single sporangium, × 25; 8 _a_, reverse.

Fig. 8 _b_. The same after spore-dispersal.

Fig. 8 _c_. Capillitium, × 750.

[Illustration: PLATE VIII]


EXPLANATION OF PLATE IX


_Physarum didermoides_ (Ach.) Rost., p. 78.

Fig. 1. Sporangia, × 15.

Fig. 1 _a_. A single sporangium open; shows calcareous capillitium, ×
15.

Fig. 1 _b_. Spores, × 900.


_Physarum notabile_ Macbr., p. 80.

Fig. 2. A cluster of sporangia, × 15.

Fig. 2 _a_. A single sporangium open, × 15.

Fig. 2 _b_. Spores, × 900.

See also Plate XV., Figs. 2, 2 _a_, and the frontispiece.


_Physarum contextum_ Pers., p. 56.

Fig. 3. A group of sporangia, × 15.

Fig. 3 _a_. Spores of the same, × 600.


_Physarum cinereum_ (Batsch) Pers., p. 59.

Fig. 4. A group of sporangia, × 4.

Fig. 4 _a_. A single sporangium, × 20.

Fig. 4 _b_. Capillitium of the same, × 240.

Fig. 4 _c_. Spores, × 450.


_Physarum albescens_ Ellis, p. 86.

Fig. 5. Sporangia, × 5.

See also Plate XVI., Figs. 4 and 4 _a_.

Fig. 5 _a_. Spore of the same species, × 450.

Fig. 5 _b_. Capillitium of the same, × 240.


_Physarum serpula_ Morg., p. 49.

Fig. 6. Plasmodiocarps, about natural size.

Fig. 6 _a_. A bit of the plasmodiocarp, showing structure, × 6.

Fig. 6 _b_. A spore of the same species, × 1400.


_Physarum leucopus_ Link., p. 79.

Fig. 7. A single sporangium, × 15.

Fig. 7 _a_. A spore of the same species, × 900.

Fig. 7 _b_. A fragment of the capillitium.

[Illustration: PLATE IX]


EXPLANATION OF PLATE X


_Badhamia rubiginosa_ (Chev.) Rost., p. 43.

Fig. 1. A group of sporangia, × 5.

Fig. 1 _a_. Two sporangia, same species, × 18, to show persisting
capillitium.

Fig. 1 _b_. Capillitium fragment, × 240.

Fig. 1 _c_. Spore of the same species, × 750.


_Fuligo septica_ (L.) Gmel.; form _laevis_, p. 29.

Fig. 2. An æthalium, natural size.

Fig. 2 _a_. A section of the same, × 10.

Fig. 2 _b_. A spore of the same, × 750.


_Fuligo cinerea_ Pers., p. 26.

Fig. 3. A small æthalium borne upon a blade of grass, natural size.

See also Plate XXIII.

Fig. 3 _a_. Capillitial fragment from the same specimen, × 450.

Fig. 3 _b_. Spores of the same, × about 750.


_Didymium minus_ List., p. 121.

Fig. 4. A single sporangium, × 25.

Fig. 4 _a_. The capillitium and fragment of the peridium of the same
species, × 380.

Fig. 4 _b_. A spore of the same species, × 1000.


_Trichia iowensis_ Macbr., p. 269.

Fig. 5. Tip of an elater, × 1400.

See also Plate III, 3, 3 _a_, 3 _b_.


_Badhamia papaveracea_ Berk. & Rav., p. 42.

Fig. 6. Sporangia, a cluster, × 8.

Fig. 6 _a_. A cluster of spores, × 400.

Fig. 6 _b_. A single spore of the same, × 1400.


_Reticularia lycoperdon_ Bull., p. 210.

Fig. 7. A fragment of the capillitium, × 240.

Fig. 7 _a_. A single spore of the same species, × 1400.

See also Plate XII., Fig. 3.

[Illustration: PLATE X]


EXPLANATION OF PLATE XI


_Comatricha nigra_ Pers., p. 178.

Fig. 1. A group of sporangia, × 10.

Fig. 2. A single sporangium as in section, × 60.

Fig. 3. A single spore, × 1600.


_Stemonitis confluens_ Ell. & Cke., p. 158.

Fig. 4. A group of sporangia, × 10.

Fig. 4 _a_. A thread of capillitium with adhering disk, × 30.

Fig. 5. A spore of the same, × 2000.


_Stemonitis webberi_ Rex, p. 163.

Fig. 6. A group of sporangia, × 4.

Fig. 7. A single sporangium as in section, × 40.

Fig. 8. A single spore, same species, × 1250.


_Comatricha suksdorfii_ Ell. & Ev., p. 178.

Fig. 9. A group of sporangia, × 4.

Fig. 10. A bit of the capillitium, × 60.

Fig. 11. A single spore, × 1600.


_Comatricha cæspitosa_ Sturg., p. 172.

Fig. 12. A cluster of sporangia, × 4.

Fig. 13. The capillitium highly magnified.

Fig. 14. A single spore, × 1600.

[Illustration: PLATE XI]


EXPLANATION OF PLATE XII


_Lindbladia effusa_ (Ehr.) Rost., p. 204.

Fig. 1. Fructification, natural size.

Fig. 2. Portion of same in section, × 3.


_Reticularia lycoperdon_ Bull., p. 210.

Fig. 3. Residual capillitial structure, the spores blown away; about
natural size.


_Enteridium splendens_ Morg., p. 211.

Fig. 4. Fructification, a large one, natural size.

Fig. 5. Same in section, × 3.


_Arcyria ferruginea_ Sauter, p. 253.

Fig. 6. Three sporangia, magnified about 10 times.

Fig. 6 _a_. A single spore, magnified.

Fig. 6 _b_. Capillitial thread.


_Licea variabilis_ Schrad., p. 200.

Fig. 7. Sporangia, magnified about 6 times.

Fig. 8. Spore, magnified to show surface characters.


_Tubifera casparyi_ (Rost.) Macbr., p. 207.

Fig. 9. A group of sporangia; shows the pseudo-columellæ; × about 5.


_Licea biforis_ Morg., p. 201.

Fig. 10. Sporangia dehiscent, magnified about 10 times.


_Orcadella operculata_ Wing., p. 203.

Fig. 11. Sporangia, magnified about 30 times.


_Cribraria argillacea_ Pers., p. 218.

Fig. 12. Sporangia, magnified about 10 times.

Fig. 13. A single sporangium, × about 40.

See also Plate XVII., Fig. 1.


_Tubifera ferruginosa_ (Batsch) Macbr., p. 206.

Fig. 14. Sporangia magnified to show apiculate tops. Cf.


_Comatricha ellisii_ Morg., p. 184.

Fig. 15. Sporangium, × 40.

Fig. 15 _a_. A single spore, × 1000.


_Comatricha pulchella_ (Bab.) Rost, p. 183; vid. p. 284.

Fig. 16. Sporangium, × 20.

Fig. 16 _a_. A single spore, × 1000.


_Comatricha subcaespitosa_ Peck, p. 185.

Fig. 17. Sporangium, × 20.

Fig. 17 _a_. A single spore, × 1000.


_Comatricha gracilis_ Wingate, p. 183.

Fig. 18. Sporangium, × 20.

Fig. 18 _a_. A single spore, × 1000.

[Illustration: PLATE XII]


EXPLANATION OF PLATE XIII


_Heterotrichia gabriellæ_ Mass., p. 257.

Fig. 1. A group of sporangia, one expanded, the others empty, × 15.

Fig. 1 _a_. Capillitium of the species, × 600.


_Calonema aureum_ Morg., p. 266.

Fig. 2. A cluster of sporangia, magnified about 15 times.

Fig. 2 _a_. The tip of an elater of the same species, × 1000.

Fig. 2 _b_. A single spore, × 1000.

Fig. 2 _c_. A bit of the sporangium wall, × 600.


_Stemonitis pallida_ Wing., p. 169.

Fig. 3. Sporangia, magnified about 5 times.


_Comatricha pulchella_ (Bab.) Rost., form _C. persoonii_ R., p. 183.

Fig. 4. Sporangia, magnified about 15 times.

See Addenda, d, p. 283.


_Stemonitis carolinensis_ Macbr., p. 170.

Fig. 5. Sporangia, magnified about 5 times.


_Clastoderma debaryanum_ Blytt., p. 191.

Fig. 6. Sporangium, magnified about 60 times.


_Trichia contorta_ Rost., p. 269.

Fig. 7. Tip of an elater, × 1400.

Fig. 7 _a_. Spore of the same species, × 1400.


_Trichia botrytis_ Pers., p. 274.

Fig. 8. Tip of the elater, × 1400.

Fig. 8 _a_. Spore of the same species, × 1400.

[Illustration: PLATE XIII]


EXPLANATION OF PLATE XIV


_Badhamia magna_ Peck., p. 38.

Fig. 1. A cluster, of sporangia, × 10.


_Cienkowskia reticulata_ (Alb. & Schw.) Rost., p. 111.

Fig. 2. Plasmodiocarp, × 15.

Fig. 2 _a_. A bit of the capillitium of the same, × 800.

Fig. 2 _b_. A single spore, × 1000.


_Physarum oblatum_ Macbr., p. 91.

Fig. 3. Sporangia, × 15.

Fig. 3 _a_. A piece of capillitium, × 800.

Fig. 3 _b_. A single spore, × 1000. The roughness much exaggerated.


_Badhamia orbiculata_ Rex., p. 37.

Fig. 4. A group of sporangia, × 10.


_Physarum newtoni_ Macbr., p. 73.

Fig. 5. A group of sporangia, × 16.

Fig. 5 _a_. A single spore, × 1000.

Fig. 5 _b_. A bit of the capillitium, × 800.


_Physarum maculatum_ Macbr., p. 77.

Fig. 6. A cluster of sporangia, × 10.

Fig. 6 _a_. A piece of the capillitial net, × 800.

Fig. 6 _b_. A single spore, × 800.


_Lepidoderma tigrinum_ (Schrad.) Rost., p. 145.

Fig. 7. A group of sporangia, × 20.

[Illustration: PLATE XIV]


EXPLANATION OF PLATE XV


_Physarum confertum_ Macbr. _n. n._, p. 64.

Fig. 1. Sporangia on a bit of leaf, × 4.

Fig. 1 _a_. Capillitium, × 800.

Fig. 1 _b_. A single spore, × 1200.


_Physarum notabile_ Macbr., p. 80.

Fig. 2. A group of sporangia, stipitate form, × 10.

Fig. 2 _a_. A single spore, × 1200.


_Physarum flavicomum_ Berk., p. 93.

Fig. 3. A cluster of sporangia, one closed, × 10.

Fig. 3 _a_. A single spore, × 1200.


_Physarum tropicale_ Macbr., p. 82.

Fig. 4. Sporangia, × 10.

Fig. 4 _a_. Capillitium, × 800.

Fig. 4 _b_. A single spore, × 1200.


_Craterium minutum_ (Leers) Fr., p. 107.

Fig. 5. Sporangia, the stalks unusually long, × 15.


_Physarum penetrale_ Rex, p. 70.

Fig. 6. A group of sporangia; the calcareous crust has fallen in all.

Fig. 6 _a_. A single sporangia, enlarged to show columella, × 20.


_Physarum nicaraguense_ Macbr., p. 83.

Fig. 7. A group of sporangia, × 15.

Fig. 7 _a_. Capillitium, strongly calcareous, × 800.

Fig. 7 _b_. A single spore, × 1200.

See also Pl. XVII., Figs 11 and 11 _a_.

[Illustration: PLATE XV]


EXPLANATION OF PLATE XVI


_Physarella oblonga_ (Berk. & C.) Morgan, p. 109.

Fig. 1. Fully opened sporangium, × 10.

Fig. 1 _a_. Tubular sporangia closed, × 5.

Fig. 1 _b_. Transverse section of sporangium; shows trabecular
calcareous nodules of the capillitium, × 15.


_Craterium cylindricum_ Mass., p. 106.

Fig. 2. Group of sporangia, × 10.


_Physarum wingatense_ Macbr., p. 72.

Fig. 3. Group of sporangia, × 10.


_Physarum albescens_ Ellis, p. 86.

Fig. 4. Group of sporangia, × 10.

Fig. 4 _a_. Capillitium of the same species, × 200.


_Dianema harveyi_ Rex, p. 238.

Fig. 5. Group of sporangia, × 10.

Fig. 5 _a_. Clustered spores, D. corticatum, × 500.

Fig. 5 _b_. Capillitial threads and spores, D. harveyi, × 200.

Fig. 5 _c_. Twisted, spirally striate single threads, × 500; _D.
corticatum_, List.


_Physarella oblonga_ Berk. & C., p. 109.

Fig. 6. Terrestial, plasmodiocarpous phase, × 10.


_Physarum megalosporum_ Sturg., p. 63.

Fig. 7. Group of sporangia, × 8.

Fig. 7 _a_. Capillitium and spores, × 150.


_Didymium complanatum_ (Batsch) Rost., p. 116.

Fig. 8. Capillitial structure, × 200.


_Physarum wingatense_, p. 72.

Fig. 9. Sporangium, × 20, enlarged to show dehiscence.


_Didymium xanthopus_ (Ditm.) Fr., p. 123.

Fig. 10. Sporangium--diagram to show columella, × 20.


_Didymium eximium_ Pk., p. 124.

Fig. 11. Group of sporangia, × 10.

Fig. 11 _a_. Section of sporangium, × 30; diagram.

Fig. 11 _b_. Spore, × 750.

Comatricha elegans (Racib.) List., p. 182.

Fig. 12. A single sporangium, × 20.

Clastoderma debaryanum, p. 191.

Fig. 13. Sporangium, seen in section, × 20.

Stemonitis herbatica Pk., p. 171.

Fig. 14. Group of sporangia, × 2.

Fig. 14 a. The same enlarged to show general outline.

Fig. 14 b. The same; capillitial section, × 20.

Fig. 14 c. A single spore, × 1000.

[Illustration: PLATE XVI]


EXPLANATION OF PLATE XVII


_Cribraria argillacea_ (Pers.) Schrad., p. 218.

Fig. 1. Sporangium, highly magnified.


_Cribraria macrocarpa_ Schrad., p. 219.

Fig. 2. Sporangium, highly magnified.


_Cribraria aurantiaca_ Schrad., p. 221.

Fig. 3. Sporangium containing spores, × 30.


_Cribraria microcarpa_ Schrad., p. 226.

Fig. 4. Sporangium containing spores, × 30.


_Cribraria tenella_ Schrad., p. 225.

Fig. 5. Sporangium containing spores, × 40.


_Cribraria minutissima_ Schw., p. 220.

Fig. 6. A single sporangium calyculate, × 50.

Fig. 6 _a_. A smaller sporangium without calyx, with spore-mass.

_Cribraria cuprea_ Morg., p. 229.

Fig. 7. A single sporangium, × 50.


_Cribraria violacea_ Rex, p. 227.

Fig. 8. A single sporangium, × 40.


_Cribraria piriformis_ Schrad., p. 224.

Fig. 9. A single sporangium, × 30.


_Perichaena depressa_ (Libert) Rost., p. 242.

Fig. 10. A cluster of sporangia, one open, × 8.


_Physarum nicaraguense_ Macbr., p. 83.

Fig. 11. Single sporangium, × 10.

Fig. 11 _a_. A cluster of sporangia and hypothallus, × 5.

[Illustration: PLATE XVII]


EXPLANATION OF PLATE XVIII


_Margarita metallica_ (Berk. & Br.) List., p. 237.

Fig. 1. A group of sporangia, × 15.

Fig. 1 _a_. Capillitium and spores, × 300.

Fig. 1 _b_. A single spore, × 1200.


_Diderma cor-rubrum_ n. s., p. 140.

Fig. 2. A group of sporangia, × 15.


_Diderma asteroides_ List., p. 143.

Fig. 3. Sporangia-spread, × 6.

Fig. 3 _a_. Same sporangia still unopened, × 4.


_Comatricha laxa_ Rost., Cf. Pl. V., 5 & 5 _a_, p. 184.

Fig. 4. Sporangia, × 10.


_Diderma lyallii_ (Mass.) Macbr., p. 136.

Fig. 5. A group of sporangia, × 10.

Fig. 5 _a_. Capillitium and spores, × 200.


_Lepidoderma chailletii_ Rost., p. 146.

Fig. 6. A group of sporangia, × 15.

Fig. 6 _a_. Capillitium and spores, × 150.

Fig. 6 _b_. A single spore, × 800.


_Didymium anellus_ Morg., p. 117.

Fig. 7. A group of sporangia, × 10.


_Diderma radiatum_ Linn., p. 141.

Fig. 8. A group of sporangia, × 8.


_Physarum diderma_ Rost., p. 55.

Fig. 9. A group of sporangia, × 10.


_Diderma rugosum_ (Rex) Macbr., p. 144.

Fig. 10. A group of sporangia, × 10.


_Diderma niveum_ (Rost.) Macbr., p. 137.

Fig. 11. A group of sporangia, × 10.

Fig. 11 _a_. Spore and Capillitium, × 600.


_Prototrichia metallica_ (Berk.) Mass., p. 258.

Fig. 12. A group of sporangia, × 10.

Fig. 12 _a_. Same; capillitium and spores, × 300.

Fig. 12 _b_. Tip of a capillitium thread to show spiral markings and
end-fraying, × 800.


_Comatricha aequalis_ Peck, p. 180.

Fig. 13. A group of sporangia, × 5.

Fig. 13 _a_. Sporangium tip, capillitium, × 200.

Fig. 13 _b_. Spore, × 800.


_Physarum compressum_ Alb. & Schw., p. 80.

Fig. 14. A group of sporangia to show compressed form, × 10.

See also Plate XIX., Fig. 12.

[Illustration: PLATE XVIII]


EXPLANATION OF PLATE XIX


_Dictydium cancellatum_ Batsch, p. 230.

Fig. 1. The finest phase, as the form appears in the Mississippi valley,
× 15.

Fig. 1 _a_. Sporangium of the same seen from below, × 35.

Fig. 1 _b_. Sporangium--same--seen from above, × 35.

Fig. 1 _c_. Cribraria-like net from the top, × 200.

Fig. 2. Vertical section of what is believed the typical European form,
× 20.

Fig. 3. An ellipsoidal piriform phase--var. _prolatum_, × 15.


_Physarum compressum_ Alb. & Schw. form _P. affine_ Rost., p. 80.

Fig. 4. A group of sporangia, × 12.

Fig. 4 _a_. A single spore, × 600.

Fig. 4 _b_. Capillitium, same species, × 300.


_Alwisia bombarda_ Berk. & Br., p. 209.

Fig. 5. Open sporangia, × 6.

Fig. 5 _a_. Sporangium of same enlarged to show capillitium, × 20.


_Cribraria dictydiodes_ Cke. & Balf., p. 222.

Fig. 6. A group of sporangia, × 6.

Fig. 6 _a_. Single sporangium of same--lateral view, × 25.

Fig. 6 _b_. Same; base view, × 30.


_Cribraria aurantiaca_ Schrad., p. 221.

Fig. 7. Single sporangium, × 30.


_Cribraria rufa_ (Roth) Rost., p. 220.

Fig. 8. Sporangium, × 30.


_Cribraria piriformis_ Schrad., p. 224.

Fig. 9. Sporangium, × 30.


_Cribraria splendens_ (Schrad.) Pers., p. 221.

Fig. 10. Sporangium, × 30.


_Echinostelium minutum_ DeBy., p. 198.

Fig. 11. Several sporangia, × 15.

Fig. 11 _a_. Vertical section, after Rost., × 500.

_Physarum compressum_ Schw., p. 80.

Fig. 12. Sporangium, × 20, to show dehiscence.


_Didymium anomalum_ Sturg., p. 127.

Fig. 13. Plasmodiocarps, about natural size.

Fig. 13 _a_. Diagrammatic vertical section, etc., to show the
calciferous pillars distinguishing the species, × 200.

Fig. 14. Calcic crystal--enlarged.


_Physarum sinuosum_ (Bull.) Weinm., p. 52.

Fig. 15. Plasmodiocarps passing to sporangia, × 5.

Cf. Plate VIII., 6 and 6 _a_.


_Physarum bitectum_ List., p. 53.

Fig. 16. Plasmodiocarps as in 15, showing transitional phases, × 10.

[Illustration: PLATE XIX]


EXPLANATION OF PLATE XX


_Badhamia iowensis_ n. s., p. 36.

Fig. 1. Sporangia several presentations, × 15.

Fig. 1 _a_. Capillitium, × 200.

Fig. 1 _b_. Single spore, × 500.


_Physarum mortoni_ n. s., p. 58.

Fig. 2. A group of sporangia, × 20.

Fig. 2 _a_. Capillitium, × 200.


_Physarum discoidale_ n. s., p. 74.

Fig. 3. A group of sporangia, × 10.

Fig. 3 _a_. A single spore, × 800.


_Didymium annulatum_ n. s., p. 125.

Fig. 4. Group of sporangia, × 15.

Fig. 4 _a_. Capillitium and spores, × 200.


_Oligonema brevifilum_ Peck, p. 280.

Fig. 5. Capillitium, × 800.

Fig. 5 _a_. The same.

Fig. 12 _b_. A single spore, × 800.


_Amaurochaete tubulina_ (Alb. & Schw.) Macbr., p. 150.

Fig. 6. Capillitium and spores, × 200.

Fig. 6 _a_. Spore, × 1200.


_Physarum brunneolum_ (Phill.) Mass., p. 58.

Fig. 7. Group of sporangia.

Fig. 7 _a_. The same, mature, dehiscence beginning, × 10.

Fig. 7 _b_. A single spore, × 800.


_Stemonitis uvifera_ n. s., p. 161.

Fig. 8. Colony, natural size.

Fig. 8 _a_. Capillitium and spore-clusters, × 30.

Fig. 8 _b_. Single spore-cluster, × 600.

Fig. 8 _c_. Spore, × 1000.


_Stemonitis trechispora_ Berk., p. 160.

Fig. 9. Fructification--natural size.

Fig. 9 _a_. Capillitium, branch and threads, × 20--the spores enlarged.

Fig. 9 _b_. Netted spore, × 1000. Masking as an amaurochete; _A.
trechispora_ perhaps; compare 11, etc., below.


_Stemonitis flavogenita_ Jahn, p. 169.

Fig. 10. A group of sporangia, × 3.

Fig. 10 _a_. Capillitium showing columella-tip, × 50.

Fig. 10 _b_. Spore, × 1200.


_Stemonitis trechispora_ (Berk.) Torr., p. 159.

Fig. 11. A group of sporangia, × 3.

Fig. 11 _a_. Diagram of a single sporangium, a less rudimentary
specimen, × 40.

Fig. 11 _b_. Capillitium enlarged to show branching columella, × 40.

Fig. 11 _c_. A single spore, × 1200.


_Arcyria pomiformis_ (Leers) Rost., p. 255.

Fig. 12. A globose colony of sporangia, × 10; var. _conglobosa_.

Fig. 12 _b_. See under 5, above.

[Illustration: PLATE XX]


EXPLANATION OF PLATE XXI

Brefeldia maxima (Fr.) Rost., p. 154.

A typical, beautiful æthalium, about natural size.

[Illustration: PLATE XXI]


EXPLANATION OF PLATE XXII


_Brefeldia maxima_ Rost., p. 154.

Fig. 1. Plasmodium active; climbing the stump.

Fig. 2. Same plasmodium urgent; moving at the rate of 2 cm. per hour.

From photo-prints by Mr. W. A. Seaman and Mr. John T. Reeder, Mich. The
figures are about one-sixth the natural size of the object. See plate
preceding for the mature phase of this species, natural size.

[Illustration: PLATE XXII]


EXPLANATION OF PLATE XXIII


_Fuligo rufa_ (Schw.) Pers., p. 28.

1. The plasmodium; urgent!

2. The perfected fruit; quiescent.

The figures present their objects about natural size. See also Plate X.,
Figs. 3, 3 _a_, 3 _b_, for further illustration.

From photo-prints by John T. Reeder, Mich.

[Illustration: PLATE XXIII]




      *      *      *      *      *      *




Transcriber's note:


Many apparent spelling errors are in fact published synonyms and
remain as printed.

The 'Corrigenda' or errata changes are entered.

  Page 11.
    'of enviroment.'
    changed 'enviroment' to 'environment.'
  Page 26
    'anon winding,'
    may be 'and winding,'; unchanged.
  Page 29
    'PLATE X, Figs. 2, 2 _a_, 2 _b_.'
    added.
  Page 38
    '1892. _Bahamia varia_' as in original; no change.
  Page 41
    'In some case'
    changed 'case' to 'cases'.
  Page 46
    'leaving his sucessors' as in original;
    unusual spelling; no change.
  Page 47
    '24. _P. pulcherrinum_'
    changed 'pulcherrinum' to 'pulcherrimum', to match the referenced
    paragraph.
  Page 63
    'visible hyphothallus'
    changed 'hyphothallus' to 'hypothallus'.
  Page 65
    '1873. Dydymium' as in original; no change.
  Page 78
    'sheet-like hyphothallus'
    changed 'hyphothallus' to 'hypothallus'.
  Page 79
    37. Physarum leucopus _Link_.
    '37.' missing in original; added.
  Page 80
    'P. affie Rost., Plate XIX., Fig. 4.'
    changed 'affie' to 'affine'.
  Page 84
    'which has spores 10-12' changed to 'which has spores 10-12 µ'.
    added 'µ'.
  Page 98
    'PLATE VIII, Figs. 8, 8 _a_, 8 _b_.'
    added.
  Page 108
    'pendunculatum Trent.,'
    changed 'pendunculatum' to 'pedunculatum'.
  Page 110
    '=Cienkowskia= _Rost._' changed to '=6. Cienkowskia= _Rost._'
    '6.' added.
  Page 114
    'PLATE VII, Figs. 6, 6 _a_, 6 _b_.'
    added.
  Page 116
        _a._ Sporangia discoid, spores reticulate     19. _D. intermedium_
        _b._ Stipe, columella, peridium, orange-brown    20. _D. leoninum_
  changed to
        _a._ Sporangia discoid, spores reticulate     18. _D. intermedium_
        _b._ Stipe, columella, peridium, orange-brown    19. _D. leoninum_
  to match referenced text.
  Page 130
    '7. _D. niveum_'
    changed '7.' to '8.'
  Page 149
    'cushion is interestingly aborescent'
    changed 'aborescent' to 'arborescent'.
  Page 150
    AMAUROCHÆTE TUBULINA (_Alb. & Schw._) _Macbr._
    '2.' added.
  Page 200
    '3. _L. biforis_.
    '4. _L. minima_'.
    '5. _L. pusilla_'.
    changed '3, 4, 5' to '2, 3, 4' respectively to match referenced text.
  Page 212
    'name to ertain English'
    changed 'ertain' to 'certain'.
  Page 218
    'granules on the calcyulus'
    changed 'calcyulus' to 'calyculus'.
  Page 237
    '_Prototrichia_ to the _Trichiacae_.'
    changed 'Trichiacae' to '_Trichiaceae_'.
  Page 237
    Plate XVII., Figs.----
    changed 'Figs.----' to 'Figs. 1, 1 _a_, 1 _b_'.
  Page 238
    'adjoining the _Perichaenacae_' as in original. This is
    probably 'Perichaenaceae', as elsewhere in this book, however, it is
    in a quotation so is unchanged.
  Page 241
    2. 'Ophiotheca chrysoperma _Currey_.'
    changed 'chrysoperma' to 'chrysosperma'.
  Page 262
    'often, to circumscissle'
    changed 'circumscissle' to 'circumscissile'.
  Page 262
    'to be uniformily distinctly warted'
    changed 'uniformily' to 'uniformly'.
  Page 263
    'evanescent peridium suggests _Arycria_'
    changed '_Arycria_' to '_Arcyria_'.
  Page 265
    'In typical spcimens'
    changed 'spcimens' to 'specimens'.
  Page 269
    3. Trichia iowenis _Macbr._
    Changed 'iowenis' to 'iowensis'.
  Page 289
    '[Greek: klaotos]' changed to '[Greek: klastos].
  Page 289
    '[Greek: echiuos]' changed to '[Greek: echinos]'.
  Page 290
    '[Greek: lanchos]' changed to '[Greek: lachnos]'.
  Page 290
    LEPIDODERMA, 144
    [Greek: lepis], a scale, and [Greek: 'depma'], a covering. Gr.
    changed 'depma' to 'derma'.
  Page 290
    '[Greek: gala], a, milk. Gr.' changed to '[Greek: gala], milk. Gr.'.
    Removed 'a,'.
  Page 290
    '[Greek: ophix]' unchanged.
    Maybe '[Greek: tricha]' would be more appropriate.
  Page 292
    'Diachafa 185' changed to 'Diachaea 185' to match the referenced page.
  Page 297
    'pulchripes _Peck_, 69.' changed to 'pulcherripes _Peck_, 69.' to
    match the referenced page.
  Page 304
    _Badhamia macrocarpa_ Rost., p. 7.
    'changed p. 7.' to 'p. 37.'
  Page 324
    _Comatricha subcaespitosa_ Peck, p. 282.
    changed 'p. 282' to 'p. 185'.
  Page 324
    _Comatricha gracilis_ Wingate, p. 184.
    changed 'p. 184.' to 'p. 183'.
  Page 328
    _Badhamia orbiculata_ Rex., p. 66.
    changed 'p. 66.' to 'p. 37.'
  Page 338
    'showing transional phases'
    changed 'transional to 'transitional'.
  Various pages
    Inconsistent hyphenation:
    flavo-fusca          flavofusca
    flavo-fuscum         flavofuscum
    net-work             network
    wide-spread          widespread