Transcriber’s Note: Italic text is enclosed in _underscores_; boldface
text is enclosed in =equals signs=. Additional notes will be found near
the end of this ebook.




[Illustration]




WINNERS IN LIFE’S RACE

[Illustration: _Frontispiece._ LUMINOUS FISH OF THE DEEP SEA. (For
description see Footnote 25, and List of Illustrations.)]




                                  THE
                         WINNERS IN LIFE’S RACE

                                 OR THE
                        GREAT BACKBONED FAMILY.


                                   BY
                          ARABELLA B. BUCKLEY,
               AUTHOR OF “THE FAIRYLAND OF SCIENCE,” ETC.

                               NEW YORK:
                        D. APPLETON AND COMPANY,
                        1, 3, AND 5 BOND STREET,
                                 1883.




PREFACE.


Although the present volume, as giving an account of the _vertebrate_
animals, is a natural sequel to, and completion of, my former book,
_Life and her Children_, which treated of _invertebrates_, yet it is a
more independent work, both in plan and execution, than I had at first
contemplated.

This arises from the nature of the subject. The structure and habits of
the lower forms of life are sufficiently simple to be treated almost
without reference to geological history. When, however, I began to
sketch out the lives and structure of the vertebrate animals, which are
so closely interlinked one with another and yet so sharply separated
into groups, I soon found that I must carry my readers into the past in
order to give any intelligible account of the present.

I have therefore endeavoured to describe graphically the early history
of the backboned animals, so far as it is yet known to us, keeping
strictly to such broad facts as ought in these days to be familiar to
every child and ordinarily well-educated person, if they are to have
any true conception of Natural History. At the same time I have dwelt
as fully as space would allow, upon the lives of such modern animals
as best illustrate the present divisions of the vertebrates upon the
earth; my object being rather to follow the tide of life, and sketch in
broad outline how structure and habit have gone hand-in-hand in filling
every available space with living beings, than to multiply descriptions
of the various species. If my younger readers will try and become
familiar with the types selected, either alive in zoological gardens or
preserved in good museums, they will, I hope, acquire a very fair idea
of the main branches of the Backboned Family.[1]

In order to treat so vast a subject simply and within narrow limits, it
has often been necessary to pass lightly over new and startling facts.
I trust, however, it will not be inferred that such passages have been
lightly or carelessly written, for in all cases I have sought, and most
gratefully acknowledge, the assistance of some of our best authorities;
and I have endeavoured that what little is said upon difficult subjects
shall be a true foundation for wider knowledge in the future.

Among the many friends who have rendered me valuable assistance, I
cannot sufficiently express my obligations to Professor W. Kitchen
Parker for his unwearying kindness in explaining obscure points
of anatomical structure, and to my friends Mr. Alfred R. Wallace,
Professor A. C. Haddon of Dublin, and Mr. Garnett of the British
Museum, for constant suggestion and encouragement. I am also indebted
to Mr. J. P. Anderson of the British Museum for aid in the arrangement
of the Index.

The geological restorations given as picture-headings (some of which
are here attempted, I believe, for the first time) have been most
carefully considered, though the exact forms of such strange and
extinct animals must necessarily be somewhat conjectural. My thanks are
due to the artist, Mr. Carreras, jun., for the patience and care with
which he has followed my instructions regarding them, and also to Mr.
Smit for his masterly execution of the frontispiece.[2]

I have been asked why, in this and the former work, I have not given
genealogical tables to help the reader to follow the relations of the
various groups. My reason is, that it is impossible to construct
tables of this kind without giving a false idea of the fixity of
natural divisions and of the extent of our knowledge. To men of
science, who know how provisional such tables are, they have a certain
value, but they would be positively harmful in a work of this kind,
which will have fully accomplished its purpose if it only awakens in
young minds a sense of the wonderful interweaving of life upon the
earth, and a desire to trace out the ever-continuous action of the
great Creator in the development of living beings.

                                                ARABELLA B. BUCKLEY.

LONDON, _September 1882_.




CONTENTS.


  CHAPTER I.
                                                                    PAGE
  THE THRESHOLD OF BACKBONED LIFE                                      1


  CHAPTER II.

  HOW THE QUAINT OLD FISHES OF ANCIENT TIMES HAVE LIVED ON INTO
      OUR DAY                                                         20

    PICTURE-HEADING--Ideal restoration of _Pterygotus_, the huge
        extinct sea-scorpion nine feet long; with the earliest
        known fish _Pteraspis_, _Cephalaspis_, and small shark-like
        animals swimming among Stone-lilies, Trilobites, etc. (From
        various sources.)


  CHAPTER III.

  THE BONY FISH, AND HOW THEY HAVE SPREAD OVER SEA, AND LAKE, AND
      RIVER                                                           43

    PICTURE-HEADING--Restorations of _Osmeroides_ and _Beryx_, the
        earliest known bony fishes living in the Cretaceous Period.
        (From well-known figures.)


  CHAPTER IV.

  HOW THE BACKBONED ANIMALS PASS FROM WATER-BREATHING TO
      AIR-BREATHING, AND FIND THEIR WAY OUT UPON THE LAND             70

    PICTURE-HEADING--A Carboniferous Forest with ancient Amphibians
        (Labyrinthodonts). In the water _Baphetes_; on land
        _Dendrerpeton_, _Hylonomus_, and _Hylerpeton_. (Animals
        taken from Dawson’s _Air-Breathers of the Coal_.)


  CHAPTER V.

  THE COLD-BLOODED AIR BREATHERS OF THE GLOBE IN TIMES BOTH PAST
      AND PRESENT                                                     89

    PICTURE-HEADING--Reptiles of the Cretaceous Period. On land
        _Iguanodon_, 20 feet high, attacked by _Megalosaurus_; in
        the air _Pterodactyls_, or flying lizards; in the water
        _Ichthyosaurus_, _Mosasaurus_, and _Teleosaurus_, with
        _Plesiosaurus_ in the background. (From various sources.)


  CHAPTER VI.

  THE FEATHERED CONQUERORS OF THE AIR--PART I. THEIR WANDERINGS
      OVER SEA AND MARSH, DESERT AND PLAIN                           123

    PICTURE-HEADING--Toothed Water-birds of the Cretaceous
        Period. Swimming and standing, _Hesperornis_; flying,
        _Ichthyornis_. (Restored from Marsh’s Skeletons.)


  CHAPTER VII.

  THE FEATHERED CONQUERORS OF THE AIR--PART II. FROM RUNNING TO
      FLYING, FROM MOUND LAYING TO NEST-BUILDING, FROM CRY TO
      SONG                                                           153

    PICTURE-HEADING--_Archæopteryx_, the lizard-tailed land-bird
        with teeth. (Restored from figures of the British Museum
        and German specimens.)


  CHAPTER VIII.

  THE MAMMALIA OR MILK-GIVERS, THE SIMPLEST SUCKLING MOTHER, THE
      ACTIVE POUCH-BEARERS, AND THE IMPERFECT-TOOTHED ANIMALS        181

    PICTURE-HEADING--Scene in the Triassic Period, with small
        Marsupials _Microlestes_, whose remains are found earlier
        than the toothed birds. (Restored conjecturally from the
        nearest living representative, Myrmecobius.) In the water
        large swimming reptiles.


  CHAPTER IX.

  FROM THE LOWER AND SMALL MILK-GIVERS WHICH FIND SAFETY IN
      CONCEALMENT, TO THE INTELLIGENT APES AND MONKEYS               209

    PICTURE-HEADING--Ideal forms of the early Herbivora
        and Carnivora. In the foreground _Paleotherium_,
        _Anoplotherium_, and _Eohippus_ (this last only restored
        conjecturally); in the background, _Xiphodon_ and
        _Arctocyon_ (this last also only an approximation); on the
        tree, a small lemur; and in front, a hedgehog.


  CHAPTER X.

  THE LARGE MILK-GIVERS WHICH HAVE CONQUERED THE WORLD BY
      STRENGTH AND INTELLIGENCE                                      256

    PICTURE-HEADING--Animals which lived in Europe during
        the warm periods before the Glacial Cold. On the
        right, _Deinotherium_, _Mastodon_; in background,
        _Helladotherium_, ancient giraffes; on the left,
        _Hippopotamus_, _Tapir_, _Rhinoceros_, _Hyæna_; in the
        tree, _Pithecus pentelicus_. All these animals, except
        the giraffe, were living in England in the late Tertiary
        Period. (From various sources.)


  CHAPTER XI.

  HOW THE BACKBONED ANIMALS HAVE RETURNED TO THE WATER, AND LARGE
      MILK-GIVERS IMITATE THE FISH                                   299

    PICTURE-HEADING--An ideal scene of Europe in the Glacial Period
        with the “Hairy Mammoth” in the foreground.


  CHAPTER XII.

  A BIRD’S-EYE VIEW OF THE RISE AND PROGRESS OF BACKBONED LIFE       333

    PICTURE-HEADING--Man as he lived in caves after the Glacial
        Period, among animals of species many of them now
        extinct--the cave bear (_Ursus spelæus_), cave lion,
        cave hyæna (_Hyæna spelæa_), elk, musk-sheep (_Ovibos
        moschatus_), mammoth (_Elephas primigenius_), and the
        sabre-toothed tiger (_Machairodus_), fighting with the man.




LIST OF ILLUSTRATIONS.

              PICTURE-HEADINGS described under “Contents.”


  _Frontispiece._ FISH OF THE DEEP SEA--1. Chauliodus, one foot long;
      2, 9, 10, 11. Harpodon or Bombay Duck, six inches; 3. Plagiodus,
      six feet; 4. Chiasmodus, one foot, with Scopelus in its stomach;
      6. Beryx, one foot and a half; 8. Scopelus, one foot.

                                                                    PAGE

  The Lancelet, _Amphioxus lanceolatus_                               11

  Sea-Squirt or Ascidian                                              14

  Lamprey and Ammocœtes                                               16

  Structure of Minnow and Living Fish                                 23

  The Blue Shark                                                      29

  The Sturgeon, _Acipenser sturio_                                    31

  The Sturgeon’s Head and Feelers                                     32

  The Ceratodus of Queensland                                         34

  Remoras clinging to a Shark                                         51

  Flying-Fish pursued by the Dorado                                   54

  The Fishing Frog, _Lophius piscatorius_                             59

  The common Sole, _Solea vulgaris_                                   61

  The Hippocampus or Sea-Horse                                        63

  Sticklebacks and their Nest, _Gasterosteus aculeatus_               65

  Metamorphosis of the Frog                                           72

  The common smooth Newt, _Lissotriton punctatus_                     78

  Proteus of the Carniola Caverns                                     79

  The Axolotl and Amblystoma                                          80

  The Flying Tree-Frog of New Guinea, _Rhacophorus Rheinhardti_       86

  The Tortoise                                                        96

  Carapace of the Tortoise                                            98

  Back of a young Tortoise                                            99

  Skeleton of a Lizard                                               103

  Gecko and Chamæleon                                                105

  The Nile Crocodile                                                 108

  Skeleton of a Snake                                                111

  Common Ringed Snake                                                113

  The Boa Constrictor                                                115

  The Cobra di Capello                                               118

  Jaw of a Rattlesnake                                               119

  Common English Viper, _Pelias berus_                               121

  The Sparrow                                                        125

  Skeleton of a Sparrow                                              126

  The Adjutant Bird                                                  128

  The Ostrich at full Speed                                          137

  The Giant Moa and Tiny Apteryx                                     140

  A Group of Sea-Birds                                               144

  Albatrosses and Penguins                                           147

  A Group of Wading Birds                                            149

  The Flamingo                                                       150

  Brush Turkeys and their Egg Mounds                                 158

  Wood-pigeon on her Nest                                            160

  The great green Woodpecker, _Gecinus viridis_                      163

  The Kingfisher, _Alcedo ispida_                                    166

  Nest of the Common Wren, _Troglodytes parvulus_                    171

  Nest of the Tailor-Bird                                            173

  Eagle bringing Food to its Young                                   175

  Jaw of Dromatherium, and Tooth of Microlestes                      183

  The Duck-billed Platypus and the Echidna                           188

  Head and Feet of Ornithorhynchus                                   189

  Australian Marsupials                                              193

  Tasmanian Marsupials                                               197

  South American Marsupials and imperfect-toothed Animals            200

  African imperfect-toothed Animals                                  202

  Skulls of an Insect-Eater and a Rodent                             217

  A Group of Insect-Eaters                                           220

  A Group of Rodents                                                 221

  The Pyrenean Desman                                                226

  The Beaver                                                         227

  The Taguan and the Colugo                                          231

  Skeleton of a Bat                                                  233

  A Bat Walking                                                      235

  Fruit-Bats hanging in a Mauritius Cave                             238

  Aye-aye and Lemur                                                  244

  Woolly Monkey and Child                                            247

  The Gorilla at Home                                                254

  The Babirusa, a double-tusked Hog                                  262

  Skeleton of a Wild Ass                                             266

  The Camel                                                          270

  The Red-deer with branching Antlers                                272

  A Buffalo Cow defending her Calf                                   274

  The Elephant                                                       277

  The Weasel                                                         280

  The Ichneumon                                                      281

  The Wolf                                                           283

  The Tiger                                                          287

  The Claw of the Cat or Tiger                                       289

  The Polar Bear and Walrus                                          294

  The Sea Otter                                                      302

  Skeleton of the Sea Lion                                           304

  Sea Lion and Seal                                                  306

  Sea Lions on the Watch for Wives                                   311

  The Manatee                                                        314

  Skeleton of a Whale and Mouth                                      318

  Whale suckling her Young                                           319

  The Porpoise                                                       324

  The Sperm Whale                                                    327




[Illustration: THE GREAT BACKBONED FAMILY]




CHAPTER I.

THE THRESHOLD OF BACKBONED LIFE.


Life, life, everywhere life! This was the cry with which we began our
history of the lowest forms of Life’s children, and although we did
not then pass on to the higher animals, is it not true that before we
reached the end we were overwhelmed with the innumerable forms of
living beings? The microscopic lime and flint builders, the spreading
sponges, the hydras, anemones, corals, and jelly-fish filled the
waters; the star-fish, sea-urchins, crabs, and lobsters crowded the
shores; the oysters, whelks, and periwinkles, with their hundreds of
companions, struggled for their existence between the tides; while in
the open sea thousands of crustaceans and molluscs, with cuttle-fish
and terribly-armed calamaries, roamed in search of food. Upon the land
the snails and slugs devoured the green foliage, while the vast army of
insects filled every nook and cranny in the water, on the land, or in
the air. Yes! even among these lower forms we found creatures enough to
stock the world over and over again with abundant life, so that even
if the octopus had remained the monarch of the sea, and the tiny ant
the most intelligent ruler on the land, there would have been no barren
space, no uninhabited tracts, except those burning deserts and frozen
peaks where life can scarcely exist.

Yet though the world might have been full of these creatures, they
would not have been able to make the fullest use of it, for all animal
life would have been comparatively insignificant and feeble, each
creature moving within a very narrow range, and having but small powers
of enjoyment or activity. With the exception of the insects, by far the
greater number would, during their whole lives, never wander more than
a few yards from one spot, while, though the locust and the butterfly
make long journeys, yet the bees and beetles, dragon-flies and ants,
would not cross many miles of ground in several generations.

What a curious world that would have been in which the stag-beetle and
the atlas-moth could boast of being the largest land animals, except
where perhaps some monster land snail might bear them company; while
cuttle-fish and calamaries would have been the rulers of the sea, and
the crabs and lobsters of the shores! A strangely silent world too.
The grasshopper’s chirp as he rubbed his wings together, the hum of
the bee, the click of the sharp jaws of the grub of the stag-beetle,
eating away the trunk of some old oak tree, would have been among the
loudest sounds to be heard; and though there would have been plenty of
marvellous beauty among the metallic-winged beetles, the butterflies,
and the delicate forms of the sea, yet amid all this lovely life we
should seek in vain for any intelligent faces,--for what expression
could there be in the fixed and many-windowed eye of the ant or beetle,
or in the stony face of the crab?

These lower forms, however, were not destined to have all the world
to themselves, for in ages, so long ago that we cannot reckon them,
another division of Life’s children had begun to exist which possessed
advantages giving it the power to press forward far beyond the
star-fish, the octopus, or the insect. This was the Backboned division,
to which belong the fish of our seas and rivers; the frogs and toads,
snakes, lizards, crocodiles, and tortoises; the birds of all kinds and
sizes; the kangaroos; the rats, pigs, elephants, lions, whales, seals,
and monkeys.

Is it possible, then, that all these widely different creatures, which
are fitted to live not only in all parts of the land, but also in the
air above, and the seas and rivers below, and which are, in fact, all
those popularly known as “animals,” only form one division out of
seven in the real animal kingdom?

Can it be true that while the chalk-builders have one division all to
themselves, the sponges forming a transition group, the lasso-throwers
another division, the prickly-skinned animals a third, the mollusca a
fourth, the worms a fifth, and the insects a sixth, yet the innumerable
kinds of birds and beasts, reptiles and fishes, are all sufficiently
alike to be included in one single division--the seventh? It seems at
first as if this arrangement must be unequal and unnatural; but let us
go back for a moment to the beginning, and we shall see that it is not
only true, but that quite a new interest attaches to the higher animals
when we learn how wonderfully life has built up so many different forms
upon one simple plan.

Starting, then, with the first glimmerings of life, we find the minute
lime and flint builders, without any parts, making the utmost of their
little lives, filling the depths of the sea, and wandering in pools and
puddles on the land; acting, in fact, as scavengers for such matter
as is left them by other animals. But here their power ends; to take
a higher stand in life a more complicated creature is needed, and the
sponge-animal, with its two kinds of cells and its numerous eggs, is
the next step leading on to the curious division of lasso-throwers.
These, in their turn, do their utmost to spread and vary in a hundred
different ways. Possessed of a good stomach, of nerves, muscles,
powerful weapons, and means for producing eggs and young ones, they
fill the waters as hydras, sea-firs, jelly-fish, anemones, and corals.
But here they too find their limit, and, without advancing any
farther, continue to flourish in their lowly fashion. Meanwhile the
tide of life is flowing on in two other channels, striving ever onwards
and upwards. On the one hand, the walking star-fish and sea-urchin push
forward into active life under the sea, forming, with their relations,
a strange and motley group, but one which could scarcely be moulded
into higher and more intelligent beings. On the other hand, the oyster
and his comrades, with their curious mantle-working secret protect
their soft body within by a shelly covering, and by degrees we arrive
at the large army of mollusca, headed by the intelligent cuttle-fish.
And here this division too ceases to advance. The soft body in its
shelly home does not lend itself to wide and great changes, and it was
left for other channels to carry farther the swelling tide of life.
These take their rise in the lowly, insignificant division of the
worms, which may, perhaps, have had something to do with the earliest
forms even of the star-fish and mollusca, but which soon shot upwards,
on the one hand along a line of its own, while, on the other, we have
seen[3] how, in its many-ringed segments, each bearing its leg-like
bristles and its line of nerve-telegraph, the worm foreshadowed the
insects and crustacea, or the _jointed-footed_ animals of sea and land,
forming the sixth division.

Here surely at last we must have reached animals which will answer
any purposes life can wish to fulfil. We find among them numberless
different forms, spreading far and wide through the water and over the
land, and it would seem as if the sturdy crab and fighting lobster
need fear no rival in the sea, while the intelligent bee and ant were
equal to any emergency on dry ground. But here the tide of life met
with another check. It must be remembered that the jointed-footed
animals, whether belonging to land or water, carry their solid part or
skeleton _outside_ them; their body itself is soft, and cased in armour
which has to be cast off and formed afresh from time to time as they
grow. For this reason they are like men in armour, heavily weighted as
soon as they grow to any size, while the body within cannot become so
firmly and well knit together as if all the parts, hard and soft, were
able to grow and enlarge in common. And so we find that large-sized
armour-covered animals, such as gigantic crabs and lobsters, are
lumbering unwieldy creatures, in spite of their strength, while the
nimble intelligent insects, such as the ant and bee, are comparatively
small and delicate.

It would be curious to try and guess what might have happened if the
ant could have grown as large as man, and built houses and cities,
and wandered over wide spaces instead of being restricted to her
ant-hills for a home, and few acres for her kingdom; but she too has
found the limit of her powers in the impossibility of becoming a large
and powerful creature. Thus it remained for Life to find yet another
channel to reach its highest point, by devising a plan of structure in
which the solid skeleton should be--not a burden for the soft body to
carry, as in the sea-urchins, snails, insects, and crabs--but an actual
support to the whole creature, growing with it and forming a framework
for all its different parts.

This plan is that of the backboned animals. They alone, of all Life’s
children, have a _skeleton within their bodies embedded in the muscular
flesh, and formed, not of mere hardened, dead matter, but of bones
which have blood-vessels and nerves running through them, so that they
grow as the body grows, and strengthen with its strength_. This is a
very different thing from a mere outer casing round a soft body, for
it is clear that an animal with a living growing skeleton can go on
increasing in size and strength, and its framework will grow _with_ the
limbs in any direction most useful to it.

Here, then, we have one of the secrets why the backboned animals have
been able to press forward and vary in so many different ways; and
especially useful to them has been that gristly cord stretching along
the back, which by degrees has become hardened and jointed, so as to
form that wonderful piece of mechanism, the _backbone_.

Look at any active fish darting through the water by sharp strokes
of its tail,--watch the curved form of a snake as it glides through
the grass, or the graceful swan bending his neck as he sails over the
lake,--and you will see how easily and smoothly the joints of the
backbone must move one upon the other. Then turn to the stag, and note
how jauntily he carries his heavy antlers; look at the powerful frame
of the lion, watch an antelope leap, or a tiger bound against the bars
of his cage, and you will acknowledge how powerful this bony column
must be which forms the chief support of the body, and carries those
massive heads and those strong and lusty limbs.

Nor is it only by its flexibility and strength that this jointed
column is such an advantage to its possessors; the backbone has a
special part to play as the protector of a most valuable and delicate
part of the body. We have already learnt in _Life and her Children_
to understand the importance of the nerve-telegraph to animals in the
struggle for life. We found its feeble beginnings in the jelly-fish
and the star-fish; we saw it spreading out over the body of the snail;
we traced it forming a line of knots in the worm, with head-stations
round the neck, which became more and more powerful in the intelligent
insects. But in all these creatures the stations of nerve-matter from
which the nerves run out into the body are merely embedded in the soft
flesh, and have no special protection, with the exception of a gristly
covering in the cuttle-fish. We ourselves, and other backboned animals,
have unprotected nerve-stations like these in the throat, the stomach,
and the heart, and cavity of the body. But we have something else
besides, for very early in the history of the backboned animals the
gristly cord along the back began to form a protecting sheath round the
line of nerve-stations stretching from the head to the tail, so that
this special nerve-telegraph was safely shut in and protected all along
its course.

A careful examination of the backbone of any fish, after the flesh
has been cleared off, will show that on the top of each joint (or
_vertebra_) of the backbone is a ring or arch of bone; and when all the
joints are fastened together, these rings form a hollow tube or canal,
in which lies that long line of nervous matter called the _spinal
cord_, which thus passes, well protected, all along the body, till,
when it reaches the head, it becomes a large mass shut safely in a
strong box, the skull, where it forms the brain.

Here, then, besides the unprotected nerve-stations, we have a much
more perfect nerve-battery, the spinal cord, carried in a special
sheath formed of the arches of the backbone, which is at once strong
and yielding, so that the delicate telegraph is safe from all ordinary
danger. Now when we remember how important the nerves are,--how they
are the very machinery by which intelligence works, so that without
them the eye could not see, the ear hear, nor the animal have any
knowledge of what is going on around it,--we see at once that here
was an additional power which might be most valuable to the backboned
division. And so it has proved, for slowly but surely through the
different classes of fish, amphibia (frogs and newts), reptiles, birds,
and mammalia, this cord, especially that larger portion of it forming
the brain, has been increasing in vigour, strength, and activity, till
it has become the wonderful instrument of thought in man himself.

We see, then, that our interest in the backboned or _vertebrate_
animals will be of a different kind from that which we found in the
boneless or _invertebrate_ ones. There we watched Life trying different
plans, each successful in its way, but none broad enough or pliable
enough to produce animals fitted to take the lead all over the world.
Now we are going to trace how, from a more promising starting-point, a
number of such different forms as fish, reptile, bird, and four-footed
beast, have gradually arisen and taken possession of the land, the
water, and the air, pressing forward in the race for life far beyond
all other divisions of animal life.

On the one hand, these forms are all linked together by the fact that
they have a backbone protecting a nerve-battery, and that they have
never more than two pair of limbs; while every new discovery shows how
closely they are all related to each other. On the other hand, they
have made use of this backbone, and the skeleton it carries, in such
very different ways that out of the same bones and the same general
plan unlike creatures have been built up, such as we should never think
of classing together if we did not study their structure.

What the lives of these creatures are, and what they have been in past
time, we must now try to understand. And first we shall naturally ask,
Where did the backboned animals begin? Where should they begin but in
the water, where we found all the other divisions making their first
start, where food is so freely brought by passing currents, where
movement from place to place is much easier, and where there are no
such rapid changes as there are on the land from dry to damp, from heat
to cold, or from bright leafy summer, with plenty of food, to cold
cheerless winter, when starvation often stares animals in the face?

It is not easy to be sure exactly how the backboned animals began,
but the best clue we have to the mystery is found in a little
half-transparent creature about two inches long, which is still to be
found living upon our coast. This small insignificant animal is called
the “Lancelet,”[4] because it is shaped something like the head of a
lance, and it is in many ways so imperfect that naturalists believe it
to be a degraded form, like the acorn-barnacle; that is to say, that it
has probably lost some of the parts which its ancestors once possessed.
But in any case it is the most simple backboned animal we have, and
shows us how the first feeble forms may have lived.

[Illustration: Fig. 1.

The Lancelet, _the lowest known fish-like form_.

    _m_, mouth. _e_, eye-spot. _f_, fin. _r_, rod or notochord, the
    first faint indication of a backbone. _nv_, nerve cord. _g_, gills.
    _h_, hole out of which water passes from the gills. _v_, vent for
    refuse of food.
]

Flitting about in the water near the shore, eating the minute creatures
which come in his way, this small fish-like animal is so colourless,
and works his way down in the sand so fast at the slightest alarm,
that few people ever see him, and when they do are far more likely to
take him, as the naturalist Pallas did, for an imperfect snail than a
vertebrate animal. He has no head, and it is only by his open mouth
(_m_), surrounded by lashes with which he drives in the microscopic
animals, that you can tell where his head ought to be. Two little
spots (_e_) above his mouth are his feeble eyes, and one little pit
(_n_) with a nerve running to it is all he has to smell with. He has
no pairs of fins such as we find in most fishes, but only a delicate
flap (_f_) on his back and round his tail; neither has he any true
breathing-gills, but he gulps in water at his mouth, and passes it
through slits in his throat into a kind of chamber, and from there out
at a hole (_h_) below. Lastly, he has no true heart, and it is only by
the throbbing of the veins themselves that his colourless blood is sent
along the bars between the slits, so that it takes up air out of the
water as it passes.

But where is his backbone? Truly it is only by courtesy that we can
call him a backboned animal, for all he has is a cord of gristle, _r
r_, pointed at both ends, which stretches all along the middle of his
body above his long narrow stomach, while above this again is another
cord containing his nerve-telegraph (_nv_.) All other backboned animals
that we know of have brains; but, as we have seen, he has no head, and
his nerve-cord has only a slight bulge just before it comes to a point
above his mouth. Now when the higher backboned animals are only just
beginning to form out of the egg, their backbone (which afterwards
becomes hard and jointed) is just like this gristly rod or _notochord_
(_r r_) of the lancelet, with the spinal cord (_nv_) lying above it;
so that this lowest backboned animal lives all his life in that simple
state out of which the higher animals very soon grow.

This imperfect little lancelet has a great interest for us, because
of his extremely simple structure and the slits in his throat through
which he breathes. You will remember that when we spoke of the
elastic-ringed animals in _Life and her Children_, we found that the
free worms were very active sensitive creatures, whose bodies were
made up of segments, each with a double pair of appendages; the whole
being strung together, as it were, upon a feeding tube and a line of
nerve-telegraph, but without any backbone. Now among these worms we
find many curious varieties; some have the nerve-lines at the sides
instead of below, and one sea-worm, instead of breathing by outside
gills like the others, has slits in its throat through which the water
can pass, and so its blood is purified.

You may ask, What this has to do with backboned animals? Nothing
directly, but these odd worms are like fingerposts in a deserted
and grass-grown country, showing where roads may once have been.
The lancelet, like the worm, has a line of nerve-telegraph and a
feeding-tube, only with him the nerve-telegraph lies above instead of
below. He has also slits in his throat for breathing, only they are
covered by a pouch. Thus he is so different from the worms that we
cannot call them relations; but at the same time he is in many ways
so like, that we ask ourselves whether his ancestors and those of the
worms may not have been relations.

[Illustration: Fig. 2.

Diagram of the growth of a Sea-Squirt or Ascidian.

    A a, Young free swimming stage. a², Intermediate stage when first
    settling down. B b, Full-grown Sea-Squirt.

    _m_, mouth; _e_, hollow brain with eye; _g_, gill slits; _h_,
    heart; _r_, rod of gristle in free swimming form; _nv_, nerve cord
    in same; _t_, tail in process of absorption in intermediate form.
]

But you will say he is quite different in having a gristly cord.
True--but we shall find that even this does not give us a sharp line of
division. By looking carefully upon the seaweed and rocks just beyond
low tide, we may often find some curious small creatures upon them,
called Sea-Squirts or Ascidians (B, Fig. 2).[5] These creatures are
shaped very like double-necked bottles, and they stand fixed to the
rock with their necks stretching up into the water. Through one neck
(_m_) they take water in, and after filtering it through a kind of net
so as to catch the microscopic animals in it and taking the air out
of it, they send it out through the other neck, thus gaining the name
of sea-squirts. So far, they are certainly boneless animals. But they
were not always stationary, as you see them fixed to the rock. In their
babyhood they were tiny swimming creatures with tails (A and a), and in
the tail was a gristly cord (_r_), with a nerve cord (_nv_) above it,
like those we find in the lancelet. For this reason we were obliged to
pass them by among the lower forms of life, because, having this cord
(_r_), they did not truly belong to the animals without backbones; and
yet now we can scarcely admit them here, because when they are grown
up they are not backboned animals. They belong, in fact, to a kind of
“No Man’s Land,” behaving in many ways like the lancelet when they are
young, as if they had once tried to be backboned; and yet they fall
back as they grow up into invertebrate animals.

So we begin to see that there may have been a time when backbones had
not gained quite a firm footing, and our lancelet, with his friends the
sea-squirts, seems to lie very near the threshold of backbone life.

And now that we are once started fairly on our road, let us turn aside
before beginning the history of the great fish-world and pay a visit
to a little creature whose name, at least, we all know well, and which
stands half-way between the lancelet and the true fish. This is the
Lamprey, represented by two kinds; the large Sea-Lamprey, caught by the
fishermen for bait as it wanders up the rivers to lay its eggs, and the
true River-Lamprey or Lampern, which rarely visits the sea.

What country boy is there who has not hunted in the mud of the rivers
or streams for these bright-eyed eel-like fish, with no fins, and a
fringe on back and tail? If you feel about for them in the mud they
will often come up clinging to your hand with their round sucker-mouth,
while the water trickles out of the seven little holes on each side of
their heads. The small river-lampreys do not hurt in the least as they
cling, though the inside of their mouth is filled with small horny
teeth. But the larger sea-lamprey uses these teeth as sharp weapons,
scraping off the flesh of fish for food as he clings to them.

[Illustration: Fig. 3.

Figure of a full-grown Lamprey[6] and of the young Lamprey, formerly
called Ammocœtes.

_Showing the seven holes through which it takes in water to breathe._]

These Lampreys, together with some strange creatures, the “Hags”
or “Borers,”[7] belong to quite a peculiar family, called the
Round-mouthed fishes,[8] and, though they stand much higher in the
world than the lancelet, yet they are very different from true fish.
Like the lancelet they have only a gristly cord for a backbone, but
this cord has begun to form arches over the nerve battery, and it
swells out at the end into a gristly skull covering a true brain. They
have clear bright eyes too, and ears, which if not very sharp, are
at least such as they can hear with; they have only one nostril, and
their mouth is both curious and useful. When it is shut it looks like
a straight slit, but when it is open it forms a round sucker with a
border of gristle, and this sucker clings firmly to anything against
which it is pressed, so that a stone weighing twelve pounds has been
lifted by taking a lamprey by the tail. Inside the mouth the palate and
tongue are covered with small horny teeth, and these are the lamprey’s
weapons.

Salmon have been caught in the rivers with lampreys hanging to them,
and where the mouth has been the salmon’s flesh is rasped away, though
he does not seem much to mind it.

Lastly, the lamprey has a peculiar way of breathing. He has seven
little holes on each side of his head, reminding us of the slits in
the worm’s throat and those hidden under the skin of the lancelet, and
behind these holes are seven little pouches lined with blood-vessels,
which take up air out of the water. These pouches are all separate, but
they open by one tube into his throat. When the lamprey is swimming
about it is possible that he may gulp water in at his mouth and send
it out at the slits. But when he is clinging to anything he certainly
sends water both in and out at the slits, so that he can still breathe,
though his mouth is otherwise occupied.

And now, what is the history of his life? For three years he lives
as a stupid little creature, with a toothless mouth surrounded by
feelers, and tiny eyes covered over with skin, and he is so unlike a
lamprey that for a long time naturalists thought he was a different
animal and called him _Ammocœtes_. But at the end of the three years he
changes his shape, and then he is as bright and intelligent as he was
dull and heavy before. His one thought is to find a mate and help her
to cover up her eggs. To do this a number of lampreys find their way
up the river and set to work. Sometimes one pair go alone, sometimes
several together, and they twirl round and round so as to make a hole
in the sand, lifting even heavy stones out with their mouths if they
come in the way. Then they shed the spawn into the hole, where it is
soon covered with sand and mud, to lie till it is safely hatched, and
when this is done the marine lampreys swim out to sea to feed on the
numberless small creatures in it, or to fasten upon some unfortunate
fish.

But there are round-mouthed fishes even more greedy than these. It is
not only among the lower forms of life that some creatures, such as
worms, which are driven from the outer world, find a refuge inside
other animals. But here again we meet with the same thing, for those
relations of the lampreys, the hags or borers, which we mentioned
above, use their sharp teeth to bore their way into other fish so as to
feed upon them. These greedy little creatures actually drill holes in
the flesh of the cod or haddock and other fish, and eat out the inside
of their bodies, so that a haddock has been found with nothing but the
skin and skeleton remaining while six fat hags lay comfortably inside.

So the round-mouthed fishes, feeble though they are, hold their own
in the world. How long ago it is since they first began the battle of
life we shall probably never know for certain; but if some little horny
teeth[9] found in very ancient rocks belong to their ancestors, they
were most likely among the first backboned animals on our globe. At any
rate they are very interesting to us now, for they have wandered far
away from the true fishes, and give us a glimpse of some of the strange
by-paths which the backboned animals have followed in order to win for
themselves a place in the race for life.




[Illustration: THE ANCIENT FISH & THEIR HUGE RIVAL]

    NOTE.--For description of the Picture-Headings see the Table of
    Contents.




CHAPTER II.

HOW THE QUAINT OLD FISHES OF ANCIENT TIMES HAVE LIVED ON INTO OUR DAY.


Who is there among my readers who wishes to understand the pleasures,
the difficulties, and the secrets of fish life? Whoever he may be he
must not be content with merely looking down into the water, as one
peeps into a looking-glass, or he may, perchance, only see there the
reflection of his own thoughts and ideas, and learn very little of how
the fishes really feel and live. No! if we want really to understand
fish-life we must forget for a time that we are land and air-breathing
animals, and must plunge in imagination into the cool river or the
open sea, and wander about as if the water were our true home. For
the fish know no more about our land-world than we do about their
beautiful ocean-home. To them the water is the beginning and end of
everything, and if they come to the top every now and then for a short
air-bath they return very quickly for fear of being suffocated. Their
great kingdom is the sea--the deep-sea, where strange phosphorescent
fish live, lying in the dark mysterious valleys where even sharks and
sword-fish rarely venture;--the open sea, where they roam over wide
plains when the ocean-bottom makes a fine feeding-ground, or where
they thread their way through forests of seaweed, while others swim
nearer the surface and come up to bask in the sun or rest on a bank of
floating weed;--and the shallow sea, where they come to lay their eggs
and bring up their young ones, and out of which many of them venture up
the mouths of rivers, while others have learnt to remain in them and
make the fresh water their home.

The tender little minnows that bask in the sunny shallows of the river
have never even seen the sea, their ancestors left it so long long
ago; yet to them, too, water is life and breath and everything. The
green meadow through which the river flows is just the border of their
world and nothing more, and the air is boundless space, which they
never visit except for a moment to snap at a tiny fly, or when they
jump up to escape the jaws of some bigger fish. Every one knows the
minnow, and we cannot do better than take him as our type of a fish
in order to understand how they live and move and breathe. Go and lie
down quietly some day by the side of the clear pebbly shallows of some
swiftly-flowing river where these delicate little fish are to be seen;
but keep very still, for the slightest movement is instantly detected.
There they lie

   “Staying their wavy bodies ’gainst the streams
    To taste the luxury of sunny beams
    Tempered with coolness. How they ever wrestle
    With their own sweet delight, and ever nestle
    Their silver bellies on the pebbly sand!
    If you but scantily hold out the hand,
    That very instant not one will remain;
    But turn your eye and they are there again.”

[Illustration: Fig. 4.

The structure of the Minnow and the living fish.

    A _n_, nose-pit; _e_, eye-nerve; _ea_, ear-nerve; _g_, gills; _h_,
    heart; _t_, food-tube; _s_, stomach; _k_, kidney; _v_, vent; _da_,
    dorsal-artery. _a_, air-bladder; _b_, backbone; _nv_, nerve cord or
    spinal cord.

    B _n_, nose; _gc_, gill cover; _af_, arm-fin; _lf_, leg-fins; _sf_,
    single fins; _ms_, mucous scales.
]

If you can be motionless and not frighten them you may see a good deal,
for while some are dashing to and fro, others, with just a lazy wave of
the tail and the tiny fins, will loiter along the sides of the stream,
where you may examine their half-transparent bodies. Look first at one
of the larger ones, whose parts are easily seen, and notice how every
moment he gulps with his mouth, while at the same time a little scaly
cover (_g c_, B, Fig. 4) on each side of the head, just behind the eye,
opens and closes, showing a red streak within. This is how he breathes.
He takes in water at his mouth, and instead of swallowing it passes
it through some bony toothed slits (_g_, A Fig. 4) in his throat into
a little chamber under that scaly cover; in that chamber, fastened to
the bony slits, are a number of folds of flesh full of blood-vessels,
which take up the air out of the water; and when this is done he closes
the toothed slits and so forces the bad water out from under the scaly
cover back into the river again. It is the little heart (_h_), lying
just behind the gills, which pumps the blood into the channels in
those red folds, and as it keeps sending more and more, that which is
freshened is forced on and flows through the rest of the body. It goes
on its way slowly, because a fish’s heart has only two chambers instead
of four as we have, and these are both employed in pumping the blood
_into_ the gills, so that for the rest of the journey through the body
it has no further help. For this reason, and also because taking up air
out of the water is a slow matter, fish are _cold-blooded_ animals, not
much warmer than the water in which they are.

But while our minnow breathes he also swims. He is hardly still for a
moment, even though he may give only the tiniest wave with his tail
and fins, and he slips through the water with great ease, because his
body is narrow and tapers more or less at both ends like a boat. At
times, too, if he is frightened, he bounds with one lash of his tail
right across the river; and if you look at one of the small transparent
minnows you will see that he has power to do this because his real
body, composed of his head and gills, heart and stomach, ends at half
his length (see Fig. 4, A), and all the rest is tail, made of backbone
and strong muscles, with which he can strike firmly. This is one
great secret of fish strength, that nearly one half of their body is
an implement for driving them through the water and guiding them on
their way. Still although the tail is his chief propeller, our minnow
could not keep his balance at all if it were not for his arm and leg
fins. You will notice that it is the pair of front fins (_af_) which
move most, while the under ones (_lf_) are pressed together and almost
still. Besides these two pairs he has three single fins (_sf_), one
under his body, one large V-shaped one at the end of his tail, and
another single one upon his back. All these different fins help to
guide him on his way; but while the single ones are fish-fringes, as
it were, like the fringe round the lancelet’s body, only split into
several parts, the two pair under his body are real limbs, answering to
the two pair of limbs we find in all backboned animals, whether they
are all four fins, or all four legs, or wings and legs, or arms and
legs.

These paired wings are most important to the minnow, for, if his
arm-fins were cut off, his head would go down at once, or, if one of
them was gone he would fall on one side, while, if he had lost his fins
altogether, he would float upside down as a dead fish does, for his
back is the heaviest part of his body. It is worth while to watch how
cannily he uses them. If you cannot see him in the stream you can do so
quite well in a little glass bowl, as I have him before me now. If he
wants to go to the left he strikes to the right with his tail and moves
his right arm-fin, closing down the left, or if he wants to go to the
right he does just the opposite; though often it is enough to strike
with his tail and single fin below, and then he uses both the front
fins at once to press forward.

But how does he manage to float so quietly in the water, almost without
moving his fins? If your minnow is young and transparent you will
be able to answer this question by looking at his body just under
his backbone, and between it and his stomach. There you will see a
long, narrow, silvery tube (_a_, Fig. 4) drawn together in the middle
so that the front half near his eyes looks like a large globule of
quicksilver, and the hinder half like a tiny silver sausage. This
silvery tube is a bladder full of gas, chiefly nitrogen, and is called
the _air-bladder_. Its use has long been a great puzzle to naturalists,
and even now there is much to be learnt about it. But one thing is
certain, and that is, that fish such as sharks, rays, and soles, which
have no air-bladders, are always heavier than the water, and must make
a swimming effort to prevent sinking. Fish, on the contrary, which have
air-bladders, can always find some one depth in the water at which they
can remain without falling or rising, and we shall see later on that
this has a great deal to do with the different depths at which certain
fish live. Our minnow floats naturally not far from the top, and, even
if he were forced to live farther down, the gas in his bladder would
accommodate itself after a few hours if the change was not too great,
and he would float comfortably again.

And now the question remains, What intelligence has the minnow to
guide him in all these movements? If you will keep minnows and feed
them yourself every day you will soon find out that they see, smell,
and feel very quickly, though their hearing and taste are not so
acute. They are cunning enough too, and will often steal a march upon
heavier and slower fish, snatching delicate morsels from under their
very noses. For our little minnow can boast of a real brain, though
it is a small one in comparison with his size. All along, above his
delicate backbone, the thread of nerve telegraph (_nv_, Fig. 4) runs
under protecting bony arches, and sends out nerves on all sides to the
body and fins; and when it reaches the head it swells out, under a
bony covering, into a small brain, sending out two nerves to the ears
(_ea_), in front of which is a second part, with two nerve-stations
(_e_) for the eyes, and beyond this a third part, with two more for the
nostrils, besides others which go to the face. Look on the top of a
minnow’s head and you will see two little raised bumps (_n_). These are
its nostrils, but remember _they have nothing to do with breathing_;
they have not even any connection with the mouth, but are simply little
covered cups, each with two openings for water to flow in and out, and
they are lined with nerves, which, tickled by good or bad scents in the
water, carry to the brain a warning, or a promise of good things.

Such, then, is our little minnow, and the different parts of his body
are supported by a slender bony-jointed backbone, with ribs growing
from it, supporting a strong mass of flesh on his sides. He is a
delicate tender creature, but is protected and buoyed up by the water,
out of which he never attempts to go. The thin, rounded, transparent
scales which cover his body, growing out of little pockets in his skin,
just like our nails on the tips of our fingers, protect this skin from
the water and from rough treatment; while they themselves are kept
soft by a slimy fluid which oozes out from under them, and especially
through the dark line of larger scales (_ms._ Fig. 4) running along his
body.

       *       *       *       *       *

Now the minnow is a bony fish, and from it we can learn very fairly
what bony or modern fishes are like. But these fish were not the
founders of the race; long before they existed there was another very
ancient group of fishes in the world, which were in many ways more like
the lancelet and the lamprey; and to find such descendants of this
ancient group as are now living we must leave the river and find our
way into the open sea.

If we do this, we shall travel not many miles from the shore in summer,
wending our way through shrimps and lobsters, gurnards, cod-fish,
soles, and turbot, before we may chance to come across a great Blue
shark, with his slaty-coloured back and fins, swimming heavily but
strongly through the water, and turning sharply from time to time to
seize a passing fish, his white belly gleaming like a flash of light as
it comes uppermost, and then disappearing again in the dark water.

   “His jaws horrific, armed with threefold fate,
    Here dwells the direful shark.”

Or if this formidable monster does not happen to be in the
neighbourhood another kind, the Dogfish, may cross our path, perhaps
the Smooth hound, crushing the crabs and lobsters in his tooth-lined
mouth, or the Rough hound fastening her purse-like egg to the seaweed
by its long string-like tendrils; or, farther out still, we may perhaps
see the Thresher shark lashing the water with his long pointed tail, to
drive the frightened fish within his reach; or, if we were off the west
coast of Ireland, the huge but harmless Basking shark might be floating
calmly by in the warm sunshine. For sharks travel all over the ocean,
and though they prefer the warm seas, where they sometimes reach a size
of forty feet long and more, yet many of the smaller kinds visit our
coasts in summer.

[Illustration: Fig. 5.

The Blue Shark[10] (_from Brehm_).

To show the five slits in the neck, the uneven tail, and the mouth
opening under the pointed snout.]

Now, at first sight we might imagine that these huge monsters, the
terrible tyrants of the sea, must be the last and most finished
production of fish-life; but if we look a little closer we shall be
undeceived. Examine a shark in any good museum, and you cannot fail to
be struck with his strange form. Look first at his tub-like body, so
different from the narrow wedge-shape of the minnow, the herring, or
the salmon. Then observe his skin, which is either tough, more like
that of other animals, or thickly covered with short blunt teeth, which
sometimes, especially in front of the fins, become long pointed spines.
There is no trace of fish-scales here. Look at his mouth opening under
his pointed snout, and you will see that as the skin turns over the
lips these blunt teeth line his mouth, so that he has several rows fit
for biting, and they are sometimes so formidable that they can cut a
man in two at one snap. Then look more especially at the sides of his
throat, and there you will see on each side from five to seven slits,
reminding you at once of the slits of the lamprey, though they are long
instead of round. For the shark has never arrived at having true gills
under a horny cover like the minnow, but still breathes by pouches
and slits somewhat after the way of the lowly round-mouthed fishes.
Lastly, observe his curious tail. In nearly all living fish the tail is
even[11] or V-shaped, but in the sharks the top point is usually longer
than the lower one,[12] and in some, such as the Thresher, it is very
remarkably so.

This uneven tail is the badge of a very ancient race; out of the shark
family we scarcely find it anywhere now except among the sturgeons,
who, we shall see, are old-fashioned too.

And now when we inquire into the growth of the shark and the kind of
backbone he has, we find that he has still more links with the lower
fish-like animals. For when he is young he has nothing but a rod of
gristle or cartilage running between the long narrow feeding-tube
and the spinal cord; but this rod is flattened in front, and as the
young shark grows up the flat part enlarges so as to form a boat-like
box--the skull, round the swollen end of the nerve telegraph--the
brain. Meanwhile the rod becomes divided into rings, and from each ring
an arch of gristle growing upwards surrounds the nerve cord so as to
protect it from injury, and the whole skeleton becomes firm and strong.
But though the shark is one of the strongest of sea-animals _he never
loses this gristly state of his backbone or his skeleton_; however much
he may strengthen it by hard matter it never becomes true bone, but
remains quite distinct from the skeleton of the bony or osseous fish.

[Illustration: Fig. 6.

The Sturgeon[13] entering a Russian river.]

We see, then, that there is a race of gristly or _cartilaginous_
fishes, which, though they have grown strong and powerful, still hold
to many primitive habits in forming both their body and skeleton. Nor
do the sharks stand alone, for the large sturgeons, which live partly
in the sea and partly in fresh water, crowding up the rivers of Russia
and America to grope in the river mud for food, and to lay their
millions of eggs, are also remnants of the ancient type. It is true
that with them the slits in the neck are covered by a horny flap like
the bony fish, and like them too they have an air-bladder under the
backbone.[14] But they too have a gristly skeleton, and the gristly rod
more or less hardened runs right along their back. In other respects
they are perhaps even more peculiar than the sharks; for the sturgeon’s
head is covered with hard bony shields, and five rows of bony bucklers
are arranged along his body. We seem almost to have got back among the
armour-covered animals as we look at his shiny plates, reminding us
that with a mere gristly skeleton within, it may have been wise for
the early types of fish to wear some outward protection. His snout is
long and pointed, with four delicate feelers hanging down from it, and
his mouth, which is quite under his head, is a soft open tube without
teeth, which he can draw up or push out to suck up fish or any animal
matter he finds in the mud.

[Illustration: Fig. 7.

The Sturgeon’s head seen from below, showing the tube-like mouth and
the four barbels or feelers.]

Clearly the sturgeon is an old-fashioned fellow, as you may see for
yourself, when specimens caught at the mouths of our rivers are shown
in the fishmongers’ shops. I have often wondered, when standing looking
at him and at the sharks in the British Museum, whether the people who
stroll by have any idea what a strange history these quaint old fishes
have, or how they stand there among the scaly and bony fishes lying in
the cases around, just as an Egyptian and a Chinaman might stand in an
English crowd, descendants of old and noble races of long long ago,
whose first ancestors have been lost in the dim darkness of ages, whose
day of strength and glory was at a time when the modern races had not
yet begun to be, and whose representatives now live in a world which
has almost forgotten them.

In the silent depths of the large lakes of North America there is a
fish called the Bony pike,[15] a huge fellow often six feet long,
with a long beak-shaped mouth, which he snaps as he goes, devouring
everything that comes in his way. This fish has his body covered with
lozenge-shaped, bony, enamelled scales, like the fish of long ago, and
so too has the strange Bichir,[16] which wanders above the cataracts of
the Nile, with its row of eight to eighteen fins raised upon its back
like tiny sails. Then again there are the curious calf-fish of North
America,[17] of the Amazons,[18] of the Nile,[19] and of the rivers
of Queensland in Australia.[20] These all have gristly skeletons,
and together with the sharks and sturgeons make up all that remains
of those strange shadows of the past moving among the bony fishes of
to-day.

The mud-fishes are indeed the most curious of all, for they breathe
both water and air, and in the Nile and Gambia often coil themselves
round in the mud when the water goes down, and, lining their bed
with slime, sleep comfortably till the rains refill the pools with
water.[21] The fact is they have two quite separate ways of breathing.
They have gills with which they can take air out of the water like
other fish, and these they always use when they can. But they have a
tube in their throat leading into the air-bladder lying under their
backbone, and through this they can breathe in air when they cannot get
it from the water. In _Amia_ especially, which is a true enamel-scaled
fish, this air-bladder is divided into numerous cells, and it breathes
with it just as with a lung.

[Illustration: Fig. 8.

The Ceratodus of Queensland, an air-breathing and water-breathing
mud-fish of the ancient type, with paddle-fins.]

It was in the year 1870 that the _Ceratodus_, or the “Barramunda,”
as the Australian natives call him, was discovered in the rivers of
Queensland; and since then he has become very famous, for, more than
any of the others, he is like the fishes of long ago. He is a lumpy
fish, sometimes as much as six feet long, with a gristly cord for a
backbone. His body is covered with large rounded scales, and he has a
broad fringe round his pointed tail. His fins are more like paddles
than fish fins, having several joints, and he uses them, together with
his fringed tail, to flap along in the water, or even to wander over
the reedy flats at night, chewing the weeds with his broad ridged
teeth. And as he flaps along, from time to time, when the water is too
muddy for his liking, he comes up to the top, and with a great gulp
swallows air into the air-chamber. But before he can do this he must
send out the bad air within, and in doing so he gives a grunt which
is often heard far away at night in those still Australian wilds. He
need not come up for air-breathing, however, if the water is pure, for,
strange to say, the whole course of his blood can be altered to suit
his wants. When he can get clear water to breathe through his gills the
blood flows to them to be freshened, and his air-bladder simply takes
in gas from the body as it does in other fishes, and wants feeding with
good blood. But when he comes up to breathe then the blood is carried
the other way, and comes to the air-bladder to be freshened.

And now if we want to read the history of all these strange forms, you
must let me take you by the hand and lead you in imagination back, back
through millions of years, to a time so long ago that we cannot even
count the ages between. As we recede from our own day we shall leave
behind us all the kinds of plants and animals we now know so well, and
meet with strange kinds only bearing a general resemblance to them.
After a long journey of thousands and thousands of years, in which
the plants and animals, and even the very shape of the continents and
islands, have gone through many changes, we shall get back to the time
when the lime-builders were forming thin layers of chalk at the bottom
of the sea, which were afterwards to become our enormous chalk hills.
Still backwards we must go through all that long period, and then
through three others quite as long, with ever-changing scenes of life
and climate and geography, till we find ourselves in those grand old
forests whose trees and plants we now dig out as coal.

Even then we must not stop to rest, though we are getting back to
the dim ages of the world, for the journey is not yet ended. On,
on, backwards through countless years, till we lose sight not only
of beasts and birds and reptiles, but even of insects and flowering
plants, which, at the time we are reaching, had not yet begun to be. At
last we lose almost all life upon the land, so far as we can tell, and
after another long period has passed before us we find ourselves in a
scene of _water, water everywhere._

True, there is a line of shore where strange ferns and unknown
club-mosses and reed-like plants are growing; but these only border the
vast water-world, and we have reason to believe that no living animal
wanders over that wild and barren country. But the water itself is full
of life, though its inhabitants are of low kinds, as if Nature herself
was as yet only half-awake.

Rich and rare seaweeds carpet the floor of the ocean, mingled with
delicate flint-sponges and old massive corals; beautiful feather-stars
in the form of rooted stone-lilies wave their slender arms; greedy
star-fish, grazing sea-urchins, and all their many relations, grope
upon the rocks; and sea-snails crawl or float in countless numbers. The
Nautilus, too, is there, with curious half-uncoiled companions of forms
we have never seen before; and huge sea-woodlice, the Trilobites of
olden time with their three-ridged shields, burrow in the sand, or roll
themselves up at the bottom of the water. And above all these, among
many kinds of armour-covered animals, a huge form, nine feet long, like
a lobster, with an imperfect head, rows himself along with his oar-like
hind feet, seizing the smaller creatures with his long nipping claws
in front. For we have travelled back to a time when the crustaceans
were the most powerful animals in the world, and the huge lobster-like
Pterygotus was the monarch of the seas.

It was in the midst of a scene such as this that we first find the
feeble ancestors of the Sturgeon and the Shark beginning to make their
way in the world. It may be that creatures such as the sea-squirts,
the lancelet, and the lamprey, were there to bear them company, but
these soft animals could leave no trace behind except the tiny teeth
of the lampreys; for they had no enamelled plates like the plated
fish, no hard teeth-spines like the sharks, which could become buried
in the soft mud when they died, and remain, together with the hard
shell of their enemy the Pterygotus, to be dug out now in our day and
bear witness to the fight they fought. But the plated-scaled fish
had something to leave behind, and from their remains we can picture
to ourselves a group of clumsy fish scarcely a foot long, with hind
fins like paddles and single-fringe fins on their back, with enamelled
lozenge-shaped plates on their bodies and unevenly pointed tails.
These fish would keep well out of the way of the Pterygotus, because
they were small and weak and he was large and strong. We may imagine
them gliding among the seaweeds, and hugging the shore as they chewed
the plants with their flat-ridged teeth, for their skeletons were
probably feeble and their armour-like shields were heavy, and they
would not be so active as the little shark-like animals, not bigger
than a half-pound perch, with tough skins and sharp spines, which swam
more boldly out to sea. These more active fish were the founders of
the shark group, and those sharp spines, together sometimes with the
tough skin, remained buried in the mud, and have come down to us as
fossils.[22]

We should find it difficult to say exactly to what class all these
early fish belonged, for there were very few kinds, and therefore fewer
distinctions, between them in those days; and many peculiarities which
afterwards appear in different groups either did not exist or were
united in one fish. It is enough for us that they were the ancestors
of our sharks and sturgeons and mud-fish of to-day; and though they
were but small and weak, yet they were the beginning of a powerful race
of creatures, for they had the great advantage of a growing inside
skeleton, which could vary and strengthen with their bodies from
generation to generation, while their rivals, the Pterygotus and his
companions, had only their heavy cumbrous armour with a mass of soft
flesh inside, and were but lumbering creatures at best.

And so we find that as thousands and thousands of years rolled by, the
descendants of the enamel-shielded fish began to improve, and became
larger and more powerful as the generations passed on, till they became
masters of the shallow seas, and after awhile of the rivers and lakes.
By the time that the first air-breathing creatures, the May-flies and
Dragon-flies, had found their way out of the water into the forests
of pines and tree-ferns on the land, and left their tender wings in
the soft ground of the ponds and lakes, large fishes[23] whose tails
were uneven-pointed like the sturgeon,--whose bodies were covered with
lozenge-shaped enamelled scales and their heads with shields,--were
grazing along the shores and in the rivers and bays, with probably
swarms of smaller kinds which have left no traces behind.

These were peaceable fish which fed upon plants, and among them were
some curious forms with paddle-like fins and broad-ridged teeth, which,
as they swam under the shade of the huge forest trees, would come to
the top and take in air through their mouth. These were the distant
ancestors of our present mud-fishes, and through all the passing ages,
from the time of the coal forests till now, they have kept their
fish-like form, so that we have their descendants among us now in the
Australian _Ceratodus_ and the mud-loving _Protopterus_ of the Nile.

But besides these gentle vegetarians there were in the sea huge
enamel-scaled monsters, with terrible jaws and gigantic teeth,
floundering about and making great havoc among the crab-like animals.
One of these, whose head-shield has been found in the ancient rocks of
Ohio in America,[24] must have been at least fifteen feet long, with a
huge head, three feet long and a foot and a half broad; and no doubt
there were many others like him, having a fine time of it now that they
were the strongest creatures living. For this was the Golden Age of
fishes, just before the time when the coal-forests grew; and the clumsy
crab-like animals, and the trilobites, which had had their innings when
the fish were small, now began gradually to be exterminated by their
powerful enemies. Little by little they gave up the battle of life,
and the larger ones died out altogether, leaving only those smaller
crustaceans which did not clash with the fish.

So time passed on. The coal-forests grew, and died away and were
buried; and as the ages rolled by a still stronger class of animals
began to grow up which was to pay back upon the enamel-scaled fish
the vengeance they had wreaked upon the crustaceans. For in the coal
forests we first meet with creatures like our newts and salamanders,
and after these came the true air-breathing reptiles (see Chap. v.),
which swarmed over land and sea. There were the fish-lizards, with
their strong swimming paddles and sharp teeth, and the swan-like
lizards, with their long necks, which enabled them to strike their prey
in the water; and these, together with the flying-lizards, and the huge
dragon-like reptiles which haunted the shore, made the life of the
heavily-moving enamelled fish a burden to them. So they, in their turn,
began to give way, and became smaller and rarer as the history went on,
till at the time when the chalk-building animals were at work at the
bottom of the sea we begin to lose sight of all but those few forms
which linger still. It was about this time that the Sturgeon, as we now
know him, became the chief representative of these old cartilaginous
fishes, and to this day he and his children go on travelling up the
rivers of Europe, Asia, and America, or crossing from sea to sea--a
living example of those ancient races which ruled the seas of long ago.

The history of the small shark-like animals was rather different. They
too grew strong and powerful before the reptiles came, and they did
not afterwards lose much of their greatness. With the wide ocean for
their home, and not troubled with the heavy enamelled plates of their
companions, they kept clear of the monster reptiles, or struggled with
them bravely. Some took to the open sea, and from them are descended
the giant sharks of to-day which still remain masters of the ocean.
Others still lingered near the shore, where we find quite new forms
springing up; some, like the Chimæra or “King of the Herrings,” formed
a group of their own, half-way between sharks and sturgeons; and
some, slightly flattened like the huge Monk-fish, hide themselves in
the loose sand when seeking their prey. Others, the Skates and Rays,
with flat bodies, and long tails serving as rudders, shoved smoothly
along with a wavy flapping motion of their broad arm-fins. These too
lie chiefly at the bottom of the sea, where their dusky colour hides
them both from the fish they would wish to attack and those that
would attack them; for while the sharks trust to their strength, the
skates and rays trust to stratagem, and, coming along stealthily in
the shadow, flap rapidly over their prey and suck them into their
open mouth below. And for further protection we find some of them,
such as the Sting-rays, armed with barbed spines; others, such as
the Torpedo-fish, with electric batteries in their heads, which they
can use to stun and kill their enemies; while others again, such as
the Saw-fishes of the Tropics, have the front part of their skull
lengthened out in a long bony weapon, armed with teeth, which they use
to rip open the bodies of their prey.

All these formidable fish are descendants of the shark family, which,
with powerful gristly backbones, strong fins and tails, and highly
developed brains, refused to be suppressed as their plated companions
were, but found room in the wide ocean to do battle for themselves,
and improve in many ways upon their ancestors. They do not, like the
sturgeon and the bony fish, lay their thousands of eggs, but are
content with one or two at a time, such as the leathery purse-eggs of
the skate and the rough hound shark; or give birth to a dozen or twenty
living young ones. Yet they are so well fitted for their life that they
flourish and keep their ground, so that while the enamel-scaled fish
and the mud-fish are small groups, many of them fading away, the sharks
and rays bid fair to be the race which will keep up the traditions of
those quaint old Fishes of ancient times, which were once the masters
of the world.




[Illustration: THE BONY FISH IN THE EARLY DAYS]




CHAPTER III.

THE BONY FISH, AND HOW THEY HAVE SPREAD OVER SEA AND LAKE AND RIVER


When the palmy days of the enamel-scaled fish had passed away, and
the sharks and rays had taken up their various quarters in different
parts of the sea, there still remained vast tracts and many snug nooks
and bays admirably fitted for fish-life. But these were not empty,
for long before this time another order of fish--light, strong, and
active,--had been pressing forward to take possession of every vacant
space.

If we could dive under the water and watch the fishes at home we should
see at once how much more agile and easy the bony fish are in their
movements than their gristly companions. Look at a shoal of silvery
herrings as they swim and leap and gambol, or a fine salmon sailing up
the river or springing over a waterfall, or a tiny stickleback darting
across the stream, and compare their graceful motion with the ponderous
though powerful movements of an unwieldy shark. Any one who has done
this will feel at once that though the sharks have still kept their
power as tyrants of the sea, because they are so strong and big, yet
these light skirmishers are much more at their ease, and move with much
less effort in the water, so that it is natural they should have made
their way into all parts of the rivers and seas. But where have they
come from? We know very little of their early history, but what little
we do know leads us to think that long ago they branched off from the
enamel-scaled fish, and struck out a path of their own to make the most
of the watery world.

Turn back for a moment to our little minnow, and recall his tender
backbone made of joints hollowed out before and behind, with cushions
of gristle between; those cushions, when the minnow was growing out
of the minnow egg, were one long gristly cord, like the cord of the
sturgeon, and it was only as the minnow grew that the bony joints
hardened round it and separated it. Moreover, that huge bony pike
which we find now wandering in the American lakes has bony joints
hollowed out like the minnow’s, although by his enamel-scales and
uneven tail we know him to be one of the ancient fishes. Some time
or other, then, the sturgeon, the bony pike, and the modern minnow,
must have had a common ancestor, though we should have to reach him
through millions of generations. In the same way, too, we find the
red-folded gills covered by a scaly lid, both in the sturgeon and the
minnow, though in other ways they are not exactly alike; while even
the V-shaped tail of the modern fish is not so different from the
ancient shape as it seems, for the end of the backbone runs up into
the top branch of the fork as it does in the uneven tails of the olden
fish. Lastly, the delicate rounded scales on our minnow’s body are not
entirely the property of bony fishes, for we find such scales on the
mud-fishes, the _Amia_ and _Ceratodus_ (see p. 33); while the little
modern stickleback, on the other hand, has bony plates, reminding us of
those of olden times. We see, then, that the bony fish still carry upon
them many signs of their origin from the older fish, and when once the
coast was left clear, and they got a fair start, we can easily imagine
that the fish of this younger race which was still in its childhood,
and easily moulded to suit different kinds of life, would press forward
in every direction and make the most of every chance.

And so we find that little by little, from the time of those chalk seas
till now, the remains of enamel-scaled fish grow rarer and rarer in the
hardened mud, and the bones and scales of modern fish take their place,
till this bony race has spread so far and wide that in our own day, if
we were to start from the head of a river and swim down into the open
sea of the Atlantic or Pacific, we should meet on our way bony fish of
all shapes and sizes and habits of life. River-fish and lake-fish and
sea-fish; shore-fish, surface-swimming fish, and fish of the deep sea;
flat-fish like the sole, half hidden in the sand, and long rounded fish
like the eel, threading their way through holes and passages all over
the world; flying fish with long arm-fins, and clinging fish whose fins
form a sucking disk; nay, even so strange a thing as an angling-fish,
whose back fin is turned into a fishing-rod to attract his prey.

All these, during the long ages since they first started in life, have
been learning to make use of some area in the wide expanse of water
spread over our globe, and it remains for us now to see how they have
succeeded. Where shall we make our start? If we begin at home in the
rivers we should have to work, as it were, backwards, for the sea is
the chief home of fishes, and the rivers only the refuge of a few stray
kinds. The sea-shore would be, perhaps, our truest starting-point, but
then we should have to travel two different ways. Will it not be best
to dive down first into the silent depths of the ocean, and learn what
little is known of those which have taken refuge there? Thence we can
rise up to the open sea, from there swim in to the shore, and then up
the rivers and back to our own land-home.

It makes but little difference where we take our plunge into the deep
sea, for changes of climate are scarcely or not at all known there,
and the fish seem to wander over every part. Wherever it may be,
then,--let us say in the seas of the Tropics, which have given us most
of our specimens--let us dive down, down, till we reach about 1800 feet
(300 fathoms).

    ... “For who can know
    What creatures swim in secret depths below,
    Unnumber’d shoals glide thro’ the cold abyss
    Unseen, and wanton in unenvied bliss.”

We shall be groping more and more in darkness as we go, for the
sunlight scarcely reaches beyond 1000 feet, and we have left its last
rays behind us, and the water is growing icy cold. How strange, then,
that the first fish we meet should have large wide-open eyes! This is
the Beryx,[25] shaped something like a perch, but about a foot and a
half long, and genealogists ought to look at him with respect, for his
ancestors (see heading of Chapter) are almost the oldest known bony
fish, and lived in the chalk seas.

Has he come down here because the upper world was too rough for him?
If so, he has found comparative stillness, for he is far beneath the
turmoil of the waves, and only the slowly creeping currents make any
movement around him. But he has not escaped from the struggle for life,
for not only is a good-sized shark coming his way, but a huge monster
of the bony race, six feet long,[25] with wide-opened jaw, sharp
pointed teeth, and large keen eyes, is wandering near in search of
prey, devouring large and small fish with great impartiality.

Still in the dense darkness the Beryx must surely escape? No! for,
strangely enough, lights are travelling about in this midnight region.
The monster himself carries lamps upon his body, and a shoal of
small oblong fish, something of the size and shape of a gudgeon, come
swimming by, carrying on their sides whole rows of shining spots
giving out phosphorescent light; while not far off another fish,
called in India the Bombay duck, glows all over, as if his whole
body had been rubbed in phosphorus. Nay! so far as we know the Beryx
himself is probably gleaming with light, for his body is covered with
a large quantity of the same slimy fluid which makes the “Bombay duck”
phosphorescent when he is freshly drawn out of the sea.

So these curious fish, living in eternal darkness except when they make
an expedition to the surface, carry many of them their own lights; and
as we go deeper still more and more of them are found with shining
mother-of-pearl-like spots on their head, or sides, or tail, so that
the very darkness is alive with light. What slaughter and hunting
there is among them! for they all eat each other, and even their own
young, there being no plants for any of them to feed on. There are
the deep-sea cod-fish; strange forms with large heads, long tapering
tails, and thread-like fins, chasing the smaller fish, and falling
victims themselves to the fierce _Stomias_ which comes sailing along
with its row of glowing lights, and its huge sharp teeth, ready to
seize its prey. Both these fish go down as deep as ten thousand feet
and more, accompanied by another fish quite as ferocious, though only
a foot long, with large teeth sticking out of its mouth like the tusks
of a boar, and curious round spots, with lenses in them, on its side,
which may be eyes, or may be lanterns to light it on its road; and
among these luminous fishes are wriggling along the deep-sea Conger
eels, with toothless mouths and elastic stomachs, swallowing large
fish whole; while another curious cod-like fish, whose stomach can
stretch to more than four times its natural size, draws itself over
its prey just as a snake does, and carries it in the hanging bag till
it is digested. And deeper yet in the dead calm water roam many fishes
with delicate feelers hanging from their mouths, while their fins are
slender and tapering, so that they feel their way along the still
depths. Among these are the Ribbon-fish, twenty feet long but only a
foot deep, and never more than two inches thick in any part, with their
long rosy fins floating like ribbons back from their heads and from
under the body.[26]

Strange monsters are all these deep-sea fish, some of them living
as much as 16,000 feet under the surface of the sea, so that if
Switzerland were turned upside down in mid-ocean, the peak of Mont
Blanc would not reach down to where they swim. Yet they are only
modified forms of ordinary fish from the world above, which have become
fitted to live under that vast pressure of water. Their skeletons,
though bony and well-knit together at that depth, are fibrous and
slight compared to those of their surface relations, for although
they have to resist a weight of from two to sixteen tons pressing
all round them, a ton weight being added for every thousand feet, no
special strength is required, because the dense water permeates their
whole structure, and the pressures are everywhere equal. It is the
same with them as with the most delicate and fragile insects living
in our atmosphere, the pressure of which would tear them to pieces if
unbalanced by equal pressures within and without.

But when these deep-sea fishes are brought up quickly to the surface,
the outside pressure no longer balances that inside, and so their
tissues loosen and their whole framework starts apart, so that they
almost fall to pieces at a touch; and their air-bladder, if they have
one, expands so much as to force the stomach out of the mouth, turning
them almost inside out. Neither are their lanterns a special creation
for their use, but merely adaptations of that slimy fluid which we
saw oozing from the scales of the minnow. In some of the deep-sea
fish even the outer bones are filled with this fluid, and the line of
scales along the side has large openings, so that the body is bathed in
glowing slime. In others it collects in glands on the sides, making the
phosphorescent spots.

In this way the deep-sea fish have become fitted to make a home in the
very heart of the ocean. Some with large eyes, seeing by means of their
own and their neighbours’ light, others with small eyes and delicate
feelers, testing each step as they go, and feeding, probably, on the
shower of minute sea-animals that falls continually from above; while
some, like the Beryx, the Bombay Duck, and the light-carrying Scopelus,
which live nearer the top, come up on still nights to feed at the
surface of the sea.

[Illustration: Fig. 9.

Remoras[27] clinging by their sucking-disk to the under part of a
shark.--(_Adapted from Brehm._)]

And now, as we rise again from the dark still depths up to warm layers
of the tropical seas into which the sun is pouring his penetrating
rays, it may happen that a large dark body moves between us and the
surface, as the Great Blue Shark, or one of his smaller relations,
ploughs his way through the water. But what are these little dark brown
fish, with round gaping mouths, which are hanging by the top of their
head and back from under the shark’s belly? (see Fig. 9). Where he goes
they go with him, and, as they are borne along, they feed upon the
tiny sea-animals among which they are carried so easily. These cunning
passengers, of whose very existence the shark seems unconscious, are
the Remoras, or sucking-fish. You would scarcely think that they
belong by descent to the mackerel tribe, a strong-swimming, active,
and almost warm-blooded group of fish, with a large supply of nerves
and blood-vessels to their muscles, so that they swim boldly out to
sea, and make more use of the open ocean than almost any other group.
But among all tribes there will be some weak members, and these must
live by stratagem. The little remora is a feeble swimmer, and, having
to live out at sea, has acquired a curious sucker by which he clings
to sharks, and whales, and even ships, so that he is carried along
without exertion. Yet this sucker, again, is only a special adaptation
of the back-fin, which, instead of being single, as in other mackerel,
has its spines divided and bent, one set to the left, the other to the
right, and joined by a double set of plates, surrounded by a fringe of
skin. This forms an oval disk, and, as the remora glides along under
the shark’s belly, he presses the damp membrane against the fish, and,
drawing together the muscles of the plates, clings as firmly as a
limpet to a rock.

Nor is the remora the only companion of the shark--

   “Bold in the front the little Pilot glides,
    Averts each danger, every movement guides;”

for the little steel-blue striped Pilot-fish,[28] another distant
connection of the mackerel tribe,[29] is hovering around, feeding
upon the scraps of the shark’s food, and finding protection in his
neighbourhood, though in olden times he was supposed to protect the
shark. A brave little fish this, which has succeeded in making the
shark his friend: while near him he is safe from other fishes.

And now, as we continue our way in the open sea, it is nearly always
forms more or less related to the mackerel tribe which cross our
path. The slender Bonito[30] and the heavier Tunny[31] sometimes ten
feet long, are hunting below or on the surface, and the beautiful
Dorados,[32] or gold-mackerel, as the Germans call them, with their
silvery blue backs tinged with a sheen of gold, their dull-coloured
fins, and their golden eyes, are driving by in large shoals in pursuit
of the flying-fish. All these are powerful swimmers, and they have no
air-bladder, which is an advantage to such active hunters which wish
to turn rapidly, to go down deep or rise to the top, and change their
position at every moment; for in all these movements a natural float
inside is a hindrance to be overcome. And so we find that in fish, even
of the same family, some have lost the air-bladder, while others have
it enlarged to meet their wants, as in the case of the lovely blue and
silver sun-fish[33] for example, which, though quite near relations
of the dorado, have very large air-bladders, enabling them to float
quietly on the top of the water, waving their deep scarlet fins.

[Illustration: Fig. 10.

Flying-Fish[34] pursued by the Dorado.[35]]

But while we are watching all these large and strong swimmers an active
and bloodthirsty struggle is going on, for the bonitos and the dorados
are looking to make their meal upon the little Flying-fish, which are
straining every nerve to escape them, while here and there one drops
down into their very mouths. Lovely little creatures these are, of
the Pike family, which have taken to the open sea, where they rise
with a stroke of the tail many feet out of the water, their bright
purple backs and silvery sides gleaming in the sun, as, with their
long transparent arm-fins outspread, they float for as much as two
hundred yards before they fall back, to spring up again with another
stroke. Their air-bladder, which is half as long as their body, and
contains in a six-inch fish as much as three and a half cubic inches
of gas, stands them in good stead, and they rise and fall with quick
rapid flights out of the reach of their foe, so that in the open sea
they do fairly well on the whole, though, if they venture near land,
the sea-birds persecute them in the air. Nor do they stand alone in
this curious habit of flying, or rather floating, in the air, for a
larger fish of quite another family, the “Flying Gurnards,”[36] with
a smaller but still ample air-bladder, and long arm-fins, may also be
seen rising in the Mediterranean and tropical seas, out of reach of the
fish-hunters of the water.

And now we must leave the open sea and steer for the shore. It is true
that many other fish are wandering in the broad watery main, but many
of them, such as the globe-fish, feeding on the small crustaceans
and the sea-horses,[37] whom we shall meet nearer shore, are feeble
forms carried hither and thither by currents or on floating banks
of seaweed, while others have no special interest. The sharks, the
mackerel, and the flying-fish, are the most remarkable colonisers of
the ocean-surface, for even the enormous Sword-fish,[38] which attacks
the bonitos and whales with its long wedge-shaped bony jaw, and is said
to sail by raising his back-fin, is a distant off-shoot of the mackerel
tribe.

So we cannot do better than follow our own common Mackerel, as they
migrate in shoals out of the deep sea to feed on the fry of the herring
or the pilchard in shallower water, or to leave their eggs floating not
many miles from land, so that the tiny mackerel, when hatched, may live
in the quiet bays till their strength comes.

But stop! Long before we have come so far as this, and while we are
still a hundred miles or more from the shore, let us peep down into the
sea-valleys, where forests of seaweed and marine plants are growing,
and myriads of tiny sea-lice and crustaceans throng the water. What
is that army of thin spindle-shaped forms rising and falling in such
numbers? It is a shoal of herring, which have come there to feed upon
the sea-animals, keeping out of sight of the sea-birds above, and the
cod and sharks and ravenous fish which hunt them without mercy, so that
they only venture to come to the surface on calm dark nights. It was
in valleys such as these that the herrings were living when the older
naturalists thought they were gone away to the Polar Seas, because they
only saw them in spring and autumn, when they come into shallower water
to drop their myriads of eggs,[39] which sink down, and stick to the
seaweed and stones below.

But now they are revelling in the deep ocean, rising and falling with
ease, for their air-bladder has two openings, one to the stomach and
one to the outside of the body, so that the gas can adjust itself
to their movements; and surely if the shark is the type of the old,
lumbering, powerful, slow-breeding fish, the herring, with its narrow
lissome body, light playful movements, and myriads of young, is the
type of the new and active race. They are as truly social animals
as any herds on land, for they travel in shoals of many hundreds of
millions; and as they can squeak, and have a very good apparatus for
hearing, it is more than likely that they call to each other. They
make both the salt and fresh water their own; for when the eggs are
hatched at the mouths of rivers the tiny fish take refuge there from
the violent persecutions of the cod and mullet and haddock, flat-fish
and whiting, and, together with the small fry of other fish, stroll up
the rivers, where we call them “white-bait.”

And now, as we come nearer to the shore, where countless numbers of
small fry are filling the water, and all creatures are struggling
together to accomplish three objects, namely, to get food, to avoid
being turned into food, and to lay their eggs, we find many strange
weapons and devices adopted by the different fish for protection and
attack.

                       ... “Each bay
    With fry innumerable swarms, and shoals
    Of fish, that with their fins and shining scales
    Glide under the green waves, in sculls that oft
    Bank the mid sea.”

There are the Mullets,[40] with tender feelers under their chin, with
which they brush the ground lightly as they swim, feeding on the tiny
creatures. There are the walking fish, the Gurnards,[41] which have
three of the spines of their arm-fins separate, and moved by strong
muscles and nerves, so that they can walk on the sea-bottom, feeling
their way, while the stiff, spiny rays of their back-fin stand up to
wound any enemy attacking them from above. There are the tiny Blennies
which walk too, but by means of the few rays which alone remain of
their leg-fins growing close under the head. Then there are the
clinging-fish, the Gobies,[42] living on the rocky shores, where the
waves beat and roar, and they have their leg-fins joined together, so
as to form a kind of funnel under their throat, with which they cling
to the rocks and then dart across the waves to feed, coming to anchor
again out of the dash of the water; some of these little fellows make
nests and guard their eggs after the mother has left them, till the
young can shift for themselves. More curious still, the Lumpsucker[43]
has its arm-fins and leg-fins all joined together into a round disk
under the throat, and so holds on bravely against the dashing tide,
defending the eggs which have been laid in the seaweed near the shore,
and even remaining to take up the young ones when hatched, and carry
them safely back into deep water as they cling to his sides.

Meanwhile, close down upon the sand are the hiding-fish, the Weevers,
the Anglers, and the Flat-fish.

The weevers[44] are the most dangerous. Their shaded yellow colour
hides them from view, while the sharp spines of their back-fins, which
they keep raised, will inflict very severe, if not poisonous, wounds
on any creature striking against them. Nor is this all, for behind the
cheeks, fastened on to the horny gill cover, are daggers with which
they can strike, deliberately jerking them back so as to give a sharp
blow. These are fighting aggressive fish, waging the war that goes on
so sharply all round our coasts.

[Illustration: Fig. 11.

The Fishing Frog.[45]]

But there is one even more cunning than they, lying hidden in the
seaweed or the sand--a large, flat, soft fish, about three feet in
length, and quite half as broad as he is long, with a soft stumpy
tail, stretching out behind, and a kind of wrist-joint to arm and leg
fins, by which he can creep noiselessly along. His wide mouth is gaping
open, so that a two-foot rule could be passed crossways into it, and
his pointed teeth are bent back to allow his prey to enter. But how is
this prey to be caught, for he is not going to move to fetch it? Notice
all round his head and his body, the skin is fringed like blades of
seaweed and plays about in the water; while above his head and back
the spines of his fin stand up quite separate, and the front one is
tapering and long like a fishing-rod, with a lappet at the end like a
bait. And now, as the shallow water ripples over his head, the lappet
plays to and fro, and the unwary fish come up to nibble at it, lower
and lower he waves it, and the nibblers follow, till, opening his wide
gape, he gulps them down, even if they are as large as himself, and
lies passive with his swollen stomach till they are digested. This is
our own Fishing-frog,[46] of which one was once found with seventy
herrings in his stomach. He has relations all over the world--in the
open sea and down in its depths, and all of them more or less follow
his fishing habits. Yet there is no creation of special parts for these
strange weapons; the altered back-fin and the jagged skin do all the
work, just as in some curious fish of the weever family in the tropics,
called the Stargazers,[47] the feelers on their lips, longer than those
of other fishes, and a lengthened thread from below the tongue, play in
the watery currents and attract the small animals, while the fish with
upturned eyes watches them as they are lured to destruction.

Lastly, among all these curious forms upon our shores there is an
abundance of flat-fish--soles and turbot, brill and plaice--flapping
along at the bottom, covering themselves with sand, or rising up with
that strange wavy movement of the whole body in which they use what
look like long side-fins, but which are really the back-fin and the
belly-fin.

[Illustration: Fig. 12.

The Common Sole.[48]

    Above are two small soles as they swim when young. At that time
    they are not larger than a grain of rice.--(_Adapted from Figuier
    and Malm._)
]

If we wanted to pick out the strangest and strongest proof of how the
shape of fish is altered to suit their wants, we need seek no further
than the flat-fish.

When we were speaking of the shark order we saw that the rays and
skates are flattened forms suited to hide in the sand, and these fish
are truly spread out as if they had been squeezed under a heavy weight,
their broad arm-fins edging the sides of their body. But the bony
flat-fish, the Soles and Turbot, have a far stranger history. The young
sole, when it comes out of the egg, is not flat like the young skate,
but a very thin spindle-shaped fish, something like a minnow. He is
then about the size of a grain of rice, very transparent, and lives at
the top of the sea. He has one eye on each side, like other fish, only
one eye is higher up than the other, and the single fin on its back and
the one under its body reach almost from head to tail. In this way he
swims for about a week, but he is so thin and deep, and his fins are so
small, that swimming edgeways is an effort, and soon he falls down on
one side, generally the left, to the bottom of the sea. Many times he
rises up again, especially at first, till he has got used to breathing
at the muddy bottom, and meanwhile the eye that lies underneath is
gradually working its way round to the upper side, his forehead
wrinkles so as to draw the under eye up, while his whole head and mouth
receive a twist which he never afterwards loses. His skeleton, it must
be remembered, is still very soft, and the bones of his face are easily
bent; and at last this eye is screwed round, and as he lies at the
bottom he can look upwards with both eyes and save the under one from
getting scratched by the sand, as it must have done if it had remained
below.

Nor is this all, for while his under side, shaded from the sunlight,
remains white and colourless, his upper side gradually becomes coloured
like the sand in which he lies, and he is safely hidden from attack as
he flaps along, feeding on worms and other animals. And now when he
swims he no longer uses his arm and leg fins, which are quite small and
insignificant, but bends his whole body, using the back and belly fins
to help him. What we then call the top of the sole is really his side,
where you may see the dark line of scales running along the middle,
and one arm-fin lying close to his head. Yet he can swim strongly and
to far distances, for in the winter the soles, too, migrate into the
open sea, where they may be found in the deep water of the Silver Pit,
between the Dogger Bank and the Well Bank.

[Illustration: Fig. 13.

Hippocampus, a fish commonly called the Sea-Horse.]

And now, before we leave the shore, we must glance at a curious weakly
little fellow clinging by his curly tail to the seaweed, whom you
will certainly not take for a fish, even if you can find him out, so
entangled is he generally in weeds of the same colour as himself. Yet
the Sea-horse[49] is a true fish, covered not with scales but with
plates, with which he makes a clicking noise by scraping them together.
What look like large ears are really his arm-fins, while at the end of
his long snout is a mouth shaped like an ordinary fish’s mouth, but
toothless, and he breathes with fish’s gills arranged in round tufts
instead of folds. What the use of his strange shape is to him we cannot
tell, but at any rate his fleshless bony body must protect him from
other fish, while his power of clinging causes him to be often carried
by floating weed even into the open ocean, and make up for his feeble
powers. In one thing he surpasses most other fishes, for he is a most
careful father, carrying the mother’s eggs in a little pouch under his
body till the young ones escape. There is one form of these sea-horses
in tropical seas which has long red fringes floating from its body, so
that it cannot be distinguished from the seaweed in which it hides.

So we see that the deep sea, the open sea, and the shore, are filled so
full of different forms that there are enough not only to make use of
every part, but also to provide food for each other, and we also see
that by far the larger number even of widely-spread fish come near to
the shore to leave their spawn, while the young ones often make their
way into the brackish water at the mouths of rivers, and spend their
youth in the shelter of the still fresh water.

Now it is very natural that many such fish should learn to remain in
this quiet refuge, and in time to live there altogether. And because
fish-life in the rivers is comparatively uneventful and little varied,
we find much fewer peculiarities in river-fish. Many of them are very
near relations of sea forms. There is the salmon, a true sea-fish,
which wanders up the river to spawn in the pebbly shallows; and there
are the trout, his near relations, which have learned to live entirely
in the rivers. There are the sea-perches, large strong fish, and the
smaller river perch, which have made their homes very successfully in
the rivers, for their spines are so sharp that even the greedy pike
hesitates to swallow them. There are the sea-sticklebacks, and the
little river-stickleback.[50] This last is a very clever little fish,
which hollows out the foundation of his nest very carefully in the bed
of the river, and then builds it up for several inches with blades of
grass and weeds (Fig. 14), gumming them together with the slime of his
body. Then, when all is ready, he swims about to drive and coax the
mother to the nest, sending her in to lay her eggs, and then driving
her right through and out at the other side, so that a stream of water
flows constantly over the eggs till they are hatched. Nay, his care
does not end here, for when the young fish come out of the egg with a
bag of yelk hanging under the body, as all young fish have at first,
and so cannot swim easily and escape their enemies, the courageous
little father will defend them and fight fiercely with any fish which
thinks to make a meal upon them, not leaving them till all the yelk is
absorbed, and they are able to swim and feed themselves.

[Illustration: Fig. 14.

STICKLEBACKS AND THEIR NEST. (Gasterosteus aculeatus.)]

Besides these active river-fish there are the little stupid Miller’s
Thumbs,[51] hiding under the stones to feed on tiny animals; they are
feeble relations of the gurnards which we saw walking on the bottom
of the sea. Then there are the purely freshwater fish, the Pike and
the large Carp family, with its many branches, the Roach, and Dace,
and Gudgeon, and Minnow; and the enormous family of Cat-fish and
Sheat-fish,[52] of which we have none in England, but plenty in America
and other parts of the world, a family in which the fathers sometimes
carry the eggs in their mouths till hatched. And last but not least
among the freshwater forms is that irrepressible family of the Eels
which we saw wandering in the deep sea, and which are also to be found
near the shores all over the world. These fish will even travel through
pipes and into cisterns; and will climb up trees so as to drop into
neighbouring streams and continue their wanderings; they sleep in the
mud in winter; and even after being frozen come to life again; and in
the spring they go to the sea to spawn, giving rise to those shoals
of young ones from three to five inches long which come in incredible
numbers up the rivers in summer, making the eel-fairs,[53]--

              “The silver eel, in shining volumes rolled,”

so much spoken of in old books, when the eels will often climb high
banks, nay, even pass over miles of dry land, closing down their narrow
gill-openings, and so shutting in water to serve them as they go.

All these, and many other freshwater families, show us how the fish
have wandered into every possible nook of the waters, so that even in
those inland salt lakes of North America and Asia into which no rivers
flow fish-life is abundant; and we can only suppose that the eggs must
have been carried by water-birds in their flight, or by gusts of wind,
or have arrived there in ages long ago, before these lakes were cut off
from the rest of the watery world.

Yet some few fish besides the eels have been known to travel over land
to find watery “pastures new;” the Climbing Perch[54] of India and
the Doras of Tropical America will both travel many miles when their
own ponds are dried, the perch breathing by the help of a special
apparatus, and the doras probably shutting water into its gills; for
necessity, even in fishes, proves the “mother of invention,” and in
special works on fish you will find accounts of numberless strange
devices and adaptations by which they manage to survive in the struggle
for life.

And now, collecting together all we have learned, let us in conclusion
form a rough picture of the history of the fish-world. All over our
globe, from pole to pole, and from the Indian Ocean round to the east,
back to the Indian Ocean again, is one vast world of waters, with
inlets and land-locked seas bordering its margins, and rivers pouring
into its depths. In the past ages of the world these rivers and coasts
and inlets have varied innumerable times, but the great ocean-mother
has always been there to bear the increasingly-varied forms in her
bosom, and to enable them to wander where best they could preserve life.

And so from their beginning, when they were probably as feeble as the
lancelet, these earliest and simplest backboned animals with their two
pair of limbs as yet very variable both in their position and shape,
have been spreading far and wide over the watery three-quarters of
the globe. We have seen how the enamel-scaled fish had their time of
glory, but were not able to hold their ground, because they were not
agile and fish-like enough to escape their foes; and how the sharks by
their strength and boldness remain monarchs of the sea to the present
day. Then we have seen that in old chalk seas the new and active race
of bony fish appear in force; some like the herring and the carp,
with air-bladders, which had openings like the enamel-scaled fish,
and these can dart from heights to depths; while others had closed
air-bladders, and these remain with most ease at one level, and can
sometimes, if necessary, use the gas in their bladder for breathing,
if they are oppressed with muddy water; and lastly, some, such as the
dorado, have lost their air-bladder altogether, and gain in freedom
of action what they lose in lightness and buoyancy. And during the
ages that have passed since this bony race began, different branches
each in their own way have thrown out curious weapons and developed
strange organs to help them in the battle of life, so that now we have
deep-sea fish carrying their own light; fish with distensible stomachs
swallowing prey larger than themselves; fish with large air-bladders
and long arm-fins springing out of their own element and floating in
air; angling-fish, walking-fish, clinging-fish, and hiding-fish; and
even those whose shape is distorted, like the sole, to enable them
to hide and hunt in safety; while, when the sea is full, we find new
varieties pressing their way into every river and tiny stream, and even
overland into enclosed waters. Nay! when we descend into the recesses
of the earth and visit the underground pools of the dark caverns of
Kentucky, there we come upon fish which have found a refuge in eternal
darkness, and have lost not only the power of sight but actually the
eyes themselves.

And here we must leave them to go to higher vertebrate animals.
Although but little is known of fish-life, a very small part even of
that little has been given here, and yet we take leave of it with
the feeling that its changes and chances are greater than we can ever
thoroughly learn. How much pleasure these creatures have in their
water-world it would be difficult for us to say; but since we find them
playing together, hunting together, sporting in the warm sunshine, and
diving and gambolling in the open sea, and sometimes even calling to
one another, we cannot but think that life has great charms for them in
spite of the many dangers surrounding them. And when, low though they
are in the scale of life, we find them (though curiously enough always
the fathers) carrying the eggs, building nests for them, and defending
the young, we see that even here, in the very beginning of backboned
life, we touch the root of true sympathy, the love of parent for child.




[Illustration: THE HOME OF THE EARLY AIR BREATHERS]




CHAPTER IV.

HOW THE BACKBONED ANIMALS PASS FROM WATER-BREATHING TO AIR-BREATHING,
AND FIND THEIR WAY OUT UPON THE LAND.


So the backboned animals, as fish, have peopled the seas and rivers,
and, as the ages have past on, have become more and more fitted to
their watery life, little dreaming of another and different life in
the world of air above them. And yet in the same pond with the little
stickleback, so busy building his nest, there is a creature which could
tell him that it is possible to live in both worlds, if only you have
the proper machinery to do it with.

It is clear that if the backboned animals were ever to live upon land,
after they had begun their career in the water, there must have been
some among them which learned gradually to give up water-breathing,
and to make use of free air; and we shall not have far to seek for
creatures which will help us to guess how they managed it.

From almost every country pond, or ditch, or swamp, a chorus of voices
rises up in the springtime of the year, calling to us to come and learn
how Life has taught her children to pass from the water to the air; for
it is then that the frogs lay their eggs, and every tadpole which grows
up into a frog carries us through the wonderful history of an animal
beginning life as a fish with water-breathing gills, and ending it as a
four-legged animal with air-breathing lungs.

Come with me, then, to some stagnant pool in a country lane, towards
the end of March, and there we shall no doubt find a whole company of
frogs, croaking to their hearts’ content after their long winter sleep
in the mud at the bottom of the pond. They are wide awake now, and are
actively employed laying their eggs. Look carefully around the edges of
the pond, especially in that part where the wind has driven the scum
to the side, and you will doubtless find in some still corner a gluey
mass (_e_, Fig. 15), which looks like a lump of jelly with dark specks
in it. Take this up carefully, for it is frog spawn; carry it home
together with some weeds from the pond; put it in a glass bowl with
water; and then from day to day you may study the history of a frog’s
life.

[Illustration: Fig. 15.

Metamorphosis of the Frog.

    _e_. Eggs. 1. Tadpoles just out of the egg. 2. With outside gills.
    3. With gills hidden, and beak-like mouth. 4. Hind legs appearing.
    5. All legs grown, but fish-tail remaining. 6. Putting on Frog
    appearance; tail being absorbed. 7. Young perfect Frog.
]

That jelly-like mass is a collection of frog’s eggs. When they were
laid, each egg was a small round dark body in a gluey covering, and
they all fell to the bottom of the pond, where, by degrees, the
water oozing through the envelope swelled each egg, till they clung
altogether in a mass, and, rising, floated at the top. Then very soon
each round dot lengthened out into a long streak, and in a few days an
eyeless head appeared at one end with a soft closed mouth under it,
and at the other a tail, with a soft fin round it like the tail of
the lancelet; so that by the time you find the spawn, you may, most
likely, be able to see the tiny creature wriggling every now and then
in its watery bed. This will go on for some time, and a week or two may
pass before the moving tadpole breaks through its egg skin, and coming
out into the world, fastens on to a piece of weed (1, Fig. 15) by two
little suckers behind its mouth. And now that it is out of the egg the
interest begins. Look carefully day after day and you will see some
branching tufts (2, Fig. 15) growing larger and larger on each side of
its head. What are these? We have not seen them in any fish. No! but if
you take a young hound-shark out of his leathery egg before his time,
you will find that he has outside gills much like these, only he loses
them before he comes out into the world, whereas the tadpole keeps them
to breathe with a little longer. If you put the tadpole, at this stage,
under the microscope, you can see the red blood flowing through these
gills to take up air out of the water.

Meanwhile the tadpole’s lips are gradually forming into a round mouth,
much like the lamprey’s, and by-and-by the inner part of this mouth is
covered with two little horny jaws, forming a sharp beak (3, Fig. 15)
with which he will nip off pieces of weed for food. Meanwhile, as he
grows larger and larger, and eyes, nostrils, and flat ears form in the
head, a covering begins to grow back over the sides of the neck, and
little by little the branching tufts disappear (3, Fig. 15). How, then,
can he breathe now? Watch carefully and you will see that he gulps
every moment as we saw the minnow doing (p. 23). The fact is that the
outside tufts have faded away, and under the cover the tadpole has six
slits in his throat, like the slits of the lamprey, which are covered
in somewhat similar fashion to those of the amphioxus (see p. 11), and
he breathes through them.

Here is our tadpole, then, to all intents and purposes a fish. He
swims with a fish’s tail; he gulps in water at his mouth, passing it
out at the slits in his throat after it has poured over his fish’s
gills. Moreover, he has a fish’s heart, of two chambers only, like
the minnow’s (p. 23), which pumps the blood into these gills to be
freshened, while, like the lamprey, he has a gristly cord, enlarged
at the end to form a gristly skull, a round sucking mouth, and no
limbs. All this time, however, though he has a fish’s fin round his
tail, he has no arm or leg fins. Wait a while and you will see that
under his tender skin far more useful limbs are being prepared. As he
grows bigger and more active week by week, wriggling among the weeds
and feeding greedily, two little bumps appear one on each side of
his now bulky body, just where it joins the tail. These bumps grow
larger every day, until, lo! some morning they have pierced through the
skin, and two tiny hind legs (4, Fig. 15) are working between the body
and the tail. The two front legs are longer in coming, for they are
hidden under the cover which grew over the gills, but in about another
week they too appear, and we have a small four-legged animal with a
lamprey’s tail (5, Fig. 15). These legs are something far in advance of
fish fins, for they have shoulders and thighs, arm and leg bones, wrist
and ankle bones, hand and foot bones; and instead of the large number
of rays in a fish’s fin they have four fingers on their short front
legs, and five toes at the end of long hind ones; the toes being joined
together by a web, which helps him wonderfully in striking the water as
he swims.

The tadpole has now become fitted to jump and leap on the land or
swim by his legs in the water; and, moreover, while these legs have
been growing, another change has been taking place. You will notice
by careful watching that at first he still gulps in water as he used
to do, but he comes more often to the top, and, poising himself so
that his mouth is out of the water, gives out a bubble of bad air,
draws in some fresh, and goes down again. Why does he do this? Have
you any recollection of another fish-like animal which comes up to
take in air? Look back at our friends the mud-fishes (p. 34), and read
how the Ceratodus fills his air-bladder when he is short of good air
in the water. When you have re-read this, you will suspect that the
tadpole, too, has something like an air-bladder, which he fills from
time to time. And so he has. While his legs are growing a bag has been
forming inside at the back of his throat, which afterwards divides
into two, and he fills these by shutting his mouth, drawing air in at
his nostrils, putting up the back of his tongue to shut it in, and
then swallowing it down into the lungs; so that he is now a truly
double-breathing animal, using his gills when below water and his lungs
when above. Moreover, if you could watch inside his body, you would
now see that little by little the blood-vessels going to the gills
grow smaller and smaller, and those going to the lungs grow larger
and larger; while the fish’s two-chambered heart divides into three
chambers, one to receive the blood from the body, another to receive
it from the lungs, and one to drive this blood back again through the
whole animal. And when at last this change is so complete that all
the blood goes to the lungs to be freshened, the gills shrivel up and
disappear, and our tadpole is a true air-breathing animal.

Notice, though, that he is still cold and clammy, not warm like a mouse
or a bird. For his blood still moves slowly, and as he has only three
chambers to his heart instead of four, as warm-blooded animals have,
the good blood from the lungs and the worn-out blood from his body
become mixed each time they come round, so that his breathing work is
still of a low kind all his life. And now that he can leap and swim
with his legs, his tail is no longer of use to him, and it is gradually
sucked in, growing shorter and shorter till it disappears, and the
young frog is complete.

Thus our backboned animal has succeeded in getting out of the water
on to the land, and in doing so he has quite changed his habits. A
peaceful vegetarian before, he is now a greedy eater of insects,
slugs, and other animals. His horny beak has been pushed off; his lips
have stretched back farther and farther, till they now open right
back as far as his flat little ear; and he is a gaping, wide-mouthed,
leaping frog[55]--

          ... “Hoarse minstrel of a strain
    Aquatic, leaping lover of the rain;”

(7, Fig. 15), with teeth in the roof of his mouth. But perhaps his
tongue is the most curious of all, for instead of being fixed at the
back, and free in the front, as in most other animals, the root of it
is fastened to the front of his lower jaw, and the tip lies back in his
mouth, so that when he wishes to catch an insect he throws his tongue
quickly forward, captures his prey on the sticky point, and flings it
back down his throat.

So he hops about the summer long, if he can only escape from ducks and
rats and other frog-eating animals. He often takes to the water, for he
can fill his lungs with air and use it very slowly, and, moreover, his
soft skin is of great use to him in still breathing in the water or in
the moist air; and when winter comes he takes refuge with many others
at the bottom of the pond, and sinks into a state of torpor, till the
spring brings croaking and egg-laying time round again.

[Illustration: Fig. 16.

The Common Smooth Newt[56]--male and young in the water; female on the
bank.]

Our little frog, then, is truly an animal with a double life, a genuine
amphibian,[57] meaning by this, not merely an animal that can swim in
the water and move on land, for seals and water-rats, white bears and
hippopotamuses, can do this, but one that in the early part of its life
would die if taken out of the water, while afterwards it lives and
breathes in the air.

[Illustration: Fig. 17.

Proteus of the Carniola caverns,[58] with its external breathing
gills.--(_Adapted from Brehm._)]

Have these double-lived creatures, then, such a great advantage over
real water animals, or how can we account for their having adopted
this strange life? If we only look upon them as they are now, we can
scarcely call them particularly successful, compared to other animals.
For though there are plenty of them, yet they are comparatively small
and insignificant; and when we find large ones like the gigantic
salamander of Japan, they are sluggish and feeble. Look at the
common newts, or water-salamanders of our ponds, with their weak
crawling limbs, as they wander round the edges of a pond, feeding on
water-insects and tadpoles, the male with his crested back, the smooth
mother, and the young eft-tadpole with its branching tufted gills (Fig.
16). They are much less active than the frog, for they never lose their
tails, and they come less often out of the water, although they are
true air-breathing animals. Then, when we go to other countries, there
is the Proteus (Fig. 17), that curious half-transparent newt, with a
round body and tiny helpless legs, which lives in eternal darkness in
the still underground pools of the Carniola caverns near Adelsberg. He
has become well fitted for his dismal life, for his tiny eyes are grown
over with skin, and he never loses the feathery gills on each side of
his neck, but lives like a tadpole all his life, although he has true
lungs. Again, in America we have the Siren, with its long snake-like
body, and only front legs, with which it cannot walk. It, too, keeps
its gills as it wanders about the stagnant waters of South Carolina,
feeding on worms and insects. Then in the Mexican lakes there are the
curious Axolotls, which also wear outside gills, as a rule, all their
lives, and fathers, mothers, and children remain breathing in the water
together, although they have real lungs. But about twenty years ago,
some of those axolotls, which were kept in the Jardin des Plantes in
Paris lost their gills, came out upon the land, and astonished people
by becoming true land salamanders, like some already well known and
called Amblystomes, breathing only with their lungs. It was difficult
for some time to make the world believe that grown-up water-breathing
creatures which could lay eggs were able to turn into other creatures
without gills. But at last a lady, Fraulein Marie von Chauvin, took
some axolotls when they were full-grown, and kept them on land in
wet moss, washing and feeding them every day, and thus succeeded in
teaching them to breathe air, so that their gills shrivelled up and
disappeared. Then there could no longer be any doubt that the axolotl
is only the lower water-form of the amblystoma, which in the Mexican
lakes, owing to the increased dryness of the surrounding country, has
lost the habit of coming out on to the land, and remains in the water
with its little ones all its life; but which, when brought to a moist
climate where it can breathe comfortably on land, sometimes returns to
its old double life.

[Illustration: Fig. 18.

    Axolotl, a creature living and breeding for generations in the
    water. Amblystoma coming out of the water,--an axolotl which has
    lost the gills and acquired lungs.
]

We have, in fact, in Europe real land salamanders, which live in cool
damp places, looking like lumpy soft-skinned lizards, but going down
to the water to lay their eggs, that their little ones may go through
their tadpole life--and one of these, the black salamander,[59] which
lives high up in the mountains of Germany, France, and Switzerland,
does not even go to the water, but carries the young tadpoles in her
body till they can breathe air and run alone; and yet they are still
true _amphibia_, for if they are taken out of their mother and put in
water, they go through all their changes like common efts and newts.

Lastly, there is a strange group of legless creatures called Cæcilians,
which have taken refuge underground, burrowing like worms, though they
are true amphibians and their young have gills in their babyhood hidden
under a slit in the neck. These cæcilians are the only amphibians which
have scales something like fishes, yet they never live in the water,
but in the marshy ground of tropical countries, feeding on worms and
insects.

       *       *       *       *       *

Now when we think that these sluggish newts, and salamanders, and
cæcilians, with their more nimble but comparatively unprotected
relations, the frogs, are all the amphibians now living, we cannot but
wonder how Life came to produce such a feeble set of creatures to fight
the battle of existence.

But if we glance back to that far-off time when the ancient fishes were
wandering round the shores and in the streams of the coal-forests, we
shall be better able to read the riddle. For in those days it was a
great step for an animal to get out of the water at all, and those that
did so had a much better time of it than our frogs and newts have now,
when the country is full of land enemies.

And so we find that the _amphibia_ were not then the small scattered
groups they are now, but strong lusty animals, with formidable weapons.
In the hardened mud, which in those days formed the soft swampy ground
of the coal-forests, but is now stiffened into the roofs and floors
of our coal-mines, footprints have been left which tell us of large
and formidable creeping animals, with toed feet and long flat tails,
dragging themselves over the marshes of the coal-forests, and finding
their way to many places which even the mud-fish with their paddles
could not reach; and from time to time, in these same roofs and floors
of our mines, both here and in America, we find the bones and coverings
of these _amphibia_, buried in Nature’s catacombs for ages, and only
brought to light by the rude hand of man.

These remains remind us that

   “A monstrous eft was of old the lord and master of earth,
    For him did the high sun flame, and his river billowing ran.
    And he felt himself in his force to be Nature’s crowning race;”

for they show us huge and powerful creatures[60] which sported in the
water or wandered over the land with sprawling limbs, long tails, and
bones on which gills grew, while their heads were covered with hard
bony plates, and their teeth were large, with folds of hard enamel
on the surface. Some of these were fish-like, with short necks and
broad flat tails, but they had true legs and toes; others, more like
crocodiles, and sometimes ten feet long, were able to walk firmly, but
still dragging their bodies and long tails over the swampy ground on
which their footprints are still found; some were small and more like
lizards, with simple teeth, scaly armour, and light nimble bodies; and
these, probably, ran about quickly on the land, and have sometimes left
their skeletons in the hollow trunks of the old coal-forest trees.

All these plated and formidable creatures were _amphibia_ or
double-lived animals, and this was _their_ Golden Age, as they preyed
upon the fishes in the swamps and ponds, probably not sparing even
their nearest connections, the mud-fishes, who, less fortunate than
themselves, had followed the road of fish-life instead of coming out
upon the land. They lived so long ago that we can tell but little of
their daily lives, but it is clear that they played a very different
part from our small frogs and newts of to-day, and in their well-formed
limbs were worthy forerunners of land and air-breathing animals.

But like the old race of fishes these large amphibians were only to
have their day, for as other branches of the family tree grew up, and
reptiles grew strong and mighty, and other true land animals began to
flourish, these huge plated forms dwindled away, and we lose sight
of them; and when we find any of their relations again it is only as
our present frogs and newts, salamanders and cæcilians, which have
taken up their refuge in lakes, ponds, ditches, underground waters,
or damp mud. And, curiously enough, those forms of to-day which are
most like the huge _Labyrinthodonts_,[61] as they are called, of the
old coal-forests, are the feeble cæcilians, with their horny scales
and their numerous ribs, although they have now fallen the lowest of
all amphibians, and, with their sightless eyes and ringed and legless
bodies, have taken to burrowing in the ground like worms.

Not so the frogs, which, like the bony fishes, began their career in
later times, and have known how to fit themselves into many nooks and
corners in life. In almost all countries of the globe they hop merrily
about the ponds and ditches, never wandering far from the water, into
which they jump and dive whenever danger threatens. It is true they
are eaten by thousands, both as tadpoles and frogs, by birds, snakes,
water-rats, and fish, and even by each other, but they multiply fast
enough to keep up the supply, and find plenty of insects both in and
out of the ponds. Nor have they kept entirely to a watery life, for
their near relations, the toads, which have toothless mouths and toes
less webbed, have ventured much farther on to the land, protected
partly, no doubt, by the disagreeable acrid juice which they can throw
out from a gland behind the eye whenever they are attacked.

It is curious to notice the quiet leisurely waddle of the sluggish
toad, as he spreads out his short fat legs and puffs out his warty
skin, and to compare him with the nervous, anxious, little frog,
starting at every danger. And still more curious is it to see him
getting out of his skin, as he does several times a year. For his skin
does not peel off in pieces as it does in the watery frogs, but splits
along his back; then he wriggles about till it lies in folds on his
sides and hips, and, putting one of his hind feet between the front
ones, draws the skin off the leg like a stocking off a foot. With the
other leg he does the same, and then, drawing out his front legs, pulls
the whole skin forward, and stripping it over his head, swallows it;
thus deliberately putting his old coat inside him, and appearing in one
that is glossy, fresh, and new. The toad has many enemies in spite of
his acrid taste, and he shows his wisdom by hiding in walls and under
stones in the daytime, and coming out in the dusk of evening to hunt
the beetles and grubs so often out of reach of the water-loving frog.

[Illustration: Fig. 19.

The Flying Tree-Frog of New Guinea[62] (_Wallace_).]

But the toad is not the only land relation of the frog; there are
others of the group that venture even farther from water; for in most
parts of the world (though not in England), tree-frogs, with sucking
disks at the ends of their toes and fingers, climb the trees and hunt
for insects among the leaves and branches; while in Borneo Mr. Wallace
found one (Fig. 19) with webbed feet, which it spread out, and so flew
down from the trees. There are plenty of the ordinary tree-climbing
frogs to be seen in the south of France, their small green bodies
peeping out from under the dull gray olive-leaves; and to be heard,
too, in an endless chorus all night long when the spring arrives.

But how can these tree-dwellers bring up their little ones in water?
Some of them come down and lay their eggs in the ponds, and even sleep
down in the mud in winter. Others lay their eggs in little puddles of
water in the hollows of the trees, and there the young ones live their
tadpole life; while in one curious tree-frog of Mexico, called the
_Nototrema_, the mother has a pouch in her back, and the father places
the eggs in it for the little tadpoles to live in a moist home till
they leap out as perfect frogs.

Nor is this the only case in which fathers and mothers take care of
their young. In one species of frogs living near Paris, the father[63]
winds the long string of gluey eggs round his thighs, and buries
himself in the ground till the young tadpoles are ready to come out,
and then he leaps into the water. And in one of the tongueless toads,
the Surinam toad,[64] the mother’s soft skin swells up, forming ridges
and hollows, and when her eggs are laid the father clasps them in his
feet, and, leaping on her back, puts an egg into each hollow. Then
the mother goes into the water, and remains there while each tadpole
completes its changes in its own hole, jumping out at last a finished
toad.

Yet, in spite of curious habits such as these, the frogs and their
companions on the whole lead a very monotonous life. They are, it is
true, more intelligent than fish, and have learned to know more of the
world, but in the long ages that have passed since their ancestors
roamed in the coal-forest marshes, other and higher animals have taken
possession of the land, and left room only for a few scattered groups
of _amphibia_. Still, however, they remain hovering between two lives,
and filling such spots as neither the fishes nor the land animals can
occupy; and when we hear them croaking in the quiet night, or see them
leaping on the marshy ground, they remind us that we have still living
in our day, a link between the fish whose world is a world of waters,
and the air-breathing animals which have become masters of the land.




[Illustration: THE REPTILES IN THEIR PALMY DAYS.]




CHAPTER V.

THE COLD-BLOODED AIR-BREATHERS OF THE GLOBE IN TIMES BOTH PAST AND
PRESENT.


And now the transformation is complete, for when we pass on to the next
division of backboned animals, the “Reptiles,” we hear nothing more
of gills, nor air taken from the water, nor fins, nor fishes’ tails.
From this time onward all the animals we shall study live with their
heads in the air, even if their bodies may be in the water; they swim
with their legs or, as in the case of the snakes, with their wriggling
bodies, and they lay their eggs on the land where their young begin
life at once as air-breathers.

Yet they can often remain for a long time both under water and under
ground, for they are still cold-blooded animals, breathing very slowly,
and easily falling into a state of torpor when the air around them is
cold and chill. They are but the first step, as it were, to active
land-animals; yet they have played a great part in the world, and when
we know their history we shall be surprised to find how much Life has
been able to make of her cold-blooded children.

To learn how this has been, however, we must travel away from home and
our own surroundings. The tiny brown lizard which runs over our heaths,
while its legless relation, the slowworm, burrows in the ground,--the
few snakes which glide through the grass of our meadows, and the
stray turtles thrown at rare intervals on our shores,--tell us very
little about true reptile life. It is to Africa, India, South America,
and other warm countries, that we must go to find the formidable
crocodiles, huge tortoises, large monitor-lizards, and dangerous
boa-constrictors, cobras, and rattle-snakes. And even then, strong
and powerful as some of these creatures are, they do not tell us half
the history of the cold-blooded air-breathers. For the day of reptile
greatness, like that of the sharks and enamel-scaled fish, was long
long ago.

Now that we know how frogs pass from water-breathing to air-breathing,
and how axolotls, accustomed to live all their life in the water, can
lose their gills and become land-animals, we can form an idea how in
those ancient days, while still the huge-plated newts were wandering
in the marshes, some creatures which had lost their gills would take
to the land, and their young ones starting at once as air-breathers,
as the black salamanders do now (see p. 80), would in time lose all
traces of the double or _amphibian_ life, and become true air-breathing
reptiles.

At any rate, there we find them appearing soon after the coal-forest
period passed away, at first few and far between, in company with the
large amphibians, but spreading more and more as the ages passed on,
till they in their turn became monarchs of the globe. Already, when the
coal-forests had but just passed away, a lizard,[65] in some points
like the monitors that now wander on the banks of the Nile, was living
among his humbler neighbours; and from that time onwards we find more
and more reptiles, till just before the time when our white chalk was
being formed by the tiny slime-animals at the bottom of the sea, we
should have seen strange sights if we could have been upon the globe.
For the great eft was no longer

                    “... lord and master of earth.”

All over the world, and even in our own little England, which was then
part of a great continent, cold-blooded reptiles of all sizes, from
lizards a few inches long to monsters measuring fifty or sixty feet
from head to tail, swarmed upon the land, in the water, and in the
air. There were among them a few kinds something like our tortoises,
lizards, and crocodiles; but the greater number were forms which have
quite died out since birds and beasts have spread over the earth, and a
wonderful and powerful set they were.

Some were vegetable-feeders, which browsed upon the trees or fed upon
the water-weeds, as our elephants and giraffes, our hippopotamuses and
sea-cows do now. Others were ferocious animal-eaters, and their large
pointed teeth made havoc among their reptile companions, as lions and
tigers do among beasts. Some swam in the water devouring the fish,
while others, like birds or bats, soared in the air.

In the open ocean were the sea-lizards, some called Fish-Lizards,[66]
like huge porpoises thirty feet long, but really cold-blooded reptiles,
with paddles for legs, and long flattened tails for swimming. Woe to
the heavily-enamel-scaled fish when these monsters came along, their
pointed teeth hanging in their widely-gaping mouths as they raised
their huge heads, with large open eyes, out of the water! Then among
these were others with long swan-like necks and small heads,[67] which
would strike at the fish below them in the water, while other slender,
long-bodied monsters,[68] measuring more than seventy feet from tip to
tail, flapped along the sea-shore with their four large paddles, or
swam out to sea like veritable sea-serpents, devouring all that came
in their way. These were all water-reptiles, while there were also
many smaller land-lizards playing about upon the shore, and among the
trees and bushes. But the strangest of all were perhaps the “Flying
reptiles”[69] of all sizes, from one as small as a sparrow to one which
measured twenty-five feet from tip to tip of its wings. These reptiles
did not fly like birds, for they had no feathers, but only a broad
membrane, stretching from the fifth finger of their front claw to their
body, and with this they must have flown much as bats do now, while
some of them were armed not only with claws, but also with hooked beaks
and sharp teeth, with which they could tear their prey.

And meanwhile upon the land were wandering huge creatures, larger than
any animal now living, which were true reptiles with teeth in their
mouths, yet they walked on their hind legs like birds, probably only
touching the ground with their short front feet from time to time, as
kangaroos do. They had strong feet with claws, the marks of which they
have left in the ground over which they wandered, supporting themselves
by their powerful tails as they went.

Some of them were peaceful vegetarians,[70] browsing on the tree-ferns
and palms, and rearing their huge bodies to tear the leaves from the
tall pine-trees. But others were fierce animal-feeders. Fancy a monster
thirty feet high,[71] with a head four or five feet long, and a mouth
armed with sabre-like teeth, standing upon its hind legs and attacking
other creatures smaller than itself, or preying upon those other
huge reptiles which were feeding peacefully among the trees. Surely
a battle between a lion and an elephant now would count as nothing
compared to the reptile-fights which must have taken place on those
vast American lands of the west, or on the European pasture-grounds,
where now the remains of these monsters are found.

But where are they all gone? We know that they have lived, for we
can put together the huge joints of their backbones, restore their
gigantic limbs, and measure their formidable teeth, but they themselves
have vanished like a dream. As time went on, other and more modern
forms, the ancestors of our tortoises, lizards, crocodiles, and
afterwards snakes, began to take the place of these gigantic types;
while warm-blooded animals, birds and beasts, began to increase upon
the earth. Whether it was that food became scarce for these enormous
reptiles, or whether the birds and beasts drove them from their haunts,
we are not yet able to find out. At any rate they disappeared, as the
ancient enamelled fishes and large newts had disappeared before them,
and soon after the beds of white chalk were formed, which now border
the south of England and north of France, only the four divisions of
tortoises, lizards, crocodiles, and snakes, survived as remnants of the
great army of reptiles which once covered the earth.

       *       *       *       *       *

Ah! if we could only have a whole book upon reptiles to show how
strangely different these four remaining groups have become during the
long ages that they have been using different means of defence; and
how, even in a single group, they employ so many varied stratagems to
survive in the battle of life! Look at the tortoises with their hard
impregnable shells, the crocodiles with their sharp-pointed teeth and
tough armour-plated skins, and the silently-gliding snakes with their
poisonous fangs or powerful crushing coils. See how the tiny-scaled
lizard darts out upon an insect and is gone in the twinkling of an eye,
and then watch the solemn chamæleon trusting to his dusky colour for
protection, and scarcely putting one foot before another in the space
of a minute.

Each of these has his own special device for escaping the dangers of
life and attacking other animals, and yet we shall find, before we
finish this chapter, that they are all formed on one plan, and that it
is in adapting themselves to their different positions in life that
they have become so unlike each other.

We shall all allow that the Tortoises are the most singular of any, and
it is curious that they are also in many ways the nearest to the frogs
and newts, although they are true reptiles. Slow ponderous creatures,
with hard bony heads (Fig. 20), wide-open expressionless eyes, horny
beaks, and thick clumsy legs, the tortoises seem at first sight to be
only half alive, as they lumber along,

   “Moving their feet in a deliberate measure
    Over the turf,”

carrying their heavy shell, and eating, when they do eat, in a dull
listless kind of way. They do, in truth, live very feebly, for they
can only fill their lungs with air by taking it in at the nostrils
and swallowing it as frogs do, and then letting it drift out again as
the lungs collapse, for their hard shell prevents them from pumping
it in and out by the movement of their ribs like other reptiles. This
slowness of breathing and the fact that they have only three-chambered
hearts like frogs (see p. 76), so that the good and bad blood mix at
every round, causes them to be very inactive, and they digest their
food very slowly, and have been known to live months and even years
without eating.

[Illustration: Fig. 20.

The Greek Tortoise.]

This sluggishness would, indeed, certainly be their ruin in a bustling
greedy world, if it were not for the strong box in which they live.
Take in your hand one of the small Greek[72] or American[73] tortoises,
so often sold as pets, and you will see how well he can draw back out
of harm’s way, while at the same time you will, I think, be sorely
puzzled to understand how he is made. His head, his four legs, and his
tail, with their thick scaly skin, are intelligible enough. But why do
all these grow on to the inside of his shell, so that when you trace
them up you cannot find the rest of his soft body? You would hardly
guess that his shell _is_ the rest of his body, or at least of his
skeleton. But it is so. The arched dome which covers his back is made
of his backbone and ribs, and the shelly plates arranged over it are
his skin hardened into horny shields, which, in the Hawksbill turtle,
form the tortoise-shell which is peeled off for our use; while the flat
shell under his body is the hardened skin of his belly, and the bones
which belong to it.

[Illustration: Fig. 21.

Carapace of the Tortoise.

    _j_, Joints of the backbone grown together; _r_, ribs formed into
    a solid cover; _sh_, shoulder bones; _h_, hip bones covered by
    carapace, which has grown over them.
]

Let us make this clear, for it is a strange history. If you look at
the skeleton of a lizard (Fig. 23, p. 103), it is all straight-forward
enough. His head fits on to his long-jointed backbone, which is able to
bend in all parts freely, down to the very tip of his tail. His front
legs with their shoulder bones (_s_), and his hind legs with their hip
bones (_h_), are attached in their proper places to his backbone, and
lastly, his ribs (_r_) protect the inside of his body, and by expanding
and contracting pump the air in and out of his lungs, the front ribs
being joined underneath in a breastbone. It is easy to see, therefore,
that the lizard may be active and nimble, twisting his body hither and
thither, and escaping his enemies by his quickness. But the tortoise
is slow and sluggish, and has only managed to baffle the numberless
animals which are looking out for a meal by fabricating a strong box to
live in. But he had to make this out of the same kind of skeleton as
the lizard, with the one difference that he has no breastbone. Let us
see how it has been brought about. The bones of his neck are jointed
and free enough as you can see (Fig. 21), and so are the joints of his
tail, beginning from behind his hip bones (_h_). But with his back it
is different. The backbone can be clearly seen inside the empty shell,
running from head to tail so as to cover the nerve-telegraph, but the
joints (_j_) have all grown together, and on the top they have become
flattened into hard plates,[74] while the ribs (_r_) which are joined
to them have also been flattened out and have grown firmly together so
as to make an arched cover or _carapace_. If now you look at the back
of the young tortoise (Fig. 22), which has been taken out of the egg
before it was full-grown, you will see these plates (_p_) on the side
where the tortoise-shell (_ts_) has been peeled off. They have not yet
widened out enough to be joined together, and the ribs (_r_) are as yet
only united by strong gristle. But what is that row of oblong plates
(_mp_) round the edge? Those are the marginal plates, and they are
mere skin bones, like the bony plates of the crocodile, but they are
all firmly fixed together so as to bind the edges of the ribs, while
plates of the same kind form the shell under the body, and the whole is
covered by the horny skin.

[Illustration: Fig. 22.

Back of a Young Tortoise.--(_From Rathke._)

    _ts_, Tortoise-shell covering the whole carapace; this has been
    removed on the right side; _mp_, marginal plates binding the edges
    of the ribs; _np_, neck-plate; _p_, plates formed of the top of the
    backbone joints which have grown together; _r_, ribs which have not
    yet spread out so as to form a continuous shell; _lm_, _lm′_, front
    and hind leg muscles not yet covered by the carapace.
]

But there still remains another great puzzle. How come the shoulder
bones and hip bones of the tortoise to be inside his ribs instead of
being outside them, as in other animals? But look again at our baby
tortoise, and you will see that the muscles of his front legs (_lm_,
Fig. 22) are not covered by ribs, neither are those of his hind legs
(_lm′_). They stand just like those of other animals, in front between
the ribs and the neck, and behind between the ribs and the tail. But as
the tortoise grows up, the bony plates press forwards and backwards,
and cover up the shoulders and hips, protecting the soft legs and neck,
and giving him the curious appearance of living inside his own backbone
and ribs.

In this way, then, the tortoises have managed to hold their own in the
world. Living slowly, so that they sometimes go on growing up to eighty
years old, wanting but little food, and escaping the cold by sleeping
the winter months away in some sheltered nook, they ask but little from
Life, while they escape the dangers of sluggishness by growing their
skeletons so as to form a citadel which even birds and beasts of prey
can rarely break through. They are, it is true, often eaten when young,
and the jaguar of Brazil knows how to dig the poor American tortoise
out of his shell and eat him; while large birds are formidable enemies
to our Greek tortoise, and are said to drop it down on the rocks,
and break it to pieces. But, on the whole, they escape most of these
dangers, and wander in the woods and dry sandy places of sunny Greece
and Palestine, laying their bullet-shaped eggs in warm spots to hatch,
seldom wandering far from home, and lying down for their winter’s sleep
under heaps of drifted leaves or in holes of the ground.

These are true Land-tortoises,[75] and so are the gigantic tortoises
which used to live in the island of Aldabra, and others still surviving
in the Galapagos and other islands near Madagascar, which weigh at
least 200 pounds, and on whose backs Mr. Darwin rode when he found
them travelling up the island to get water to drink, feeding on the
juicy cactus as they went. Some carapaces in our museums belonging to
these tortoises measure four feet long and three broad; yet they were
timid fellows when alive, drawing back completely within their shells
when danger was near. We even find some smaller land-tortoises[76] in
America, called the Box-tortoises, which have soft joints in their
under shell, so that they can draw it up both in front and behind,
shutting themselves completely in.

Not so the River-tortoises,[77] which are greedy animal-feeders, and
as they live in the water do not need the same protection. Their box
is much flatter and more open at the ends, so as to allow them to
swim freely with their webbed feet; and they are fierce and bold,
the Snapping Turtle[78] of the lakes and rivers of America being a
terrible fellow, tearing the frogs and fishes in the water with his
sharp claws, and even snapping strong sticks in half with his powerful
beak. The Mud-tortoises, too, which swim swiftly with their strong legs
and long neck outstretched, do not need a hard shell, and they have
scarcely any plate below, and only a gristly leathery covering above,
which looks very like the mud in which they hide.

Lastly the Sea-tortoises or Turtles, which swim in the warm parts of
the Atlantic and Pacific Oceans, have only an open flat shell under
which they cannot draw their head and feet, for they strike out boldly
into the open ocean, feeding on seaweed, jelly-fish, and cuttle-fish,
rowing grandly along with their broad paddles which they feather like
oars as they go. They have only one time of weakness--when they come
on islands, such as Ascension and the Bahama Islands, which they
choose probably because they find fewer large animals there. There
the mother turtle arrives at night, looking fearfully around, and if
all is still comes flapping in over the sand, and, clearing a hole
with her flippers, lays about 200 soft round eggs and covers them up
and leaves them. Then in about a month the young turtles come out and
make at once for sea, though many of them fall victims to large birds
of prey on their way. Woe, too, to the mother when she is laying her
eggs, if these large birds are near, for she cannot defend her soft
body; or, worse still, if the natives are on the look-out; for then
the Green Turtle,[79] coming ashore from the Atlantic, is tilted over
on her back and killed for food; and the Hawk’s-bill Turtle[80] from
the Indian or Pacific Oceans is cruelly stripped of its shell for
ornaments. Yet they must run these risks, for their eggs would not
hatch without the warm sun, and we see how great is the gap between the
last water-breathers and the first air-breathers, when we remember that
the frogs go back to lay their eggs in the water, while the tortoises,
even when they live far out at sea, are forced to come in to shore, in
spite of great dangers, to lay their eggs that their little ones may
begin life upon land.

       *       *       *       *       *

[Illustration: Fig. 23.

Skeleton of a Lizard.

    _sp_, Spinous processes, which in the tortoise are flattened into
    plates; _r_, ribs; _s_, shoulder bone; _a_, upper arm; _e_, elbow;
    _fa_, forearm; _h_, hip bone; _th_, thigh bone; _k_, knee; _l_,
    bones of the leg; _q_, quadrate bone between upper and lower jaw.
]

And now, if we leave the tortoises and turn to the Lizards, we find
them meeting life’s difficulties in quite a different way. Here are
no sluggish movements, horny beaks, and strong boxes; but bright-eyed
creatures covered with shining scales, their mouths filled with sharp
teeth, with which even the small lizards can bite fiercely, and having
nimble lissome bodies, which wriggle through the grass or up the
trees in the twinkling of an eye. Yet the lizards, as we have seen,
are formed on the same plan as the tortoise, and their scales are
thickenings in their outer skin, just as his tortoise-shell is, and not
true scales like those of fish. They have learned to hold their own by
sharpness and quickness, and are probably the most intelligent of all
the cold-blooded animals, though even they are only lively in a jerky
way under the influence of warmth. They can breathe more easily than
the tortoise, for their ribs rise and fall, drawing in and driving out
the air they need; but they are still cold-blooded, for their heart has
only three chambers. It is when the bright sun is shining that they
love to dart about, chasing the insects upon which they feed; and the
joints of their backbone move so easily upon each other that they can
twist and turn in all imaginable ways, keeping their heads twisted in a
most comical manner when on the watch for flies. Nay, the very vertebræ
themselves are so loosely made that they can split in half, and if you
seize a lizard by the tail he will most likely leave it in your hand
and grow another.

They can live both in dry sandy places, where larger animals cannot
find food and water, and in thick underwood, and marshy unhealthy
places, where more quickly-breathing animals would be poisoned by the
fetid air; and we find them swarming in hot countries in spite of
enemies, their scales protecting them from the rough surface of the
rocks and trees on which they glide, their feeble legs scarcely ever
lifting their body from the object on which they glide rather than walk.

[Illustration: Fig. 24.

Gecko and Chamæleon.]

The true land-creepers, like our little Scaly Lizard,[81] lurk in
dry woody places, and on heaths and banks, darting out on the unwary
insects. Many of them lay their eggs in the warm sand or earth, but
the Scaly lizard carries them till they are ready to break, so that
the young ones come out lively and active as the eggs are laid. Others
have taken to the water, and among these are the Monitors of Africa
and Australia, which feed on frogs and fish and crocodiles’ eggs, and
are so strong and fierce that they often drag larger animals under the
water. Some are tree and wall climbers, such as the “Geckos,” with
thick tongues and dull mottled skins, and they have sharp claws and
suckers under their toes, so that they can hang or walk upside down,
on ceilings or overhanging rocks, or on the smooth trunks of trees;
and they love to chase the insects in the hot sultry nights, tracking
them to their secret haunts. They are far more active than the large
gentle Iguanas or Tree-Lizards of South America, from a few inches to
five feet long, which may be seen among the branches of the trees of
Mexico, their beautiful scales glistening in the sun as they feed on
the flowers and fruit. They swarm on all sides in those rich forest
regions, scampering over the ground, and then clinging with their claws
to the tree-bark as they gradually mount up into the dense foliage; and
they have many advantages, for not only can they climb to great heights
out of the reach of beasts of prey, but they can also swim well, having
been known to fling themselves from the overhanging branches into the
water below when danger was near. They do not, moreover, descend as
gracefully as the “Flying Lizards” of the East Indies, which have a
fold of skin stretched from the lengthened ends of their hinder ribs,
so that they sail from branch to branch as they chase the butterflies
and other insects.

But the most curious of all tree-lizards is the Chamæleon, with his
soft warty skin, his round skin-encircled eyes, his bird-like feet, and
his clinging tail. He never hurries himself, but putting forward a leg,
at the end of which is a foot whose claws are divided into two bundles,
he very deliberately grasps the branch, as a parrot does, loosens his
tail, draws himself forward, and then fastens on again with tail and
claws; while his eyes, each peering out of a thick covering skin,
roll round quite independently of each other, one looking steadily
to the right, while the other may be making a journey to the left.
What is he looking for? Just ahead of him on a twig sits a fly, but
he cannot reach him yet. So once more a leg comes out, and his body
is drawn gradually forwards. Snap! In a moment his mouth has opened,
his tube-like tongue, with clubbed and sticky tip, has darted out and
struck the fly, and carried it down his throat, while the chamæleon
looks as if he had never moved. It is not difficult to imagine that
such a slow-moving animal, whose natural colour is a brownish green
like the leaves among which he moves, would often escape unseen from
his enemies. And when light falls upon him, his tint changes by the
movement of the colour-cells in his skin, which seem to vary according
to the colour of the objects around, whenever he is awake and can see
them.

So by the waterside, on the land, and among the trees, the lizard tribe
still flourish in spite of higher animals; and just as we found some
legless kinds among the _amphibia_ burrowing in the ground, so here,
too, we find legless lizards, some with small scaly spikes in the
place of hind legs, others, like the glass-snake of America[82] and
our English slowworm[83] (or blindworm), which have no trace of feet
outside the skin, but glide along under grass and leaves, eating slugs
and other small creatures, though they are true lizards with shoulder
bones and breastbones under the skin.

       *       *       *       *       *

Here, then, we seem to be drifting along the road to snake-life, but we
must halt and travel first in another direction, upwards to a higher
group of animals, which may almost be called gigantic flesh-eating
lizards, though they are far more formidable and highly-organised
creatures. These are the Crocodiles, and no one looking at them can
doubt for a moment that they at least are well armed, so as to have an
easy time of it without much exertion. Huge creatures, often more than
twenty feet long, with enormous heads and wide-opening mouths, holding
more than thirty teeth in each jaw, they look formidable indeed as
they drag their heavy bodies along the muddy banks of the Nile, their
legs not being strong enough to lift them from the ground. Their whole
body is covered with strong horny shields, and under these shields, on
the back, are thick bony plates, which will turn even a bullet aside,
and quite protect the crocodile from the fangs of wild beasts. Their
eyelids are thick and strong, and they have a third skin which they can
draw over the eye sideways like birds; their ears, too, have flaps to
cover them, and their teeth are stronger and more perfect than any we
have yet seen, for they are set in sockets, and new ones grow up inside
the lower part of the old ones as they are broken or worn away.

[Illustration: Fig. 25.

The Nile Crocodile.--(_Tristram._)]

But it is in the water that we see them in their full strength; there
they swim with their webbed feet and strokes of their powerful tail,
and feed upon the fishes and water animals--monarchs of all they
survey. Nor is the crocodile content with mere fish-diet. Often he
will lie with his nostrils just above the water and wait till some
animal--it may be a goat, or a hog, or even a good-sized calf--comes
to drink, then he will come up slowly towards it, seize it in his
formidable jaws, or sometimes strike it with his powerful tail, and
drag it under water to drown. For he himself can shut down his eyelids
and the flaps over his ears, and he has a valve in the back of his
throat which he can close, and prevent the water rushing down his
open mouth; and after a while he rises slowly till his nostrils are
just above the water, and he can breathe freely while his victim is
drowning, because his nose-holes are very far back behind the valve.
Then when it is dead he brings it to shore to tear it to pieces and eat
it.

Thus the crocodiles of the Nile and the Ganges, the Gavials with their
long narrow snouts, and the Alligators of America, with their shorter
and broader heads, feed on fish and beasts, and all dead and putrid
matter, acting as scavengers of the rivers; while they themselves are
almost free from attack, except when tigers fall upon them on land.
But it is the young crocodiles which run the most risks when they come
out of the small chalky eggs which have been hatched in the warm sand
of the shore. True, their mother often watches over them at this time,
and even feeds them from her own mouth; but in spite of her care many
of them are eaten in their youth by the tortoises and fishes which they
would themselves have devoured by-and-by, if they had lived to grow up;
while the monitors, ichneumons, waterfowl, and even monkeys, devour
large numbers of crocodiles’ eggs.

       *       *       *       *       *

And now, if we were to turn our backs upon the great rivers in which
these animals dwell, and wander into the Indian jungle or the South
American forest, we might meet with enemies far more dangerous and
deadly, although they stand much lower in the reptile world. Who would
think that the huge boa of South America, and the python and poisonous
cobra of India, or even our own little viper, whose bite is often death
to its victim, are creatures of lower structure than the harmless
little lizard or the stupid alligator? Yet so it is. For Snakes have
no breastbone and have lost all vestiges of front legs and shoulder
bones, nor have they any hips or hind legs except among the boas and
rock-snakes; and even these have only small traces of hips, which carry
some crooked bones, ending in horny or fleshy claws, in the place where
hind legs ought to be. They have no eyelids (and by this we may know
them from the legless lizards), but their skin grows right over the
eyes, so that when a snake casts its skin there are no holes where
the eyes have been, but only clear round spaces like watch-glasses, in
the scaly skin. Their ears have no drum, and are quite hidden under
the scales with which their body is so thickly covered that they must
feel very little as they glide along. These scales, like those of the
lizard, are thickened parts of the outer skin, and if you stretch a
piece of snake-skin you can see them lying embedded in it, the clear
skin itself showing between.

[Illustration: Fig. 26.

Skeleton of a Snake.

    _sp_, Spinous processes of the joints; _r_, ribs; _q_, quadrate
    bones, joining upper and lower jaws; _e_, front of the lower jaw,
    where there is an elastic band in the place of bone; _b_, ball end
    of joint, facing the tail; _c_, cup end of joint, facing the head.
]

We must not, however, imagine that the snake is at a disadvantage
because he has lost so many parts which other reptiles possess. On
the contrary, he has most probably lost them because he can do better
without them. The transparent tough skin over his eye is a far better
protection in narrow rugged places, and among brakes and brambles,
than a soft movable eyelid; and if he does not see as well as the
crocodile, he has a most delicate organ of touch in his long, narrow,
forked tongue, with which he is constantly feeling as he goes, touching
now on one side, now on the other, each object he comes near, and
drawing the tongue in at every moment to moisten it in a sheath at the
back of his throat. A breast bone, moreover, would have been a decided
hindrance to him, for he wants the free use of all his ribs; and as
to the loss of his legs--in the place of four he has often more than
two hundred. For all along his backbone, except just at the head and
tail, a pair of ribs grow from each vertebra, being joined to it by a
cup-and-ball joint (_c_ and _b_, Fig. 26), and the muscles between them
are so elastic that the ribs can be drawn out so that the body seems to
swell, and then drawn back towards the tail. In doing this they strike
the ground and the snake moves forwards, just as a centipede does on
its hundred legs.

It is worth while to take our harmless Ringed Snake in your hand to
feel this curious movement to and fro of the ribs, and to notice how
the creature forces itself through your grasp. Moreover, you will learn
at the same time one use of the broad single plates under the snake’s
body (see Fig. 27), for they, like all the scales, are loose from the
skin on the side towards the tail; and as they are fastened by muscles
to the ends of the ribs, you will find that at each movement they stand
up a little like tiles on a roof, and their edges coming against your
hand help to drive the snake forward.

Another thing you will learn if the snake does not know you, and that
is how strangely they hiss, often with their mouth closed, while their
whole body seems to quiver. This is very puzzling at first, till you
learn that one of their lungs has shrunk up, and the other is a very
long and narrow bag stretching nearly the whole length of the snake’s
stomach, and the hissing sound is made by drawing in and forcing out
the air from this long bag.

[Illustration: Fig. 27.

Common Ringed Snake.[84]

Where the body is coiled the single under plates are seen.]

Meanwhile, another way in which the snake will escape from your hold
unless you grasp it tightly, is by wriggling in all directions, so that
you do not know where to expect it next; for the whole of the joints
of its backbone are joined by a succession of cups-and-balls, the ball
of one joint fitting into the cup in the one behind it. It is easy to
see how such joints can move almost every way, since the ball can twist
freely in the cup wherever the muscles pull it (except where checked by
the spines on the top of the backbone), and can even turn so much to
one side that the snake can coil itself round or tie itself into a knot.

A creature that can glide along so smoothly, twist about so freely
round trees, through narrow openings and tangled brushwood, and even
swim in the water, has no small advantage in life; and the snake can
also coil itself up under a heap of dead leaves or in a hollow trunk
of a tree for safety, or to watch for its prey when no animal would
suspect it was near. But even the harmless snakes have something
besides this, namely, the power of swallowing animals much broader and
thicker than themselves. You will see on looking at the lizard’s skull
(p. 103) that its bottom jaw is not joined at once to the top one,
but there is a bone (_q_) between, which enables it to open its mouth
wider than if the two jaws touched each other. Now this bone (_q_) in
the snake’s jaw is so loosely hung that it moves very easily, and the
lower jaw also stretches back far behind the upper one, so that when
the snake brings the jaw forward it can open its mouth enormously wide.
Nor is this all; it can actually stretch the bones of its jaws apart,
for they have not their pieces all firmly fixed together. In the front
of the mouth each jaw has elastic gristle in the place of bone, and the
two halves of the jaw can thus be forced apart from each other, making
room for a very large mouthful indeed.

[Illustration: Fig. 28.

The Boa Constrictor in the Forests of South America.]

Now the snake’s teeth are all curved towards the back of his mouth, and
they are never used for chewing or tearing, but only for holding and
packing down its food. So when he seizes a creature too large to be
easily swallowed, he fastens his front teeth into it and then brings
forward _one_ side of his jaws. He then fixes the teeth of this side
into the animal, and holds it fast while he brings forward the jaws on
the _other_ side, fixes these teeth, then loosens and brings forward
the others, and so on. In this way he keeps his mouth stretched over
the prey and gradually forces it down his elastic throat, moistening
it well all the time with slime from two glands, one on each side of
his mouth, and when it is swallowed he lies down and rests while the
stomach digests its heavy load.

We see, then, that even harmless snakes have many advantages. Thus our
ringed snake, feeding on mice and lizards, frogs and fish, wanders
through the grass and bushes of warm sunny banks, feeling this side
and that with his delicate forked tongue, and gliding so fast that the
lizards and mice try in vain to escape; while in the water he seizes
the frogs by their hind legs and jerks them into his mouth. He does not
even always stop to kill his food, for a live frog has been known to
jump out of a snake’s mouth as it yawned after its meal. So he lives
through the summer, changing his skin several times by loosening it
first at the lips, so that two flaps lie back over the head and neck,
and then rubbing himself through moss, bush, or bramble, so that the
skin is drawn off inside out like a glove, and the new skin appears
underneath, fresh, hard, and bright, ready for use. Then in the warm
season the mother lays her ten or twenty soft eggs in a mass of slime,
and leaves them in some sunny spot, or under a heap of warm manure
to hatch, and she herself wanders away, and when winter comes coils
herself up in the trunk of some hollow tree, or under the hedge, to
sleep till spring comes round again. Life does not always, however,
flow so smoothly as this, for the snakes have their enemies; the fox
and the hedgehog love to feed upon them, the buzzard and other birds
of prey swoop down upon them from above, and the weasels attack them
below; and this, perhaps, is partly the reason why the ringed snake
generally keeps near the water, into which it can glide when danger
threatens.

All snakes are not, however, so harmless as our little ringed snake.
The Pythons of India and the Boas of America, though they have no
poison in their teeth, can work terrible mischief with their powerful
joints as they coil round even good-sized animals, such as an antelope
or a wild boar, and crush them in their folds. Then it may be seen what
a terrible weapon this flexible backbone is, as the muscles draw it
tighter and tighter round the unfortunate animal, breaking its bones
in pieces, till, when it is soft enough to be swallowed, the snake
gradually forces it down its capacious mouth, moistening it with saliva
as it goes. These large boas and pythons would, in fact, probably
devastate whole countries if it were not that when they are young they
are devoured by other animals, so that very few live to grow into
dangerous marauders.

Other snakes have taken a still more terrible way of killing their
prey. There may be some chance of escape from a coiling snake, unless
he already holds you with his teeth, but the poisonous Cobra[85] may
strike before you know that you have startled him, and though the
Rattlesnake[86] makes a sharp noise as he shakes the loose horny
plates to call his mate or to alarm an enemy, yet when he means to
strike his prey it is too late when the sound is heard to get out of
reach of his fatal fangs. From the snake’s point of view, however, it
is clearly an advantage to be able with one single stroke to paralyse
its prey, so that it has only to wait for the poison to do its work,
and then its meal is ready. Even our little viper (see p. 121), needs
only to strike a mouse once, and then draws back as the poor victim
springs up and falls and dies, soon to be packed down its destroyer’s
throat.

[Illustration: Fig. 29.

The Cobra di Capello.[87]--(_From Gosse._)

The mouth being closed, the poison fangs cannot be seen. The tongue is
perfectly harmless.]

Yet this terrible poison, which acts so speedily, is no special gift to
the snake. It has only lately been discovered by M. Gautier that we,
and probably all animals, have in our saliva some of the very poison
with which the cobra kills its prey, only with us it is extremely
diluted, and is useful in digesting our food. The cobra, however, has
the poison, which no doubt exists in the slimy saliva of all snakes,
specially concentrated and collected in two glands, one on each side
of its jaw. From each of these glands (_g_) a small canal passes under
the eye to the edge of the jaw (_c_), and opens immediately above a
large curved fang (_f_). This fang is fastened to a bone in the cheek
which moves easily, so that the poison teeth can be shut back and lie
close against the gum when they are not wanted, and when they are
wanted can be brought quickly down again. Though the fang looks round
like ordinary teeth, it is really flattened out like a knife-blade, and
then the edges are curved forwards so as to form a groove or, in some
snakes, a closed tube, down which the poison can run to the point.

[Illustration: Fig. 30.

Jaw of a Rattlesnake.

    _ff._ Poison fangs; _g_, gland secreting poison; _c_, canal leading
    from gland to base of fang; _t_, harmless tongue; _s_, saliva
    glands.
]

Now when the snake wishes to strike its prey it raises its head, brings
down the fangs and drives them into the creature’s flesh, and at the
same time certain muscles press upon the poison gland, so that the
liquid poison is forced into the wounds. If, however, the fang was
fixed to the canal, the snake’s weapon would be gone if the point were
broken, so we find that the canal-opening lies just _above_ the tube of
the tooth, and behind are six small reserve teeth, covered by a tender
sheath skin, ready to grow up and take its place when wanted.

Should we not think that with such weapons as these the poisonous
snakes would conquer every enemy? Yet they, too, only have their fair
chance of life, for besides the destruction of their eggs other dangers
await them. The rapacious birds, with their feathery covering, their
horny and scale-covered legs and feet, and their hard beaks, will offer
battle even to a poisonous snake. The buzzard makes short work of our
common viper or adder, whose fangs, though fatal to small animals, are
not nearly so powerful as those of snakes of hot countries. Seizing the
viper with his claws in the middle of its body, the buzzard takes no
notice of its frantic struggles as, winding itself about his feet, and
striking wildly at his breast, his wings, and his scaly legs, it

                              “... doth ever seek
    Upon its enemy’s heart a mortal wound to wreak.”

Keeping his own head well back out of danger, the bird lets the snake
exhaust itself, waiting only till he can give a fatal blow with his
beak upon its upraised head, and then, soon despatching it, tears it
to pieces for a meal. Nor is even the dreaded Cobra safe from danger,
for he finds his match in the powerful Adjutant birds (see p. 128), and
in the Indian Ichneumon or Mungoos, which attacks the snake boldly,
skilfully dodging the fatal stroke until it has broken the neck of its
enemy; while in Africa the bold Secretary bird is complete master of
the dreaded poisonous snakes of that country. In fact, there is little
doubt that every kind of snake, either in youth or age, falls a victim
to some kind of bird or beast; and even the poisonous sea-snakes,
which swarm in the tropical seas, probably find their masters in the
pugnacious saw-fish and the thick-skinned shark.

[Illustration: Fig. 31.

Common English viper (_Pelias berus_), with poison-fangs showing in
the open mouth, and the soft harmless tongue outstretched to feel.]

We see, then, that it is not without some struggle that these
cold-blooded reptiles have held their own in the world, nor is it
to be wondered at that only these four types--tortoises, lizards,
crocodiles, and snakes--should have managed to find room to live among
the myriads of warm-blooded animals which have filled the earth.
These four groups have made a good fight of it, and many of them even
make use of warm-blooded animals as food. The tortoises, it is true,
feed upon plants, except those that live in the fresh water, and
feed chiefly on fish, snakes, and frogs, while most of the lizards
are insect-feeders. But the crocodile, as he lurks near the river’s
edge, and the snake, when he fastens his glittering eye on a mouse or
bird, are both on the look-out for animals higher in the world than
themselves.

It is, perhaps, natural that we should shrink from cold-blooded
creatures, especially as they _seem_ to show very little affection.
Yet lizards, tortoises, and snakes can all be made to know and care
for those who are kind to them; while, as we have seen, the fierce
crocodile watches over and feeds her young, and the python coils
herself over her eggs, and will take no food till they are hatched.
Moreover, we can scarcely look at the quaint shell-covered tortoise, or
examine the heavily-mailed coat of the alligator, or the poison-fangs
of the snake, without admiring the curious devices by which these
animals have managed to survive in a world which once belonged to their
ancestors, before our present swarm of warm-blooded animals multiplied
and took possession of their kingdom.




[Illustration: THE EARLIEST KNOWN WATERBIRDS]




CHAPTER VI.

THE FEATHERED CONQUERORS OF THE AIR.

PART I.--THEIR WANDERINGS OVER SEA AND MARSH, DESERT AND PLAIN.


It is a warm sunny day in early spring, one of those few bright days
which sometimes burst upon us in April, just after the swallows have
come back to us, searching out their old nooks under the eaves, or
their old corners in the chimneys, to build their new nests. There
they are, clinging with their sharp claws to the edge of the cottage
thatch, while the impudent little sparrow, which has remained hopping
about all the winter long, chirrups at them from a neighbouring
apple-tree. Upon the grass-plot near a blackbird is pecking at a worm,
and from the wood beyond a thrush trills out his clear and mellow
song, accompanied from time to time by the distant cry of the cuckoo
calling to his mate. For it is the love-time of the birds; and as we
watch them flying merrily hither and thither in the bright sunshine,
we ask ourselves whether we must not have made a great leap on leaving
the cold-blooded snakes and tortoises, since now we find ourselves
among such merry, warm-hearted, passionate little beings, with their
beautiful feathery plumage, their light rapid flight, their love for
each other, their skill in nest-building, and their patient care for
their little ones.

And, indeed, we have come into quite a new life, for now we are going
to wander among the conquerors of the air, who have learned to rise far
beyond our solid ground, and to soar, like the lark, into the clouds,
or, like the eagle, to sail over the topmost crags of the mountains,
there to build his solitary eyrie.

Even the little sparrow, which flits about by the roadside, can laugh
at us with his impudent little chirp, as he flies up out of reach to
the topmost branch of a tree. And yet a glance at his skeleton will
show us that he has the same framework as a reptile, only it is altered
to suit his mode of life.

[Illustration: Fig. 32.

The Sparrow.

With wings raised, as in the skeleton on next page.]

True, his breastbone (_b_, Fig. 33) is deep and thin instead of flat,
and those joints of his backbone which lie between his neck and tail
are soldered firmly together, more like those of the tortoise, and he
stands only upon two feet. Yet this last difference is merely apparent,
for if you look at the bones of his wings you will find that they are,
bone for bone, the same as those in the front legs of a lizard, only
they have been drawn backwards and upwards so as to work in the air.

[Illustration: Fig. 33.

Skeleton of a Sparrow (from a specimen).

    _q_, Quadrate bone, peculiar to reptiles and birds and some
    _amphibia_; _b_, breastbone; _m_, merrythought or collar bone; _c_,
    coracoid bone, over which the tendon works to pull up the wing;
    _p_, ploughshare bone, on which the tail grows.

    Wing bones--_a_, upper arm; _e_, elbow; _fa_, fore arm; _w_, wrist;
    _t_, thumb; _ha_, hand.

    Leg bones--_th_, thigh bone; _k_, knee; _l_, lower part of leg;
    _h_, heel; _f_, foot.
]

There is the upper arm (_a_) answering to the same part of the lizard’s
front limb (p. 103); there is the elbow (_e_); then the two bones of
the fore-arm (_fa_); then the wrist (_w_), and a long hand (_h_), which
has lost almost all trace of separate fingers, except the little thumb
(_t_), which carries some feathers of its own, known as the “bastard”
wing. Now when the sparrow is resting he draws back his elbow, folds
his wrist joint, and brings the whole wing flat to his body. But when
he wishes to fly he stretches his arms out and beats the air with them,
and as his hand moves over most space, it is there that you will find
the longest quill feathers, which stretch right to the tip of his wing;
then next to these follow the feathers of his fore-arm, while those
of the upper arm are short and close to his body, and over all these
are the rows of covering feathers, which make the whole wing thick and
compact.

Here, then, we have the lizard’s front legs turned into a wonderful
flying machine in the bird, and this in _quite a different way_ from
the flying lizards which lived long ago, and which had only a piece of
membrane to flit with, like bats. And now what has happened to the hind
legs, the only ones used as legs by the birds? Look at the sparrow as
he clasps the bough with his toes, and you will, perhaps, be puzzled
why the first joint of his leg turns back like an elbow and not forward
like a knee. Ah! but that joint is his ankle, and the knob behind is
his heel (_h_), for the bones of his foot have grown long and leg-like;
and he always stands upon his toes, the rest of his foot forming a firm
support to hold his body up in the air. Look at the skeleton and you
will find his true knee (_k_) up above; and if you go to the Zoological
Gardens and watch the Adjutant birds, you will often find them resting
their whole foot upon the ground (see Fig. 34), and comical as it
looks, it will help to explain the curious foot and leg of a bird.

[Illustration: Fig. 34.

The Adjutant Bird.

Showing the foot resting from heel to toe upon the ground.]

Already, then, we see that the bird is using the same bones as a
reptile, though he uses them in a different way; and besides these
resemblances between the skeletons of birds and reptiles there are two
special ones easy enough for us to understand. We saw in the snakes
and the lizards that they have a separate bone (9, Figs. 23 and 26)
joining the lower jaw on to the head; now you will find this same bone
in the sparrow and in all birds (see Fig. 33), but in quadrupeds this
bone is not to be found, the part representing it being changed into
one of the bones of the ear. Again, the sparrow’s skull is joined to
his backbone by a single half-moon-shaped knob, which fits into a
groove in the first joint or vertebra. This also we find in reptiles,
while all higher animals have two such knobs, so that although they
can nod the head upon these, they cannot turn it upon them, and
consequently the first joint turns with the skull upon the second
vertebra.

These, then, are some of the reasons why Professor Huxley tells us that
though frogs and reptiles look in many ways so like each other, yet in
truth the frogs must be grouped with the gill-breathing and fish-like
animals;[88] while the cold-blooded reptiles, when we come to look
closely into them, are linked with such different looking creatures as
the bright and merry birds.[89] But we have also another and stronger
reason for thinking that reptiles and birds are distant connections;
for in those far bygone times (see p. 92), when the huge land-lizards
browsed upon the trees, the birds living among them were much more
like them in many ways than they are now. From their skeletons and
feathers which we find, we know that the strange land birds[90] which
then perched on the trees had not a fan-shaped tail made of feathers,
growing on one broad bone as our birds have now (_p_, Fig. 33), but
they had _a long tail of many joints like lizards_, only that each
joint carried a pair of feathers, and like lizards too they had _teeth
in their jaws_, which no living bird has. They must have been poor
flyers at best, these earliest known birds, for their wings were small
and the fingers of their hand were separate more like lizard’s toes,
two of them at least having claws upon them, while their long hanging
tail must have been very awkward compared to the fan-shaped tail they
now wear. For some time they were the only birds we know of, but later
on we come upon the bones of water-birds[91] telling the same story.
For some about the size of small gulls,[92] though they flew with
strong wings and had fan-shaped tails, still had teeth in their horny
jaws, set in sockets like those of the crocodile, while their backbones
had joints like those of fishes rather than birds; and with them were
other and wingless birds[93] rather larger than our swans, but more
like swimming fish-eating ostriches, for their breastbones were flat,
not thin and sharp like the sparrow’s, and they had scarcely any wings,
short tails, long slender necks, and jaws full of teeth, this time set
in grooves like those of lizards and snakes.

In these and many other points the early birds came very near to the
reptiles--not to the flying ones, but to those which walked on the
land. And now, perhaps, you will ask, did reptiles then turn into
birds? No, since they were both living at the same time, and those
reptiles which flew did so like bats, and not in any way like the
birds which were their companions. To explain the facts we must go
much farther back than this. If any one were to ask us whether the
Australian colonists came from the white Americans or the Americans
from the Australians, we should answer, “neither the one nor the other,
and yet they are related, for both have sprung from the English race.”
In the same way, when we see how like the ancient birds and reptiles
were to each other, so that it is very difficult to say which were
bird-like reptiles and which were reptile-like birds, we can only
conclude that they, too, once branched off from some older race which
had that bone between the jaws, that single neck joint, and the other
characters which birds and reptiles have in common.

But long ago they must have gone off each on their own road, the
reptiles filling the world for a time, flying and walking and swimming,
till they found at last that creeping was their most successful way of
life; the birds on the other hand becoming more and more masters of
the air and the water, so that, while keeping the same bones and parts
as the reptiles, they have grown into quite different beings in their
form and habits, giving up the long-jointed tail of the _Archœopteryx_,
or ancient-winged bird, for the compact feathered fan which helps to
balance them in their flight, and the teeth of the water-birds for the
sharp and horny beak, which, together with their claws, is their chief
weapon of attack and defence now that they have employed their front
limbs as wings.

Nor shall we have far to look for the secret of their success in life.
Just as the reptiles have an advantage over the naked frogs and newts
by having strong scaly coverings in their skin, so the birds have an
advantage over the reptiles in that beautiful feathery plumage which
covers their body, and the powerful muscles which work their limbs. For
it is by means of these that they have been able to move quickly and
travel far, and to develop that bright nervous intelligence which has
grown more and more active as they have been carried into fresh scenes
and experiences, overcoming new difficulties and enjoying new pleasures.

Remember for a moment how weak the lizard’s limbs are, so that his
body always drags upon the ground; and then look at the bird’s tight
grasp of the bough and the rod-like legs which raise his body above
it. Watch him as he beats the air with his wings, rising and sinking,
turning and swerving at will, and you will see that he has earned
freedom, strength, and active life, by means of the strong muscles
which move these legs and wings, and the feathers which provide him
with an instrument for beating the air. Feel a sparrow’s fat little
breast, or see how much meat comes off the wing and breast of a pigeon,
and then, if you consider that all this flesh is muscle used for moving
his wings, you will not wonder at his easy flight. For the muscles of a
bird’s breast often weigh more than all his other muscles put together,
and while one enormous mass of muscle in front of the breast works to
pull down the wing, another smaller one, ending in a cord or _tendon_,
passing like a pulley over the top of a bone (_c_, Fig. 33, p. 126),
pulls it up, so that by using these, one after the other, the bird
flies.

But where have the feathers come from,--those wonderful beautiful
appendages, without which he could not fly? They are growths of the
bird’s skin, of the same nature as the scales of reptiles, or those
on the bird’s own feet and legs; and on some low birds such as the
penguins they are so stiff and scale-like that it is often difficult
to say where the scales end and the feathers begin. All feathers, even
the most delicate, are made of horny matter, though it splits up into
so many shreds as it grows that they look like the finest hair, and Dr.
Gadow has reckoned that there must be fifty-four million branches and
threads upon one good-sized eagle’s feather.

When these feathers first begin to grow they are like little grooved
pimples upon the flesh, then soon these pimples sink in till a kind
of cup is formed all round them, and into this cup the soft layer
just under the outer skin sends out fibres, which afterwards form the
pith. Round these fibres rings of horny matter form, and then within
these rings, in the grooves of the soft pimple, the true feather is
fashioned. First the tips of the feathery barbs, then the shaft, and
then the quill appear, as the feather grows from below, fed by an
artery running up into the pimple; till at last, when the whole is
full-grown, the quill is drawn in at the base, and rests in its socket,
complete.

Some of these feathers are weak and soft, with slender shafts and loose
threads growing all round them, and these are the downy feathers which
lie close to the body and keep the bird warm. Others, which cover the
outside and form the wings and tail are flat, with strong quills and
shafts, and a double set of barbs growing upon each shaft; and if you
look at these wing feathers under a strong microscope you will see
that they have a special arrangement for helping them to resist the
air. For not only have all the little featherlets or _barbs_ rows of
other featherlets or _barbules_ growing upon them, but these again are
covered with fine horny threads, often hooked at the tip, which cling
to the next barb, so that the feather is woven together as it were, in
a close web, and if you strike it against the air you will find that it
resists it strongly.

Now in a bird’s wing the feathers are so arranged that they lap one
under the other from the outside of the wing to the body, so that
when the bird strikes downwards they are firmly pressed together, and
the whole wing, which is hollow like the bowl of a spoon, encloses a
wingful of air, and as this is forced out behind, where the tips of the
feathers are yielding and elastic, he is driven upwards and forwards.
When, however, he lifts his wing again, the feathers turn edgeways and
are separated, so that the air passes through them, and he still rises
while preparing for the next stroke. All this goes on so rapidly that
even the heron makes 300 strokes in a minute, and the wild duck 500,
while in most birds they are so rapid that it is impossible to count
them; yet all the while the little creature can direct his flight where
he will, can pause and direct his wings to the breeze so as to soar,
can swoop or hover, wheel or strike, guiding himself by the outspread
tail and a thousand delicate turns of the wing.

All this complicated machinery, however, would not have served the
bird much if his body had been as heavy, and his blood as cold, as
those of the lizard and the crocodile. But here he has made a great
step forward. In the first place, he has a heart with four chambers,
two on the right side and two on the left; and while one of those on
the right side receives the worn-out blood from the body and pumps it
_to_ the lungs to be refreshed, one of those on the left side receives
it _from_ the lungs when it is refreshed, and the other pumps it into
the arteries to feed the body. So here we see for the first time among
our backboned animals a creature whose good and bad blood are never
mixed in the heart (compare pp. 23 and 76), but it gets all the benefit
possible from its breathing, and the blood is kept fresh and pure.

Moreover, a bird’s lungs are large, and are continued into several
large air-sacs, which in their turn open out into tubes which carry
air actually _into the bones_, many of which are hollow instead of
containing marrow like those of other animals.[94]

And now we begin to see how wonderfully these little creatures are
fitted for flying. With all this air within them, not only is their
blood kept hot by constant purifying, but their bodies are much lighter
than if their bones were solid, and they can present a much broader
surface to float upon the air without increasing equally in weight.
Meanwhile, their feathery covering prevents the cold air around from
chilling them, so that they are not only warm-blooded animals, but
actually warmer-blooded even than ourselves.

Thus, then, Life has spread her feathered favourites over the world.
For them there are no limits except the extreme depths of the
water below, and the height beyond the atmosphere above. Wherever
air-breathing creatures can go, there some bird may be found. On the
dizzy ledges of inaccessible cliffs, on the wide bosom of the open
ocean, on the sandy wastes of the desert, in the tops of the highest
trees, on the cloud-capped peaks of the mountains, diving or swimming,
flying or soaring, running, perching, darting, or sailing for miles and
miles without one moment’s rest, they find their way everywhere, and
there is no spot from the icebound countries of the Arctic zone to the
warm bright forests of the tropics where they do not penetrate; while
their sharp eyes, kept free from dust and harm by a third eyelid moving
rapidly sideways,[95] see far into the distance, and thus as they
soar into the sky they have a power, possessed by no other animals,
of overlooking a wide domain. Nor have they been obliged, like the
reptiles, to take up strangely different forms to suit their various
habits, for so wonderfully does their body meet all their wants that
very slight changes, such as a broad body and webbed feet for the
swimmers, long bare legs for the waders, a long hind toe for grasping
in the perchers, and sharp claws and beak for the birds of prey, fit
each one for his work, and are some of the chief distinctions we can
find between them.

Even the heavy running birds, the Ostriches of Africa, the Rheas of
South America, and the Emus and Cassowaries of Australia, still remain
truly bird-like, though their wings are unfit for flight. True, their
breastbones are flat instead of keel-shaped, for they have no need of
strong muscles to move their wings, which now serve only as sails to
catch the wind as they run, and in many other ways they are an older
type than our flying birds; but their wing bones are formed as if
they were used for flying, and their feathers, though loose and downy
because they have no little booklets, are like those of other birds.

[Illustration: Fig. 35.

The Ostrich[96] at full speed.]

Strong powerful creatures they are, even in confinement. Yet how little
can we picture to ourselves, when we see the Ostrich trotting round his
paddock in the Zoological Gardens, with his wings outspread, what he is
when he courses over the free desert!--

   “Where the zebra wantonly tosses his mane,
    With wild hoof scorning the desolate plain;
    And the fleet-footed ostrich over the waste
    Speeds like a horseman who travels in haste.”

There the soft pads under the _two toes_ of each foot rebound from
the yielding sand as his well-bent legs straighten with a jerk one
after the other, making his body bound forward at full speed. Then he
raises his wings, sometimes on one side, sometimes on both, to balance
himself, and to serve as sails to help him; and with this help his
stride is sometimes as great as twenty feet, and he dashes along at the
rate of twenty-six miles an hour. He is not so heavy as he looks, for
many, of his bones are hollow, his feathers are downy and soft, and his
wing-bones are small; and it is to his featherless thighs that you must
look for the strong muscles to which he trusts for all his speed, as
with outstretched neck he bounds across the plain.

If we go back to long bygone times, before the lion, the leopard, and
other ferocious animals found their way into Africa, we can imagine
how this great running bird took possession of the land and became too
heavy for flight; while as time rolled on, he gained that strength of
body and leg which now is his great protection as he dashes along, his
four or five wives following in his train. The ostriches can travel
over wide distances from one oasis to another, feeding on seeds and
fruit, beetles, locusts, and small animals, and fighting fiercely with
legs and beak if attacked. And when the springtime comes the wives lay
their eggs in a hole scooped in the sand, or often in some dry patch of
ground surrounded by high grass, till sixteen or twenty are ready; and
then they take their turn (the father among the rest) of sitting upon
them, at least at night, even if they leave them to the heat of the sun
by day. And when six weeks have passed the father grows impatient,
and, pressing the large bare pad in front of his chest against each egg
in turn, breaks it, pulls out the membranous bag with the young bird
in it, shakes him out, and, swallowing the bag, goes on to another. In
this way the whole downy brood are soon set free, and begin picking up
small stones to prepare their gizzard or muscular second stomach for
grinding, while their parents scrape the sand and find and break up
food for them.

So the ostrich lives its life in Africa, from Algeria right down to
Cape Colony; while its smaller and lighter-coloured relations, the
Rheas, with their _three-toed_ feet, course over the plains of Paraguay
and Brazil, on the other side of the Atlantic, often swimming from
island to island, in the bays or across the rivers, but quite unable to
fly with their soft hair-like feathers, though their wings are larger
than those of the ostrich. Then when we turn to the East we find other
running birds; the Cassowary, with its three toes, its horny helmet,
its five long single feathers, and its five naked pointed quills in
the place of a wing, feeding on fruit and vegetables in New Guinea, or
sharing the dreary scrubs of Australia with the almost wingless Emus
wandering in pairs, the only constant married couples among the running
birds.

Nor is New Zealand left without a representative of this family, for
there we have the curious little Apteryx or Kiwi (Fig. 36), with its
thick stumpy legs, its long beak, and its soft downy body, under which
are hidden its aborted wings. Perhaps it is because he is small and
insignificant that the apteryx has lived on till now, crouching under
the bushes by day and creeping about in the twilight, thrusting his
long nose-tipped beak into the damp ground to draw out the worms. For
long ago, though in the memory of man, as we learn from the traditions
of the Maories, other wingless birds called Moas,[97] which were six
or seven feet high, lived in New Zealand, and had fierce fights with
the natives. We find their bones now, often charred from having been
cooked in the native ovens, and when they are put together they give us
skeletons which show that these birds must have been as formidable as
that great bird of Madagascar, the Æpyornis, whose gigantic bones and
eggs, three times the size of ostrich eggs, have been found, though the
bird itself has never been seen.

[Illustration: Fig. 36.

Wingless birds of New Zealand.

The giant Moa (_Palapteryx_) and the tiny Apteryx. The Moa is no longer
to be found alive.]

But these are gone now, and their relations the Emus are fast following
them: for however well these flightless birds may flourish on the
broad plains and deserts, where only their wild companions are around
them, they are sadly at the mercy of man. The proud eagle can fly far
beyond the reach of the hunter’s gun; the little lark, if she be only
wary enough, may trill out her song in the blue vault above and leave
the cruel destroyer far below; but the emu and the cassowary, the rhea
and the ostrich, have lost the power to leave the earth; and if it were
not that we prize the two last for their feathers, they, too, like
their companions, might live to rue the day when they became runners
instead of conquerors of the air.

       *       *       *       *       *

It is very different, however, with the water-birds, for they have not
only kept the power of flight, but have gained the double advantage
of also floating safely on the water. Look at our common wild duck.
We might have taken him just as well as the sparrow for our type of a
bird, and yet while the sparrow leads a land life in the trees, the
duck’s home is on the water, and many of his relations live cradled on
the open ocean.

See his broad boat-like body which floats without any effort of his;
notice how closely it is covered with short thickly-grown feathers,
which protect him from the chilly water, while he keeps them well-oiled
with his beak, from an oil-gland which all flying birds have at the
base of the tail. Watch how he swims, drawing his webbed foot together
as he brings it forward, and spreading it like a fan to strike the
water as he drives it back. Then, as he feeds, watch him gobbling in
the mud and then shaking his head as he throws his beak up in the air.
For he, like all ducks and geese, has a set of thin horny plates inside
his broad bill, and they sift the mud, while the tender tooth-like
edges of his beak and tongue feel out the suitable morsels.

All this time he is a water animal, but when he rises and flies he is
also master of the air, for his strong wings carry him stoutly, so that
he can migrate from one pool to another; or in winter, when the pools
are frozen, to the open sea. He is by no means the best flyer of his
family, and yet he is spread over Europe and North America, and even as
far east as Japan, while his ocean-loving cousin, the eider-duck, lines
her nest and lays her eggs high up in Arctic latitudes, and dives and
swims in the open ocean. So too his relations, the wild swans and geese
which wander in the lakes and swamps of Lapland, Siberia, and Hudson’s
Bay, feeding on water-weeds, worms, and slugs, build their nests in the
summer in the far north, and then fly thousands of miles southwards to
their winter homes, their strong wings whirring in the air as they go.

Yet these are scarcely as true sea-birds as the divers, the Guillemots
and Puffins, the Auks and Grebes, which swim out all round our coasts,
and dive deep down to feed on the fish below. How clumsy they are on
land and how skilful in the water! You may see numbers of guillemots
and puffins in summer on the high cliffs of the north of Scotland, or
of Puffin Island in the Menai Straits; the guillemots laying their
eggs on the bare ledges, and the puffins in holes which they burrow
in the cliffs face; and they sit so doggedly upon their nests, and
shuffle and hop along so awkwardly, that men climbing up, or let down
by ropes from above, knock them over as they go. But wait till the
eggs are hatched, and the little ones have broken out of their shelly
prison, each one cracking his shell from inside by means of a little
horny knob, which all baby birds have for this purpose at the end
of their beak, and which falls off when they are fairly born. Then
fathers, mothers, and young ones, able to take care of themselves as
soon as hatched, launch out into the open sea in August, and there is a
sight of diving and swimming and fishing grand to behold. The awkward
legs, placed so far back on their body, now serve as powerful oars and
rudders to drive their smooth satiny bodies through the water. Their
thin narrow legs cut through the waves like knives, while their short
stumpy wings, closely laid against their down-covered bodies, keep them
from being chilled, and so do the air-bubbles which are entangled in
their short thick feathers, and which give their backs the appearance
of being covered with quicksilver when they dive[98] after the fish
below.

And then when the winter comes, those which have bred in the north
fly and swim southwards to our coasts, where they are joined by the
true divers and grebes which have come from the rivers and estuaries,
where they have made their nests on some reedy bank or floating upon
the water, and lived till their young ones are strong. This is their
seafaring time; and whether near the shore, or miles out at sea, they
dive and swim and make the ocean their home till spring comes round
again.

[Illustration: Fig. 37.

A Group of Sea-Birds.

1. Cormorant. 2. Black-winged Tern. 3. Gulls. 4. Puffins. 5. Guillemots.]

Still all their roving is done chiefly by swimming, and they leave it
to the Gulls and Petrels, the Terns and the powerful Cormorants and
Gannets, to fly hither and thither over the wide sea. These birds have
indeed reached the climax of a seafaring life, with their powerful
wings, their sharp and often hooked beaks, and their short legs. They,
too, feed upon the water, coming up with a fish in their mouth, but
they do not dive under and swim like the guillemots. On the contrary,
flying is their forte; they swoop down, and scarcely have they gone
a few feet under water than they are up again, skimming on the waves
as they swallow their prey, which may be anything from dead floating
creatures to living fish which have ventured too near the surface. Yet
they swim well too, and though the common gulls rarely go more than
twenty miles from the shore, they are quite at home on the open ocean,
and there is no habitable part of the globe without them. Still more
venturesome are the petrels:--

   “Up and down, up and down,
      From the base of the wave to the billow’s crown,
    And amidst the flashing and feathery foam
      The stormy petrel finds a home.”

They are smaller and lighter than the common gulls, and are never so
happy as when darting over the foam of an angry sea, while their more
delicate relations, the Terns or sea-swallows, with their long pointed
wings and forked tails, are taking shelter in the quiet bays.

Lastly, king among all sea-flying birds is the gigantic petrel, the
Albatross. What a grand fellow he is when he is once on the wing,
though he has some difficulty in starting. Flying onward, onward,
without resting day or night, his pure white body near down to the
water, his large head and short thick neck slightly bent, and his
long, narrow, black wings, often measuring ten feet from tip to tip,
widely outspread, he beats a few powerful strokes, and then sails
along, using his head and tail as rudders to turn his wings to the
wind. Often he will follow a ship for days, sailing round and round in
circles, and yet keeping easily ahead, while all the time his bright
eye watches the water to catch every chance of food. Jelly-fish,
cuttle-fish, and real fish of all kinds, together with any dead
creatures he may find afloat,--all is food to him, and his powerful
beak will cut through the toughest morsel. For days and days he will
fly on, never tiring, and feeding as he goes; and if he alights for
a time upon the water he rises with difficulty, unless the waves are
high and bear him up on their crests; and when he comes to rest it is
on some island in mid-ocean, where he seeks a mate, and brings up his
nestlings either on the low ground or on the top of a high mountain, in
a hollow lined with grass and moss. Truly, if we look at the far-flying
albatross we must acknowledge that the wings of a bird have given him
the command of the sea as well as the land.

[Illustration: Fig. 38.

Albatrosses and Penguins.]

He forms a strange contrast to the curious stunted bird form which we
may find in those same islands where the mother albatross lays her
eggs. For there, in the islands of the South Pacific, close by the side
of the albatross nest, are whole groups of strange-looking birds, the
Penguins, with their fat, white, feathered breasts, their dark head
and beak, their curious hind legs set right at the end of their body,
and their small paddle-like wings, covered with short stiff feathers,
quite useless for flight. We have come upon a strange story here, for
our penguin is a low relation, of the guillemots and puffins whom we
left in the north, and, like the great northern auk, which has now been
extinct for many years, he has lost the use of his wings. He has no
dangerous enemies on these rocky inaccessible islands, where he and his
companions form dense penguin rookeries upon the ground, unless it be
the large gulls or skuas which steal the eggs. Nor has he any need for
flying, for the sea is all around him, and even if he wishes to migrate
to warmer waters in winter, he does so by swimming. Therefore we find
that his wings are lost to him for any flying purpose, and nothing
can be more awkward than he looks, shuffling or hopping along with
outstretched arms, like a fat baby, till he comes to the water’s edge.
But when he dives in and swims it is quite a different matter. Then his
easy wavy motion, like that of a seal, shows at once that his stumpy
imperfect wings are excellent fins, while his feet serve him both as
oars and rudders.

Thus we have traced our swimming and web-footed birds to their
extreme types--the strongest flyer in the albatross, and the lowest,
most fish-like bird in the penguin; while, if we were to follow the
pointed-winged frigate-bird in his flight, or see the pouched pelican
in his home, we should find another group of these web-footed birds,
no longer merely standing upon rocks, but perching upon the boughs of
trees, and building their nests by the side of rivers in warm countries
nearly all over the world, or among the mangrove bushes of the tropical
islands.

       *       *       *       *       *

And now, if we return to our northern shores and pause upon the broad
wet sands at low tide, we may chance to find whole flocks of active
little birds hovering and running and wading in the water, or pecking
on the sands; and the double-noted whistle of the Curlew, or the
musical cry of the Peewit (or Lapwing), tell us at once that they are
“waders,”--birds with bare legs, flat toes, and long beaks, which drop
down on the muddy flats by the sea, seeking their food at the edge
of the water. There they are, Curlews and Dunlins and Sandpipers,
Plovers and Knots, Oystercatchers feeding on mussels and limpets, and
Turnstones tilting up the lumps of mud to find food beneath. One and
all they are running hither and thither, to seize here a shrimp or
sandhopper or a tiny fish, there a worm or a sea-slug; making the most
of their time before the sea comes up and covers their feeding ground.

[Illustration: Fig. 39.

A group of Wading Birds.

1, Stilt; 2, Avocet; 3, Peewit; 4, Dunlins; 5, Curlew Sandpiper;
6, Sanderling; 7, Oystercatcher; 8, Curlew; 9, Turnstone.]

Here we have no webbed feet or legs set far back, but three long, flat,
straight toes, well fitted for walking on marshy ground and treading
lightly on water-plants, and slender bodies well balanced on long thin
legs, which move so quickly as they run that you can scarcely see them;
while, when they fly, their long wings carry them lightly through the
air, with their legs stretched out behind.

[Illustration: Fig. 40.

The Flamingo.

A duck-billed and web-footed bird among the waders.]

What connection can there be between these active light little beings,
and the broad-bodied web-footed swimmers? Go to the Zoological Gardens,
and look at the Flamingo, with his long legs and curious curved
beak. He is of the true swimming type, with his webbed feet and his
sieve-like bill, with its rows of horny strainers like the geese; yet
he feeds by wading in salt-water lakes and pools on the sea-shore,
raking the bottom for food, and showing how a swimmer and a wader may
once have had the same starting-point, before the one went out to sea,
and the other in to shore. And then when we come back to our own little
waders, and learn that they visit the sea, and feed upon the wet sands
from the autumn to the spring, and then fly inland to build their nests
in the damp meadows, feeding on earthworms, slugs, and insects of the
land, we can see what an advantage this double life must be to them.

Notice, too, how shy and timid they have become from living among other
animals, and watching for every danger. Try to get near one, and see
how it will run on, turning its head hither and thither to watch, and
at last will rise and be out of sight in no time. Or go and look for
plover’s eggs on the swampy grounds in our northern counties in the
early summer, when

                  “... from the shore
    The plovers scatter o’er the heath,
    And sing their wild notes to the listening waste.”

The mother will no sooner see you than she will crouch down, running
along a rut, and then move slowly away with a drooping wing as if
wounded, hoping to make you follow her and pass by the little earthy
hollow where her precious eggs are lying. The experience of life has
made these little ground-nesting birds very intelligent, since they
have had a land as well as a watery home, and the little moor-hen,
which, like the rails and crakes, has taken entirely to a freshwater
life in ponds, brooks, canals, and rivers, has learned to hide her nest
so skilfully, and to dive and swim so cleverly, that even a trained
water-spaniel often loses her when close upon her home.

And as the swimmers have their large birds in the albatross, so the
waders too have theirs in the Herons, the Storks, and the Cranes.
Who does not know how the storks fly in flocks to the sunny south
in winter, and come back in the spring to build their nests in the
chimneys of the houses of Holland and Germany, feeding on the banks of
rivers, and in the fens on lizards, fish, frogs, and water-snakes; or
how the cranes pass their summer in the stormy north, and their winter
among the old ruins of Egyptian greatness? But the herons remain with
us all the year, feeding on shrimps and crabs on the weed-covered
shores, or more often in ponds and lakes upon frogs, water-rats, and
fish. How patiently you may see a heron stand with his head slightly
bent, still and motionless, till a fish passes by! Then quick as a
flash of lightning, his head darts forward, impaling or seizing the
prey in the strong beak, and he is off to eat it at his leisure. Thus
he lives a solitary life all the year until the springtime, when he
flies off to some group of lofty trees where for generations his family
have built their nests, and, meeting with his fellows, piles up huge
masses of sticks and grass among the tangled boughs.

And there the young herons are hatched and fed in the ancient heronry
till they can perch and fly. For now among the waders we have come
to birds that can perch, as we did among the swimmers (see p. 148).
The heron has no longer the three-toed flat foot of the wader, with
perhaps a slight spur behind, but a large fourth toe, with which he
can grasp the bough; and as he flies across the country, uttering his
strange harsh cry, often rising even higher than the hawks and falcons,
and alighting on the top of some tall tree, few people would think of
classing him among the waders, so like is he to those true land-birds
whose life is spent in the air and whose home is in the trees.




[Illustration: THE FIRST KNOWN LAND BIRD]




CHAPTER VII.

THE FEATHERED CONQUERORS OF THE AIR.

PART II.--FROM RUNNING TO FLYING: FROM MOUND LAYING TO NEST BUILDING:
FROM CRY TO SONG.


So the deserts and plains have their ostriches and cassowaries, the
open ocean its albatrosses and its penguins, the shores their ducks,
gulls, and waders, and the little inland pools and marshes their
water-birds, which come there to build their nests and seek for food.
Yet these are after all not by any means the larger portion of the bird
world. It is in the woods and forests, the moors and pastures, on the
solitary mountain peaks above, and in the snug valleys nestling below,
that we find the myriads of song birds and game birds and birds of
prey; of climbing birds such as the Woodpeckers; swiftly sailing birds
such as the Swifts, cooing Wood-pigeons and cawing Rooks; terrible
Eagles and Hawks, or sweet-singing Nightingales and Thrushes.

All these birds have had a very different education from that of the
far-sailing albatross or the running ostrich. They have grown up in
the midst of innumerable dangers; for enemies of all kinds--beasts and
reptiles and other birds--live all round about them, making food scarce
and destroying their young, so that of the millions born into the world
thousands upon thousands perish every year before they grow up. We
should expect, then, that these land birds would learn many devices for
protecting themselves and their little ones. The guillemot can afford
to lay her egg on the bare rock, for few animals can climb the high
cliffs where she makes her home; and the penguin on her solitary island
may lay hers in the mud on the ground. But the little lark must look
carefully for high grass in which to build her nest, and the rook must
weave a strong basket-work of twigs to make a home for her nestlings in
the top of the high elm.

Moreover, the land birds cannot sleep safely on the ground, where
weasels and stoats, foxes and wild cats, prowl by night in search of
prey; they must take their rest on the boughs of the tall trees and
cling on by their toes even when they are in the deepest slumber. This
they could not do if they had the stumpy cushioned feet of the ostrich,
the webbed feet of the duck, or the flat three-toed feet of the waders.
It is the fourth toe turned backwards, and growing very long in many
of the perching birds, which gives them their grasp; while a special
muscle, beginning behind the thigh (_th_, Fig. 33, p. 126), coming
round over the front of the knee (_k_), and then passing behind the
heel (_h_), and on to the toes, keeps them bent. Picture for a moment
this muscle sending its cords or tendons from behind the leg over the
knee, and then drawn back by the heel, and you will see that the more
heavily the bird sleeps, pressing upon its legs, the more the knees
will be bent forward, the tighter the cord must be stretched, and the
stronger the grasp will be upon the bough.

Again, as to food, the land birds will be more closely pressed than
those which can at all times fish in the sea. There is great scarcity
of land food in the winter, while in summer whole flocks of newly-born
fledgelings are clamouring for their daily bread. So we shall find
that every kind of eatable thing is turned to account, and we have
among land birds seed-eaters, vegetable-feeders, and fruit-eaters;
insect-devourers, and feeders on slugs and worms and snails; and
flesh-eaters which feed on other birds, or on mice, bats, and larger
animals; while large flocks of birds of all kinds visit different
parts of the earth in the various seasons, going north in summer to
build their nests, and south in winter, in search of food. All these
birds live chiefly in the air; while on the ground there are the
scratchers--fowls, partridges, turkeys, and grouse, which rake out
the hidden grains, and rarely rise into the air except when they are
frightened, or to roost on the trees at night. And between these ground
birds and the true tree birds we have the doves and pigeons, some of
which feed on fallen seed and grains, and others on fruit. And each
and all of these birds have some difference in beak and claw, in their
manner of nest building and rearing their young, and in their habits
and ways, which enables them to make the most of their lives.

       *       *       *       *       *

Even nest building does not come to all land birds by nature, and, as
we shall see, it depends very largely on the habits and the structure
of the builders. Thus the Partridges, and their relations the Pheasants
and Grouse, lay their eggs in the thick grass of the meadows or among
the heather, and at most sometimes scratch together a few dry grass
blades for a bed. In this they remind us much of the ostrich family,
which also scrape a hole in the ground for their eggs and scratch
food for their children; and in fact there is a group of curious
heavily-flying birds, called Tinamous, in South America, which are so
like quails and partridges on the one hand, and ostriches on the other,
that they lead us to wonder whether it was not from the ancestors of
such birds as these in ancient times that the heavy running birds
started on one road, while the lighter and swifter birds took to the
wing.

The wings of all the scratching birds are even now short and round, and
their flight is feeble. Their chief home is on the ground, where they
crouch among the thick herbage when the keen-eyed hawk is hovering
overhead, never taking to their wings till no other chance is left
them. The mother partridge runs many dangers as she sits upon her
dark-coloured eggs in some sheltered spot, for weasels and stoats will
attack her and steal her eggs if she leaves them for a moment, or kill
her herself if they can take her unawares in the dark night. She could
never hope to rear her young ones if they did not come out of the egg
well covered with down, and able to run and pick by her side while she
and the father scratch the ground with their short blunt claws to get
ant-cocoons, and later on worms and insects for them.

Yet so well does scratching answer, in getting at buried food such as
other birds cannot find, that there are a large number of these ground
birds all over the world. The Guinea fowls of Africa, the spurred
Peacocks, Pheasants, and Jungle fowls of India (from which last our
tame fowls probably come), the wild Turkeys of America, the Quails
which live in all parts of the old world from Australia to England,
and the Ptarmigans of our northern countries, which put on their white
plumage in winter--all these show how advantage has been taken of every
nook in which ground birds could find shelter. We find them hiding in
thick jungles and shady woods, or even in open ground among high grass
and corn, scratching mother earth for their daily food; washing not in
water but actually in the dust, by rolling in it, and then shaking it
off; escaping many dangers by wearing a plumage very much the same in
colour as the different grasses and leaves among which they hide; and
feeding on insects, worms, and seeds, and whatever they can find upon
the ground or under it.

[Illustration: Fig. 41.

Brush turkeys[99] and their egg mounds.]

And when we travel far off to Australia, we find ground birds which
do not even sit on their eggs, nor take care of their young, but
leave them as reptiles do to be hatched in the sun. The Brush-turkeys
and Megapodes of Australia and the islands near, and the Maleos of
Celebes--all of them scratching birds--come out of the thick jungle
and lay their brick-red or pale-coloured eggs on the shore, never
taking any more notice of them. The maleos simply scratch a hole in the
sand and bury the eggs, the brush turkeys and megapodes[100] scratch
together all kinds of rubbish and dead leaves, carrying them in their
long curved claws, and adding them to the heap till they have made a
mound sometimes more than seven or eight feet high, and twenty feet
across at the base; an astounding size, when we consider that the
brush turkeys are not nearly as large as a good-sized turkey, and the
megapodes not larger than hens. It is to these mounds that the mothers
come about every ten days, and lay an egg _upright_, till each has laid
eight or nine, and then she comes no more; but after many weeks the
little chicks work their way out fully fledged, and fly away to get
their own living. The probable reason, Mr. Wallace tells us, for this
curious habit of mound-building, is that the eggs are so large that the
mother can only lay one every ten days, so that if she sat upon them
she would be worn out with fatigue and want of proper food before they
were all laid and hatched.

       *       *       *       *       *

We see then that the scratching birds live nearly all over the world,
yet, no doubt, it is a disadvantage to them that in their ground life
they have become so heavy that they cannot fly so lightly or so far as
their near allies, the pigeons, which, like them, feed on the ground.
For the Pigeons have already made many steps forward in life. Their
wings are strong, so that they can fly for great distances; their
toes are slender and well fitted for perching; and though it is true
that our tame pigeons and the wild rock-pigeons from which they are
descended do not build nests, but lay their eggs in dovecots or church
towers, or, if they are wild, in holes in the rocks, yet the beautiful
blue-gray wood-pigeon, with her pure white collar and soft cooing note,
builds a nest in the trees--

   “The stock-dove builds her nest
    Where the wild flowers’ odours float;”

though it is but a rough one, made, as well as her weak feet and bill
can do it, of a few stout twigs, laid so loosely that her two little
white eggs may be seen from below, and even sometimes fall through.

[Illustration: Fig. 42.

Wood-pigeon on her nest.]

Yet, though but a beginner in nest building, she is a true tree bird,
and her little ones are born naked and helpless, far out of reach of
the ground, and must be fed and cared for till they can fly. So she
feeds them with infant pap from her own mouth. The “crop” or bag in
which the partridge or hen stores the grain she picks up is large and
single; but the pigeon has two bags, one on each side of the throat,
and when she is feeding her young these bags secrete a large quantity
of milky fluid, which, mixing with the tender shoots she has pecked
off in the spring, or with the oily seeds she has gathered for her
autumn brood, makes a soft food, which she pours into the mouths of her
nestlings till they fly and feed themselves.

In the pigeons, then, we are gradually rising from the ground
birds,--where the father generally has many wives[101] and the young
ones run as soon as they are hatched,--to the tree birds, where father
and mother, taught by the helplessness of their brood, share the cares
of nest building and the pleasures of love. Even the pigeons did not
all at once become tree birds, for we have them in all stages now from
the ground to the air. Many years ago, in the island of Mauritius,
there were heavy flat-breasted pigeons, the Dodos, which lived entirely
on the ground without the power to rise, so that when the Dutch settled
there, bringing rats with them in their ships, the Dodos soon fell
victims to the intruders, and now there is not one left. Again, in New
Guinea now, there are ground pigeons which fly heavily and slowly, and
only go to the trees to roost. Then come our own tame pigeons, the
rock-pigeons, and the stock-dove which builds in boles in the trees;
and then our wood-dove and his relations, with their rude nests and
their mixed food of grain and grass. And among these are the wonderful
long-winged passenger pigeons[102] of America, which fly in flocks of
hundreds of thousands through Ohio, Kentucky, and Indiana, in search of
nuts and seeds, breaking down the boughs of the trees by their weight
where they alight, and then darkening the whole sky as they start off
again in a succession of vast multitudes to another forest where beech
nuts, acorns, and chestnuts are plentiful, or to the rice-grounds of
Carolina, to take their fill.

And, lastly, we come to the beautiful green fruit-eating pigeons of
India and the East--the feeders on nutmegs and palm-fruits and juicy
berries of all kinds. These are true tree birds, difficult even to
find, so like are they to the colour of the leaves; yet they still
build the loose untidy nests of their kind.

Nor need we wonder at this, for fine nest building requires both
strength and delicacy in the bill and feet; and the next group of birds
escapes it altogether by finding or making holes in trees and banks,
and lining them with moss or leaves. This group is the Climbers, which
come, as it were, between the ground birds and birds of active flight,
for they clamber swiftly up the trunks and over the branches of trees
in search of fruits and insects, seldom going down to the ground, but
flitting from tree to tree to find fresh hunting grounds.

[Illustration: Fig. 43.

The great green Woodpecker.[103]]

What is that green object, about as large as a small squirrel, which we
see mounting the trunk of one of the elm trees, as we lie resting on
the moss in some quiet wood? There it goes, dodging now to this side,
now to that, with its head well lifted and its stiff tail bent against
the trunk. It is the green woodpecker at his work. His long large feet,
with toes divided _in pairs_, two in front and two behind, take firm
hold of the tree with their sharp claws; his breast, which is flatter
than that of most birds, lies close against the bark, as he mounts
by a number of rapid jumps, which are made by pressing his strangely
stiff horny tail against the trunk, while he hops forward with both
feet, making a slight rustling noise, and moving so fast that it is
difficult to see how he does it.

Now he pauses; it is to try a suspicious place in the bark, and tapping
it with his beak he finds that it gives a hollow sound. This tells
him at once that it is rotten, and there is an insect within; and
pecking, a hole with rapid blows of his chisel-like bill, he inserts
his narrow bill, and darts a long gluey tongue, with barbed tip, into
the dark passage, bringing out the intruder, which is swallowed in a
moment. A strange tongue this is of the woodpecker, for it has two
long bony branches at its roots, and each one is like a bow bent under
and round the back of the bird’s head, and as these bows are tightened
or slackened by the slender muscles the tongue is drawn in, or thrust
out to an extraordinary length. Moreover, it has at its tip a horny
covering beset with tiny barbs, and every time it goes back to the
mouth these are bathed in gluey slime to catch the next insect it may
meet. Nor is the woodpecker obliged always to drill for his food. The
tiny ants, as they wander up and down the trees, the beetles and bees
settling on the branches--all may fear this gluey weapon, for all alike
disappear within the long thin beak.

And now, perhaps, our friend has flown to another tree, and is some
way up it. Where is he gone? Climb up and look, and you will find a
small round hole, small outside but not inside, for the woodpecker has
hollowed out the soft rotten wood, and within, if it be early summer,
the mother is still sitting upon five or seven pure white eggs, out
of which the naked little ones will soon creep. He is a clever fellow
the woodpecker, but he is by no means the chief or most conspicuous
of the climbers, for in this group we have some of the most gaudy and
remarkable of birds. The brilliantly-coloured Barbets, the gaudy-headed
Toucans, with their clumsy bills and long barbed tongues, and the
gorgeously-tinted Parrots and Parroquets, with their soft fleshy
tongues so well adapted for speech, are all climbers, with toes divided
two and two, and they wander about the trees of South America and the
East, feeding on fruits and seeds.

Where in any other part of the animal kingdom can we find so many
brilliant colours crowded together as in the plumage of birds, and
especially in birds of tropical countries? The large land animals
cannot afford to wear such bright coats lest they should attract their
enemies, nor can even birds often put on gay plumage in our northern
climates, where the trees are bare for half the year. But in warm sunny
latitudes, where the trees are always green and the foliage thick and
heavy, and where brilliant fruits and flowers often peep out among the
leaves, the gaily-coloured birds can wander in comparative safety, and
even the gaudy parrots are not easily detected as they clamber from
bough to bough, using not their _tail_ like the woodpecker, but their
_beak_, as a third foot to hold on by as they climb.

None of these birds build nests; indeed, they could hardly do so with
their clumsy beaks and thick heavy feet; they either, like the ground
parrots, put together a few leaves in hollows of the earth or in ants’
nests; or, like the fruit-eating parrots and toucans, they lay their
eggs in tree-holes, where the bright-coloured mother is safely hidden
till she is set at liberty again. Even the cuckoos which, though they
are climbers, have taken much more to the wing than their associates,
sometimes avoid the trouble of nest building by laying their eggs in
the nests of other birds, as our own spring visitor always does. Some
of them, however, in America and elsewhere, have contracted better
habits, and build very respectable nests of their own.

[Illustration: Fig. 44.

The Kingfisher.[104]]

Indeed, we shall now soon begin to make progress in nest building, for
the next group of birds, which _dart_ at their food with wide-gaping
mouth and seize it on the wing, have among them many clever little
architects. It is true our English kingfisher builds in holes on the
river bank, lining her nest with fishes’ bones, and the Nightjar
(wrongly called the goatsucker), with her wide-gaping mouth, lays her
egg on the ground. But both these are lowly Darters, for the kingfisher
sits on a bough close above the water, and pounces down upon the fish
or water-insects; and the lonely nightjar, with her strange wailing
cry, flits among the bushes in the twilight, or often even creeps after
her prey.

Neither of these birds can compare in flight with the Swifts, as they
dart upon the wing from some high pinnacle to collect a mouthful of
insects, and come back to eat them, nor to the lovely little Humming
Birds of America, which poise themselves so deftly on the wing,
while their slender bill searches the long-tubed flowers for insects
or seizes these as they pass. These living jewels of nature build
beautiful and delicate nests of leaves and grass and spiders’ webs
interwoven like fairy cradles; while the swift makes a far stronger
home of hair and feathers, grass and moss, glueing them together with
saliva[105] from his mouth, and fastening them under the eaves or
on the top of some tall waterspout. It is easy to see why the swift
chooses such lofty spots, for his slender weak toes are ill-fitted for
standing on the ground, and he rises with great difficulty when once
he has alighted there, but from a height he can drop easily on to the
wing, and skim the air for his food.

Now the swift, which visits us only in summer to build his nest, when
insects are plentiful, and spends the rest of his time in Africa, is
a type of a whole army of birds, lovely, bright, and gay, with short
weak feet, long wings, and a gaping mouth surrounded by bristly hairs,
which swarm in hot countries where insects are to be found all the year
round. Among these are the beautiful little Bee-eaters and Rollers of
the East and Africa, which revel in insect food, and sometimes visit
us in the summer, coming over to the south of Spain, or even, in the
case of the rollers, as far north as Sweden; while in South America
the dull-coloured Puff-birds, the brilliant Jacamars with their
metallic-looking feathers, the delicate little Todies, the bright green
Motmots, and the lovely Humming-birds, swarm in countless numbers,
hiding among the dense foliage, or darting in the bright sunshine after
bee or butterfly, or other unwary insects.

       *       *       *       *       *

But we must not pause too long among these smaller groups of birds, for
the multitude of perching birds, which form nine-tenths of the whole
bird kingdom, await us with their delicate nests and their happy family
life. Ah! now we are really coming to nature’s feathered favourites,
for what can be sweeter than the song of the nightingale, the skylark,
or the thrush? or more touching than the fact that the young ones learn
from their father the loving notes; that they, in their turn, may be
able to woo and win some gentle mate to share their nests and bring up
their young ones? It is for this that they have gained that wonderful
singing instrument which they have deep down in their throat. For
they do not produce their sounds as we do, just below the back of the
mouth, but at the lower end of the windpipe, just where it divides into
two branches, one going to each lung. There, where the rush of the air
is strongest, is found a complicated apparatus, moved by a whole set
of muscles, upon which the little fellow plays, and seems never to be
exhausted, so much air has he in all parts of his body. And as the song
pours through the windpipe there again he can help to give it its soft
mellow tones, for while in hoarse-crying birds, like the sea birds and
the waders, this tube is long and stiff, in the sweet singing birds
it is short, and the bony rings composing it are thin and far apart,
with soft delicate membrane between them, which can be shortened or
lengthened to modulate the tones. And so we hear them in the springtime
pouring forth their full tide of song to tempt a young wife to come
and help them to build a nest; or, in the full pleasure of success,
trilling out their delight in the warm bright sunshine, and calling on
all the world to be as happy as they.

Yet it is not by any means all the perching birds which have this
wonderful gift of song. Even among our own birds, the jay, the crow,
the raven, and others, use their musical instrument for talking in a
way that is no doubt useful to them, but scarcely pleasant to hear;
and in America there is a whole group of songless perching birds--the
bright coloured chatterers, the fly-catching tyrant-birds, the American
ant-thrushes, which have not even developed a true singing instrument
in their throat, and only utter shrill or bell-like cries. Yet they
all build nests and cherish their helpless young ones; and so large and
varied is the group of perching birds, whether in the Old or New World,
that they fill all the stray nooks and corners of bird-life, often
imitating the habits of the other smaller groups so as to get at food
of all kinds. Thus, while the Finches with their delicate matted nests,
the Warblers, and a large number of the smaller birds, lead a true tree
and bush life, feeding on fruits and insects, the Thrushes, Blackbirds,
Crows, Redbreasts, and Larks are _ground-feeders_, which, though they
do not scratch with their feet like the partridges, turn up the ground
with their bills and pick out the worms and grubs.

For this reason the Song-thrushes love to build their nest of twigs and
moss lined with soft wood chips, in some thick hedge near to a meadow
or garden, where they can drop down and pull up the unfortunate worms
before they have gone home underground after their nightly rambles, or
pounce upon unwary snails, and, taking them in their beak, crack the
shell upon a stone, and carry off the dainty morsel to their brood;
while the Lark, with her long hind toe, so well fitted for walking,
hides her nest in a furrow on the ground; and the greedy cunning
Magpie, feeding, as she often does, on young animals, seems to fear
the same fate for her own brood, and builds a large egg-shaped dome of
thorny branches, with the thorns sticking out on all sides, and lined
with mud and soft roots, leaving only a small hole for a door. Lastly,
the sagacious Rooks, though ground-feeders, build strong homes which
last from year to year, in the top of the high elms, and set out in
companies in the early morning to their feeding grounds.

[Illustration: Fig. 45.

Nest of the Common Wren.[106]]

Then, as there are ground-feeders among the perchers, so, too, there
are _climbers_, for the Creepers, the Wryneck, and the Nuthatch, run
up and down the trees, feeding on insects and nuts, which the nuthatch
breaks so cleverly with his beak; and we might almost fancy them to be
first cousins to the woodpeckers, if it were not for their three toes
in front and long claw behind, and their short thick beak and tail.
Even the little Wren, with her cocked-up tail, imitates the climbers
as she creeps through the hedges and underwood, though she is a true
perching bird, and builds one of the most perfect of nests of moss and
grass, woven into the shape of a ball, with a tiny hole for a door.
Then, to match the _darting_ birds, we have the Swallow and the Fly
Catcher which follow insects on the wing, so that the swallow and swift
were long confounded together, though the skeleton of the swallow shows
that it belongs to perching birds. Again, the Shrike imitates the birds
of prey, feeding on small mice, reptiles, and birds, and impaling them
upon a sharp thorn while he tears them to pieces with his beak. Yet he
is a true percher, singing as beautifully as many of the smaller birds,
and he is even said to use his power of song to lure victims within
reach. Lastly, and perhaps most curious of all, the little Dipper or
Water-Ouzel, with his clear loud song, and his structure so like to the
thrushes, has actually taken to the habits of water-birds, and dives
into the depths of the river, running along upon the bottom and feeding
on water-snails and water-insects.

[Illustration: Fig. 46.

Nest of the Tailor-Bird[107] of India or China.]

All these we find among English birds; and if we had space to speak of
other countries, we should find the same history there, for the more we
study bird-life the more we find that these Perchers are its highest
types, and have learned to make the most of their kingdom. It is they
who build the most perfect nests, from the rough strong basket-work
of the crow or the magpie, to the wren’s thickly-woven ball, or the
finches’ matted cups; while in America the Hang-nests weave their
lovely pear-shaped homes, and suspend them like fruit from the tips
of the branches; and in India and China the Tailor-birds actually sew
leaves together with cotton fibre or cobweb threads, which they draw
through with their slender bill and strengthen with saliva.

The smaller the bird and the more delicate its feet and bill, the more
closely woven, as a rule, is its nest. Yet all are built with care; the
mother bird, as a rule, choosing the position and laying the twigs,
while the father helps her to collect the materials. So rapidly do
these little creatures work, that among our smaller English birds the
early morning sees the work begun, and by evening it is ended. Other
birds are longer, according to the amount of material they have to
collect; but all labour industriously till the cradle is finished, and
then begins the laying, the sitting, the tender care of the mother for
her little ones, and of the father for his wife and brood.

       *       *       *       *       *

And indeed there is much need both of skill in nest building and
of watchfulness for many a long day after, for if the perchers are
the highest, they are not by any means the strongest of birds; and
while they feed on insects and smaller creatures, they have to guard
their little ones with anxious care against the larger birds of prey
which rule as masters in the higher regions of the air. It is on
rocky pinnacles and in the clefts of inaccessible heights among the
mountains that we must look for the nests of the Eagle, the Vulture,
and the Falcon. Strong, powerful, and untiring in flight, they sail
majestically high up in the air, not to sing a joyful song like the
lark, but with piercing eye to search every corner for miles around,
for animals of all sizes, from the dead ox or mule to the tiny living
mouse or bird, which can serve for a meal.

[Illustration: Fig. 47.

The Eagle bringing food to its young.--(_From a coloured lithograph by
Keulemann._)]

It needs only a glance at them to see that they are strong destroyers,
with their powerful wings, their sharp hooked beaks, their long toes
with pointed claws, and their strong muscular thighs; and because
most men admire strength and power, we call such birds _noble_,
though their nobility chiefly consists in loving their little ones,
and asking neither pity nor shelter from others, as they themselves
are pitiless in return. Those which we are apt to like the least, the
carrion-feeding Vultures of hot countries, are really the most useful
and harmless, for they feed chiefly on dead animals and clear the land
of carrion; and for this reason neither their beak nor their claws are
as strong as those of the fighting birds. But though they are grand
in flight they are but repulsive-looking birds when compared with the
lordly eagles. The beautiful Golden Eagle of Europe, with its dark
plumage and the golden sheen on its back and tail, is indeed a splendid
object, as

   “He clasps the crag with hooked hands,
    Close to the sun in lonely lands,”

or still more, as he sweeps along with steady flight, circling round
and glancing with searching eye over the plain beneath. Suddenly his
attitude changes; he closes his wings, and, head downwards, drops to
earth slantingwise with a rushing noise, seizing in his claws the
startled fawn as it dashes by at full speed, the frolicking rabbit
darting into its hole, or the terrified bird upon whom his choice has
fallen. Then, with a powerful stroke he rises up again, and is lost to
sight as he soars aloft and regains the rocky peak where his eyrie is
built and his children are clamouring for food.

So, too, the dexterous Falcon swoops upon his prey swift as an arrow,
his pointed wings striking the air, and then closing at once upon his
body, while his long rounded tail guides him in his flight. Who would
think that such a powerful and bold robber could have anything in
common with the soft feathered owl which sits blinking its large eyes
in the hollow of the tree till the twilight falls? And yet the Owl,
with very little change in structure, has become as fitted to follow
prey at night as the falcon is by day--

   “What time the preying owl, with sleepy wing,
    Sweeps o’er the cornfield, studious.”

The soft, round, broad wings, which would serve badly for striking a
quarry from on high, are exactly fitted for gliding in the silence
of the night, as, guided by wide open eye and ear, he skims over the
fields or round the stacks in the yard to pounce noiselessly upon the
unwary mouse or to seize the flying beetles and bats. Then the sharp
claws appear quickly from under the downy feathered feet, and clutch
the smallest prey with needle-like precision; and away the owl flies
to his nest, so quietly that even the other animals close by are not
alarmed, but in ignorant security remain till he comes to strike again.

And as the day and the night by land have their relentless freebooters,
so the sea too has its eagle king; for the Osprey, with its nest on
a high rock, hovers over the open sea, and, dashing into the deep,
returns with a large fish in its claws; and, as it tears the flesh from
under the glittering scales, reminds us that there is no spot on the
earth in which some bird does not seek its prey.

We have now in very brief outline followed the feathery tribe from
the flightless penguin to the boldly-soaring eagle, the king of the
air. Those feathers which in the swimming bird are scarcely more than
finely-divided scales, and in the ostrich mere loose nodding plumes,
have become in the albatross, the vulture, and the soaring falcon,
flying instruments of such power and strength that the earth and the
water are as nothing to them compared with the free ocean of air; while
even the tiny graceful swallow flies for hundreds of miles to its
winter home.

Indeed, we have here one of the great secrets of bird success; for
while most animals must roam within limited districts, and get their
food there as best they can, thousands and tens of thousands of birds
set off, when the colder weather makes food scarce in any one region,
and travel hundreds of miles to more genial climates, where insects
are still to be found, and the trees are still covered with fruit and
leaves. How strange it is to think that while we are making the best
of our winter, the swallow has taken her unerring flight to Africa,
the swans and cranes have long since made their southward journey,
and myriads of small birds have gone in search of food and warmth, to
return next spring as certainly to their old haunts, where they can
breed in cool and comfortable quarters!

If we could only get the birds to tell us how they have learned the
routes they take, and by what rules they are guided! One thing we know,
that each kind of bird makes its nest in the coldest region which it
visits, and where, at the time its young brood are ready, insect and
other life is abundant; so that while the wild duck and goose, the
woodcock, snipe, and field-fare, go to the far north to lay their eggs,
and come to us in the sharper weather to feed when there is nothing
but ice and snow in the home they have left, the swallow, the cuckoo,
the swift, and the wheatear, on the other hand, visit us in the spring
to build, and when autumn comes on take their flight to Africa and the
East; and even many of the song-thrushes and robin-redbreasts which
remain with us in England start off from Germany to warmer climates.
Others, again, such as some of the Reed-warblers, the Stint, and the
Ortolan Bunting, only make our island a house of call between the
arctic regions where they breed in the summer when mosquitoes are
swarming there, and the south where they winter after flying thousands
of miles.

It would take too long to discuss here why and how they go, even if we
knew it with certainty; but it is most probable that their ancestors
first learned the routes now taken when Europe and Africa had not
so wide a sea between them, and we can see that it must be a great
advantage to be able to travel from climate to climate, so as to find a
plentiful table spread at all times of the year; while they may return
to the north to breed, not merely because there is food there, but also
because in still earlier times, when the northern countries were much
warmer than they are now, they doubtless lived there altogether, and,
though now obliged to go south, have never lost the tradition of their
old home.

Thus the birds, with their feathery covering and powerful wings,
have left their early friends, the reptiles, far far behind. Taught
by their many dangers, many experiences, and many joys, they have
become warmhearted, quickwitted, timid or bold, ferocious or cunning,
deliberate as the rook, or passionate as the falcon, according to the
life they have to lead; or, in the sweet tender emotions of the little
song-birds, have learned to fill the world with love and brightness and
song. If mere enjoyment were all that could be desired in life, where
could we expect to find it better than in the light-hearted skylark as
she rises in the early summer morning to trill forth her song of joy,
or in the happy chuckle of the hen as her little ones gather around her.

Yet we cannot but feel that, happy as a bird’s life may be, it still
leaves something to be desired; and that, with their small brain and
their front limbs entirely employed in flying, they cannot make the
highest use of the world. The air they have conquered; and among the
woods and forests, over the wide sea, and above the lofty mountains,
they lead a busy and happy existence, bringing flying creatures to
their highest development, and showing how Life has left no space
unfilled with her children. Yet, after all, it is upon the ground,
where difficulties are many, conditions varied, and where there is
so much to call for contrivance, adaptation, and intelligence, that
we must look for the highest types of life; and while we leave the
joyous birds with regret, we must go back to the lower forms among the
four-footed animals, in order to travel along the line of those that
have conquered the earth and prepared the way for man himself.




[Illustration: HOME OF THE EARLIEST KNOWN MILK GIVERS]




CHAPTER VIII.

THE MAMMALIA OR MILK-GIVERS.

THE SIMPLEST SUCKLING MOTHER, THE ACTIVE POUCH-BEARERS, AND THE
IMPERFECT-TOOTHED ANIMALS.


Our backboned animals have now travelled far along the journey of
life. The _fish_, in many and varied forms, have taken possession of
the seas, lakes, and rivers; the _amphibia_, once large and powerful,
now in small and scattered groups, fill the swamps and the debateable
ground between earth and water; the _reptiles_, no longer masters of
the world, but creepers and skirmishers still holding their own in many
places either by agility, strength, or the use of dangerous weapons,
swarm in the tropics, and even in colder countries glide rapidly
along in the warm sunshine, or hide in nooks and crannies, and sleep
the winter away. And the _birds_,--the merry, active, warmhearted
birds,--live everywhere, making the forests echo with their song,
rising into the heights of the clear atmosphere, till the world lies as
a dim panorama below them, crowd the water’s edge with busy fluttering
life, and even wander for days and weeks over the pathless ocean, where
nothing is to be seen but sky and water.

Yet still the great backboned division is not exhausted; on the
contrary, the most powerful if not the most numerous group is still
to come; that group which contains the kangaroos and opossums, the
dreamy sloths, the night-loving moles and hedgehogs, the gentle lemurs
and the chattering monkeys, the whales, seals, and walruses for the
water; the herds of wild cattle and antelopes, of noble elephants and
fleet horses, for the forests, mountains, and plains; and the ferocious
beasts of prey, which make these gentler animals their food; while
last, but not least, comes man himself, the master and conqueror of all.

Where, then, shall we look for the beginning of this vast multitude
of warm-blooded, hairy, and four-limbed animals? If we turn back to
the past, we get but little help; for though in that early time, when
huge reptiles overran the world and swam in the waters, we find small
animals (see Fig. 48), probably of the marsupial or pouched family,
living in the forests, yet even if these were the earliest of their
race, which is not at all likely, they would tell us very little about
the beginning of the milk-givers, since only their lower jaws remain,
and we can only guess at their relationship by these having that
peculiar inward bend which we still find in all pouched animals.

[Illustration: Fig. 48.

    A, Jaw of Dromatherium; B, Tooth of Microlestes; both milk-givers,
    probably marsupials, found in beds of the same age as those
    containing the ancient swimming lizards.
]

No! for the few scattered facts about the lowest _mammalia_ or
milk-giving animals we must inquire of our own day, to learn something
as to the causes of their success in life. And first let us notice two
important changes which give them an advantage over other backboned
creatures. We have seen that, as we have gradually risen in the scale
of Life, parents have taken more and more care of their eggs and their
young ones. Among the boneless animals which we studied in _Life and
her Children_, it was not (with very few exceptions) till we reached
the clever, industrious, intelligent insects, that we found them taking
any thought for the weak and helpless infants. There we did find it,
for insects in their own peculiar line stand very high among animals;
when, however, we turned back again to begin with the first feeble
representatives of the backboned family, we found the fish casting
their eggs to the bottom of the sea, or on the pebbly gravel of a
flowing stream, and, as a rule, taking no more thought of them. The
tiny stickleback with his nest, and the lumpsucker watching over his
young ones, were quite exceptions among the finny tribe. So it was
again with the frogs, so with the reptiles (the turtles, lizards, and
snakes), whose eggs, even when carefully buried by the mother, are
often devoured by thousands before the little ones have a chance of
creeping out of the shell. But when we come to the birds, there, as
with the insects, we find parental care beginning--the nest, the home,
the feeding, the education in flying, in singing, in seeking food, the
warm-hearted love which will risk death sooner than forsake the little
ones.

Yet still these same little ones have many perils to run even before
they break through the shell. In spite of their parents’ care, more
eggs probably are eaten by snakes or weasels, field-rats, and other
creatures, than remain to be hatched; while, even if they escape being
devoured, the eggs must not be allowed to grow cold; and should the
parents be too long away or be scared off the nest by some enemy, or
should a damp cold season spoil the warm dry home, the young bird is
killed in the egg before it has ever seen the light.

It is not difficult to see, therefore, that if the mother could carry
the egg about with her till the little bird was born, as we found our
little common lizard doing (see p. 105), it would be much safer than
when left in the nest exposed to so many dangers.

Now something of this kind takes place with all that great group of
animals we are going to study. The cat and the cow, as we all know, do
not lay eggs as birds do; but the mother carries the young within her
body while they are going through all the changes which the chicken
goes through in the egg. Thus they go wherever she goes, the food which
she takes feeds them, and they lie hidden, safe from danger, till they
are born, perfectly formed, into the world. Nor is this all; for when
at last her little ones see the light, the mother has nourishment ready
for them; part of the food which she herself eats is turned into milk,
and secreted by special glands, so that the newly-born calf or kitten
is suckled at its mother’s breast till it has strength to feed itself.

These two advantages, then,--namely, that the young have no dangerous
egg-stage, but are sheltered by their mother till they are perfect,
and that their mother has milk to give them for food,--at once divide
the _Mammalia_ or milk-giving group of animals from the rest of the
backboned family.

But how will this help us to learn where that great group begins? Is it
possible that such creatures as these can have anything in common with
reptiles and birds? To answer these questions we must travel to a part
of the world which has long been separated from the great continents
of Europe, Asia, Africa, and America, and where the low and feeble
milk-giving animals had a chance of still keeping a place in the world.

Take a map and look at Australia, New Guinea, and Tasmania, and you
will see that they are separated by a number of scattered islands from
the great continents, which are not only large in themselves, but are
all nearly joined together, with only narrow straits dividing them.
Moreover, Australasia stands even more alone than appears at first
sight; for Mr. Wallace has pointed out that a very deep sea separates
New Guinea and Australia on the one hand from Borneo and China on the
other; so that the land might rise several thousand feet, and yet the
Australasian islands would not be joined to the great continents.

Now, if the milk-givers once had feeble beginnings, and gradually
branched out, as the ages went on, into all the many forms now living,
it is clear that on the great battlefield of Europe, Asia, Africa,
and America, the first poor weak forms would gradually be destroyed
by the stronger ones that overran these great continents. They would
be crushed out, as so many of the reptiles and newts and fishes had
been before them; and only their bones, if any remained, would tell
us that they had once lived. But if some of them could find a refuge
in a domain of their own, where after a time they had a good open sea
between them and their stronger neighbours, they might have a chance of
living on and keeping up the old traditions.

And this is just what we have reason to believe has been their history;
for it is exactly in Australasia that we find that curious group of
pouched animals, the kangaroos and other _Marsupials_,[108] as they
are called, which are different from all the other milk-giving animals
in the world, except the opossums of America, whom we shall speak of
by-and-by.

And together with these marsupials we also find the simplest
milk-giving animals now living. Come with me in imagination to a quiet
creek in one of the rivers of East Australia. It is a bright summer
day, and the lovely acacias are hanging out their golden blossoms in
striking contrast to the tall graceful gum-trees and dark swamp oaks
in the plain beyond. Come quietly, and do not brush the reeds growing
thickly on the bank; for the least noise will startle the creature
we are in search of, and he will dive far out of sight. There he is,
gently paddling along among the water plants. His dark furry body,
about a foot and a half long, with a short broad tail at the end, makes
him look at first like a small beaver. But why, then, has he a flat
duck’s bill on the tip of his nose, with a soft fold or flap of flesh
round it, with which he seems to feel as he goes? Again, he has four
paws, with which he is paddling along; but though these paws have true
claws to them, they have also a thick web under the toes, stretching,
in the front feet (C Fig. 50), far beyond the claws, yet loose from
them, so that while it serves for swimming it can be pushed back when
the animal is digging in the ground. His hind feet have a much shorter
web, and a sharp spur behind, like that of a game cock.

And now, as this animal turns his head from side to side you can see
his sharp little eyes, but not his ears, for they are small holes which
he can close quite tightly as he works along in the water, pushing his
bill into the mud of the bank, just as a duck does, and drawing it back
with the same peculiar jerky snap; for he too has ridges in his beak
like the duck family, through which he sifts his food; while, at the
same time, he has in his mouth eight horny mouth-plates, peculiar to
himself.

What, then, is this four-footed animal with a beaver’s fur and tail,
and teeth in his mouth, and yet with a duck’s bill and webbed feet?
He is the lowest and simplest milk-giving animal we know of in the
world--the duck-billed Platypus or Ornithorhynchus, called by the
settlers the Water-mole.

[Illustration: Fig. 49.

    The Duck-billed Platypus[109] swimming and rolled up, with its
    underground nest laid open behind; on the right hand bank is an
    Echidna.[110]
]

If we could search along the bank we should find, somewhere below the
water’s edge, a hole, and again, a few feet back on the land, another
among the grass and reeds; and both of these lead into a long passage,
which ends in a snug underground nest--a dark hole lined with dry grass
and weeds--where in the summer time (about December) we should find the
mother platypus, with two or four tiny naked young ones, not two inches
long, cuddled under her. How these little ones begin life we do not
know. The natives talk about finding soft eggs like those of reptiles;
but it seems more likely that these eggs break just as they are laid,
like those of our common lizard (see p. 105), and the naked little ones
come out alive into the nest.

[Illustration: Fig. 50.

A, Head of Ornithorhynchus, showing serrated bill; B, Hind foot
with claw _a_, found on the males only; C, Webbed fore foot.]

And how are they fed? Their mother has no teat, like the cow, to put
into their mouth, for she is a very primitive creature; only in one
spot amid her fur are a number of little holes, and from these she can
force out milk for them to drink as they press against her with their
soft flat bills. So here, in a dark underground nest, away from the
world, because she cannot, like the higher animals, carry her little
ones till they are perfect, the duck-billed platypus, which may well be
called “paradoxical” (see Fig. 49), enables us to picture to ourselves
how, in ages long gone by, mothers first began to feed their little
ones with their own milk.

And now, perhaps, you will be struck by this animal’s likeness to a
bird, especially when you hear that the little baby water-moles have
a soft horny knob on their nose, just where young birds have a hard
knob for breaking through the shell; and you will ask if milk-giving
animals came from birds. Not at all; young tortoises, too, have such a
knob, and so have crocodiles; and, moreover, these duck-billed moles
have many parts of their skeleton, especially the shoulder bone and
the separate bones of the skull, very like our living reptiles, and
still more like some which lived in ages long gone by.[111] And yet at
the same time they differ essentially both from reptiles and birds in
many points besides those we have been able to mention, and in one in
particular, which we can understand now we have studied these groups,
namely, that the platypus, like all milk-giving animals, _is without
that curious quadrate bone_ (_q_, Figs. 23 and 33) _which we find in
all reptiles and birds_.

Now, notice the frog, which is an amphibian and therefore lower than
the reptiles, has not got this quadrate bone, though his companions the
newts have; and he seems to tell us that among those old amphibians
which roamed in the coal-forests of ages past, there must have
been some which,--while they had that great mass of cartilage which
imperfect, unborn, milk-giving animals have even now, out of part of
which this bone is formed,--yet never went so far as to have the bone
itself. If this is so, then here at last, in the distant past--so
remote that we cannot even guess how long ago it may have been--we have
a point from which the earliest ancestors of the milk-giving animals
may have gone off in one direction, and those of reptiles and birds in
another. And this would explain how it is that they have so many points
in common, while yet the mammalia are without that special bone and
other characters which are found both in reptiles and birds.[112]

Be this as it may, here is our lowest mammalian form, and he has a
relation, the Echidna, very like him in many respects, but who has made
a decided step forward; for on the sandy shores and in the rocky gorges
of Australia, creatures about a foot long, covered with prickly spines
like hedgehogs, and called by the settlers “Porcupine Ant-eaters” (see
Fig. 49), shuffle along in the twilight, thrusting out their long thin
tongues from the small mouth at the end of their beak-like snout, and
feeding on ants and ants’ eggs. These do not belong, however, to the
real ant-eater family, but are near relations to the platypus; and they
are well protected by their spines in the battle of life, for when
attacked they either roll themselves up into a ball like a hedgehog,
or burrow down into the sand so fast that they seem to sink into it,
leaving only the points of their prickles sticking out to pierce the
feet of their enemy. Now these creatures have a little fold of skin
under their body, which forms two little pouches over the milk-giving
holes, and the little echidna when _very_ tiny is put into this pouch,
and keeps its head there while its body grows larger and sticks out
beyond. In this way the Echidna can carry her child about with her, and
she only turns it out to shift for itself when its prickles are hard
and sharp.

       *       *       *       *       *

You see, then, that though we began with the simplest known milk-giving
animal, we are, in the Echidna, already fairly on our way to the
curious pouched creatures of Australia, the “Marsupials,” which,
instead of a small fold, have indeed a large pouch of skin, into which
they put their little ones when they are less than two inches long, and
so imperfect that their legs are mere knobs, and they can do nothing
more than hang on to the nipple with their round sucking mouths as if
they had grown to it.

There the little ones hang day and night, and their mother from time
to time pumps milk into their mouth, while they breathe by a peculiar
arrangement of the windpipe, which reaches up to the back of their
nose. Then, as they grow, the pouch stretches, and by-and-by they begin
first to peep out, and then to jump out and in, and feed on grass as
well as their mother’s milk. For a long time they take refuge in the
pouch whenever there is any danger or they are tired, and Professor
Owen has suggested that this curious pouch arrangement may be of great
use in a country where water is often so far to seek that the little
ones could not travel to it unless the mother could carry them.

[Illustration: Fig. 51.

Australian Marsupials.

Kangaroos; a flying Phalanger; and the Kaola or native Bear, with a
young one on its back.]

Now this race of pouched animals we find spreading all over a land
where they had none of the higher four-footed animals to dispute
the ground with them, for there are no ordinary land mammalia in
Australia, except bats, which could fly thither; mice and rats, which
could be carried on floating wood, and a fierce native dog, the Dingo,
which was probably brought by the earliest native settlers long after
the marsupials had spread and multiplied. And what is more, though
we find the bones of marsupials of all sizes buried in the rocks of
Australia, some of them as large as elephants,[113] showing that these
creatures too had their time of greatness, we do not find those of
ordinary mammalia.[114] It would seem, then, that for long ages the
pouched animals had the field to themselves, and they made good use of
it, filling all the different situations which in other parts of the
world are filled by ordinary four-footed creatures.

On the plains, mountains, and red stony ridges are the long-legged
Kangaroos every child knows so well in the Zoological Gardens. There
they browse upon the grass and leaves as our cattle do in Europe, and
some of them, such as the great gray Kangaroo,[115] grow to be as much
as five feet high, and can make a good fight even against the fierce
dingo dog, hugging him in their arms and ripping him up with the strong
nail of the long middle toe of their hind foot, which answers in them
to the hoofs of our cattle and deer. And yet they are peaceable enough
unless attacked, as they lurk among the tall ferns and grass, and will
far rather leap away than turn and attack an enemy. Others are much
smaller, such as the Kangaroo Rats, which feed on roots and grasses,
one of them, the Tufted-Tailed Kangaroo-Rat,[116] biting off tufts of
grass and carrying them in his tail to make a soft nest to sleep in;
while the Tree Kangaroos[117] of New Guinea live in the trees, feeding
on the leaves and jumping from bough to bough.

All these, from their long hind legs and jumping movements, we should
recognise at once; but the plump furry Wombat (see Fig. 52) looks more
like an ordinary four-footed animal, as it wanders by night burrowing
and gnawing the roots of plants. So too do the tree-climbing animals,
the Kaola or tailless bear (Fig. 51), which often carries its young one
on its back, and the beautiful Phalangers or “Australian Opossums,”
which live in hollow trees and come out on moonlight nights to feed
upon the leaves, hanging from the boughs by their long prehensile
tails. Yet all these animals have a pouch for their young, and while
the long-tailed furry Phalangers play the part of the fruit-eating
monkeys in a land where monkeys have probably never been, another group
of them, the “Flying Phalangers” (Fig. 51), with a membrane stretching
between their front and hind legs, represent the flying squirrels, and
live at the very top of the gum trees, feeding on leaves and flowers,
and taking flying leaps with their limbs outspread.

These are all vegetable-feeders; and they leave plenty of room for the
little insect-feeders, the Myrmecobius, with its long bushy tail, and
the Bandicoots or rabbit-rats, which feed partly on bulbs and roots,
and more often on insects, grubs, and even small mice and vermin.

But where are the animal-eaters? Surely here, as in other parts of the
world, some of the group have taken to feeding on their neighbours?
There are very few carnivorous animals in Australia, and these are
small, though fierce, and feed chiefly on rats and mice; yet the bones
of huge marsupials, with long pointed teeth, found in the rocks, tell
us that dangerous animals were once there before they were driven out,
probably by the Dingo and savage man. And when we get to Tasmania,
where no Dingos are found, there the flesh-eating marsupials still
live, as fierce as any wolves and wild cats of Europe, and still they
are pouch-bearers. Slim and elegant as the fierce and furry Tiger-wolf
(Fig. 52) looks as he courses over the Tasmanian plains in search of
prey, yet the mother carries her young in a pouch like the gentler
wombat or the powerful kangaroo; and so does the mother of the Native
Devil or Tiger-cat (Fig. 52), which is so fierce that even the natives
are afraid of it when it turns at bay, and it will attack and devour
large sheep, though it is only the size of a terrier dog.

We see, then, that the marsupials in a world of their own, cut off by
the sea from the struggling world beyond, play all parts in life; and
squirrels, monkeys, insect-eaters, gnawing animals, hoofed animals, and
beasts of prey, all have their parallel among the pouch-bearers. But
just because they are so isolated it becomes a curious question why,
when we travel right across the wide Atlantic or Pacific to America, we
find another set of pouched animals slightly different but belonging
to the same group. How comes it that the clever little opossums of
Guiana, Brazil, and Virginia (see Fig. 53, p. 200), which grasp the
trees with the free nailless great toe of their hind feet and hang by
their long tails, should be marsupials, carrying their little ones in
pouches, when all their relations are thousands of miles away over the
sea?

[Illustration: Fig. 52.

Tasmanian Marsupials.

    The two to the left of the picture are Wombats;[118] the front
    right hand figure the Tasmanian Devil;[119] and the background
    figure the Tasmanian Wolf.[120]
]

Stop a moment, and let us go back to those times when the marsupials
were living with the great flying reptiles in Europe and North America.
These forms (see p. 183) were like the little myrmecobius now living
in Australia, and at some period, we do not know exactly when, their
descendants must have found their way to that part of the world, where
they have since branched out into so many curious forms, gnawing,
leaping, running, and flying, and filling the place of ordinary
quadrupeds. But they must also have lived on in the Northern Hemisphere
and branched out into other forms; for much later, when tigers and
other ferocious beasts had begun to prowl about in the forests of
Europe and America, opossums were leaping in the trees, as we know by
finding their bones in Suffolk, under Paris, and in North America.
And so we see that when these opossums found their way down south to
Brazil and Guiana, the simile that we used a little while ago (p. 131)
probably became literally true, and the Australian and South American
pouched animals are related to each other, not because they come one
from the other, but because they both come from the same very ancient
stock which once lived in Europe.

This would explain how these active, furry, little beings of all sizes,
from that of a good-sized cat to a rat, come to be sporting among the
leaves of the grand forests of Brazil or on the edges of the Virginian
swamps, sleeping during the day in the hollow trees, and prowling by
night over the plantations, and among the rice-fields feeding on fruit
and seeds, worms and insects, and even on young birds and rats. On the
ground they walk heavily, with flat feet, but in the trees they swing
from bough to bough (see Fig. 53), the little ones curling their tails
round that of their mother and clinging to her back as she goes. Some
of these opossums have even lost the pouch, and put their little ones
at once on to the thick fur of their back as soon as they come out of
their snug nests in the tree-hollows. They seem to have a happy time
of it, these merry tree-climbers, and know well how to swing out of
danger, or to feign death if they cannot escape, so that “cute as a
’possum” is a common American proverb. One kind, living in the swamps
of Guiana, feeds almost entirely on crabs, while another, called the
Yapock, has webbed feet and dives under water, feeding on fish and
other water-animals.

But here another question presents itself. How is it that these curious
pouched animals have lived on in America as well as in Australia when
they have been killed off in Europe and Asia? The answer to this is
not far to seek if we remember that geology teaches us that there
have been many changes of land and sea in past times, for the neck
of land which joins South America to North America is very low and
narrow, and a change of level of scarcely more than 2000 feet would
break it up into islands; and as we know that such changes have taken
place in past geological times, there is no doubt that once this neck
was partially under the sea, and South America, like Australia, was a
huge continental island, where the lower animals might struggle on and
become settled, before the higher ones poured in to interfere with them.

       *       *       *       *       *

Indeed, if the opossums did not teach us this history, we might learn
it from another singularly old-fashioned race of animals; for in the
same Brazilian forests in which our little opossums are sporting,
the dreamy Sloth, with his long arms, short legs with the knees bent
outwards, and long thick hair drooping over his eyes, is hanging back
downwards from the boughs; while the strange Ant-bear is tearing open
the ant-hills with his strong bent claws in the damp earth below, and
licking up the insects with his long sticky tongue; and the Armadillo,
whose back is covered with bony shields like the crocodile, issues out
of his burrow at night to dig for worms or roots or buried animals. We
may look all the world over and we shall not find another group so
strange and old-fashioned as this one, nor even any creatures of their
kind, except the ant-eaters of the Cape and the scaly Manises of Africa
and India, which also live, as you will notice, upon continents which
jut out into the water, and not on the great northern mass of land.

[Illustration: Fig. 53.

South American pouched animal, the Opossum;[121] and imperfect-toothed
animals--Sloth,[122] Ant-bear,[123] and Armadillo.[124]]

In many ways these curious animals (_Edentata_) of South America and
Africa are more singular, though not of so ancient a race, as the
“pouch-bearers.” Many of them, the American ant-bears and the African
Pangolins, are quite toothless, and those which like the sloth have
teeth, have very imperfect ones more like the teeth of reptiles than
those of marsupials; again, their feet have the toes much joined
together, and the sloths have only three toes on the hind feet and
sometimes two only on the front, and the joints of their neck are
irregular in number. Thus we see in them that variability of structure
which always points to a low order of animals; and, moreover, the
armadilloes are the only milk-giving animals which are covered with
bony plates like reptiles.

[Illustration: Fig. 54.

African imperfect-toothed animals--Aard-Vark or Cape Ant-eater in the
background, and scaly Manis or Pangolin in the foreground.]

What, then, is the history of these old-fashioned animals? Much the
same as that of the marsupials, so far as we can read it; for at
the same time that opossums were living in Europe, strange animals,
with imperfect rootless teeth, and toes with immense claws, bent
inwards like the claws of the ant-eaters, were wandering over France
and Greece, where we now find their bones. Then, a little later we
find, on the shores of the Pacific in North America, other huge
imperfect-toothed creatures, which lived, died, and were buried in
the mud; and lastly, in South America, still later, we find whole
skeletons of gigantic sloth-like animals the size of elephants,[125]
which had not yet such long arms as the Sloth of to-day, but walked
on four feet upon the ground and browsed upon the trees, while huge
armadillo-like creatures,[126] with solid bony shields covering their
backs, wandered in the vast forests and lived on animal food. Making
use of these facts, then, cannot we picture to ourselves how these
large unwieldy creatures, with their stiff bent claws and their weakly
teeth, which if once broken or lost could not be replaced by a second
set, were no match for the large tigers, bears, and other beasts of
prey which were roaming over Europe and Asia; while those, on the
contrary, which found their way from North to South America, and were
cut off from the crowded world, just as the marsupials were, might live
on and fill the land with large creepers and burrowers. In the old
world the same would probably happen in Africa, where the sea certainly
flowed at one time over the low-lying desert of Sahara; and so the
Cape Ant-eater and the Pangolin, both so different from their American
relations, would keep their place in the world.

This would explain how they gained a firm footing; but the next
question is how they kept it, when jaguars and pumas began to roam over
America, and lions and panthers over Africa? Now, if we inquire into
the history of the Aard-Vark or great Cape ant-eater, which is in many
ways much more like the American armadilloes,--for he has like them
teeth in the back of his mouth, and walks flat-footed, though he has a
thick skin and bristles instead of armour,--we find that he is a very
timid animal, and lives almost entirely underground, only venturing out
at night to scratch open the ant-hills with his strong claws, so that
he may thrust his long sticky tongue into the ant-galleries to draw
it back covered with food. Even then he never ventures far from his
hole, so we can easily conjecture that it is by concealment that he has
escaped destruction.

Still more would the Pangolins flourish, for though they are toothless
and walk very clumsily, because their front feet are bent under so that
they tread on the upper part, yet they have two means of protection.
First, like the ant-eater, they live chiefly underground and come out
at night; and secondly, their back is covered with sharp-edged scales,
which grow from the skin as hairs do, and can be raised into a complete
_cheval-de-frise_ as they roll themselves up, or tuck their tail and
head between their legs when they are attacked. Thus protected, the
scaly ant-eaters not only flourish in Africa, but have even kept their
ground in India, China, and Ceylon.

In America, on the other hand, we find that the armadilloes have gone
strangely back to the bony armour of the reptiles or the ancient
Labyrinthodonts, and have shields on their backs and heads formed of
skin-plates exactly like those of the crocodile, so that the only
delicate part of their body is the under side, which is kept close to
the ground. When we see how well they are protected, and also remember
that they are extremely quick burrowers and can get out of the way of
dangerous enemies, while they feed on vegetables, insects, and dead
creatures, we see why the plains and forests of South America should
abound in armadilloes of all sizes, from the Great Armadillo, as large
as a moderate-sized pig, to the little Pichiciago, not larger than a
rat.

It would be more difficult to understand how the great hairy
Ant-bear[127] (p. 200), with his twisted feet, united toes, and
toothless tube-like snout, has managed to live on in the dense forests
of South America, if we did not know that he is immensely strong, and
his sharp claws and the deadly hug of his muscular arms are avoided
even by large animals, while the small American Ant-eaters[128] live
chiefly in the trees, feeding on bees, termites, and honey. A strange
fellow is the great ant-bear as he wanders at night slowly and heavily
along the river-banks, his long bushy tail sweeping behind him and his
head bent low; or, if it be a mother, she may be carrying her little
one clinging to her back, or pause to hold it in her long arms as it
sucks. Be this as it may, by-and-by the ant-bear reaches a group of
nests of termites (wrongly called white ants), looming six feet high in
the dark night; at once the sharp claws are at work tearing the hill to
pieces, though they are so strongly built that men have to open them
with a crowbar, and as the alarmed termites rush out, the long sticky
tongue wanders among them and they are drawn into the ant-bear’s mouth
by thousands. Yet the ant-bear has his enemies, for it may be that in
his night-walk he may come across the fierce jaguar in search of prey.

Now, D’Azara, the great traveller, doubted the stories of the natives
when they said that the ant-bear could kill the jaguar, but Mr.
Cumberland, who has lived much in South America and has himself killed
the ant-bear, assures me that the animal is quite a match for such
a wild beast. The muscles of his shoulder and arms are tremendous,
the claws so hard and strong and sharp that when once stuck in they
never lose their hold, and the ant-bear when attacked stands up and
gives a death-hug so dreadful that the natives never dare to come to
close quarters with him. Moreover, he is very difficult to kill. Mr.
Cumberland, by the help of his dog and man, caught and disabled one of
these creatures so as to tie his legs together and keep him stunned,
but his skull was so hard that repeated blows with heavy quartz rock
on his nose, the most vulnerable point, only succeeded in stunning him,
and his skin was so tough that an ordinary small dagger-knife made no
impression whatever. With all their efforts they could not put the
poor animal to death till the following morning, when they could get
a strong and sharp knife to butcher him. Such a creature as this need
scarcely fear a jaguar or any beast of moderate size.

Such, however, is not the case with the dull-looking hairy forms which
move among the tall cecropia trees above the ant-bear’s head; for the
sloths, though busy enough in the trees, would fare but badly if they
were condemned to live upon the ground. The sloth is surely one of the
most curious examples of how an animal may live and flourish by taking
to a strange way of life. We have seen (p. 202) how his ancestors, the
Megatheriums, walked upon the ground, while he himself was formerly
pitied by all travellers because his arms are so long in comparison
with his legs that if he wants to walk he has to drag himself along
upon his elbows, and while the ankles of his hind feet are so twisted
that he can only rest on the side of the foot. But then they forgot
that he seldom or never descends to the ground, for the buds and leaves
of the trees are his food, and they are so juicy that he does not need
to come down to drink, and when he is in his natural place in the trees
he is no longer helpless.

There, safe from prowling animals on the ground below, he hangs like
a hammock from the bough. The long fingers of his hand (in some
sloths two, in others three, in number) and the three toes of his
twisted hind feet, all armed with long claws, seize the branch like
grappling irons; while his long flexible neck, which in one kind of
sloth has more joints than in other mammalia, enables him to look over
his shoulder and take a wide survey around. In the daytime he sleeps
with his back in the fork of a branch and his head bent forward on
his chest, but as the sun goes down he rouses to life and feeds by
stretching out those long arms to tear the leaves and twigs, which he
stuffs into his mouth and chews with his few back teeth. He has no need
to hurry or disturb himself, for his long thick hair protects him from
insects; and from the very fact of his being fitted for a tree-life he
is safe from other animals except snakes, and even they do not find him
out easily, so like is his dull matted hair to the colour of the bark
and moss. Even the young ones run very few risks, for they are not born
till they are perfect, and then the baby sloth clings to its mother’s
hair, and goes with her wherever she travels, sucking till it is old
enough to hang on to a bough and feed itself. So they live a completely
tree-life, and sleepy as they seem, yet they can move quickly enough
when they wish; and they often take advantage of a time when the wind
is blowing so that the branches from tree to tree sway against each
other, and by seizing the boughs as they touch, pass along and find new
feeding-grounds.

We see, then, that while the duck-billed water-mole and the echidna
have found a comparatively peaceful home in Australia, where the
pouched animals have reigned as monarchs, and still hold their own
in spite of the animals brought in by man; and while the opossums,
by taking to a tree-life, revel in the forests of America: so the
imperfect-toothed animals, an old and antiquated race of Life’s
children, still remain in a few scattered forms by reason of their
power to adapt themselves to peculiar conditions of life. What they
may have been in olden times we can scarcely guess; but one thing is
certain, namely, that before such strangely different forms as the
sloth, the ant-eater, the manis, and the armadillo could each have
settled down and taken on their special protective armour and habits,
many others must have tried, flourished awhile, and died out. When we
look at the bones of the gigantic Ground-sloths or Megatheriums of
olden times, which walked on four feet and are supposed to have lived
by tearing the trees up by the roots and feeding on the branches, or
when we examine the huge shield of the monster Glyptodon, and find
that it had no movable bands between the plates such as enable the
armadillo to burrow with ease, or in some kinds to roll up in a ball,
we see that it is not always size and strength that win in the battle
of life; but that the sloth of to-day has probably lived on because,
in taking refuge in the trees, it has secured great advantages by
those peculiarly long arms and twisted feet for which men used to pity
it; while the ant-eaters and armadilloes in their underground homes,
and the pangolins rolled up into prickly balls, show that passive
resistance and retiring habits, especially if fortified by a thick
skin, are sometimes quite as useful in the struggle for existence as
fierce passions and aggressive weapons.




[Illustration: THE PIONEERS OF THE ARMY OF MAMMALS]




CHAPTER IX.

FROM THE LOWER AND SMALLER MILK-GIVERS WHICH FIND SAFETY IN
CONCEALMENT, TO THE INTELLIGENT APES AND MONKEYS.


Having now taken leave of the curious pouch-bearers and the strange
primitive sloths and armadilloes, we find ourselves left to deal with
an immense multitude of modern mammalia, which have spread in endless
variety over the earth, and which may be divided into five great
groups--the _Insectivora_ or insect-eaters; the _Rodents_ or gnawers;
the climbing and fruit-eating Lemurs and Monkeys; the _Herbivora_ or
large vegetable-feeding animals; and the _Carnivora_ or flesh-eaters.

All these groups are very distinct now, and we naturally turn back
to ancient times to ask how they first started each upon their own
road. But when we do this, we meet with a history so strange that it
makes us long to open the great book of Nature still further, and by
ransacking the crust of the earth in all countries to try and find the
explanation, which will no doubt come some day to patient explorers.
The history is this. We saw in the last chapter that in those far
distant ages, when even reptiles were only beginning to spread and
multiply by land and sea, and when, although birds probably existed,
still they did not as yet leave any traces behind, small milk-giving
and insect-eating animals, the _Microlestes_ and _Dromatherium_ (see p.
183), were already living upon the earth, and left their teeth and jaws
in the ground.

Now, as ages passed on and the reptiles increased in strength, these
little milk-giving animals evidently flourished, for though we have not
yet discovered any of their bones in the rocks of the Chalk Period, yet
as we find them both before and after that time, they must have lived
on in some part of the world, the rich vegetation and abundant insect
life affording them plenty of food. Meanwhile the huge reptiles, of
kinds now long extinct, reigned over land and sea and air, and were in
the height of their glory,--when suddenly there comes a blank and their
history ends. When we look again, “a change has come o’er the spirit
of the dream,” and in the next period we find their bones no more.
From that time we meet only with the four groups of lizards, snakes,
tortoises, and crocodiles, which still survive; and the place of the
swimming, flying, and walking reptiles is taken by four-footed and
milk-giving animals.

Some of these were still marsupials like those that had gone before;
others were of strange forms, distantly related to them; others were
curious ancestral forms of our hyænas and bears, dogs and civets,
horses and tapirs,[129] in which the characters which distinguish these
groups were not so distinct as they are now, while others again were
old forms of moles, hedgehogs, squirrels, bats, and lemurs. In what
part of the world, then, had all these been growing up, that we come
upon them so suddenly? Before the seas of the chalk only the small
marsupials; after them, when the areas of land began to increase in
extent, a whole army of milk-givers, so different from each other and
so well adapted for their lives, that we even find among them such
peculiar forms as whales, with their arms converted into paddles, and
bats with their arms acting as wings.

What an idea this gives us of the immense period of time that must have
elapsed while the chalk was forming, the reptiles becoming extinct, and
the mammalia taking their place!

We have had a hint of this before, when we learned in _Life and her
Children_ how infinitely minute the shells are of which chalk is made,
and what enormous thicknesses remain of the chalk-beds. And now we find
these facts strengthened by the great changes which then took place in
the animal world, for even if (as is likely) older forms of these large
milk-givers existed in earlier times, and we have not yet found them,
yet there are such great differences between whales, bats, dogs, and
lemurs, that our imagination stands appalled at the time required to
account for them.

Again, where are the traces of all the forms which must have existed
between the little marsupials and this great army of four-footed
beasts? At present no one can answer. Forty years ago we knew nothing
even of those early marsupials, and people said there were no
milk-giving animals until after the time when the chalk was formed. Now
a few jaws have told us that milk-givers had been already in the world
for ages; and it may be that before forty years more have passed, some
child now reading these lines, and following in the footsteps of such
patient explorers as Beckles and Gaudry, or the American naturalists
Leidy, Cope, Marsh and others, who have such a grand field before them,
may discover bones which will unravel the history of that crowd of
mammalia which now seems to start up like Cadmus’ army from the ground.

But for the present we can only begin with them as we find them
immediately after the Chalk Period, and a strange motley group they
appear. There, roaming among the palms, evergreens, screw-pines and
tree-ferns, which flourished in Europe and North America in those
warmer times, were beasts larger than oxen, with teeth partly like
the tapir, partly like the bear, and feet like the elephant,[130]
which may have been both animal and vegetable feeders. With them were
true vegetarians, which could be called neither rhinoceroses, horses,
nor tapirs, but had some likeness to each.[131] Others, half-pigs
half-antelopes, were thick-skinned, but graceful and two-toed,[132]
while a little fellow no bigger than a fox,[133] with five toes on his
front feet and three behind, the ancestor of our horses, grazed in
the open plains. There too, moles, hedgehogs, and dormice had already
begun to make their underground homes, and squirrels and lemurs sprang
about the trees of the forest, where bats roamed at night in search of
insects. Nor was this life without its dangers, for beasts of prey,
half-bears half-hyænas,[134] were there to feed upon their neighbours,
and with them a creature half-dog half-civet,[135] with several
other carnivorous animals with feeble brains and partly marsupial
characters,[136] and lastly a large flat-footed dog-bear,[137]
something between a dog, a cat, and a bear, with a very small brain but
plenty of teeth, represented the most primitive flesh-eating animal
known to us.

None of these forms were of the same species as those now living, and
many of them, as we see, had characters which we now find in two or
three different animals; showing that they had not yet specialised the
various weapons of attack and defence, and the difference of limbs and
teeth which now distinguish their descendants. So that, for example,
though there were fierce animals of prey, none had yet the formidable
teeth of the tiger nor the muscular strength of the lion, neither had
the vegetarians the fleetness of the horse, the horns of the deer, nor
the large brain of the elephant.

This had all to come with time, and from that day to this their
descendants have been spreading over the earth. Some, large and
powerful, have conquered by strength; some, by superior intelligence,
have learned to herd together and protect each other in the battle of
life; some have gone back to the water and imitated the fish in their
ocean home; and others, smaller and feebler, have lived on by means of
their insignificance, their rapid multiplication, and their power of
hiding, and feeding on prey too minute to attract their more powerful
neighbours.

Among all these there are hundreds of different forms, branching out
here and there, crossing each other’s path and often jostling on the
way; while during the long period between our first knowledge of them
and now, they have been driven or have travelled from one country to
another, from the northern to the southern hemisphere, or from the
Old to the New World, till in many cases it is impossible to say what
routes they have taken.

How, then, shall we get a glimpse of the nature of these large groups?
Shall we take the moles and hedgehogs as the lowest, and the monkeys
as the highest, and then travel in a straight line through the forms
between? Scarcely, I think, for it is very doubtful whether the lemur
and the dormouse may not be able to boast of ancestors as ancient as
the moles, while the elephant and the dog are surely as intelligent
and far nobler animals than the monkey. No! we must make up our minds
at once that the different branches have grown side by side to much
the same height, so that our genealogical tree, if it were possible to
make one, would, like a real tree, be a mass of entangled twigs, some
of which would, indeed, be less aspiring than others, yet on the whole
we could scarcely say that one reached nearer to the sky than another.
What perfection they have each obtained in their own line is quite
another question, and one which we are able to trace out.

       *       *       *       *       *

Thus, for example, the gnawing animals or _Rodents_, and the
insect-eaters or _Insectivores_, are undoubtedly the lowest types next
to the sloths and armadilloes, the insect-eaters especially having very
primitive skeletons and small brains. Yet we shall find that we pass
very naturally from them to the intelligent monkeys, while, on the
other hand, the vegetable-feeders and flesh-eaters go off upon quite a
different line of their own.

Let us, then, begin with these two lowly groups, the _Rodents_ and
_Insectivores_, and see how they have conquered their humble place in
the world. One thing is clear, that they do not hold it by strength or
audacity, for taken as a whole they are small and weak animals; the
giants among rodents, the Capybaras of South America, where all lower
kinds of animals thrive, are only as large as good-sized pigs, and
the smallest, the “Pocket-mice” of North America, are not bigger than
large locusts; while the insect-eaters have nothing larger than the
“Tenrecs” or soft-bristled hedgehogs of Madagascar, about the size of a
tailless cat; and the rest of the group vary from two to eight inches
all over the world. Moreover, they are as a rule timid, and though some
of them fight fiercely among themselves, yet they scamper away and hide
at the least alarm, and generally choose the twilight or the dark night
for their feeding time.

Stroll out some fine summer’s evening, when the sun has set and the
moon has not yet risen, and as you wander in the fields and woods with
eye and ear open, you will scarcely have gone far before you will
be aware that there is plenty of stir going on. Some active little
field-mouse will cross your path in her eager search for grain and
seeds to lay up for her winter store, or you may startle a hare in the
long grass and watch her run across the field, or see her sit upright
on her haunches surveying the quiet night-world. Or, if you pass over a
common, the number of little white tips glancing in the twilight from
under the furze bushes will tell you that the rabbits have not yet
disappeared into their burrows; while as you enter the wood the sharp
little eyes of the squirrel will peep down upon you from the beech
trees, as she watches over her little ones in their comfortable nest in
the branches.

All these are _Rodents_, and you may know them by their four long
chisel-like front teeth (see B, Fig. 55), which have a large gap on
each side, between them and the grinding teeth behind. These chisel
teeth have not bony roots like the teeth of most animals, but rest in
a deep socket, and continue growing during the whole of the animal’s
life; and they have a hard coat of enamel in front, so that as the
tooth wears away behind, this enamel stands out and forms a sharp
cutting edge, and there is perhaps no tool more efficient for gnawing
a root, a nutshell, or the solid wood of a tree, than the tooth of a
beaver or rat.

[Illustration: Fig. 55.

    A, Skull of an insect-eating animal (_Insectivore_), showing the
    numerous pointed teeth. B, Skull of a gnawing animal (_Rodent_)
    showing the large chisel teeth in front, and the gap between these
    and the hind teeth.
]

But these animals have another and quite a different set of companions,
as you will learn if you are lucky enough, by looking carefully along
the hedge, to startle a little shrew in its quest for worms, or to
catch a hedgehog shuffling along at a sharp trot after his nightly
meal of beetles, slugs, and snails; nay, you may even, if it be early
summer, come across a mole, or find two fighting fiercely together for
possession of the only thing they come to the upper world to fetch--a
wife.

These creatures have not the long front chisels of the hare or the
shrew; on the contrary, their mouth is small, and crowded with a number
of fine pointed teeth (see A, Fig. 55), of which even the back ones
have sharp cusps or points, well fitted for crushing insects. For these
are _Insectivora_ or insect-eaters; and while the rodents are gnawing
at roots and leaves and nuts, these devourers of small fry mingle with
them very amicably; while both groups only ask that the night-owl
may not see them in their evening wanderings, nor the weasel and his
bloodthirsty tribe attack them in their homes.

For, ever since they began the race of life, long long ago, these two
very different orders of animals have been trying to feed without risk,
and to keep out of the way of flesh-eating birds and larger creatures.
And so it has come to pass that, though the rodents are mostly
plant-eaters, while their associates are insect-eaters, yet, as both
are trying to conceal themselves, and get their food by stealth, they
have acquired curiously similar external forms, weapons, and habits of
life, with the one exception of their teeth and the manner of eating
their food.

Even in our English meadows a casual observer might easily mistake
the little _insect-eating_ shrew, with its soft velvety coat and bare
paws (Fig. 56), for a near relation of the _gnawing_ Harvest-mouse
nibbling the grass tips just above its head (Fig. 57); though a nearer
inspection of the shrew’s long snout, small ears, and sharp teeth,
would show the difference. And as to their way of life, the Field-shrew
and the larger Field-mouse live like two brothers of the same race.
They both make burrows in the banks, though the field-mouse digs the
deeper hole, and they both line their home with dry grass to bring up
their little ones. And when the winter comes they both retreat into
their homes; the shrew to sleep away the dark days, and the mouse to
wake from time to time to feed upon his store. Only their food is quite
different, and when they come out in the twilight of the summer’s
evening, the mouse is on the look out for acorns, nuts, grains, and
roots, which it gnaws off with its sharp chisels, while the shrew is
chasing worms and insects, or cracking tiny snails with its pointed
teeth.

Then if you lie and watch quietly by the bank of a river, there you
may see the Water-rat or Vole (not the land-rat which sometimes hunts
for prey in the water) diving under with a splash to gnaw the roots
of the duckweed or the stems of the green flags, and coming up to sit
on the bank, and hold them in his paws as he eats them; while not far
off a pretty little Water-shrew, this time too small and different to
be mistaken for his companion, is swimming along with his hind feet,
the air bubbles covering his velvety back with silvery lustre as he
chases water-shrimps, or feeds on fish-spawn or young frogs. Both these
animals live in streams and rivers, and bring up their young in holes
in the bank, where they can jump into the water if the weasel attacks
them, or the common snake pokes his head too near their home.

These are perhaps the chief examples we shall find in England of
insect-eaters and gnawers living near together and following the same
kind of life; but if we look over the world it is most curious how many
parallels we can draw between them, showing how the same dangers have
led to the same defences.

[Illustration: Fig. 56.

A group of Insect-eaters.

Common Shrew, Hedgehog, Mole, Bat.]

Look among the _insect-eaters_ at our Hedgehog (Fig. 56), so weak
and shuffling in his movements that he would have been cleared out of
the world long ago but for the sharp elastic spines which grow upon
his back in the place of hair. There he goes trotting along under the
hedges in the twilight, cracking the horny skins of beetles, or sucking
eggs, or devouring worms, slugs and mice when he can get them, without
a thought of fear. For he can roll himself up in an instant if danger
be near, and his sharp spines will keep off even dogs and foxes, unless
they can catch him unawares, and bite him underneath in his soft
throat. Nay, he can actually master a poisonous snake, and use it for
food, not suffering even from the adder’s fangs when they pierce his
tender nose.

[Illustration: Fig. 57.

A group of Rodents.

Harvest-mouse, Porcupine, Mole-rat.]

It is curious to see how quickly he can roll himself up by drawing
together the strong band of muscle which passes along the sides of his
body from head to tail, sending out bands of muscle to feet, head,
and legs. When he contracts this band his limbs are all drawn in, and
the spiny back forms a kind of prickly bag all round them, even his
tender snout being safely hidden. Nor are his spines merely sharp--they
are as elastic as the hair of which they are modifications; and the
hedgehog can drop safely from a height when he is in his ball-shape,
falling on the spines, which bend and straighten again as though made
of whalebone. So he lives under hedges and in ditches till the winter
comes, when he settles down in a nest of moss and leaves in a hedgebank
or a hollow tree, and sleeps the cold weather away. And when the spring
comes he takes a wife, who brings up her little ones in the nest of
moss and leaves under the hedgerow, watching over them as long as their
spines are soft.

And now where shall we look among the _rodents_ for a creature to match
the hedgehog among insect-eaters? Surely to the “fretful Porcupines,”
which feed on all kinds of vegetable food in Southern Europe, Africa,
Asia, and America, protecting themselves by the formidable array of
spines which they can raise at will. Even the European porcupine,
which is about two feet long and the weakest of his tribe, is better
protected than is generally believed. It is true that his long black
and white ringed spines only cover the hinder part of his body, but
the hair of his head and neck hides a number of short spines which can
give very sharp pricks; and though he is a timid night-loving animal,
hiding by day in burrows and holes of the rocks, yet when attacked he
jerks himself up against his enemy, so that the long spines wound very
severely. And when we come to the Tree-porcupines, which hang by their
tails from the palm trees in Mexico and Brazil, we find that their
short stout spines are a very efficient defence both against birds
of prey and the deadly coils of the boa constrictor and other large
snakes; while the Western porcupine and the almost tailless Canada
porcupine, which climb trees and strip off their bark and buds, have
a clothing of such dangerous weapons that pumas and wolves have been
known to die of inflammation from the wounds.

The porcupine among the rodents, then, like the hedgehog among
insect-eaters, has adopted prickles as a defence. But there are many
soft-haired creatures living upon the ground in both families which
have no protection but concealment, and we find them both gaining it by
burrowing into the ground. Among the _insect-eaters_ the Mole is the
most successful digger, and as he works his tortuous way through the
ground in search of worms and grubs, it is scarcely possible to imagine
a miner more usefully equipped for his work. His skeleton, it is true,
is, on the whole, more primitive and roughly finished than that of
higher animals, his ear is almost closed, and his eye though bright
is deeply hidden; but the parts specially necessary to him are most
wonderfully fitted for the work they have to do.

His broad shovel-like front paws (see Fig. 56), with their five strong
claws, set each in a long groove at the tip of the last finger-joint,
are powerful tools for shovelling away the earth, as he turns them
outwards and pushes with them as if he were swimming; and they are
carried on strong, short, and broad front legs, fixed to collar-bones
and a shoulder blade of unusual strength, while the breastbone is so
formed as to throw the legs forward and bring them on a level with his
nose when he is burrowing. This nose, too, has its part to play, for
it is long and slender, with a small bone at the tip, which helps him
in pushing his way forwards while his hind feet are planted flat and
firm on the ground behind, while it also serves to pick out the grubs,
worms, and beetles from their narrow holes.

Here, then, we have the very best of miners, who has secured food and
safety far from the busy world above, and spends his time hunting for
grubs and earth-worms in the dark earth below. He is a most voracious
animal, and makes the ground above him heave and swell as he toils
through it eager for prey, pushing up every now and then with his nose
the loose earth he has excavated, thus marking the line of his route by
molehills.

But when he builds his home and fortress where he takes his long
winter’s sleep, and hides from weasels and pole-cats, he takes care to
throw no loose rubbish above; on the contrary, he presses the earth
together so as to make the walls of his chamber firm and hard, and
carries out from it a number of passages, by any of which he can reach
his home in safety when he is pursued too closely.

Thus by his cleverness in burrowing, and the useful tools which he
carries upon his body, the mole has managed to find safe feeding-ground
and shelter, when no doubt many of his relations living above ground
have been killed off. Even underground he has his enemies, for the
Weasel, the Stoat, and the Badger find him good eating, while if he
meets one of his own brothers in a narrow passage they will fight till
one is killed and eaten; yet though fierce he is also tender-hearted,
for mole-catchers say that when a mother-mole is caught in a trap the
father may sometimes be found dead by her side.

And now if we turn to the _rodents_ for rivals to the mole, we are
almost confounded by the multitude of creatures which have found safety
in burrowing. Not only have we the rabbit-warrens, by which the sandy
soil of our commons is riddled in every direction with holes, leading
to burrows where the mother lies snugly hidden with her five or six
naked little ones in a bed of her own fur; but we have the extensive
burrows of the little, long-legged, leaping, gnawing Jerboas of Africa,
which are so like the Jumping Shrews among insect-eaters. Then again
there are the underground cities of the South American Viscachas
and Chinchillas, and the extensive subterranean settlements of the
Lemmings,--those curious rodents, which from time to time start off in
vast swarms across Norway, over mountain and valley, through flood and
fen, over rivers and plains, preyed upon by eagles and hawks, foxes and
weasels, on their way, but never stopping or swerving in their course
till they reach the sea, into which they plunge and drown themselves.
Again, every inhabitant of Switzerland knows the Marmot and the burrows
he forms, scratching up the earth with his hind feet and patting it
together with his front paws and his broad nose; while every American
child has heard of the hillocks thrown up by the “Prairie Dogs,”[138]
which undermine whole plains in the far west with their underground
cities, where the burrowing owl shares their home with them, and the
rattlesnake steals their young.

[Illustration: Fig. 58.

The Pyrenean Desman,[141] an insect-eating water animal.]

But all these come out upon the land and use their burrows chiefly
for homes and nurseries. We can match the mole better than this among
_rodents_, for in Eastern Europe, India, and Africa, there are blind
creatures called Mole-rats[139] (see Fig. 57), with broad flat heads,
small eyes hidden in their fur, short tails, and feet with sharp
claws, which live almost entirely underground, burrowing subterranean
galleries in the sandy plains in search of roots, as the mole does
for worms; while the Pouched Rats[140] of North America also live in
burrows, throwing up hills just like mole-hills, and gnawing roots and
buried seeds, which they carry in their large cheek-pouches, to store
up in their underground chamber for winter food.

Nevertheless, the rodents can scarcely compete with the mole as
burrowers, and it is not till we come to the water-animals that
_they_ begin to have the best of it. True, the insect-eaters have the
Water-shrew and the curious West African Shrew,[143] with its broad
tail; while the Desman[144] of Russia and the Pyrenees (see Fig. 58),
with his dense furry coat, his broad tail, and his webbed feet, is
quite a match for the gnawing Musk-rat or Musquash of North America,
for they both live in fortresses on the river-banks, to which hidden
passages are well contrived to elude pursuit; and while the desman,
with his curious movable snout, pokes about in the Russian or Pyrenean
streams after leeches, water-snails and insects, the musquash in
America gnaws off the roots and stems of water-plants.

[Illustration: Fig. 59.

The Beaver,[142] a gnawing water-animal.]

But the insect-eaters have no water-animal to match the Beaver in
sagacity, judgment, or engineering. For here we have a creature not
much larger than a good-sized cat, cutting down trees, dragging logs
six feet long to the water’s edge, and building with them the most
elaborate log-houses and water-dams. With hind feet webbed up to the
claws, and his broad tail as a rudder, the beaver has so much swimming
power that his fore legs are free to carry and place the wood, while
his broad orange-coloured teeth, as sharp as chisels, which grow as
fast as he wears them away, are his cutting instruments. With them
he gnaws a deep notch in the trunk of a larch or pine or willow, as
deep as he dares without fear of its falling, and then going round
to the other side, begins work there till the trunk is severed and
falls heavily on the side of the deep notch, and therefore away from
himself. Then, after stripping off the bark and gnawing the trunk into
pieces about six feet long, he uses his fore-paws and his teeth to
drag them into position to build his dam. The lighter branches he uses
to make his oven-shaped lodge, laying them down in basket-work shape,
plastering them with mud, grass, and moss, and lining the chambers with
wood-fibre, and dry grass; and the logs he piles up to form dams, lest
at any time the stream should flow away and leave the entrances to his
home dry. These dams are very skilfully and cunningly formed. He always
makes the deep notch in the trunk on the side near the water, so that
the tree in falling comes as near as possible to the stream; then he
does not always clear away all the branches, but he and his companions
place the logs with these lying _down_ the stream, so that they act as
supports to resist the current and prevent the dam being washed away.
Thus they make a broad foundation, sometimes as much as six feet wide,
and upon this they pile logs and stones and mud till they have made a
barrier often ten feet high and more than a hundred feet long.

In this way they clear the woods just round their stream, as if a whole
gang of wood-cutters had been there at work; and as the dams check back
the water and form broad meres, there are soon swamps on all sides,
where peat moss grows and “beaver-meadows” are formed.

Here the beavers live in companies, each in his own chamber with his
wife and family, though underground passages often lead from one to the
other, and when water-plants and soft bark are scarce, they will often
travel some way inland to feed on fruits and grain. But if among the
community any are lazy or will not take partners, they are driven out,
to find a refuge in holes of the river-banks, where they sulk alone.

In Western Europe, indeed, where they have been so much persecuted,
most of the beavers live alone in holes, though communities are still
left in parts of Germany, Scandinavia, and Siberia. But in North
America they still carry on their true communal life, and those who
visit their wonderful settlements will not be surprised to learn that
they possess the largest brain for their size of any of the gnawing
animals.

Indeed, they would have no rival among rodents if it were not for the
clever sagacious rats, and these have probably sharpened their wits by
living so long in contact with man, for they are burrowers chiefly in
human dwellings, granaries, stables, mines, ships, and every available
dwelling-place where they can rob and plunder, and outwit even man
himself by working their way into his stores, and acting together in
carrying away his goods.

So the insect-eaters and rodents hold their own both by land and
water, penetrating, in the forms of bats and mice even to Australia,
though the rodents are most widely spread, for except two very rare
animals[145] in the West Indian Islands, there are no Insectivora
except bats in South America. The bats, however, remind us that both
these groups have also found homes above the ground and in the trees.
There the _rodents_ have the lovely little Squirrels, which, with their
brown red backs, white waistcoats, and graceful bushy tails, scamper
up the trees of our English woods. It is very tempting to dwell upon
the squirrel, with his little wife, to whom he remains faithful all his
life, his beautiful round nest, in which his young are so carefully
reared, and his pretty ways as he sits upright gnawing beechnuts or
acorns, holding them in his tiny hands. He has made good use of his
opportunities, being almost as widely spread as the rat, for there
are squirrels of some kind all over the world, wherever there are
forests, except in Australia. Several of them in the East and North
America have folds of skin at the side of the body, which, when tightly
stretched, by extending the four limbs, enable them to take flying
leaps from tree to tree (see Fig. 60). Even without flying, however,
the squirrel is so nimble that he manages well to escape his enemies,
except some of the birds of prey and the fierce tree-marten and wild
cat; and as in cold countries he sleeps soundly in snug holes of a
tree till the leaves grow again to give him shelter, he is not often
detected even by these.

[Illustration: Fig. 60.

On the tree, the Taguan[146] or flying squirrel, a rodent; Flying
below, the Colugo,[147] an insectivorous animal.]

Nevertheless, in tree-life and in the air it is the turn of the
_insect-eaters_ to claim the advantage. It is true that the
insect-eating Bangsrings,[148] which scamper up the trees in Sumatra
and South-East Asia, and were long mistaken for squirrels, are a small
family and not of much importance; but what shall we say to the Bats,
the only true flying milk-givers? Or what, again, to that curious
animal the Colugo or Flying Lemur of the Malay Islands, which belongs
to the insect-eaters, and yet has some points like marsupials, some
like fruit-bats, and some like the true lemurs? This strange creature,
which seems like the remnant of some branch-line from very ancient
times, climbs the tree like a squirrel by means of its claws, and
then spreading out its limbs displays a broad membrane (see Fig. 60)
stretching not only along its sides but across its tail, and from the
front of the arms to the neck as in bats, and so sails down from one
tree to another. The mother, which Mr. Wallace examined, nurses the
little one on her breast just as the lemurs do, while large folds of
her skin protects the small, bald, naked little creature, something
after the manner of an imperfect pouch. Lastly, while they sometimes
feed on insects, the chief diet of these colugos is fruit, like the
lemurs, to which group they were once supposed to belong.

       *       *       *       *       *

But of all modified insect-eaters the most extraordinary are the Bats,
which are so different from all the others that they have been placed
in a distinct order[149] of their own. Imagine a little creature about
three inches long, with a body something like a shrew, large ears,
a protruding snout, and plenty of sharp teeth (see Figs. 61 and 62).
Let it have a breast bone projecting more than in most milk-givers,
and covered with a large mass of muscle as in birds, fitted to move
the wings, but having nipples to suckle its young. Let it have large
shoulder-blades and collar-bones, a strong upper arm, a very long
lower arm (_fa_, Fig. 61), and four immensely long fingers to its hand
(_ha_), and a short clawed thumb (_t_). Let its hind legs be short and
weak, with a long spur behind the heel (_h_) of its five-toed feet,
and finally let the skin of its body grow on over the arms and long
fingers, filling in the space between the elbows and the neck in front,
and stretching away behind, over the legs down to the ankle, and on
behind the legs, so as to enclose the tail. This skin growing from the
back above, and the under part of the body below, will enclose the
bones of the arms, hands, and legs, like a kite with calico stretched
on both sides (see Fig. 56, p. 220), and when the long fingers are
outspread and the legs opened, no limbs will be seen, but only a small
body and head, with an immense expanse of skinny wing, from which the
short clawed thumbs and the four toes of the feet stick out before and
behind.

[Illustration: Fig. 61.

Skeleton of a Bat.

(Lettered to compare with bird’s skeleton, p. 126).

_fa_, fore arm; _w_, wrist; _t_, thumb; _ha_, hand; _h_, heel; _f_,
foot.]

Now this creature is no longer like the flying squirrels or the colugo,
which can only take floating leaps; for though like them it has only
a membrane stretching out from its body, yet this has become a long
flexible wing, formed on a widely outstretched arm and abnormally
long hand, and moved by powerful muscles like the wings of birds or
insects. It is essentially fitted for flitting through the air in
search of prey, while it makes but little use of the running power
which it possesses in common with all other insect-eaters. If you see
a bat moving along the ground, you will acknowledge at once that it is
a true quadruped, yet, by its awkward gait as it shuffles along on its
clawed thumb and toes, you will judge that it is not an earth-loving
animal. Watch it at night on the wing and it is quite another creature;
then it will flit about in and out of cracks and crevices, under the
eaves, round the haystacks, or among the trees, and never once strike
its wings against anything, though it has been proved that it does not
trust chiefly to its bead-like eyes to guide it.

Bats have been blinded, their ears stopped with wool, and their noses
with sponge dipped in camphor; and yet, without sight, hearing, or
smell, they steered quite successfully between outstretched threads
or tree-branches, or found their way into a hole in the roof. In
truth, as they have become fitted to navigate the air, they seem also
to have become sensitive to its currents. Their wings are abundantly
supplied with nerves and blood-vessels, and have little rough points
all over the surface; their ears have generally a second ear-lobe or
leaf within the outer one, and those which have not this have leaves of
skin or membrane round their nose. With all these they seem to feel the
slightest difference in the air, so as to detect at once whether they
are in the open, or whether any resisting object is near them.

[Illustration: Fig. 62.

A Bat walking.]

Now it is clear that a creature of this kind, able to chase insects
in the air, even in the darkest night, can secure much food that the
running insect-eaters can never reach. When the little common English
bat, the Pipistrelle, awakes from his day’s sleep, which he has been
taking, head downwards, hanging by his feet in some old tree or under
the roof of a barn, he finds the gnats and flies abroad, and begins his
chase in the twilight--up and down, from side to side he flits, and his
wide-open mouth takes in insects at every turn. And by-and-by, as the
dark nights come on, the Long-eared Bats begin gradually to stir from
their clusters in the barns and old buildings, and, unfolding their
wings so as to display their ears as long as their bodies, commit sad
havoc among the night-moths. All night long their shrill squeak may
be heard, but before day dawns they are away again, and may be found
hanging in dense masses by their hind legs to the timbers of some old
church belfry, or in caves, or even under the roofs of houses, where
they find an entrance by some hole, and go in by hundreds to hang from
the rafters.

Many accounts are given in American writers of the thousands of bats
collected in the caverns which abound in the Western States, while in
the Egyptian catacombs they hang in myriads. For of all things a bat
dreads the light when beasts of prey are abroad, and next to that he
fears any position near the ground where weasels, wild cats, or other
flesh-eating animals may seize him in his sleep. Nay, the smaller
bats live in constant fear of the larger ones, for they feed upon one
another with evident relish.

Yet in spite of dangers the bat family, aided by its power of flight,
has spread all over the world, from the Arctic Circle to the Equator,
east, west, north, and south. In cold countries they hang by their feet
in the winter, or sometimes by their clawed thumbs, and sleep in dark
recesses, scarcely breathing till the warm weather and the insects
return; but in warm countries they are active all the year, sleeping by
day and feeding by night.

In England and North America they are content chiefly with insect food,
but in South America the Vampires, among the leaf-nosed bats, fasten
on to large animals and suck their blood. Mr. Darwin had his servant’s
horse bitten and disabled for two days by a vampire in Chili; while Mr.
Wallace, when on the Amazon River, was himself twice bitten, once upon
the great toe, and once on the tip of his nose while asleep! A bat is a
grotesque-looking animal at best; but some of these leaf-nosed bats are
simply hideous, with their wide-open mouth, sharp teeth, and the skinny
leaves sticking up round their nose.

How different are the gentle-looking fruit-eating bats of the Tropics,
which seem to belong to quite a different branch of the family. Their
fox-like and intelligent faces are a pleasure to look at, reminding one
of the lemurs, and harmonising beautifully with their quiet peaceful
life among the fig-trees, guavas, mango-trees, and plantains of the
East. There they hang in dense masses from the tall silk-cotton trees
till night comes on, and then take wing as soon as the sun is set, and
hooking themselves by one thumb to the fruit-trees, hold the fruit in
the other as they feed.

[Illustration: Fig. 63.

Fruit-bats[150] hanging from the ledges of a cave in the Mauritius.]

Thus we have a wide range of habits in bats, from the insect-eaters to
the blood-sucking vampires on one hand, and the gentle fruit-bats on
the other.

But one virtue the most bloodthirsty and the most gentle have in
common, and that is maternal love. As soon as the little ones are born
they cling to their mother’s breast, and she often folds over them
the skin which covers her tail, so as to form a kind of pouch, so that
wherever she flies they go with her, and are carefully tended and
suckled by her till they can take up the chase for themselves.

And now we have followed out the Rodents and Insectivora in their
various lines. Both lowly groups, of simple structure and with
comparatively feeble brains, they have chiefly escaped destruction
from higher forms by means of their nocturnal and burrowing habits or
arboreal lives, and the marvellous rapidity with which they breed,
combined with their power of sleeping without food during the winter
in all cold countries. Nevertheless, though they are often strangely
alike in outward form, they differ in many remarkable respects. The
insect-eaters now existing are chiefly a few straggling forms of a once
widely-spread group; while the rodents, on the contrary, are still
a very numerous and varied family, spread all over the earth, and
boasting of such intelligent forms as the squirrel, the beaver, and the
rat. But here their advantages appear to end, while the insectivora
point onwards not only to the bats, the only flying milk-givers, but
also through the colugo to the lemurs, and thus onwards to the monkeys.
It may be, and indeed probably is true, that the colugo started off
from some very early type, more nearly related to the pouch-bearers
than the present insect-eaters are; while the monkeys, again, branched
off long ago on another line quite separate from the modern lemurs.
But if the tiny shrew wished, like many little people, to boast
of distinguished connections, he might with justice suggest that
somewhere among his primitive ancestors one would probably be found
whose descendants had risen far higher in the world than himself.

       *       *       *       *       *

It may perhaps seem strange to many readers that instead of leaving
the apes and monkeys to the last, as standing at the head of the
animal kingdom, we should bring them in now, directly after such lowly
creatures as hedgehogs and mice, bats and beavers. It must, however,
be repeatedly borne in mind that we are not following a direct line
upwards, but a family tree, which branches in all directions; and
though the gap between monkeys and insectivora may be great, yet they
have many more points in common than the monkeys have with any of
the vegetable-feeders or carnivorous animals, and probably we should
find these links even more marked if it were not that we know so very
little of the early history of Monkeys. The reason of this probably is
that they live and die in woods, where any remains of their bodies not
eaten by other animals decay and crumble to dust, so that we have only
here and there a few skeletons to tell any tale of their ancestors.
And so it comes to pass that when we first meet with the great army of
milk-givers (see p. 209), lemurs, and soon after true monkeys, existed,
with thumbs on their hands and grasping great toes on their feet.

In those times, when the climate of Europe and North America was warm
and genial, they spread far and wide with the other animals over
Germany, England, and the United States, where forests of palms,
fig-trees, and evergreens afforded them a congenial home. But as soon
as these began to fail and the climate of the northern countries became
cold and cheerless, we find the monkey-kingdom growing narrower and
narrower, till in our own day, while the flesh-feeders range from the
Arctic Circle to the Equator, and the vegetarians have their reindeers
travelling over ice and snow on the one hand, and their hippopotamuses
and giraffes wandering under the burning sun of Africa on the other,
the tender monkeys, which shiver in cold and damp and are constant
victims to consumption, have shrunk back into the Tropics, where there
is abundance of fruit and vegetation for their food. It is true a
few kinds still linger in Japan, and one[151] on the sunny Rock of
Gibraltar, while one or two wander up the mountains of Tibet into the
regions of frost and snow; but, on the whole, monkeys are essentially
inhabitants of warm countries, where the trees are perpetually covered
with leaves and fruit, as in the luxuriant forests of South Asia and
Tropical Africa in the Old World, and Tropical America in the New.

Though they have but a narrow kingdom, however, there can be no doubt
that they make the most of it, and have managed to develop shrewdness
and a sense of fun and frolic which would be quite unaccountable if it
were not for one peculiarity which they possess. This peculiarity is
the grasping power of their hands and feet, which has caused them to
become such active nimble creatures, swinging, leaping, and running
quickly along the boughs of the tangled forests in which they live.

Yet the monkeys do not stand alone in this grasping power, for we have
seen that the opossums have hind-thumbs among the pouch-bearers, while
among the rodents the little dormouse has a nailless grasping toe-thumb
on his hind feet. So that here already we have some clue to possible
descendants of poor relations of the monkeys down in the lower forms
of life; and when we remember that the colugo (see p. 232) is related
on the one hand to marsupials and insect-eaters, while on the other it
leans towards the lemurs, and through them to the monkeys, we begin
to suspect that somewhere low down in all these groups we might find
ourselves among a family party from which all the different branches
have sprung; just as we found the birds, reptiles, and milk-givers
starting in past ages among the amphibia.

It must, however, be very long ago since the monkeys scrambled to the
top of this family tree, for even the Lemurs,--which are not true
monkeys, but a lower type with an irregular number of teeth like the
insect-eaters, hairy hands and fox-like faces, without any change of
expression,--have well-developed thumbs and toe-thumbs, with nails on
hands and feet, and they have besides that free movement of the arm
and wrist which gives at once an advantage to the _Quadrumana_[152] or
four-handed animals.

These lemurs are a gentle and loving race of creatures, which run on
all fours like cats, and have none of the mischievous half-reasoning
pranks of monkeys. They must have crept down long long ago from the
great battlefield of Europe and Asia, and taken refuge in the forests
of South Africa and India, and especially in the Island of Madagascar,
where they were sheltered from the attacks of larger and fiercer
animals. They are splendid climbers, with very sensitive tips to
their fingers, which are often of different lengths, and many of them
have eyes with pupils which expand and contract like those of a cat,
enabling them to see well by day and night, while a quick sense of
hearing warns them of any danger near.

In India, indeed, their relations the “Lories” are most of them
slow-moving night-loving animals, while in South Africa the “Galagos”
sleep all day in a nest of leaves, and are only active at night, crying
to each other as they leap from bough to bough, seizing the beetles and
moths in their little hands. It was probably from such night-wanderers
as these that the general name of “lemurs” or “ghost-like” animals
was given to the group, for the _true_ lemurs, which live in
Madagascar,--their special home, where they have few enemies,--may be
seen by day running along the branches, snatching the fruit, sucking
birds’ eggs, and even feeding on the young birds themselves, for they
have plenty of crushing teeth, as well as incisors for clipping the
leaves. Sometimes they sit in companies, huddled together, wrapping
their soft furry tails round each other’s necks, for they are chilly
creatures, and even in that warm country their thick tails, which are
quite useless for clinging, seem to be a comfort to them. More often
they are running and jumping, especially in the evening time, the
mothers carrying their naked little ones nestled in the fur of their
stomach, or, when they are older, on their backs; and whether slow or
quick, day-lovers or night-hunters, these happy thoughtless little
beings flourish in the quiet island home they have found, cut off from
the struggling world beyond.

[Illustration: Fig. 64.

The Aye-Aye and a Lemur in the forests of Madagascar.]

And among them at night, when the soft clear moonlight shines down
on the thick forests in the interior of the island, comes a small
ghost-like animal, the “Aye-Aye,” with wide-staring eyes, furry body,
and long bony jointed fingers. He utters a plaintive cry as he creeps
from bough to bough, stripping the bark off the trees with his strong
chisel-like teeth to find some worm-eaten hole into which he thrusts
his skinny fourth finger to pick out a grub, and then moistens his meal
by drawing the same long finger rapidly through some watery crevice,
and then through his lips for drink. This strange creature too is a
kind of lemur, so far as he can be classed at all, with his gnawing
teeth, his hind feet like a monkey’s, his large spoon-shaped ears,
and his uneven fingered hands, with strong curved claws. At any rate
he belongs to no other group, but tells us once more the old story of
creatures in isolated countries putting on strange shapes suited to
extreme habits of life.

Now between these gentle, but low-brained and dreamy lemurs, and the
active, intelligent, mischievous monkeys, there is a great gap. The
creatures most like them are the little Marmosets of South America,
which run like squirrels among the forest trees of Brazil, feeding
on bananas, spiders, and grasshoppers, and making their nests in the
topmost boughs. But these marmosets are true monkeys, with expressive
faces, and the peculiar wide-spread nostrils which we find in all the
monkeys of the New World. For it is to South America, that land of the
less advanced forms of life, that we must look for the lower kind of
quadrumana, with side-opening nostrils,[153] thumbs which move in a
line with the fingers of the hand, and not nearly so much across the
palm as in the higher apes, and thirty-six teeth in their mouth instead
of thirty-two,[154] as in man and in the Old World monkeys.

None of these American monkeys ever become so man-like as the Apes of
Africa and Asia, but in many ways they bring monkey-life in the trees
to greater perfection, in the dense forests of Brazil and Paraguay,
and even as far north as Guatemala. The lumbering heavy Gorilla of
Africa, though higher in the scale, is a cumbersome fellow compared
to the nimble little thumbless Spider monkeys of the Amazons, which
hang by their bare tipped tails to the branches and to each other,
chattering away like a troop of children as they gather the bananas and
other fruits, or catch insects and young birds, or fly screaming with
fear from the stealthy puma or the fierce eagle. With the trees for
their kingdom, their tail for a fifth hand, and the warm sun to cheer
and invigorate them, these spider-monkeys and their quieter friends
the Capucine monkeys (often seen on London organs), and the Woolly
monkeys (Fig. 65), lead a pleasant life enough, till misfortune or old
age overtakes them. Their friends the Howler monkeys, which also have
grasping tails, seek the deep recesses of the forest and creep quietly
from tree to tree until night comes, when hundreds of them at once will
make the woods re-echo with their deep howling cry, which they produce
by a special voice-organ in their throat; and with them come out the
little Owl monkeys, which sleep by day in the hollows of the trees.
These, with the various kinds of Saki monkeys, which cannot cling by
their tails, but have fairly good brains and quick intelligence, make
up the monkey population of America.

[Illustration: Fig. 65.

A Woolly Monkey and child (Lagothryx Humboldtii), showing grasping
tail. (Proc. Zool. Soc.)]

Here, then, we have a whole group of quickwitted tree-monkeys, which,
from their structure, we know must have started long ago on a line of
their own, wandering down into South America, where they had but few
enemies except the boas and pumas and birds of prey, till man came to
kill and eat them. And if we wonder how they have gained their quick
mischievous intelligence in those quiet pathless forests, we must
remember that though a grasping hand and foot seem at first sight of
very little importance, yet by means of them the monkey moves rapidly
from place to place, swinging, leaping, running, and climbing along the
boughs, which are its paths from tree to tree. And since rapid change
of any kind makes the eye quick of sight, the ear acute, and the brain
active and alive to take in new impressions, it is no wonder that the
monkey mind has become alert and ready during the ages that these
animals have been chasing and cheating and outwitting each other, or
tenderly rearing their young ones among the dangers of the forest.

And now if we turn back to the Old World, it is not so much the smaller
active tree-monkeys that interest us, for they live much the same life
as their American cousins, although they differ from them in never
having grasping tails, in having thirty-two teeth like man, in the
openings of their nostrils which turn downwards[155] like our own, and
in having either cheek-pouches to stow away their food, or stomachs
with three compartments like animals that chew the cud, so that they
can keep a store within. But in spite of these differences they appear
outwardly much the same as the American monkeys; they leap and jump
among the trees, and it is not till we come to the Baboons and the
tailless man-like apes, that we find ourselves studying quite another
kind of life.

Imagine an undulating country of corn-fields and rough vegetation in
Abyssinia, or southwards towards the Cape, with long ranges of rocky
hills rising up behind, and precipices leading to the narrow defiles
of the mountains, and then picture to yourself, descending from those
mountains, a troop of two hundred or more large hairy monkeys, with
short tails growing from between bare seat-pads, dog-like faces and
something of a dog’s shape, as they gallop clumsily along with all four
feet flat upon the ground. These are the African Baboons, and they form
a goodly company, the chiefs marching first, grand old elders with
stout hairy manes to protect them when fighting. These come cautiously,
peering over the precipices, and climbing up rocks and stones to survey
the country round before allowing the troop to advance; and behind
them follow the young males, and the mothers with their children on
their backs, shambling down till they reach the fertile grounds, where
sentinels are set to watch for danger, while the multitude feed,
filling their cheek-pouches and even storing the corn under their
armpits. Then when all are satisfied, if no alarm has been given they
wander slowly back, resting by the way to chew their food or drink at
some mountain stream, but never leaving the company till they are safe
back under the rocky ledges of the steep hillside, where they make
their home.[156]

For these baboons, unlike other monkeys, live in hilly rocky places,
and not in forests, and therefore they are in much more danger from
wild beasts, especially the leopard, so that they rarely venture abroad
except in company, and lead an extremely gregarious life. Yet though
they run on all fours, and look less human than most monkeys, even the
lowest baboon, the Mandrill (easily known by the coloured swellings on
its cheeks and hind quarters), which has many points in its skeleton
like four-footed animals, has true thumbs on its hands and toe-thumbs
on its feet, and uses them to lift up stones to search for scorpions
and other insects; while the mother baboons dandle their little ones,
or give them a box on the ear when troublesome, in true human fashion.

Moreover, they have developed great intelligence in their social life,
and the youngsters are soon taught to keep silence when danger is near,
to follow their leader, and to obey the sign of command; while, in
their turn, the leaders will defend the weak and feeble of the troop,
as in the well-known case of the brave old baboon who came down alone
in the face of the dogs to fetch away a little one only six months old,
which had been left behind crying for help.

Still, notwithstanding their cleverness and courage, these baboons,
with their long hind legs and dog-like faces, running on all fours,
travelling in troops, and feeding in the corn-fields and meadows,
remind us more of four-footed animals than any other of the monkey
tribe, and we must turn again to dense forests and tangled jungles to
find those large and tailless apes which have risen highest in monkey
life.

If we go back in imagination to those days when the wild beasts of the
forests, the strong elephants and rhinoceroses, the fierce tigers,
lions, and leopards, had not yet been persecuted by man, but roamed
in great numbers over the whole tropical and temperate world, we can
easily imagine that a set of animals which could climb along the
tops of the lofty trees in impenetrable forests would have a great
advantage, even though elephants, rhinoceroses, and buffaloes were
crashing through the underwood below, and the fierce leopard was on the
watch for them when they ventured to descend. With their tree-loving
life, the monkeys would have every chance of escape, climbing along
the topmost boughs with wonderful rapidity, to find refuge in gloomy
recesses where they might bring up their young in safety. And as they
grew in strength and intelligence, gradually retiring to the thickly
wooded part of Southern Asia and tropical Africa, they might even
succeed in driving out their opponents, as the Gorilla is said to have
driven the elephant from the Gaboon country, because he interfered with
the trees which he makes his special home.

So we must go to such tangled virgin forests as those of Sumatra,
Borneo, and Malacca, to find the long-armed tailless Gibbons,[157]
which once wandered over Europe, but now roam no further than Southern
Asia, where they swing themselves along from branch to branch by means
of their lengthy arms, which are so out of proportion to their legs
that when they stand upright they can touch the ground with their
knuckles. These gibbons are gentle creatures, with not too much brain,
but wonderfully elegant and agile, which is more than can be said for
the intelligent Orangutan[158] or Mias which wanders in the same
forest. He has shorter arms, only reaching to the ankle, and he climbs
half upright from tree-top to tree-top, grasping the boughs and swaying
slowly onwards, or holds on by his toe-thumbs while he stretches up to
the more slender branches to gather the fruit and young buds.

A strange object he looks, a great red, hairy, man-like creature,
between four and five feet high, thrusting his huge black face from out
of the dense foliage as he devours the Durian and Mangosteen fruits,
seated comfortably in a fork of the tree, and then if disturbed he is
off far more quickly than you would suppose possible for such a heavy
creature, running, climbing, and creeping half upright till he is lost
in the forest. He rarely comes down, except to shamble across some open
space from one wood to another, or to drink in the river, where the
natives say the crocodile attacks him, but he beats him and carries
off the victory; while in the trees his only enemy is the python,
which tries to encircle him in its coils. Nor does he often wander in
company, for Mr. Wallace tells us that he never saw a father and mother
orangutan together, though either of them may be seen with the young
ones. He seems to lead, on the whole, a solitary life, and when the sun
goes down retires into a nest of leaves low down in one of the trees,
and sleeps till it is broad daylight and the dew is dried off the
leaves.

But, though the orangutan is both strong and cunning, he is not nearly
so human as the intelligent and docile Chimpanzee, which shares with
the fierce Gorilla the dense forests of palms, amomas, and gigantic
tropical trees of Africa, where the grass and brush grow fifteen feet
or more high, and the native man scarcely dares to venture for fear of
the man-like apes. In these endless African forests there is quite a
population of these wild creatures; bald-headed apes which build bowers
in the trees; the Soko, a kind of gorilla, which loves to steal the
native children, and always defends himself by biting off the fingers
or paws of his enemy; the true chimpanzee, so human in its affection
and its fun when it is caught and tamed; and the fierce gorilla,
between five and six feet high, which rules as master in Western Africa
near the equator.

Though each of these tailless apes has its own advantages, yet
the gorilla is, on the whole, most advanced and nearest to man in
structure. But his legs are still too short and thick, and his arms
long, reaching to his knee; and the large projections on the back of
his neck bones prevent him throwing his head well back, so that he
stoops like a hunchback, while his feet are twisted so that he treads
on the outside and not on the sole. His eye-teeth are huge, his eyes
deeply sunken, his jaws heavy and strong, but his brain is not one-half
the size of that of the lowest races of men, and though it has foldings
very like those of the human brain, these are larger and less complex.
When he walks it is not upright but on all fours, resting the knuckles
of his hand on the ground; but when he is in his natural home--the
trees--then his long strong arms and broad naked palmed hands grasp
the boughs with immense power, and pull his heavy body upwards as
he climbs hand over hand, his twisted toe-thumbed feet clutching the
branches below far better than a straight foot could do.

[Illustration: Fig. 66.

The Gorilla at home.]

And so he lives with his wife and family in the thick solitary parts of
the West African forests, feeding only on fruits and leaves, so that
his stomach becomes large and heavy with the amount of food necessary
to nourish him. He is more sociable than the orangutan, for several
will travel together, but he asks for no shelter beyond the trees and
the nest of leaves, which is his home and the cradle of his young
ones, nor does he seem to attack other animals except in self-defence,
and then his gigantic strength and his formidable teeth are his chief
weapons, and woe betide the creature that comes within his grasp.

It is strange to picture to ourselves these huge apes, living in the
depths of lonely forests and looking like human savages to those who
can catch a glimpse of them, so that the ancient Carthaginians landing
on the shores took them for “wild men” and “hairy women.” We know very
little of their daily life, for they are seldom seen except by those
who hunt them, and who have but little chance of watching their habits.
But all that we do know teaches us that in their rough way they have
developed into strangely man-like though savage creatures, while at the
same time they are so brutal and so limited in their intelligence that
we cannot but look upon them as degenerate animals, equal neither in
beauty, strength, discernment, nor in any of the nobler qualities, to
the faithful dog, the courageous lion, or the half-reasoning elephant.




[Illustration: TROPICAL EUROPE OF LONG AGO]




CHAPTER X.

THE LARGE MILK-GIVERS WHICH HAVE CONQUERED THE WORLD BY STRENGTH AND
INTELLIGENCE.


If we now glance back in imagination over the almost endless variety
of creatures which we have met with since we started with the fish,
we must acknowledge that even if there were no other kinds than those
we have already mentioned, the world would be very full of different
living beings, and that to succeed in the struggle for life in the
midst of such a multitude, new forms must be endowed with great
strength or armed with specially effective weapons.

Such animals, however, we know were already in the field, for we saw
at the beginning of the last chapter that, together with the small
rodents, insect-eaters, and lemurs, there were two groups of much
larger animals, first the _Herbivora_ or grass-feeders, including the
hoofed animals (_Ungulata_) and the elephants; and secondly, their
great enemies the _Carnivora_ or flesh-feeders.

Now these two groups, on account of their size, strength, and agility,
have spread very widely over the earth, especially the grass-feeders,
for there is no part of the world which has not some vegetable-feeding
animal in it, if only a few green shoots grow there. It is true the
Rodents take some part of this green food, but then they are small
and insignificant compared to the large Rhinoceroses, Elephants,
Hippopotamuses, Oxen, Antelopes, Goats, Pigs and Sheep, which roam
over wide spaces, and are even less restricted than the flesh-eating
animals, for they live in the open air or the thick jungle, never in
caves and holes, and their young ones are born wherever they may happen
to be, and in a few hours run by their mother’s side, so that young and
old wander together wherever food and shelter is to be found.

And so we shall see that these vegetable-feeders have filled every spot
where they could possibly find a footing. In the regions of snow and
ice the reindeer in Europe, and the elk and musk-sheep in America,
rake the snow to uncover their scanty food, while the burning deserts
of North Africa and East Asia have bred their camels and wild asses,
and those of South Africa their quaggas. On the prairies of America
the bison, and on the plains of Asia the wild cattle, feed in herds of
thousands, while the zebra courses over the African hills. If we look
to the tops of mountains, to dangerous crags where the merest tufts
of grass are to be found, there we meet with the goats and sheep in
India and Asia, the chamois and ibex in Europe, the big-horn sheep in
the Rocky Mountains of America; or if we turn to the dense forests and
tropical jungles, there we find the giraffes in Africa, the elephants,
rhinoceroses, buffaloes, antelopes, and wild boars in Africa and India,
some feeding on the branches of the trees, some grazing on the grasses
and lower brushwood, and some digging up roots and underground food.
Only the rivers remain, and here too, in Africa, the hippopotamus has
taken possession, feeding on the water plants and wallowing on the
muddy banks.

In this way every available spot is used by one herbivorous animal or
another, and if we could only trace out their pedigree we should be
surprised to find how wonderfully each one has become fitted for the
special work it has to do. But three things they all require and have,
though they may arrive at them in different ways. The _first_ of these
is a long face and freely moving under jaw, with large useful grinding
teeth to work up and chew the vegetable food; the _second_, a capacious
stomach to hold and digest green meat enough to nourish such bulky
bodies; and the _third_, good defensive weapons to protect themselves
against each other, and against wild beasts. Weapons of attack they do
not need, except for fighting among themselves; for being grass-feeders
they do not attack other creatures, and this is one of the great
differences between them and the flesh-feeding or _carnivorous_ animals.

We need not look far to see these three chief characters of the
vegetable-feeders in active work. Look at any horse as he grazes in the
meadow, and see how his under jaw works from side to side as soon as he
has a good mouthful. A peep into his mouth will show that he is using
broad flat back teeth to grind the grass to pulp (see Fig. 67), and he
will go on eating all day without overfilling the large stomach which
lies within his barrel-shaped body. And as to his defences, if he is
vicious, he will soon show that his front teeth are good weapons, while
his hoofs will deal an ugly blow.

Then turn to the cow, quietly chewing the cud by his side; you will
find that she has no upper front teeth, but only a hardened gum, upon
which her under teeth bite as she crops the grass; but she too has
broad flat teeth behind, while within she has a stomach with four
compartments, and when she has filled one of these full of half-chewed
grass, she lies down, and with a slight hiccough returns a ball of
food to her mouth to be leisurely ground down. It is not difficult
to see that to animals, such as wild cattle, antelopes, goats, and
sheep, which often have to go far to seek their food, an arrangement
of this kind, by which they may store provender in a larder for quiet
enjoyment by-and-by, must be a great advantage. But the cow cannot
defend herself with her teeth since she has no upper ones in front; in
their stead she has strong horns which are quite as dangerous, so that
an angry bull is an enemy not pleasant to meet.

Lastly, there is another fierce vegetable-feeding animal almost as
dangerous as a bull, though we no longer come across him in England;
for the Wild Boar, as he still flourishes in the forests of Germany,
can inflict very ugly wounds with his lower eye-teeth which grow out
and project over his upper lip, forming large tusks.

So we see that while the vegetable-feeding animals have three
characters in common, namely, large flat grinders, a capacious stomach,
and defensive weapons, their defences, on the other hand, may be of
three different kinds, and they may depend upon horns, hoofs, or teeth
for protection.

Now in the beginning, when we first meet with the milk-givers, these
defences were not so complete in any of the vegetable-feeders as they
are now. Of the elephants alone it may perhaps be said that they
had large and formidable ancestors.[159] As to the rest, the huge
hippopotamus and sharp-tusked boar were only represented by small
animals;[160] and even later, when the hogs branched off in a line of
their own, they had at first only ordinary teeth, which did not grow
out as tusks.

So, too, the fierce horned rhinoceros had as an ancestor a hornless
tapir-like creature,[161] and the graceful hoofed horse a little
creature no larger than a fox, with five separate toes on his
feet.[162] Lastly, all the horned animals which chew the cud,--oxen,
buffaloes, antelopes, and deer,--were nowhere to be seen, and in their
place were only some small elegant creatures without horns.[163]

It is only at a later period when the flesh-feeding animals grew strong
and dangerous, and the vegetable-feeders had to struggle for their
lives, that we begin to find the remains of hogs and hippopotamuses
with tusks, rhinoceroses with nose-bones, and fleet horses which could
take to their heels, or bite and kick their enemy to death; of stags
with antlers, ever increasing in size; and of bulls and buffaloes,
goats and antelopes, with true horns. For not only by this time
were they persecuted by the flesh-feeders, but they themselves were
becoming very numerous, and it was the strongest only that could secure
feeding-grounds or carry off wives.

       *       *       *       *       *

It is very curious to see the different ways in which the three chief
lines of vegetable-feeders secured these advantages to themselves.
First, there were the hogs and hippopotamuses. The hogs did not grow
to any enormous size, but their thick skins were a great protection to
them, and their eye-teeth became their defence, growing out from the
lower, and sometimes from both jaws into huge tusks; while their broad,
round, flexible snouts served them to turn up the ground, and so get at
roots and underground fruits such as other grass-feeding animals could
not find; though at the same time they did not despise snakes or toads,
and have become omnivorous animals. And so they have spread nearly all
over the world; in Europe and Asia as wild hogs, and their wives the
sows; one peculiar form, the Babirusa, being found only in Celebes;
in Africa as large Wart-hogs, some as big as donkeys, with two pair
of strong tusks curling out of the mouth; while in South America the
family is represented by the small Peccaries, which travel about in
herds, and have no tusks to show; but which, nevertheless, are bold and
fearless, for they have _within_ their lips short lancet-shaped tusks,
which inflict fearful wounds. Only in North America, north of Texas, no
_wild_ creature of the hog family now lives, though in ancient times
there were plenty of them.

[Illustration: Fig. 67.

The Babirusa; the double-tusked hog of Celebes.]

Meanwhile the warmth-loving hippopotamuses, the hog’s nearest
relations, with huge grinding teeth behind, sharp front teeth, and
tusks within their lips, took to a water-life in the Old World.[164]
When we look at their immensely powerful bodies, and their short stout
legs with four strong hoof-covered toes, and learn how rapidly they can
gallop on land, and how furiously they charge an enemy in the water,
snapping their great jaws which will kill a large animal at one crunch,
we do not wonder that they can hold their own, especially as they
always live in herds. Yet large and powerful as they are, they have not
spread far over the earth, for though in past ages the hippopotamus
swam in the river Thames, and grazed and left his bones in the ground
upon which London streets now stand, yet after a time they crept down
to warm Africa, where they may now be seen lazily basking on the
surface of the Nile or of the river Zambesi by day, and making tracks
by night into the swamps and jungle to feed on the coarse rank grass.
They are well fitted for their life, for their thick naked skin, with
pores which give out a fatty oil, keeps them from chill in the water;
their eyes are set well back on their heads, so that as they float
deep they can still look around, and the slits of their nose, and the
openings of their ears, can both be closed and made water-tight when
they dive, while their slow breathing enables them to remain a long
while under water.

The second line was that of the rhinoceroses, tapirs, and horses, or
the uneven-toed animals which have one or three toes on the hind feet.
They took to very different means of defence. The Tapirs,[165] large,
heavy, and with enormously tough hides, seem to depend chiefly upon
their great strength for defence. Starting in warm times in the Old
World, they have wandered in their day nearly all over the globe, dying
out in later times, till now one kind is left solitary in Sumatra and
Malacca, and the remainder have found their way down to South America,
where they tear the branches from the trees with their short movable
snouts, and feed peaceably at night unless attacked, when they make a
furious rush at their enemy and conquer by sheer force.

The rhinoceros, the tapir’s nearest relation, is even better defended;
his skin is so thick and hard that in the Indian rhinoceros it actually
forms a kind of jointed armour; his skull is wonderfully strong, and
his nose is supported by thick bones, on the top of which are one or
two solid horns, which are formed by a modification of the hairs of the
skin growing matted together.[165]

And now notice, just as we saw that the horned cow has no front upper
teeth, so too the rhinoceros, though his horn is of quite a different
kind, has in some cases lost his front teeth, which he does not need,
since he rushes with his horn at his enemy instead of biting. Like the
hippopotamus, the rhinoceros once wandered all over Europe and Asia,
and when the great cold came on, the woolly species which roamed far
north was often caught in the frost and snow of Northern Asia, where
his fleshy body has been found preserved in the ice. Now he too has
taken refuge in the warm parts of Asia and Africa, where he either
grazes on the plains or plucks the leaves from the trees in the jungle
with the fleshy flap of his upper lip.

[Illustration: Fig. 68.

Skeleton of a Wild Ass.

    _i_, incisor teeth; _g_, grinding-teeth, with the gap between the
    two sets as in all large grass-feeders; _k_, knee; _h_, heel; _f_,
    foot; _t_, middle toe of three joints carrying the hoof; _s_,
    splint, or remains of one of the two lost toes; _e_, elbow; _w_,
    wrist; _h_, hand-bone; 1, 2, 3, joints of the middle toe.
]

But of all the animals of this three-toed group the Horse has the most
interesting history, because we can read it most perfectly. The only
certainly original wild animals of the horse tribe now living are the
Zebras, Quaggas, and Asses of Asia and Africa; yet strange to say,
it was in America that this tribe began, for there we find that tiny
pony[166] not bigger than a fox, with four horn-covered toes to his
front feet (and traces of a fifth) and three toes on his hind ones.
Then, as ages went on, we meet with forms, still in America, first with
four toes on the front foot, and then with only three toes on all the
feet, and a splint in place of the fourth on the front ones. In the
next period they have travelled into Europe, and there, as well as in
America, we find larger animals with only three toes of about equal
size. One more step, and we find the middle toe large and long, and
covered with a strong hoof, while the two small ones are lifted off
the ground. Lastly, in the next forms the two side toes became mere
splints; and soon after, in America and in Europe, well-built animals
with true horse’s hoofs abounded, the one large hoof covering the
strong and broad middle toe. For what we call a horse’s knee is really
his wrist, and just below it we can still find under the skin, those
two small splints (_sw_) running down the bone of the hand, while the
long middle finger or toe, with its three joints (1, 2, 3), forms what
we call the foot. It is by these small splints the horse still reveals
to us that he belongs to the three-toed animals.[167]

Now while these changes in the toes were going on, the space between
the front teeth and eye-teeth gradually increased, till we arrive at
the large gap now seen in the horse and ass (see Fig. 67). The chief
bone of the fore arm (radius) increased in size, and the other bone
(ulna) became joined to it, and the same in the hind leg. The brain
increased in size mainly in the front part, and the body grew much
larger, improving in form and build, till the long, slender, flexible
legs became the perfection of running and galloping limbs such as we
find in the zebra of to-day, poised upon a strong jointed toe, with
its last joint broadened into a firm pad, and covered with a thick
nail--the hoof. We have only to compare the well-proportioned leg of
a horse with the thick, strong, clumsy leg of an elephant, to see, on
the one hand, what a shapely and beautiful limb it has become; while,
on the other hand, if we put it by the side of a giraffe’s leg, we must
acknowledge at once that it is a far stronger and more serviceable
limb than if it had gone to the other extreme. There can be no doubt
that when the horse arrived at this point of the strong single hoof and
well-shaped body, he had a wide range over the world, both Old and New;
but curiously enough, while in Asia and Africa the tribe branched out
into many forms, such as asses, quaggas and zebras, in America it died
out, so that till we found the fossil-forms,[168] it was thought that
no horses had ever been there till they were brought by the Spaniards.

Meanwhile, in the Old World, they must have led as free and joyous a
life as those horses do now which have run wild in Tartary and America,
galloping, frolicking, feeding, and neighing to each other with
delight, as they roamed over the wide plains in troops of thousands,
for solitary wanderers they would soon have fallen a prey to wolves or
jaguars; and if the mothers wished to protect their foals they had to
learn to follow one leader and act together in time of danger.

   “A thousand horse, the wild, the free,
    Like waves that follow o’er the sea,
    Headed by one black mighty steed
    Who seemed the patriarch of his breed,”

they grew accustomed, as generations passed on, to unite against their
common foes, placing the mares and their foals in the centre when
attacked, while the fathers met the enemy with hoofs and teeth. And
so they became intelligent and tractable even in their wild state,
to those of their own kind, and laid the foundation of those noble
qualities of which man now reaps the benefit.

But the horses were not the only group which combined in this way
for protection. The third great line of hoofed animals, those which
have “cloven” feet of two toes, and which “chew the cud,” have learnt
many a lesson of vigilance, fidelity, and affection, by their social
habits. Everyone has read of the herds of antelopes or deer, where
the sentinels stand faithfully watching while their companions feed,
and stamp or whistle when danger is near; while in the herds of wild
cattle, not only will the mothers keep a watchful look-out for danger,
but the bulls will join to protect the young ones at the risk of their
own lives. Mr. Allen relates how, in America, a young bison, which had
strayed from the troop and was followed by wolves, was surrounded by a
number of old bulls, who, facing about, warily conducted him across the
plain till he was safely among the dense mass of buffaloes, which the
wolves dared not attack.

Now these “ruminant” animals, with complicated stomachs and the power
of feeding at long intervals, have spread far and wide over the earth
under many different forms, and while some are still very numerous,
others are now rare, or almost destroyed.

Take, for example, the Camel, the true “child of the desert.” There
are no wild camels left now, so long has man conquered and tamed this
useful beast of burden. But in past ages vast numbers of camel-like
forms lived in North America, which found their way on the one hand
to the south, where the Llamas, Alpacas, and Guanacos now feed on the
mountains of Peru and Chili, while on the other they travelled over
Northern Asia to the deserts of Africa and Arabia, and there became
those curious desert-animals which the Arabs used and still use as
their beasts of burden. A strange old fellow is the camel, with his
two-toed hairy feet, with only nail-hoofs upon them, and his hard pads
on his thighs and legs, on which he rests when he lies or kneels. His
curious fleshy hump, which is single in the true camel or dromedary
and double in the Bactrian camel, serves him as a special provision
of fat, and it dwindles when he is short of food, recovering its size
and firmness when he is full-fed again; and he is the only cud-chewing
animal which has kept his front teeth and defends himself with them,
having no horns.

[Illustration: Fig. 69.

The true Camel (Camelus Dromedarius).]

Still more strange in some ways are the giraffes,[169] of which we
know very little, except that large forms like them once wandered
in Europe.[170] For they, with only the same number of bones as
other animals, have these so lengthened out that, as they wander in
the tropical forests, their slender legs raise them above all other
animals, and their long neck, which nevertheless has only seven joints
like all the milk-givers, enables them to reach the high trees, so as
to strip off the leaves with their ribbon-like tongues.

But we should want much space to discuss such curious forms as these,
and we need not go further than the ordinary deer of our parks to read
a strange history of how life has gradually armed her children. The
giraffe with his long neck to feed, and his wide straggling legs to fly
swiftly from danger, has only short hairy covered knobs on his forehead
for horns. But the stag, who is obliged to fight, especially when he
wishes to secure his wives, has antlers so branched and so heavy that
it is a wonder that his neck can carry them.

Now it is in the autumn that the stags fight and struggle together to
secure the leadership of the does, and it is then that their antlers
are finest and strongest, and they remain so during the whole winter.
But when the early spring comes, the bone of the antlers dries up near
the head, where there is a little ridge round it, and soon they fall
off, a skin forms over the place, and new ones begin to grow. Then as
the little knobs push forward and increase, how lovely they are, for
the skin covered with soft hair is all over them, carrying the network
of blood-vessels which secrete the bone within. So fast do they grow
that antlers weighing seventy-two pounds will be complete in ten weeks,
and when they are finished, the “velvet,” as this soft skin is called,
dries up, and they rip it off against a tree, leaving the bare bone.

[Illustration: Fig. 70.

The Red-deer with branching antlers.[171]--(_After Ridinger_).]

Thus equipped, the stag is a match for the world, and he knows it;
his bearing is proud and haughty, and instead of flying from danger
he will turn round and fight fiercely when attacked. And now comes
the curious part of his history. In the different stags of the world
we see all kinds of antlers, from one single spike like a stiletto in
some American stags, to the superb antlers of the Red-deer, some of
which have as many as sixty-six spikes. But when the red-deer begins
to grow his antlers, he does not get this splendid tree in the first
year, he has only a single spike; this falls off, and the next year he
grows them with a second branch; the third year both branches become
doubled and another appears, and so each year as he grows them afresh
they are more and more complicated, till at last the whole branched
tree grows up in a few months. Now in thus increasing his spikes year
by year, he is in his own person most curiously retracing the steps of
his ancestors in ages past; for, as we have seen, the first deerlike
animals had no horns, then as the ages passed on we find that they
had single spikes; later on, their descendants grew antlers of two
branches, and later still more complicated ones, so that the race put
on little by little those magnificent antlers which now the red-deer
and others carry, and meanwhile the various species spread all over the
world, except into Australia and Africa, south of the desert.

Still, even the stags have times in the year, before their antlers
are grown, when they are comparatively defenceless. There remains yet
another branch of the “ruminant” family, even better provided with
weapons. These are the antelopes, wild cattle, and buffaloes, for with
them the horns never fall off. The reason of this is that they grow in
quite a different manner from the stags’ antlers. Instead of the bone
being laid down by the skin, it grows out as a core from the forehead,
and the skin over it hardens into horn as it grows, so that the tip of
a bull’s horns is the oldest part.

[Illustration: Fig. 71.

A Buffalo cow defending her calf.--(Livingstone.)]

Here then we can have no branching as in the stag, but on the other
hand a firm and terrible weapon increasing from year to year; and even
the king of the beasts, the lion, when he attacks a large buffalo, is
often seriously wounded for his pains. We should not wonder then if
these animals had conquered the world wherever man had not destroyed
them; but strange to say, they have kept chiefly to the old world, for
none have travelled to South America, and only the Bisons have overrun
North America with their vast herds. All the rest, buffaloes, wild
cattle, antelopes, gazelles, goats and sheep, have made their home in
Europe, Asia, and Africa, and a fine time they must have had of it
when all Europe was one field of undulating plains and dense forests,
and the ancestors of our cattle crashed through the tangled bushes,
drank by the silent rivers, or grazed on the wild rough herbage. Then,
where town and villages now stand, there must have been scenes such as
travellers still relate of Central Africa, where amid dense jungle,
magnificent forests, and flat marshy grounds,

          “... the elephant browses at peace in his wood,
    And the river-horse gambols unscared in the flood,
    And the mighty rhinoceros wallows at will,
    In the fen where the wild ass is drinking his fill.”

There the huge buffaloes come down in troops out of the forest to
drink, while the great hippopotamuses leave their watery bed to feed
on the rough grass of the swamps. Not far off, a herd of zebras comes
galloping by to drink lower down in the river, startling the large
antelopes feeding quietly in the soft green pasture above, for they
know that this is the hour when the lions are abroad and will fall
upon any straggler with tooth and nail, while the distant howling of
the hyænas shows that they would not be far behind in seizing upon any
weak or wounded animal. But little does the heavy rhinoceros care for
all this as he too tramps slowly along on his way to drink, for with
his size and defences he runs but little risk of attack. Thus all the
country is alive with large milk-givers, and we realise that when they
ruled all over the world, as they still do in Africa, they too must
have had their time of triumph and greatness like the great fish or the
monster reptiles.

But hush! as we watch this scene a heavy thud, thud, strikes upon our
ear, like the tramping of heavy troops upon soft ground. It is the
“lords of the forest,” the large Elephants, which, after feeding all
day in the shady jungle, are coming down to drink and bathe. What,
then, is the history of these huge antiquated animals that they have
not come into our story as yet? The reason is this: as they stand
alone now with their huge flapping ears, their column-like legs and
feet, and their long grasping trunk, so they have stood apart from
the hoofed animals almost as long as we have any knowledge of them.
So far as we can judge by their skeleton, especially the shoulder
blade, they come nearer to the gnawers, or rodents, than to any of the
large vegetable-feeders. Their legs are awkward and their gait clumsy,
for the thigh bones are enormously long and thick, and the toes are
enclosed in a thick pad with only the nails to mark them; but above all
it is the head and mouth which make so strange a figure. Look at the
huge forehead, showing a skull of immense size. This skull would be
far too heavy to carry if it were not full of hollows, making a large
framework to bear the tusks of smooth white ivory, which grow out from
the upper jaw to a length of more than six feet on each side,[172] and
weigh sometimes from eighty to one hundred pounds. Surely a wonderful
size for teeth, and we shall not wonder that they are the only front
teeth that the elephant has, and that they go on growing all his life
from a permanent pulp, like the gnawing teeth of the rodents. But if
he opens his mouth you will see that, besides these, he has at the
back huge flat grinders, one, or never more than two, at a time on each
side; but those are monsters, with hard enamelled ridges for grinding
his food. During his lifetime of about a hundred years the elephant
grows six of these teeth on each side, twenty-four in all, the new ones
growing up at the back and pushing forward as the old ones wear away.

[Illustration: Fig. 72.

The Indian Elephant.]

And, last of all, look at his wonderful trunk; see how it grows out
straight from his face, his cheeks merging into it so that he is all
nose; and then consider that this trunk, a double-barrelled tube,
ending in a fleshy finger opposite to a thick cushion which acts as a
thumb, is the elephant’s arm and hand, with which he feels and grasps
and tests everything that comes in his way. With it he can pick up a
crumb or root up a strong tree, gather a leaf or tear off a branch,
draw up a gallon of water to squirt over his body when heated with the
sun, or suck up the few drops in a puddle when water is scarce; with
it he caresses those he loves, as gently as a mother strokes her child
with her hand, or uses it to dash his enemy upon the ground, before he
pierces him with his tusks or tramples him under foot.

And yet this formidable and delicate weapon is nothing more than a
long fleshy nose and upper lip, provided with millions of interlaced
muscles, which draw it in every direction, guided by the delicate
nerves. If we did not see it, could we have believed that any creature
could have gained so much experience, and learned to do so many
wonderful things as elephants do, merely by possessing a movable nose?

Yet so it is, for if the elephant stands far above all other
vegetable-feeding animals in intelligence and even reasoning power,
we can only attribute it to two causes--the long life he leads, and
the delicate implement he carries for testing things around him. The
strongest of all animals, he has reigned supreme for ages, even the
lion or the tiger often meeting a terrible death from his trunk,
his tusks, or his heavy feet, if they venture to attack him; while
everywhere, during his hundred years of life, he has handled and tested
and tried every object he has come near with his fleshy trunk, till now
when we examine his brain we find that though small for so large an
animal it is folded and refolded into those curious convolutions which
are always found in highly intelligent animals.

For many long ages this education must have been going on; for already,
when the monkeys and opossums were playing about the trees in England,
an ancient elephant called the Mastodon, having four tusks, was roaming
over Europe, Asia, and America; while soon after, the hairy Mammoth,
kept warm by his shaggy coat, wandered right up into the snows of
Siberia and the extreme of North America, and often met his death
in the ice, and true elephants ruled the world in Europe and India,
continuing down to our day. All these had the same delicate trunk, and
gained experience as they wandered over the wide world, till some have
become extinct and others have shrunk back into the dense forests of
Africa and India, where they often give proofs of a power of reasoning
which surprises us, and make them seem like old patriarchs of a bygone
time, looking thoughtfully upon a world which has grown new and strange.

       *       *       *       *       *

And here we must take leave of the Herbivora, and turn our attention to
that large army of flesh-feeders which we find throughout all past ages
harassing and destroying the vegetable-feeders on all sides, killing
their young, falling upon the stragglers, the weak and the aged, and
keeping down their numbers by constant persecution. For, since the
whole world is teeming with life, and countless new beings are coming
into existence day after day, there is no creature on the earth which
has not some other creature to prey upon it. Thus, for example, the
whole host of small animals, rats and rabbits, moles, shrews, and small
birds of all kinds, have their special pursuers in long wiry-bodied
civets and ichneumons, weasels, pole-cats, ferrets, pine-martens, and
paradoxures, which can work their way into a hole, give chase through
the long grass, or climb the trees and feed on birds’ eggs or young
birds. There is a vast multitude of these smaller flesh-eating animals,
with teeth so sharp that a weasel will kill its prey in a second by
piercing the skull by its bite; and they make sad havoc all over the
world among young and weak creatures, while a great many of them,
such as the weasel tribe, the pole-cat, and the skunk, are themselves
protected from larger animals of prey by their disagreeable smell.

[Illustration: Fig. 73.

The Weasel[173]--a small, long, narrow-bodied carnivorous animal.]

Then the birds again have their numbers greatly thinned by the wild
cats, tiger-cats, and racoons; while the fox, the badger, and the
glutton, do their share in devouring partridges and all ground birds,
hares, rabbits, and even lambs and other young creatures.

[Illustration: Fig. 74.

The Egyptian Ichneumon,[174] a long-bodied carnivore, sucking
crocodile’s eggs.]

Lastly the fish, too, have their pursuers, for the mink and the otter,
though true land animals, seek their food in the water, the sea-otter
giving us a hint as to how such flesh-eating animals as seals, which
are the great fish-devourers, took to a watery life. But though these
smaller flesh-eaters are spread in great numbers over the world, the
civets and ichneumons only in the Eastern Hemisphere, the racoons only
in America, and the weasels and their relations everywhere, yet the war
they carry on is but little seen compared with the ravages of their
more imposing relations the wolves, the bears, and the lions, tigers,
and their kin. For these animals seek their prey among the buffaloes,
antelopes, horses, sheep, and hogs, and where they go they leave the
track of blood behind them, and appear indeed as ruthless destroyers.

And yet it would not be fair to speak of these larger flesh-feeding
animals as if they had worked nothing but evil to their more peaceful
neighbours; for how would Life educate her children if she put no
difficulties in their way to be conquered, no sufferings to be endured?
We saw that in the beginning the vegetable-feeders were neither so
strong, so intelligent, nor so swift of foot as they are now, while
the flesh-feeders were not nearly so well armed for destruction as the
tigers and lions of to-day.

It was in the long long struggle for life that the animals with the
largest and strongest horns got the upper hand, that the swiftest
horses or antelopes survived and left young ones, that the best
climbers baffled their hungry pursuers, while the most intelligent
and cautious feeders learned to herd together and watch for danger;
while we must remember that it is more often the sickly, worn-out, and
diseased animals that fall a prey to the devourers, and their life is
ended far less painfully than if they dragged themselves into some
hole to die. And so, too, on the other hand, with the flesh-feeders
themselves. It was no wanton cruelty that taught them to hunt for
prey, to creep stealthily along and leap upon their victims, and to
take advantage of the weak and feeble. It was pressing hunger and the
necessity of providing their young ones with food; and they, too, have
often suffered in the struggle; so that it was only the strongest,
healthiest, and best armed, that won the victory and were able to bring
up their children.

[Illustration: Fig. 75.

The Wolf,[175] showing the dog-like form, and long mouth full of teeth.]

Moreover, it is quite a mistake to suppose that the greater part of
the life of a lion or a wolf is spent in killing and destroying, any
more than ours is because we eat beef and mutton. The Lion, at any
rate, never attacks an animal unless he is hungry, and even the wolf,
generally considered so cruel and bloodthirsty and pitiless, spends
the greater part of the year in some quiet place in the mountains with
wife and cubs, only hunting for their daily food (though sometimes he
is guilty of killing more than he needs), and playing, gambolling, and
resting the remainder of the time.

It is when winter comes, and the young ones are stronger and food is
scarce, that he grows wild with hunger, and starts off, with a number
of others, to scour the forests, so that the animals fly in terror as
they hear the howling from afar; and even the traveller, driving his
sledge across the snow, urges his frightened horses to their utmost
speed, since, with a pack of hungry wolves, even if he has firearms,
his life is at stake.

The Wolf, with his relations, the foxes and jackals,[176] is the form
of flesh-eating animals which has become least altered from the general
type of milk-givers. He has the slim form peculiar to flesh-eaters, but
the claws of his feet cannot be drawn in like those of tigers, nor has
he those powerful hindquarters which enable them to bound and leap,
or the strong paw and fore leg with which they give the death-blow to
their prey. Moreover, his face is long like a sheep’s, and his jaws are
full of teeth, some of which are blunter than the tiger’s teeth, and
more fitted for grinding, for wolves and dogs are omnivorous. But then,
on the other hand, he is not so much of a vegetarian as the bears,
nor has he their clumsy gait and cumbersome body, for he walks upon
his toes and not his flat foot; lastly, his front teeth are large and
sharp, and his fangs strong, for they are his chief weapons, and he
uses them with wonderful effect. He is essentially a running animal,
and chases his prey, rarely leaping on it but tearing it down with
his teeth. Strong as he is, he seldom attacks an animal larger than
himself, except when he has companions to help him, and then, indeed,
he makes little account of a horse or a buffalo, for combination and
co-operation are the great strength of the wolf tribe. Even their
cowardly cousins the Jackals hunt in packs when they attack living
animals, feeding at other times on offal and the remains of the lion’s
feast. Yet such is the power of numbers that there is no part of the
world, except a few islands, where some member of the wolf family is
not to be found. In Northern Europe, Asia, and North America, the
common wolves and the prairie wolves hunt in large packs, and in South
America the Red Wolf takes their place. In Africa and India the jackals
wander with their dismal howl; and even in Australia the wild Dingo
dog, probably brought there long ago by savage man, is the terror of
all peaceful creatures.

Nor must we forget the cunning clever Fox, with his keen face and
bushy tail; for he, curiously enough, is the only one of the wolf
family which always hunts alone. The reason of this probably is that
he contents himself with small prey--birds, rabbits, and game; while
his burrowing habits, his cunning, and his night-hunting, enable him to
escape destruction. He is one of the most subtle and knowing of animals
except, perhaps, the jackal; and the fact that the pupil of his eye
expands and contracts like a cat’s, especially fits him for night-work.
So, although he has only himself to depend upon, his race has spread
from the Arctic regions, where the Blue Fox wanders over the frozen
sea to eat dead seals, down to Africa where the tiny Fennecs feed upon
dates, and South America where the Gray Foxes follow the jaguar, as the
jackals in Africa do the lion.

And now, does it not seem strange that from a family so fierce and
bloodthirsty as the wolf family, our own true, faithful, large-hearted
dog should have sprung? But do not let us be too hasty. Remember that
this hunting and killing is not for pleasure but for daily bread, and
that the wolf and jackal at home are good, tender, and loving parents;
and, moreover, that they have both of them been tamed, and shown great
affection to man.

Surely we wrong the animals when we call bad men “brutes,” for men love
and forget, but a dog will die on his master’s grave, and a tame wolf,
whose mistress went away, pined and grieved till she returned, when,
on hearing her footstep, he bounded to meet her, and springing up upon
her, fell back dead,--his faithful heart had burst with the shock of
joy.

And then, also, we must remember that the family of the wolf is the
only one among the carnivora in which the animals hunt in packs, so
as to learn sociable habits and to obey the will of others. And here,
perhaps, we have the reason why, though we have tamed the cat and
brought her to our homes, she still remains half-defiant, and can never
be taught to work for man; while the dog, on the contrary, has become
our obedient servant, and will tend our sheep, guard our homes, and
defend our lives.

[Illustration: Fig. 76.

The Tiger.

    Showing slim body, muscular thighs, strong front legs and paws, and
    short face with large teeth, all with sharp edges, especially one
    (_the carnassial_), near the back in both jaws.]

Loving, and affectionate indeed, as she is, yet the cat will probably
never entirely lose the free untamable spirit of her tribe, for if we
search the whole world over we shall not find a creature better fitted
for a hunter of prey than the wild cat, the lion, or the tiger. Gentle
and loving at home with the wife and little ones, patting with soft
paws in which the claws are hidden, and doing no harm to any one till
food is needed, yet when they are once out on the chase we see that
every part of their structure is of use in approaching and overcoming
their victims.

Look at the Tiger as he moves along, crouching to spring upon his prey.
Here we have no round barrel-shaped body, with a tight-fitting skin, as
in the horse and ox, but a slim slender-waisted animal, which is lithe
and nimble, because feeding on nourishing flesh he can do with a small
stomach and short digesting tube. So, too, his loose hanging skin,
forming a flap under his body, saves him from wounds in his adventurous
life, for, when seized by teeth or claw, this skin wrinkles up, so that
even if a good grip be taken the tender flesh underneath may escape.
This flesh itself is firm and solid, being made of powerful muscles,
while the cords or tendons of the body are so thick and strong that he
can kill an ox with a blow of his paw; and under this flesh again are
bones polished like ivory, far more compact and firm than those of most
animals, and bound together by strong ligaments, the rounded joints
moving smoothly upon each other and causing those graceful movements
which enable him to creep stealthily and spring upon his prey. Lastly,
the tips of his toes, upon which he walks, are clothed underneath with
a soft pad which breaks his fall when he leaps, and makes his footfall
silent as he creeps through the jungle; while, nevertheless, he has
sharp claws hidden within to strike when needful.

These movable claws are indeed peculiar to the cat or feline tribe
(though the civets and ichneumons can draw theirs in half), and they
are caused by the second joint of the toe being grooved, while the
end joint, curved and covered with a horny claw, is drawn back by
a strong elastic band (_l_) till it lies in this groove so that the
outgrowing skin of the toe covers it. There it remains so long as it is
not wanted; but when the animal bends its paw to strike, another band
or tendon (_t_) _under_ the toe is tightened and the claws are thrown
forward, burying themselves in the flesh of the victim.

[Illustration: Fig. 77.

Claws of the Cat or Tiger.

    A, claw held back by the strong ligament _l_; B, claw pulled
    forward by the tendon _t_ being drawn back, so that _l_ is
    stretched out.
]

So in shape, in limbs, and in claws, the tiger, the lion, and their
relations, are the perfection of hunting animals; and when we examine
the well-formed head set upon the strong neck, so that it can turn
widely from side to side, ever on the watch, we see that here too
everything is fitted for the work. Not only are his ears so quick of
hearing that the smallest rustle in the grass startles him at once,
while his large round eyes have a special reflecting mirror at the
back to catch the faint rays of evening light when he prowls abroad,
but the whisker-like tufts on his face are so provided with nerves at
their base that when he raises them they are the most delicate feelers
to guide him in the dark. Then, instead of the long narrow face, flat
teeth, and sideways-moving under jaw of the horse or ox, we find that
he has a large broad brain-case with a well-formed brain within, and a
short face with rough bony ridges upon it, to support powerful muscles
which move the lower jaw _up and down_, so as to mince the food, and
even crush solid bones.

Such a small mouth cannot hold many teeth, and the front ones, though
sharp and pointed, are small, for the tiger does not fight with his
teeth like the wolf, but strikes with his heavy paw. But the eye-teeth
are immensely large, strong, and dagger-like, to hold the prey and tear
the flesh apart, and all the double teeth behind, especially the last
bottom tooth and the one to match it above, have very sharp cutting
edges, so that, when the two jaws work against each other they divide
the flesh like a pair of shears. Lastly, his tongue is not soft and
fleshy, so as to serve for tasting, but very rough, and covered with
horny pimples which serve to rasp the flesh from the bones of his prey.

Thus, in all the animals of the cat tribe, such as the lion, the tiger,
the jaguar, and their relations, every part of the body has become
fitted to help them in the work of destruction; and even their near
relation the Hyæna, though he cannot keep his claws sharp by drawing
them in, nor leap so well because his hind legs are short, makes up
for this by his immensely strong jaw and conical teeth with which he
attacks his prey, instead of using his paw, and which serve him to
split open even the strongest thigh bone of a horse or ox, or to gnaw
the ends to extract the marrow.

With all these advantages, we shall not wonder that the feline family
and their near relations were the rulers of the forests and plains
and mountains till man came to conquer them, or that lions and large
cats, something like those living now, together with the fierce
sabre-toothed tiger (Machairodus), roamed over Europe, Asia, and North
and South America, where the crowds of vegetable-feeders offered them
plenty of food. They were even numerous in England, where the lion
chased the elk and the wild cattle, before he was driven back to
Africa, Persia, and Bengal. No doubt in those days he scraped out his
den in the valley of the Thames, as he still does in some quiet spot in
the African plains where he hunts alone, except when his little ones
are born, and then for some time he lives with his lioness, helping
her to provide for them, and taking out the cubs as soon as they are a
year old to teach them to hunt, to leap upon their prey, and to strike
it with their paw, educating them like a true father in getting their
living. And when they are three years old, the young lions will go off
and meet together, two or three in a party, till in the spring each one
seeks a wife for himself, having many a fierce battle with other lions
before he can win her, and finding then the use of his thick mane in
protecting his neck from the teeth of his rivals.

So the “king of the beasts” lives

                “On the mountains bred,
    Glorious in strength;”

for though by no means so large as people generally imagine, compared
to the buffaloes, or horses, or large antelopes which he attacks, yet
his immense strength generally secures him the victory over all but the
rhinoceros and the elephant, and he feeds in a royal manner, sharing
his hunting grounds only with the leopard, and leaving the remains of
his feast for the hyænas and jackals following in his track.

Then just where his reign ends in Bengal, that of the tiger begins,
that splendid and ferocious cat, larger even than the lion, which
spares no animal, and will fight till death even with those stronger
than himself. When we see our own house-cat playing with a mouse,
striking at it, letting it escape, and at last giving it the final
grip, we are watching in miniature the cruel game which is played
in the dense jungles of Asia by the tiger with the antelopes, young
buffaloes, and other terrified animals. Yet when we see the mother cat
caressing her little ones, this too is true to tiger life, for though
the father does not watch and care for his children as the lion does,
the tigress loves them with the utmost devotion, and attacks all who
come near them, dying sooner than forsake her cubs.

So in Africa and Asia the lion and the leopard reign, while the tiger
is confined to Asia, ranging up to the snowy regions in the Caucasus
Mountains and Mantchuria, where he is covered with a warm coat of hair.
Yet all these animals have but a small kingdom now compared to olden
times; and man has so cleared the ground in other parts of the world
that we must travel away to South America to find the other large
felines, the fierce Jaguar and Puma. There the jaguar, second only in
strength to the tiger, carries all before him, making havoc among the
peccaries and the herds of wild horses, and even fishing in the rivers
for turtles and fish; scooping the turtles out of their shell with his
sharp claws, and conquering every animal except the great ant-bear
in whose embrace he has been found dead after he had also killed his
enemy. The puma, meanwhile, contents himself usually with smaller
prey,--sheep and rheas, opossums and monkeys, for he can climb like a
cat, and passes much of his life in the trees. Thus, though the cat
family wander over the whole earth, the larger kinds live chiefly in
the warm parts of the world where life is luxuriant and man has not yet
driven them out.

But these are not all the wild flesh-feeders. There remains a third
group--a lazy, easy-going, lumbering group, which, though they spread
from the equator to the poles, have taken chiefly to temperate and
colder regions for their home, to mixed food for their nourishment, and
have gone off on a line as far from the wolves on the one side as the
lions have on the other.

This group is the Bears, and it is a very curious one in many ways.
For, in the first place, though they are large and strong animals, they
have very much given up eating flesh-food, and have taken to berries
and acorns, fruits, vegetables, and honey. To get this last they even
climb the trees to dig out the comb with their paw, trusting to their
thick shaggy hair to protect them from the stings, which, however, they
sometimes receive rather heavily on the nose.

[Illustration: Fig. 78.

Polar Bear[177] and Walrus.[178]

Showing how the Bear walks with the heel flat on the ground, and the
Walrus also.]

A glance at a bear’s mouth will tell at once that he is partly a
vegetarian, for his hind teeth are smoothed down, and as he eats he
can move his lower jaw slightly from side to side, so as to chew
vegetable food. Even the Polar Bear, which eats little else but fish
and seals, has these same grinding teeth, and he can be fed for a long
time upon bread; while it is found that he keeps in better health when
in zoological gardens if he has some grass occasionally. Still it is
only the Sun Bears and Sloth Bears in India and Malacca which never
eat flesh, for the Bruin of our northern countries often varies his
food with deer or sheep, and grows more ferocious and flesh-feeding as
he grows in years. It would almost seem as if his very laziness and
awkward gait may have led him to take to vegetarianism as a convenient
change, when animal food was not handy. For though a bear can trot
along at a good pace, yet his heavy lumbering body and long foot
with the whole heel touching the ground[179] (see Fig. 78), make him
decidedly not well fitted for a hunting animal.

How different he looks from the slim wolf running on the tips of his
toes, and the graceful tiger bending his long hind legs for a leap! Yet
he is a formidable animal too, for his muscles are tremendously strong,
and his firmly-planted foot enables him to rise upon his hind legs and
give that deadly embrace which drives the breath out of the body of his
victim.

The wolf attacks with his teeth, the lion strikes with his paw, but the
bear hugs his enemy to death; and here his long stiff claws serve him
well, for though he cannot draw them in to keep them sharp, yet they
are rough and jagged, and inflict dreadful wounds. The great Grizzly
Bear of America, which is sometimes nine feet long, and strong enough
to drag along the carcase of a bison, sticks his front claws into his
prey while he tears the flesh with the hind feet; he is the only one,
except the polar bear, which lives principally upon animal food.

In fact, the bears take much the same place in the animal world that
heavy phlegmatic men do among ourselves; easy-going, but dangerous
if roused, they seem to have succeeded in life more by accommodating
themselves to things as they have found them, than by conquering and
taking by force like the wolves and tigers. Thus a bear roams leisurely
through the thick forest, for few animals care to meddle with him and
he feeds wherever food comes easy, especially in the autumn when fruits
abound and he can grow fat; and then he lies down to sleep in a cave or
hollow tree, or in a nest of moss and leaves, till spring comes round
again. Why should he trouble himself to struggle with difficulties?
Unless, indeed, food is scarce, and then he sometimes has an uneasy
winter, or attacks animals he would otherwise leave alone.

But if once he is roused, or if a she-bear is afraid that her cubs
may be attacked, then you see that under the lazy good-nature there
is plenty of pluck and ferocity. He would rather be let alone, for he
looks upon life as a thing to enjoy and take leisurely, but if you
will have a struggle then he will see who is master. And this kind of
philosophy, somewhat easy for strong powerful creatures, has stood
Bruin in good stead, for he has spread over all countries where there
are thick forests, except Africa and Australia; and with his great
strength and shaggy coat must have been very safe from attack till man
came to annoy and worry him.

Even the polar bear, living amidst perpetual snow and ice on the shores
of Spitzbergen, Nova Zembla, and Greenland, has not, on the whole, a
bad life of it, for he is master of the situation, and conquers and
devours even the tusked walrus. The polar bear is a most interesting
animal, because he shows us the bear tribe becoming adapted to a
watery life. His body is much longer and more flexible than that of
most bears, giving him the power to twist and turn in the water, as
he swims with strong broad feet; and his long neck, narrow head, and
small ears, are all fitted for a watery fishing life, while he fights
entirely with his teeth and does not hug his prey. Again, the soles of
his feet, instead of being bare, are covered with long stout hairs,
giving him foothold upon the slippery ice, over which he travels very
quickly, climbing up from time to time on the icy hummocks to see where
seals are to be found, or to scent a dead whale from afar. He is an
inveterate seal-hunter, chasing them in the water or out of it with
equal ease and great cunning, though they are quick too, and often
escape him just when he thinks he has caught them. It is when they are
asleep with their noses upon the ice or the land, that he has his best
chance, for then he will swim warily behind them, coming up close,
till, even if they wake, they have no choice but to be killed where
they are, or to leap out on the solid ice where he will soon overtake
them.

The polar bear, unlike his brown cousins, fishes and hunts all the
winter through, and it is only the mothers which take refuge in caves
hollowed out of the snow, where their little ones are born in early
spring, and nestle down by her side in their icy home. And when the
cubs can run, both father and mother care for them with true devotion,
defending them against all attacks, and pushing them before them when
pursued, even going so far as to take them in their teeth and swim away
with them when they cannot otherwise save them.

So we see that the polar bear has become more than half a water-animal,
and gives us the first hint that some milk-givers may take to a
thoroughly sea life. Neither among the wolves nor the felines do
we find any animals taking entirely to the water; but in the weasel
family, which comes near to the bears, we have the otters, and among
the bears themselves their polar cousin, which reminds us that there is
another great division of flesh-feeders which we must study in the next
chapter--the walruses, seals, and sea-bears, the porpoises, dolphins,
and whales, which with finned paddles have struck out quite a new line
of life, and imitated the fish so well that they are often wrongly
classed among them.




[Illustration: EUROPE IN THE AGE OF ICE]




CHAPTER XI.

HOW THE BACKBONED ANIMALS HAVE RETURNED TO THE WATER, AND LARGE
MILK-GIVERS IMITATE THE FISH.


“On revient toujours à ses premiers amours,” says the French song.
But who would have thought that, after rising step by step above the
fish, and tracing the history of the backboned animals through their
development in the air and over the land, till we brought them to a
stage of intelligence second only to man, we should have to follow them
back again to the water and find the highly gifted milk-givers taking
on the form and appearance of fishes? Nevertheless it is so, for seals
and whales are as truly flesh-eating milk-givers as bears and wolves;
nor are they much behind them in intelligence, for we all know how
teachable and affectionate seals and sea-lions are, while what little
is known of the life of whales shows that they are devoted mothers, and
their well convoluted though small brains are a proof that they are by
no means wanting in intelligence.

Yet the whales and dolphins, at any rate, have not only adopted a sea
life, but have limbs so like a fish’s fins that we can scarcely call
them by any other name, and they are so completely water animals that
they cannot even return to the land.

Now we should be quite puzzled to account for such curious forms as
these warm-blooded animals, half transformed into fish, if it were not
that we know of several land animals belonging to different groups
which have gone part of the way towards a fish life. Thus among the
reptiles we have the oceanic turtles and the sea snakes; among birds
the penguins, whose wings have almost become fins. Then among the
milk-givers we have the web-footed Duck-billed Platypus, the Yapock
or web-footed opossum of South America, the Desman and the Beaver,
the Polar Bear, and last but not least the Otters, web-footed animals
nearly allied to the weasels, which seek their food entirely in the
water.

The common Otter of Europe and America though he moves quickly and
actively on land, has webbed toes with only short claws standing out
beyond the swimming foot, and he spends the greater part of his life
in the river, making his home in a hollow of the bank beneath the
overhanging roots of trees. There he may still be seen in many of our
English rivers, his soft brown fur shining as he swims along, diving
under water for a fish, which he brings out on to the bank to eat,
holding it in his fore paws.

But there is an otter which has deserted the old land life much more
completely than this, for the great Sea-Otters of the North Pacific,
about four or five feet long (see Fig. 79), never care even to come on
shore, but, when they have dived for their prey, turn on their backs
and float while they eat it, holding the sea-urchins, crabs, or fish,
in their front paws. They even nurse their young ones in the same
fashion, dandling them in their arms as they lie face upwards on the
sea; and they rear them entirely on the thick beds of kelp off the
coasts of the North Pacific Ocean, never bringing them on land.

These sea-otters may be seen in hundreds off the coasts of Alaska and
California, basking on the wet rocks, playing, leaping, and plunging in
the water, till some alarm makes each mother seize her little one in
her teeth and dive under in an instant.

They are twice the size of the River Otter, and in many points more
like seals, for though their front paws are short and cat-like, their
hind feet are flat flippers, with a long outer toe; their face too is
broad and short, and their teeth are neither cutting like the weasels
nor flattened like the bears, but covered with rounded knobs, well
fitted for crushing crab-shells and the bones of the fish on which they
feed.

[Illustration: Fig. 79.

Sea-Otter.[180]--(_From Wolf._)

Showing the front paws, and the hind webbed feet.]

We see, then, that it is quite possible for land-animals to have near
relations specially adapted for a sea life. But the otter is still
distinctly a four-footed creature, with free arms and legs, and we can
trace his connection with the weasel tribe. It is quite different with
the three groups of real fin-footed animals--the Seals and Walruses,
the Manatees, and the Whales. Though we can trace their likeness bone
by bone to the land animals, yet they have become so different as to
show that they must have branched off long long ago; so long indeed
that we cannot even guess at the relations of the whales, while
the seals have only a distant resemblance to the bear family, and
the sea-cows or manatees to the ancestors of the hoofed animals and
elephants. Nor shall we wonder to find the whales so much the most
fitted for the sea, when we learn that they were already living in the
water when we first meet with the great army of milk-givers (see p.
211) just after the Chalk Period, so that they have probably had a much
longer spell of watery life than the seals and sea-cows, whose remains
we only find later.

Yet even the seals are so much altered from anything we see on land,
that few people would believe at first sight that they have the same
skeleton as a bear. We need not leave the British shores to study these
pretty creatures, for they still come to the coasts of Wales, Cornwall,
and Ireland; while in the Hebrides they may be seen lying fast asleep
on the rocks at low tide out at sea, one, placed higher than the rest,
keeping awake as sentinel to give warning at the least approach of
danger.

But if we begin our study with the common seal we shall be much
puzzled, for he is very unlike a land animal. His round neckless
body tapering away to the tail, where the hind flippers stretch out
behind like fish’s fins, reminds us far more of a tunny fish than of a
four-footed milk-giver; while the front flippers, coming out so finlike
from his side, give us very little idea of legs (see Fig. 81). No! in
order to compare these fin-footed[181] creatures with land animals
we shall do far better to travel up to the Aleutian Islands at the
entrance of Behring’s Straits, and visit the Fur Seals and Sea Lions,
from which we get our seal-skins, and the Walruses which sometimes lie
there sleeping on the rocks, though their real home is farther north
within the Arctic Circle, round the coasts of Nova Zembla, Spitzbergen,
and Greenland.

[Illustration: Fig. 80.

Skeleton of a Sea Lion.

Showing how the whole foot rests on the ground, as in the Bear Family.

    _th_, thigh; _l_, leg; _h_, heel; _f_, foot; _a_, upper-arm; _fa_,
    fore arm; _ha_, hand.
]

These creatures, although they have “flippers,” and are truly
fin-footed, are much more like land animals than the smaller seals, for
they plant their whole foot on the ground as a bear does, and walk,
or, more properly, “flop along” on all fours. A mere glance at the
skeleton of the sea lion, which is one of these higher kind of seals
with a slight outer ear,[182] shows that it is a four-footed animal,
with five toes to each foot, the great toes and the thumbs being the
largest. We can see distinctly the short thighs and the long shanks,
which give the hind flippers their lanky appearance, and we see, too,
the broad stumpy arms, which give such strength to the front flippers
in swimming. For the eared seals and walruses use their fore flippers
very much in the water, while the true seals swim almost entirely
with the hind flippers, and use the front ones chiefly for guiding
themselves.

And now if we turn to the living fur seal we find that the reasons are
twofold which make us forget that his limbs are legs. In the first
place, the skin of his body comes down very low over his arms (see Fig.
81), while the hand is encased in skin, with only mere traces of nails
upon it Then as regards his hind legs, not only are the feet made into
flippers, in which the toes are joined by a loose flexible skin, so
that they can move them freely when swimming, but the legs themselves
are strapped back by a skin passing right across his tail, so that his
thighs are kept flat against his side, and only the lower part of the
legs has power to move. We lose sight, then, of the limbs, and see very
little more than the feet, which are disguised by being turned into
flippers.

Now if we once think what is the object of a seal’s life, this curious
change in its body is at once explained. For seals are the hunters of
the sea; fish-food is to them what flesh-food is to lions, wolves, and
bears, only that they have a much wider field to hunt in, for they have
the whole ocean for their feeding ground, and no one to dispute it
with them but the sea-otter in places near the land, and the porpoises
and other fish-feeding whales out at sea. In consequence of this we
find seals of some kind in almost all parts of the world, except the
Indian Ocean, though they evidently prefer the cooler regions. Even the
large sea lions live in the North Pacific, as far up as the Aleutian
Isles, and in the South Pacific down to the Falkland Islands and
Kerguelen’s Land, and play about the shores of the Cape, New Zealand,
and Australia.

[Illustration: Fig. 81.

A Fur Seal,[183] one of the Sea Lions; and a common Seal.[184]

    Showing how the Sea Lion walks on the flat hind feet, while the
    seal’s flippers lie back in a line with the body; note also the
    absence of an external ear in the seal.
]

They have evidently been very successful in exchanging flesh-feeding
for fish-feeding, and if we consider for a moment what changes a
four-footed land animal would wish to make in its body in order to
swim and dive in the water, we shall see that these changes have taken
place in the seals.

First, a flexible body is required to wind and twist rapidly in the
water, and this the seal arrives at by having the cushions of gristle
between its joints very large and thick, while even its ribs are joined
to its back by gristly rods, making its whole body very lissom. Next,
a small head, offering little resistance to the water is an advantage,
and this we find in all seals, while the short neck and extremely
sloping narrow shoulders well encased in fat, make the body slope away
gently with no jutting angles, but a round smooth surface from head to
tail where it narrows like the tail of a fish. The next step is to do
away with long angular arms and legs, which would impede it in diving
and swimming, and here the seal meets the difficulty, not by losing
its leg and arm bones, but by having them so shortened and encased in
the skin that only the useful broad flippers are free, while the hind
legs are set upon a very narrow hip joint (see Fig. 80), so that they
bend backwards and work close to the body. Lastly, such a warm-blooded
animal would want clothing to prevent it from being chilled in icy cold
water, and here we find two protections. First, under the skin is a
layer of oily fat, which, while it reminds us of the fat accumulated
by bears before they settle down to their winter’s sleep, has become
in the seals a dense oily mass, acting like a thick blanket in keeping
up the warmth of the body; and secondly, the seal, like its distant
relations the bears, has a dense furry covering, and over this a number
of coarse long hairs, which give it that shining oily look we notice
in all seals. No doubt every one has wondered, when watching seals
in zoological gardens, where the fur can be which makes our sealskin
muffs and jackets. The fact is, that this under fur is quite out of
sight in the living seal, being covered by the coarse hairs; but if we
could turn these aside, even in common seals, we should see the soft
undergrowth beneath, and in the fur seals it is much thicker. Now the
roots of these coarse hairs are deeper in the flesh than the roots of
the soft undergrowth, and when the uppermost layer of the skin on which
the fur grows is sliced off, the coarse hairs are cut away from their
deep roots below, and can then be pulled out, leaving only the fur
behind.

The seals then, while they are in all main points constructed like
land animals, have gained many advantages, not by having new parts,
but by the old ones becoming so modified as to make them admirably
fitted for a watery life; and when we add that they have large eyes
well adapted for seeing under water, keen ears with little or no outer
ear, which would be useless, but a very acute hearing apparatus within,
and nostrils which will close firmly and keep the air in and the water
out when they dive, we must acknowledge that they make good use of all
parts of their body. Indeed, their breathing apparatus is the most
curious of all, for they can remain under water sometimes for twenty
minutes, and meanwhile the circulation of their blood is probably
controlled by large reservoirs in the veins, which prevent it going
back to the heart and lungs till it can be purified by fresh breath.

Now, if all these changes from a land to a water-frequenting
animal have been made gradually, we shall expect to find some forms
less altered than others, and so it is. The Walrus, which is not a
seal, but a creature with a thick hide having no fur and only a few
scattered hairs upon it, and long tusks in his mouth, is much more
of a land-animal than the seals. He passes a great part of his life
sauntering along on the low shores of the Arctic seas, digging up
mussels, cockles, and clams with his long canine teeth or tusks; and
in accordance with this we find that his hind legs are much freer than
even those of the sea-lions, for the skin binding them to his body is
broader and his hips are stronger, so that, as he throws his front
flippers forwards, he can also throw out his feet and walk on all fours
in a strange straddling manner. He is remarkably fierce and strong,
and Captain Scoresby caught one once in the act of killing and eating
a large narwhal, so that they are evidently not afraid of attacking
even large animals. The walrus is even said to stand at bay on shore
and fight his great destroyer the polar bear, throwing up his head so
as to strike forcibly with his sharp tusks, but in this battle he is
generally defeated. His tusks alone would suggest that he lives a good
deal on land exposed to dangers, for his more aquatic relations the
seals are without tusks, and though their teeth are sharp enough, and
they fight among themselves, yet their way of escaping the great tyrant
of the ice-fields is to slip into the water.

Beyond his tusks, and the fact that by sleeping many weeks on the ice
in autumn he reminds us of the bears, the walrus’s life is not very
interesting. They live in large shoals in the Arctic sea, climbing the
rocks and ice with the help of their tusks, which they drive into the
crevices and so haul themselves up. During the colder times just before
our own, they came down into much lower latitudes than now, and we find
their bones as far south as England in Europe and Virginia in America,
and even in our day one has been seen off the west coast of Skye; but
we know very little of their daily life or how they bring up their
young ones.

Of Fur Seals and Sea Lions, however, we know a good deal, and a
singular history it is. They spend the greater part of the year in
huge shoals in the sea, rising and falling, gambolling and diving in
the water, feeding on the fish, and probably migrating from colder to
warmer seas in the winter from either pole. But the interesting time of
their life is in the spring, when the northern eared seals have often
been watched as they come to the shores of the Aleutian Isles to bring
up their families.

For then begins the fight which seals shall get the most wives. Early
in May the fathers begin to arrive--strong old seals, which have gone
through the battle many years before and know the rules. They are huge
fellows six or seven feet long, with enormous eye-teeth and cutting
teeth next to them, which together grip like a vice. They come up at
first singly and then in greater numbers, swimming powerfully and
laying hold of the rocks with their flippers so as to haul themselves
up on land, taking the best positions they can find on the edge of the
water to watch for the arrival of the mothers. Yet still more and more
fathers arrive as time goes on, and these are obliged to go farther
inland, for all the shore stations are soon occupied, and each sea
lion defends his own plot of ground with tooth and flipper.

[Illustration: Fig. 82.

Sea Lions gathered on one of the Pribylov Islands, watching for wives.]

Thus, in about a month’s time, from the shore right inland, the whole
island is covered with male seals. And now the mothers arrive, coming
to the islands that their little ones may be born. They are very much
smaller, not much more than four feet long, lighter in colour than the
fathers, gentle and inoffensive; and as they swim up to the island each
father seal tries, by coaxing, pulling, and tugging, to persuade a mate
to come on to his rock. If he succeeds he has then to keep her, for the
sea lions behind, which cannot reach the sea, are on the watch to steal
her.

Now he might make quite sure of his prize if he would be content with
one, but he wants several; and the next young mother swimming up calls
off his attention, and while he is courting her his neighbour behind
tries to carry his first wife away, lifting her by the back of the neck
as a cat does a kitten. Then often a terrible battle begins, and the
poor mothers are pulled hither and thither till one male seal secures
her, and then the whole thing begins again. This constant fighting
and lovemaking go on for several days till all the sea lions have
wives--those on the shore many, those behind perhaps very few. Then all
settle down quietly, the little sea lions are born, bleating like young
lambs, and family life begins. But the peace does not last long, for no
sooner are mothers able to leave their little ones than the old contest
begins again, and happy the father who can keep his wives together
through a whole season!

And now comes the most remarkable point. As a rule, seals are immense
eaters, and they become very fat. But from the time that the fathers
land upon the rocks till they go back to the water after about two
months, they have never been known to leave their position to take
food, so busy are they defending their wives. And when the two months
are over, during which the little ones have been trying their strength
in the waves and learning to swim, the fathers, which have grown
thin and meagre, having used up all their fat, swim away and do not
come back. The mothers, however, with the children, and those young
bachelors, which have not yet taken wives, remain on the islands
sporting and enjoying themselves till autumn, when they, too, start
off for the open sea till spring comes round again.

Such is the history of the eared seals. And now that we have studied
their form, and seen that their skeleton is like that of other animals,
though their arms and legs are disguised as flippers, we shall
understand our own home seals better; for the chief difference between
them and the higher seals is merely that their front legs are much
shorter, and that their hind legs are turned back so as to lie in a
line with the body (see Fig. 81), while they are closely bound to the
tail down right as far as the heel, so that they cannot throw their
hind flippers forward nor use them in walking. Thus they have become
still more completely aquatic animals, using their hind legs entirely
in swimming, when they serve as great oars, working something like the
screw of a steamer. The consequence is that they are terribly awkward
on land, though they get along very fast by jerking their body forward,
or sometimes by dragging themselves by their front flippers.

This, however, matters very little to them, for their home is the sea.
True, they may often be seen lying asleep on sandbanks or on rocks
jutting out of the water, but they rarely venture far up the land,
always remaining where they can slip back into their true home at the
least alarm. So they live in the seas almost all over the world. They
may be known from the higher seals chiefly by their want of outer
ears, their backward-turned legs, and their feet with both the great
and little toes larger than the inner ones; but their life is much
the same. Some live near our own shores, especially in Scotland; some
are peculiar to Australia and New Zealand; others crowd the icy seas
of Greenland, sleeping in large herds on the ice-fields, where the
polar bear makes them his prey; while others again live on the pack ice
round the South Pole, the huge Elephant seal, with its long tapir-like
nose, basking on the shores of Kerguelen’s Land and the islands of the
southern seas--a monster twelve feet or more long, with his smaller
wives beside him.

       *       *       *       *       *

Thus the seals are bold ocean lovers, feeding entirely on animal food,
and finding plenty of it in the wide sea as they roam. But there is
another family of warm-blooded animals, pure vegetable-feeders, which
also must have found their way in distant ages into the water; for they
too are milk-givers, and though they have lost their hind legs, have
still the front legs with all their proper bones, with the hands turned
into flippers.

These animals are the curious sea-cows or Manatees, which wander under
water along the east coast of Africa and west coast of South America,
feeding in the bays and often up the rivers, on the seaweeds and
water-plants of all kinds; while another kind with tusks, called the
Dugong, feeds all along the shores of the Indian Ocean and Australia.

It is strange that while every child knows something about seals, very
few people have heard of these gentle grazing manatees and dugongs,
the only large vegetable-feeders of the sea. Yet they are curious,
interesting animals, and seem to be the forms which have given rise to
the popular stories of mermaids,[185] for they suckle their young ones
at the breast, clasping them with their flippers, and when they raise
their heads in the water have something the appearance of an uncouth
mother nursing her child.

[Illustration: Fig. 83.

The Manatee or Sea Cow grazing.]

But very uncouth indeed! for they are long barrel-shaped creatures,
with a thick skin like the elephant’s, with short stiff hairs upon it.
Their head is small, with no outer ears, and very insignificant eyes
surrounded with wrinkles; their lips are thick, heavy, and covered
with short bristles, and above them two narrow nostrils open and close
according as they are above or under water. Their front flippers, which
are all they have, are long and broad, with faintly-marked flat nails
upon them, and behind these their body tapers away gradually into a
thin, wide, shovel-shaped tail, not set edgewise as in a fish, but
_across_ the body, so as to lie like a broad leaf in the water.

Who would think that a creature like this had anything in common with
land animals? Yet so it is, for not only do we know that his ancestors
had traces of hind legs, but his front limbs are quite as true arms
and hands as those of any of the seals. Moreover, he has large broad
grinding back teeth like the elephant, and in front he has small
cutting teeth as a baby, though these are covered up by the gum as he
grows older. In the Australian dugong, however, these teeth continue to
grow and form good-sized tusks in the fathers.

What, then, is this curious animal? Simply a vegetable-feeder which
has become fitted for a watery life--a gentle, peaceable animal, which
keeps near the shore and grasps the seaweed with the sides of its
upper lip, and then nips it off by a set of horny plates, which grow
down from the roof of its mouth, and answer to the rough wrinkles
on a cow’s palate. They may often be seen together, father, mother,
and child, wandering up the river Congo in Africa, or the Amazons in
South America, feeding entirely under water, and only raising their
heads from time to time with a snort to take in fresh air. In olden
times they probably thronged all the coasts on the sea-margin, for
a hundred and fifty years ago there was another group of them, the
Rhytinas, right up in the cold seas of Behring’s Straits, where the
vast submarine forests of seaweed afforded them plenty of food. But the
sailors found them such good eating, and the fatty blubber on their
bodies was so valuable, that they were all killed twenty-five years
after Behring first discovered them, and unless some care is taken, the
more southern sea-cows may some day be exterminated in the same way.

       *       *       *       *       *

And now that we have firmly grasped the fact that the seals and
manatees, however altered in shape, belong to the four-footed and
milk-giving group, perhaps we shall be prepared to understand how it is
that the whales[186] are not fish, though this popular delusion is one
of the most difficult to overcome. “Do you really mean then,” exclaim
nearly all people who are not naturalists, “that a whale is not a huge
fish?” Certainly I do! A whale is no more a fish than crocodiles,
penguins, or seals, are fish although they too live chiefly in the
water.

A whale is a warm-blooded, air-breathing, milk-giving animal. Its fins
are hands with finger-bones, having a large number of joints (see Fig.
84); its tail is a piece of cartilage or gristle, and not a fish’s fin
with bones and rays; it has teeth in its gums even if it never cuts
them; and it gives suck to its little one just as much as a cow does to
her calf (see Fig. 85). Nay! the whalebone whales have even the traces
of hind legs entirely buried under the skin (see Fig. 84), and in the
Greenland whale the hip-joint and knee-joint can be distinguished with
some of their muscles, though the bones are quite hidden and useless.

[Illustration: Fig. 84.

Skeleton of a Whalebone Whale (Mysticete), and Section of the Mouth
with Whalebone.

    _b_, blowhole; _a_, upper arm; _fa_, fore arm; _h_, hand; _p_, _th_,
    _l_, small remains of pelvis or hip-bone, thigh, and leg; _r_, roof
    of the palate; _w_, _w_, plates of whalebone; _f_, whalebone fringe.
]

We see then that the whale undoubtedly belongs to the same type as the
four-footed land animals, although it branched off into the water so
long ago that it may have come from some _very_ early milk-giver. But
why then has it become so like a fish? For the same reason that the
penguin’s wings have become so fin-like, and the seal’s arms and legs
have become flippers, namely, that during the long time in which the
whales have taken to a watery life, those which could swim best and
float best in the water have been the most successful in the struggle
for existence; and as a fish’s shape is by far the best for this
purpose the warm-blooded milk-giver has gradually imitated it, though
belonging to quite a different order of animals.

[Illustration: Fig. 85.

The Humpback Whale[187] suckling her young (_after Scammon_).]

We saw this imitation already beginning in the seals, with their bodies
sloping off towards the tail and their legs fastened back in a line
with the body; but they have not gone so far in this direction as the
whales have, since they still have hind legs and furry bodies. The sea
cows, on their line, have gone a little farther, for they have lost
their hind legs, and their skin is smooth, with very few hairs upon it.
But it remained for the whales to take up the best fish-form, the old
spindle-shape, thinning before and behind, with the strong fleshy tail
ending in two tail lobes, which act like a screw in driving the body
along.

Any good drawing of a whale shows at once how admirably these animals
are fitted for gliding through the water (see Fig. 85). True, many of
them have enormous heads, but these always have long face-bones ending
in a rounded point, and even the huge head of the sperm whale (see Fig.
87), eighteen feet long, six feet high, and six feet wide, is rounded
off above, and gradually thins away below, like the cutwater of a ship.
The eyes are very tiny and so little exposed, that it is difficult to
find them; there are no outer ears, though the bones within are large
and probably very useful for hearing in water; the bones of the neck
are seven, as is the rule among milk-givers, but they are so flattened
and firmly soldered together, and so covered with blubber, that there
is not even a hollow between the head and the body; while to crown
all, the skin is perfectly smooth so as to offer no resistance to the
water. Here, however, would be a disadvantage in the loss of the furry
covering, since most of the whales travel into cold seas, were it not
compensated by the great mass of oily fat or blubber which fills the
cells in the under part of the skin, and keeps the whole body warm;
and thus the whale, by a covering of fat often as much as a foot and a
half thick, solves the problem of a warm-blooded animal, with a smooth
gliding body, living in icy water without having its blood chilled.

In every essential for swimming, then, whales are as well provided as
any fish, while their immensely strong backbone, and the long cords
or tendons running from the mass of muscle on the body to the tail,
give them such tremendous power that a large whale makes nothing of
tossing a whole boat’s crew into the air and breaking the boat in
two. But, though they are so far true water-animals, yet they cannot
live entirely below as fish can, for they have no apparatus for
water-breathing. The outside of their body takes on the appearance of
a fish, but inside they have the true lungs, the four-chambered heart,
and all the complicated machinery of a warm-blooded animal. Therefore,
though a whale may dive deep and remain below to seek its food, yet
before an hour has passed even the largest of them must come floating
up to the top again, to blow out the bad air through the nostrils at
the top of the head, and fill the capacious lungs with a fresh supply.
It is then that, partly because of the water which has run into the
blowhole, and partly because the rush of breath throws up spray from
the sea, we see those magnificent spouts of water which tell that a
whale is below. The older naturalists thought that these spouts were
caused by the water which the whale had taken into its mouth; but this
is not so, and Scoresby, the great Arctic traveller, states distinctly
that if the blowhole of the whale is out of the water only moist vapour
rises with the breath, while when it makes a large spout this comes
from its blowing under water and so throwing up a jet.

If, however, the whale is a simple air-breather and yet swims under
water with its mouth open, how comes it that this water does not run
down the windpipe and choke the lungs? This is prevented by a most
ingenious contrivance. At the top of our own windpipe there is a
small elastic lid which shuts when we swallow, and prevents water and
food from running down to the lungs. Now, in the whale the gristle
answering to this lid runs up as a long tube past the roof of the
mouth into the lower portion of the nose, and is kept there tightly,
being surrounded by the muscles of the soft palate. The upper portion
of the nose cavity then opens on the forehead by means of one or two
“blowholes,” as the outside nose holes are called; so that when the
blowholes are closed the whale can swim with its mouth open and feed
under water, and yet not a drop will enter its lungs.

A large sperm whale will often remain twelve minutes or more at the
top of the water, taking in air at the single blowhole in the front of
its head, and purifying its blood, and then with a roll and a tumble
it will plunge down again, and remain for an hour below, trusting to a
large network of blood-vessels lying between the lungs and the ribs to
supply purified blood to its body and retain the impure blood till it
comes up again to breathe.

But the smaller whales and porpoises, which play about our coasts,
have to come up much more often, and even when they are not tumbling
and jumping, as they love to do, you may see them rising at regular
intervals as they swim along, their black backs appearing like little
hillocks in the water, as they “blow” strongly from their single
nose-slit, take a quick breath in, and sink again to rise a few paces
farther on and repeat the process.

Thus provided both with swimming and breathing apparatus, these purely
air-breathing animals wander over the wide ocean and live the lives
of fish, making such good use of food which cannot be reached by land
animals, or those which must keep near the shore, that we shall not be
surprised to find that the whale family is a very large one.

But it is curious that the fierce animals of prey among them should be,
not the huge whales but the smaller Dolphins, Porpoises, and Grampuses;
and this shows how different water-feeding is to land-feeding, since,
because the water is full of myriads of small and soft creatures,
the sperm whale feeding on jelly-fish, and the large whalebone whale
feeding on soft cuttle-fish and the minutest beings in the sea, are
those which attain the largest size.

Most people have at one time or another seen a shoal of porpoises
either out at sea or travelling up the mouth of some large river, where

   “Upon the swelling waves the dolphins show
    Their bending backs, then swiftly darting go,
    And in a thousand wreaths their bodies throw;”

and though they are small creatures, only about five feet long, they
are very good examples of the whale shape, with their tapering bodies,
broad tails, and the back fin, which is found in some whales and not in
others. Sometimes they swim quietly, only rising to breathe, and then
they work the tail gently from side to side; at others they gambol and
frolic, and jump right out of the water, beating the tail up and down,
and bending like a salmon when he leaps; and whether they come quietly
or wildly, you may generally know they are near by the frightened
mackerel and herrings, which spring out of the water to avoid them.
For the porpoises have a row of sharp teeth in each jaw, more than a
hundred in all, and they bite, kill, and swallow in one gulp, without
waiting to divide their food, so that they make sad havoc among the
fish.

[Illustration: Fig. 86.

The Porpoise.[188]]

They are here to-day and gone to-morrow. A few kinds wander up into
fresh water, such as the Ganges and the Amazons, but by far the greater
number range all over our northern seas, together with their near
relations the dolphins, and the bottle-nosed whales, and the strange
narwhal, with its two solitary eye teeth, one only of which grows out
as a long tusk. All these roam freely through the vast ocean home,
coming into the still bays to bring up their young ones, which they
nurse and suckle tenderly, afterwards moving off again in shoals to the
open sea. There they will follow the ships, and sport and play, and
probably we shall never know exactly where their wanderings extend,
though it seems that they prefer the northern hemisphere.

Among all the dolphin family the most voracious and bloodthirsty is
the Grampus or Orca,[189] which is commonly called the “Killer Whale,”
because it alone feeds on warm-blooded animals, seizing the seals with
its strong, sharp, conical teeth, devouring even its own relations
the porpoises, and attacking and tearing to pieces the larger whales.
No lion or tiger could be more ruthless in its attacks than this
large-toothed whale, which is sometimes as much as twenty-five feet
long and has broad flippers. In vain even the mother walruses try to
save their young ones by carrying them on their backs; the cunning Orca
swims below her, and coming up with a jerk shakes the young one from
its place of safety and swallows it in a moment. Nor do they merely
fight single-handed, for many voyagers have seen them attack large
whales in a pack like wolves, and in 1858 Mr. Scammon saw three killer
whales fall upon a huge Californian Gray Whale and her young one,
though even the baby whale was three times their size. They bit, they
tore, and wounded them both till they sank, and the conquerors appeared
with huge pieces of flesh in their mouths, as they devoured their prey.
How much they can eat is shown by one orca having been killed which had
the remains of thirteen porpoises and fourteen seals in its stomach!

How strange now to turn from this ravenous hunter to the huge Sperm
Whale, eighty feet long, with a head one-third the size of its whole
body and more than a ton of spermacetic oil in its forehead, and to
think that this monster swims quietly along in the sea, drops its long
thin lower jaw, and with wide-open mouth simply gulps in jelly-fish,
small fish, and other fry, thus without any exertion or fuss slaying
its millions of small and soft creatures quietly, as the orca does the
higher creatures with so much battle and strife!

For the sperm whale (Fig. 87) must need a great deal of food to feed
its huge body. Though it has forty-two teeth in the lower jaw it never
cuts those in the upper one, and seems to depend more on sweeping its
prey into its mouth than on attacking it. And this perhaps partly
explains the use of that curious case of spermaceti which lies in its
huge forehead over the tough fat of its upper jaw. For this oil gives
out a powerful scent, which, when the whale is feeding below in the
deep water, most probably attracts fish and other small animals, as
they are also certainly attracted nearer the surface by the shining
white lining of its mouth. This light mass is also, however, useful in
giving the head a tendency to rise, so that when the whale wishes to
swim quickly it has only to rise to the top, so that the bulk of its
head will stand out of the water, the lower and narrow part cutting the
waves. In this position he can go at the rate of twelve to twenty miles
an hour.

But if the sperm whale is curious, as it carries its oil-laden head
through all seas from pole to pole, chiefly in warmer latitudes, how
much more so are the whalebone whales, which are monarchs of the
colder and arctic seas, where they feed on the swarms of mollusca,
crustaceans, and jelly animals which live there. For these large
whales, though they have teeth in their gums, never cut them, but in
their place they have large sheets of whalebone hanging down from the
upper jaw (see Fig. 84), smooth on the outside, fringed with short
hairs on the inside, and crowded together so thickly, only about a
quarter of an inch apart, that as many as three hundred sheets hang
down on each side of the mouth of the great Greenland whale.

[Illustration: Fig. 87.

The Sperm Whale.]

It is easy to see the use of these whalebones when we remember that
this huge whale feeds entirely by filling its enormous mouth with
water, and then closing it and raising its thick tongue at the back
so as to drive the water out at the sides, straining it through the
fine fringes, which fill up all the spaces between the plates and keep
back every little shell-fish and soft animal. But it is less easy to
guess where these whalebone plates come from, till we look back at the
manatee, and remember those horny ridges which it uses for biting, and
which are exaggerations of the rough fleshy ridges at the top of a
cow’s mouth.

Then we have a clue, for each blade of whalebone grows from a horny
white gum, being fed by a fleshy substance below much in the same way
as our nails are, so that these blades are, as it were, a series of
hardened ridges, which grow out from the soft palate, till they become
frayed at the edges, and form that dense fringe which is the whale’s
strainer, upon which he depends entirely for his food.

Explain it as we will, however, it is a most wonderful apparatus.
Imagine a huge upper jaw forming an arch more than nine feet high, so
that if the whalebone were cleared away a man could walk about inside,
upon the thick tongue which lies in the lower jaw fastened down almost
to the tip so that it cannot be put out of the mouth. And then remember
that this enormous mouth has to be filled with food sufficient to
nourish a body fifty or more feet long. Who would ever guess that this
food is made up of creatures so small that countless millions must
go to a mouthful? Yet the whole difficulty is solved simply by these
triangular fringed plates or mouth-ridges (see section Fig. 84, p.
318), covered with horny matter and frayed into minute threads like the
horny barbs of a feather.

Nor are we yet at the end of the wonderful adaptation, for while the
jaw is only from nine to twelve feet high, the long outside edge of
the plates is often eighteen feet long, and for this reason, that if
they were only as long as the jaw is deep, then when the whale went
fishing with his mouth open the animals would escape below the fringe,
while as they now are, he may gape as wide as he will, the long curtain
will still guard the passage of the mouth and entangle the prey in its
meshes. But what, then, is to become of this great length of whalebone
when the animal shuts his mouth? Here comes in the use of the beautiful
elasticity of the plates, for the great Arctic whaler, Captain Gray,
has shown that as the mouth shuts the lower ends of the longer plates
bend back towards the throat and fall into the hollow formed by the
short blades behind them, so that the whole lies compactly fitted in,
ready to spring open again, and fill the gap whenever the jaws are
distended.

With this magnificent fishing-net the whalebone whales go a-fishing
in all the salt waters of the world. They are not all of enormous
size,--many of them are not more than twenty feet long,--nor have they
all such a perfect mouthful of whalebone as the great Polar Whale; but
when the whalebone is shorter, as in the Rorqual, and other whales with
back fins, the stiff walls of the lower lip close in the sides of the
mouth and prevent the escape of the prey; and many of these whales have
a curious arrangement of skin folds under the lower jaw, which stretch
out and enable them to take in enormous mouthfuls of water, so as to
secure more food.

New Zealand, California, Japan, the Cape, the Bay of Biscay, and in
fact almost every shore or sea from pole to pole, has some whale
called by its name; for these gaping fishers are everywhere, and it
is not always easy to say whether the same whale is not called by
different names in various parts of the world. In the shallow bays and
lagoons they may be found with their newly-born young ones very early
in the year; while far out at sea ships meet with them travelling in
shoals, or “schools,” northwards, as the summer sets in and the Arctic
Sea is swarming with life. In fact the Californian gray whales go right
up into the ice, poking their noses up through the holes to breathe,
and then they travel far away south again into the tropics to bring up
their young ones.

And whether large or small, toothed whales or whalebone whales, active
as the dolphin and the huge fin-whales or rorquals, which dash through
the water although some are nearly a hundred feet long, or lazy and
harmless as the Greenland whale is unless attacked, in one thing
all the whale family betray their high place in the animal kingdom.
Nowhere, either on land or in the water, can mothers be found more
tender, more devoted, or more willing to sacrifice their lives for
their children than whale-mothers. Scoresby tells us that the whalers,
as means of catching the grown-up whales, will sometimes strike a
young one with harpoon and line, sure that the mother will come to its
rescue. Then she may be seen coming to the top with it encouraging it
to swim away, and she will even take it under her fin, and, in spite of
the harpoons of the whalers, will never leave it till life is extinct.
Nay, she has been known to carry it off triumphantly, for the lash of
her tail is furiously strong when she is maddened by the danger of her
child, so that a boat’s crew scarcely dare approach her.

And now there remains the question what enemies besides man these
strong-swimming milk-givers can have in their ocean home? We have seen
that the orca or killer whale will turn cannibal and devour those of
its own kind, and the swordfish is said to attack whales with its
formidable spear; but these are not their greatest enemies. With many
of the whales it is tiny creatures like those on which they feed which
hasten their death, for small parasitic crustaceans cover their head
and fins, and feed upon their fat, so that whales which have been
infested with these animals are often found to be “dry,” or to have
lost nearly all their oil. And thus we see the tables turned, and while
the whale feeds upon minute creatures, it is in its turn destroyed by
them.

Nevertheless, as a rule, they probably live long lives, till their
teeth are worn, or their whalebone frayed and broken, and their blubber
wasted away; and then, it may be after eighty or one hundred years of
life, they die a natural death. Therefore they probably share with the
elephant the longest term of life of any of the warm-blooded animals;
and though their existence cannot certainly be said to be an exciting
one, yet, when undisturbed by man, it is at least peaceful, sociable,
and full of family love.

It may perhaps seem strange that we should have taken these
ocean-dwellers last in our glimpses of animal life; but in the first
place, how was it possible to show how they are truly related to the
land mammalia until we understood the structure of these last? And
in the second place, we have as our object to see how the backboned
family have won for themselves places in the world, and surely there
are none which have done this more successfully or in a more strange
and unexpected way than the whales, which, while retaining all the
qualities of warm-blooded animals, have won themselves a home in
the ocean by imitating the form and habits of fish, and so adapting
themselves to find food in the great oceans, where their land relations
were powerless to avail themselves of it.




[Illustration: WHEN THE COLD HAS PASSED AWAY]




CHAPTER XII.

A BIRD’S-EYE VIEW OF THE RISE AND PROGRESS OF BACKBONED LIFE.


We have now sketched out, though very roughly, the history of the
various branches of the great backboned family, and we have found that,
as happens in all families, they have each had their successes and
their downfalls, their times of triumph, and their more sober days,
when the remaining descendants have been content to linger on in the
byways of life, and take just so much of this world’s good as might
fall to their share.

We have seen also that, as in all families of long standing, many
branches have become extinct altogether; the great enamel-plated
fish, the large armour-covered newts, the flying, swimming, and huge
erect-walking reptiles, the toothed and long-tailed birds, the gigantic
marsupials, the enormous ground-loving sloths, and many others, have
lived out their day and disappeared; their place being filled either by
smaller descendants of other branches of the group, or by new forms in
the great armies of fish, birds, and milk-givers which now have chiefly
possession of the earth.

Still, on the whole, the history has been one of a gradual rise from
lower to higher forms of life; and if we put aside for a moment all
details, and, forgetting the enormous lapse of time required, allow the
shifting scene to pass like a panorama before us, we shall have a grand
view indeed of the progress of the great backboned family.

First, passing by that long series of geological formations in
which no remains of life have been found, or only those of boneless
or invertebrate animals, we find ourselves in a sea abounding in
stone-lilies and huge crustaceans,[190] having among them the small
forms of the earliest fish known to us, those having gristly skeletons.
Then as the scene passes on, and forests clothe the land, we behold the
descendants of these small fish becoming large and important, wearing
heavy enamelled plates or sharp defensive spines; some of them with
enormous jaws, two or three feet in length, wandering in the swamps and
muddy water, and using their air-bladder as a lung. But these did not
turn their air-breathing discovery to account; they remained in the
water, and their descendants are fish down to the present day.

It is in the next scene, when already the age of the huge extinct
fishes is beginning to pass away, and tree ferns and coal forest plants
are flourishing luxuriantly, that we find the first land animals,[191]
which have been growing up side by side with the fish, and gradually
learning to undergo a change, marvellous indeed, yet similar to one
which goes on under our eyes each year in every country pond. For now,
mingling with the fish, we behold an altogether new type of creatures
which, beginning life as water-breathers, learn to come out upon the
land and live as air-breathers in the swamps of the coal forests.

A marvellous change this is, as we can judge by watching our common
tadpole, and seeing how during its youth its whole breathing organs are
remade on a totally different principle, its heart is remodelled from
an organ of two chambers into one of three, the whole course of its
blood is altered, some channels being destroyed and others multiplied
and enlarged, a sucking mouth is converted into a gaping bony jaw,
and legs with all their bones and joints are produced where none were
before, while the fish’s tail, its office abandoned, is gradually
absorbed and lost.

The only reason why this completely new creation, taking place in one
and the same animal, does not fill us with wonder is, that it goes on
in the water where generally we do not see it, and because the most
wonderful changes are worked out _inside_ the tadpole, and are only
understood by physiologists. But in truth the real alteration in bodily
structure is much greater than if a seal could be changed into a monkey.

Now this complete development which the tadpole goes through in one
summer is, after all, but a rapid repetition, as it were, of that slow
and gradual development which must have taken place in past ages, when
water-breathing animals first became adapted to air-breathing. Any one,
therefore, who will take the spawn of a frog from a pond, and watch
it through all its stages, may rehearse for himself that marvellous
chapter in the history of the growth and development of higher life.

And he will gain much by this study, for all nature teaches us
that this is the mode in which the Great Power works. Not “in the
whirlwind,” or by sudden and violent new creations, but by the
“still small voice” of gentle and gradual change, ordering so the
laws of being that each part shall model and remodel itself as
occasion requires. Could we but see the whole, we should surely
bend in reverence and awe before a scheme so grand, so immutable,
so irresistible in its action, and yet so still, so silent, and so
imperceptible, because everywhere and always at work. Even now to those
who study nature, broken and partial as their knowledge must be, it is
incomprehensible how men can seek and long for marvels of spasmodic
power, when there lies before them the greatest proof of a mighty
wisdom in an all-embracing and never-wavering scheme, the scope of
which is indeed beyond our intelligence, but the partial working of
which is daily shown before our very eyes.

But to return to our shifting scene where the dense forests of
the Coal Period next come before us. There, while numerous fish,
small and great, fill the waters, huge Newts have begun their reign
(_Labyrinthodonts_), wandering in the marshy swamps or swimming in the
pools, while smaller forms run about among the trees, or, snake-like in
form, wriggle among the ferns and mosses; and one and all of these lead
the double-breathing or amphibian life.

In the next scene the coal forests are passing away, though still
the strange forms of the trees and the gigantic ferns tell us we
have not left them quite behind; and now upon the land are true
air-breathers,[192] no longer beginning life in the water, but born
alive, as the young ones of the black salamander are now (see p. 81).
The Reptiles have begun their reign, and they show that, though still
cold-blooded animals, they have entered upon a successful line of life,
for they increase in size and number till the world is filled with them.

Meanwhile other remarkable forms now appear leading off to two new
branches of backboned life. On the one hand, little insect-eating
warm-blooded marsupials scamper through the woods, having started
we scarcely yet know when or where, except that we learn from their
structure that they probably branched off from the amphibians in quite
a different line from the reptiles, and certainly gained a footing upon
the earth in very early times. On the other hand, birds come upon the
scene having teeth in their mouths,[193] long-jointed tails,[194] and
many other reptilian characters. We have indeed far more clue to the
relationship of the birds than we have of the marsupials, for while we
have these reptile-like birds, we have also the bird-like reptiles such
as the little Compsognathus, which hopped on two feet, had a long neck,
bird-like head and many other bird-like characters, though no wings or
feathers.

The birds, however, even though reptile-like in their beginning, must
soon have branched out on a completely new line. They for the first
time among this group of animals,[195] have the perfect four-chambered
heart with its quick circulation and warm blood; while not only do they
use their fore limbs for flying (for this some reptiles did before
them), but they use them in quite a new fashion, putting forth a
clothing of feathers of wondrous beauty and construction, and with true
wings taking possession of the air, where from this time their history
is one of continued success.

And now we have before us all the great groups of the backboned
family--fish, amphibia, reptiles, birds and mammalia; but in what
strange proportions! As the scenery of the Chalk Period with its
fan-palms and pines comes before us, we find that the gristly fish,
except the sharks and a few solitary types, are fast dying out, while
the bony fish[196] are but just beginning their career. The large
amphibians are all gone long ago; they have run their race, enjoyed
their life and finished their course, leaving only the small newts
and salamanders, and later on the frogs and toads, to keep up the
traditions of the race. The land-birds are still in their earliest
stage; they have probably scarcely lost their lizard-like tail, and
have not yet perfected their horny beak, but are only feeling their way
as conquerors of the air. And as for the milk-givers, though we have
met with them in small early forms, yet now for a time we lose sight of
them again altogether.

It is the reptiles--the cold-blooded monster reptiles--which seem at
this time to be carrying all before them. We find them everywhere--in
the water, with paddles for swimming; in the air, with membranes for
flying; on the land hopping or running on their hind feet. From small
creatures not bigger than two feet high, to huge monsters thirty
feet in height, feeding on the tops of trees which our giraffes and
elephants could not reach, they fill the land; while flesh-eating
reptiles, quite their match in size and strength, prey upon them
as lions and tigers do upon the grass-feeders now.[197] This is
no fancy picture, for in our museums, and especially in Professor
Marsh’s wonderful collection in Yale Museum in America, you may see
the skeletons of these large reptiles, and build them up again in
imagination as they stood in those ancient days when they looked down
upon the primitive birds and tiny marsupials, little dreaming that
their own race, then so powerful, would dwindle away, while these were
to take possession in their stead.

And now in our series of changing scenes comes all at once that strange
blank which we hope one day to fill up; and when we look again the
large reptiles are gone, the birds are spreading far and wide, and we
come upon those early and primitive forms of insect-eaters, gnawers,
monkeys, grass-feeders, and large flesh-eaters, whose descendants,
together with those of the earlier marsupials, are henceforward to
spread over the earth. We need scarcely carry our pictures much
farther. We have seen how, in these early times, the flesh-feeders
and grass-feeders were far less perfectly fitted for their lives than
they are now;[198] how the horse has only gradually acquired his
elegant form; the stag his branching antlers; and the cat tribe their
scissor-like teeth, powerful jaws, and muscular limbs; while the same
history of gradual improvement applies to nearly all the many forms of
milk-givers.

But there is another kind of change which we must not forget, which
has been going on all through this long history, namely, alterations
in the level and shape of the continents and islands, as coasts have
been worn away in some places and raised up or added to in others, so
that different countries have been separated from or joined to each
other. Thus Australia, now standing alone, with its curious animal
life, must at some very distant time have been joined to the mainland
of Asia, from which it received its low forms of milk-givers, and since
then, having become separated from the great battlefield of the Eastern
Continent, has been keeping for us, as it were in a natural isolated
zoological garden, the strange primitive Platypus and Echidna, and
Marsupials of all kinds and habits.

So too, Africa, no doubt for a long time cut off by a wide sea which
prevented the larger and fiercer animals from entering it, harboured
the large wingless ostriches, the gentle lemurs, the chattering
monkeys, the scaly manis, and a whole host of insect-eaters; while
South America, also standing alone, gave the sloths and armadilloes,
the ant-bears, opossums, monkeys, rheas, and a number of other forms,
the chance of establishing themselves firmly before stronger enemies
came to molest them. These are only a few striking examples which help
us to see how, if we could only trace them out, there are reasons to
be found why each animal or group of animals now lives where we find
it, and has escaped destruction in one part of the world when it has
altogether disappeared in others.

       *       *       *       *       *

So, wandering hither and thither, the backboned family, and especially
the milk-givers, took possession of plains and mountain ranges, of
forests and valleys, of deserts and fertile regions. But still another
question remains--How has it come to pass that large animals which
once ranged all over Europe and Northern Asia,--mastodons, tusked
tapirs, rhinoceroses, elephants, sabre-toothed tigers, cave-lions, and
hippopotamuses in Europe,[199] gigantic sloths and llamas in North
America, and even many huge forms in South America, have either been
entirely destroyed or are represented now only by scattered groups
here and there in southern lands? What put an end to the “reign of the
milk-givers,” and why have they too diminished on the earth as the
large fish, the large newts, and the large lizards did before them?

To answer this question we must take up our history just before the
scene at the head of our last chapter,[200] which the reader may have
observed does not refer, as the others have done, to the animals in
the chapter itself. Nevertheless it has its true place in the series,
for it tells of a time when the great army of milk-givers had its
difficulties and failures as well as all the other groups, only these
came upon them not from other animals but from the influence of snow
and ice.

For we know that gradually from the time of tropical Europe, when all
the larger animals flourished in our country, a change was creeping
very slowly and during long ages over the whole northern hemisphere.
The climate grew colder and colder, the tropical plants and animals
were driven back or died away, glaciers grew larger and snow deeper
and more lasting, till large sheets of ice covered Norway and Sweden,
the northern parts of Russia, Germany, England, Holland, and Belgium,
and in America the whole of the country as far south as New York.
Then was what geologists call the “Glacial Period;” and whether the
whole country was buried in ice, or large separate glaciers and thick
coverings of snow filled the land, in either case the animals, large
and small, must have had a bad time of it.

True, there were probably warmer intervals in this intense cold, when
the more southern animals came and went, for we find bones of the
hippopotamus, hyæna, and others buried between glacial beds in the
south of England. But there is no doubt that at this time numbers
of land animals must have perished, for in England alone, out of
fifty-three known species which lived in warmer times, only twelve
survived the great cold, while others were driven southwards never to
return, and the descendants of others came back as new forms, only
distantly related to those which had once covered the land.

Moreover, when the cold passed away and the country began again
to be covered with oak and pine forests where animals might feed
and flourish, we find that a new enemy had made his appearance.
Man--active, thinking, tool-making man--had begun to take possession
of the caves and holes of the rocks, making weapons out of large
flints bound into handles of wood, and lighting fires by rubbing wood
together, so as to protect himself from wild beasts and inclement
weather.

In America and in England alike, as well as in Northern Africa, Asia
Minor, and India, we know that man was living at this time among
animals, many of them of species which have since become extinct, and
with his rude weapons of jagged flint was conquering for himself a
place in the world.

He must have had a hard struggle, for we find these flint implements
now lying among the bones of hyænas, sabre-toothed tigers, cave-lions,
cave-bears, rhinoceroses, elephants, and hippopotamuses, showing that
it was in a land full of wild beasts that he had to make good his
ground.

           “By the swamp in the forest
            The oak-branches groan,
            As the savage primeval,
            With russet hair thrown
    O’er his huge naked limbs, swings his hatchet of stone.

           “And now, hark! as he drives with
            A last mighty swing,
            The stone blade of the axe through
            The oak’s central ring,
    From his blanched lips what screams of wild agony spring!

            There’s a rush through the fern-fronds,
            A yell of affright,
            And the Savage and Sabre-tooth
            Close in fierce fight,
    As the red sunset smoulders and blackens to night.”[201]

Many and fierce these conflicts must have been, for the wild beasts
were still strong and numerous, and man had not yet the skill and
weapons which he has since acquired. But rough and savage though he may
have been, he had powers which made him superior to all around him. For
already he knew how to make and use weapons to defend himself, and how
to cover himself at least with skins as protection from cold and damp.
Moreover, he had a brain which could devise and invent, a memory which
enabled him to accumulate experience, and a strong power of sympathy
which made him a highly social being, combining with others in the
struggle for life.

And so from that early time till now, man, the last and greatest winner
in life’s race, has been taking possession of the earth. With more and
more powerful weapons he has fought against the wild beasts in their
native haunts; and by clearing away the large forests, cutting up the
broad prairies and pastures, and cultivating the land, he has turned
them out of their old feeding grounds, till now we must go to the
centre of Africa, the wild parts of Asia, or the boundless forests of
South America, to visit in their homes the large wild animals of the
great army of milk-givers.

       *       *       *       *       *

Since, therefore, these forms are growing rarer every century, and
some of them, such as the Dodo, Epyornis, and Moa among birds, and the
northern sea-cow or Rhytina among milk-givers, have already disappeared
since the times of history, we must endeavour, before others are gone
for ever, to study their structure and their habits. For we are fast
learning that it is only by catching at these links in nature’s chain
that we can hope to unravel the history of life upon the earth.

At one time naturalists never even thought that there was anything to
unravel, for they looked upon the animal kingdom as upon a building put
together brick by brick, each in its place from the beginning. To them,
therefore, the fact that a fish’s fin, a bird’s wing, a horse’s leg, a
man’s arm and hand, and the flipper of a whale, were all somewhat akin,
had no other meaning than that they seemed to have been formed upon the
same plan; and when it became certain that different kinds of animals
had appeared from time to time upon the earth, the naturalists of fifty
years ago could have no grander conception than that new creatures were
separately made (they scarcely asked themselves how) and put into the
world as they were wanted.

But a higher and better explanation was soon to be found, for there was
growing up among us the greatest naturalist and thinker of our day,
that patient lover and searcher after truth, Charles Darwin, whose
genius and earnest labours opened our eyes gradually to a conception
so deep, so true, and so grand, that side by side with it the idea of
making an animal from time to time, as a sculptor makes a model of
clay, seems too weak and paltry ever to have been attributed to an
Almighty Power.

By means of the facts collected by our great countryman and the careful
conclusions which he drew from them, we have learned to see that there
has been a gradual unfolding of life upon the globe, just as a plant
unfolds first the seed-leaves, then the stem, then the leaves, then
the bud, the flower, and the fruit; so that though each part has its
own beauties and its own appointed work, we cannot say that any stands
alone, or could exist without the whole. Surely then Natural History
acquires quite a new charm for us when we see that our task is to study
among living forms, and among the remains of those that are gone,
what has been the education and the development of all the different
branches, so as to lead to the greatest amount of widespreading life
upon the globe, each having its own duty to perform. With the great
thought before us that every bone, every hair, every small peculiarity,
every tint of colour, has its meaning, and has, or has had, its use in
the life of each animal or those that have gone before it, a lifelong
study even can never weary us in thus tracing out the working of
Nature’s laws, which are but the expression to us of the mind of the
great Creator.

When we once realise that whether in attacking or avoiding an enemy
it is in most cases a great advantage to all animals to be hidden
from view, and that each creature has arrived at this advantage
by slow inheritance, so that their colours often exactly answer
the purpose, how wonderful becomes the gray tint of the slug, the
imitation of bark in the wings of the buff-tip moth, the green and
brown hues of the eatable caterpillars, the white coat of the polar
bear, and the changing colour of the arctic fox, the ermine, and the
ptarmigan, as winter comes on! And when, on the other hand, we find
badly-tasting creatures such as ladybirds and some butterflies, or
stinging animals like bees and wasps, having bright colours, because
it is an actual advantage to them to be known and avoided, we see that
in studying colour alone we might spend a lifetime learning how the
winners in life’s race are those best fitted for the circumstances
under which they live, so that in ever-changing variety the most
beautifully-adapted forms flourish and multiply.

Then if we turn to the skeleton and the less conspicuous framework of
the body, the flippers of the whale, the manatee, or the seal, doing
the work of a fish’s fin and yet having the bones of a hand and arm,
reveal a whole history to us when we have once learned the secret that
in the attempt to increase and multiply no device is left untried by
any group of animals, and so every possible advantage is turned to
account.

Next, the wonderful instincts taught by long experience give us a
whole field of study. We see how frogs and reptiles, and even higher
animals such as marmots, squirrels, shrews and bears, escape the cold
and scarcity of food in winter by burying themselves in mud, or in
holes of trees or caves of the earth till spring returns; and while we
find alligators burying themselves in cold weather in America, we find
crocodiles, on the contrary, taking their sleep in the hot dry weather
in Egypt because then is their time of scarcity.

Then we learn that the birds avoid this difficulty of change of climate
in quite another manner. They with their power of flight have learned
to migrate, sometimes for short distances, sometimes for more than a
thousand miles, so that they bring up their young ones in the cool
north in summer, when caterpillars and soft young insects are at hand
for their prey, and lead them in the winter to the sunny south where
food and shelter in green trees are always to be found. So long indeed
has this instinct of migration been at work, that often we are quite
baffled in trying to understand why they take this or that particular
route for their flight, because probably, when the first stragglers
chose it, even the areas of land and water were not divided as now, so
that we must study the whole history of the changing geography of the
earth to understand the yearly route of the swallow or the stork.

And last but not least, when we look upon the whole animal creation as
the result of the long working out of nature’s laws as laid down from
the first by the Great Power of the Universe, what new pleasure we find
in every sign of intelligence, affection, and devotion in the lower
creatures! For these show that the difficulties and dangers of animal
life have not only led to wonderfully-formed bodies, but also to higher
and more sensitive natures; and that intelligence and love are often
as useful weapons in fighting the battle of life as brute force and
ferocity.

Even among the fish, which, as a rule, drop their eggs and leave them
to their fate, we have exceptions in the nest-building sticklebacks
and the snake-headed fish of Asia, which watch over and defend their
fry till they are strong, in the pipe-fish where the fathers carry the
young in a pouch, and in sharks which travel in pairs; while a pike has
been known to watch for days at the spot where his mate was caught and
taken away, and mackerel and herrings live in shoals and probably call
to each other across the sea.

Among the other cold-blooded animals--the frogs, newts, and
reptiles--it is true we find less show of feeling, but we must remember
that these are only poor remaining fragments of large groups which have
disappeared from the earth. Even among the amphibia however a tame toad
will become attached to one person; while among reptiles, lizards are
full of intelligence and affection, and snakes are well-known for their
fondness for their owners. The case of the snake which died by its
master’s side when he fell down insensible,[202] if it can be relied
upon, would show that even cold-blooded animals have tender hearts.

Yet these are all instances of affection of lower animals to man. We
must turn to the birds, that group which has gone on increasing in
strength and numbers down to our day, to find that tender devotion
which watches over the helpless nursling, defends the young at the
risk of life, nay, like the peewit with the dragging wing, will even
run in the face of death to lure the cruel destroyer away from the
hidden nest. Natural history teems with examples of birds faithful to
each other and pining even till death for the loss of a mate; while
many birds, such as rooks, starlings, wild geese, swans, and cranes,
not only live in companies and exact obedience from their members, but
even set sentinels to watch, the duties of the office being faithfully
fulfilled.

Then again it is to the higher animals, those nearer to ourselves, that
we must look for the truest affection, and the strongest proofs of that
obedience and sympathy which lead them to unite and so become strong in
the face of danger. Among the beasts of prey it is true that, except
the wolves and jackals, none herd together; but family love is strong
and true. No tiger is so dangerous as is the mother tigress if any one
approaches her young ones, or the lioness whose cubs are attacked,
and in our own homes we all know the tenderness and devotion of a cat
to her kittens. Nevertheless, these animals have very little social
feeling; theirs are the narrower virtues of courage and fidelity to
home, and to the duty of providing food for wife and children. It is
among the gentler vegetable-feeders,--the antelopes and gazelles, the
buffaloes, horses, elephants, and monkeys,--that we find the instinct
of herding together for protection, and with this the consciousness of
the duty of obedience and fidelity to the herd and to one another.

It is easy to see how this was necessary to protect these feebler
animals from the attacks of their ferocious neighbours, and also what
an advantage they had when they had once learned to set sentinels who
understood the duty of watching while others fed, as in the case of the
chamois and seals, of obeying the signal of a leader like the young
baboons on the march, or of putting the mothers and children in the
centre for protection, as horses and buffaloes do.

And there is a real significance in this gradual education in duty to
others which we must not overlook, for it shows that one of the laws
of life which is as strong, if not stronger, than the law of force and
selfishness, _is that of mutual help and dependence_. Many good people
have shrunk from the idea that we owe the beautiful diversity of animal
life on our earth to the struggle for existence, or to the necessity
that the best fitted should live, and the feeblest and least protected
must die. They have felt that this makes life a cruelty, and the world
a battlefield. This is true to a certain extent, for who will deny that
in every life there is pain and suffering and struggle? But with this
there is also love and gentleness, devotion and sacrifice for others,
tender motherly and fatherly affection, true friendship, and a pleasure
which consists in making others happy.

This we might have thought was a gift only to ourselves--an exception
only found in the human race; now we see that it has been gradually
developing throughout the whole animal world, and that the love of
fathers and mothers for their young is one of the first and greatest
weapons in fighting life’s battle. So we learn that after all, the
struggle is not entirely one of cruelty or ferocity, but that the
higher the animal life becomes, the more important is family love and
the sense of affection for others, so that at last a fierce beast
of prey with strength and sharp tools at his command, is foiled in
attacking a weak young calf, because the elders of the herd gather
round him, and the destroyer is kept at bay.

Surely then we have here a proof that, after all, the highest and most
successful education which Life has given her children to fit them for
winning the race is that “unity is strength;” while the law of love
and duty beginning with parent and child and the ties of home life,
and developing into the mutual affection of social animals, has been
throughout a golden thread, strengthened by constant use in contending
with the fiercer and more lawless instincts.

So it becomes evident that the beautiful virtue of self-devotion, one
of the highest man can practise, has its roots in the very existence
of life upon the earth. It may appear dimly at first,--it may take a
hard mechanical form in such lowly creatures as insects, where we saw
the bees and ants sacrificing all tender feelings to the good of the
community. But in the backboned family it exists from the very first
as the tender love of mother for child, of the father for his mate and
her young ones, and so upwards to the defence of the tender ones of the
herd by the strong and well-armed elders, till it has found its highest
development in man himself.

Thus we arrive at the greatest and most important lesson that the
study of nature affords us. It is interesting, most interesting, to
trace the gradual evolution of numberless different forms, and see
how each has become fitted for the life it has to live. It gives us
courage to struggle on under difficulties when we see how patiently
the lower animals meet the dangers and anxieties of their lives, and
conquer or die in the struggle for existence. But far beyond all these
is the great moral lesson taught at every step in the history of the
development of the animal world, that amidst toil and suffering,
struggle and death, the supreme law of life is the law of SELF-DEVOTION
AND LOVE.




FOOTNOTES


[1] Almost every animal mentioned in this book is to be found alive in
the London Zoological Gardens, or stuffed in the British Museum.

[2] The Figures in the text, which, with exception of about twenty,
have all been drawn expressly for this book, are the work of the
above-mentioned artists, together with Mr. Coombe and Miss Suft.

[3] _Life and her Children_, p. 135.

[4] Amphioxus lanceolatus (_amphi_ both, _oxus_ sharp).

[5] For this drawing, and also those of Figures 1 and 4, I am indebted
to Professor A. C. Haddon; the larval form A is the young of Clavelina,
found at Torquay.

[6] Petromyzon (_petra_, stone; _myzo_, to suck).

[7] Myxine.

[8] Cyclostomata (_cyclos_, circle; _stoma_, mouth).

[9] Called _conodonts_, and found in Lower Silurian rocks earlier than
any bones of true fish.

[10] Carcharias glaucus.

[11] Homocercal.

[12] Heterocercal.

[13] Acipenser sturio.

[14] Isinglass is made from the covering of this air-bladder.

[15] Lepidosteus.

[16] Polypterus.

[17] Amia.

[18] Lepidosiren.

[19] Protopterus.

[20] Ceratodus.

[21] These fish, coiled round, may be seen in the British Museum.

[22] Ichthyodorulites.

[23] Dipterus.

[24] Dinichthys.

[25] See Frontispiece. 1, Chauliodus; 2, 9, 10, 11, Harpodon or Bombay
Duck; 3, Plagiodus; 4, Chiasmodus, with a Scopelus in its stomach; 6,
Beryx; 8, Scopelus.

[26] In drawing up this sketch of the deep sea I am almost entirely
indebted to Dr. Günther’s masterly sketch of the deep-sea fish in his
excellent work.

[27] Echeneis remora.

[28] Naucrates.

[29] In this description I am not alluding simply to the
mackerel _family_ Scombridæ, but to that much larger group
_Cotto-Scombriformes_, to which so many ocean fish belong, and even the
sword-fish is allied.

[30] Thynnus pelamys.

[31] Thynnus thynnus.

[32] Coryphæna.

[33] Lampris luna.

[34] Exocœtus.

[35] Coryphæna.

[36] Dactylopterus.

[37] Hippocampus.

[38] Xiphias.

[39] At least 10,000 for each mother.

[40] Mullus.

[41] Trigla.

[42] Gobidæ.

[43] Cyclopterus.

[44] Trachinidæ.

[45] Lophius piscatorius.

[46] Lophius.

[47] Uranoscopus.

[48] Solea vulgaris.

[49] Hippocampus.

[50] Gasterosteus.

[51] Cottus.

[52] Siluridæ.

[53] More properly eel-fares (_fare_, Saxon, to travel; ex.,
way-_faring_ man).

[54] Anabas.

[55] Not “waddling;” it is the toad, not the frog, that waddles.

[56] Lissotriton punctatus.

[57] _Amphi_, all around; _bios_, life.

[58] Proteus anguineus.

[59] Salamandra atra.

[60] See Picture-heading, p. 70.

[61] Labyrinthodonts (_Laburinthos_, spiral; _odontas_, teeth).

[62] Rhacophorus Rheinhardii.

[63] Alytes obstetricus.

[64] Pipa Americana.

[65] Protorosaurus or Thuringian lizard.

[66] Ichthyosaurus.

[67] Plesiosaurus.

[68] Mosasaurus and Clidastes.

[69] Pterodactyls.

[70] Iguanodon in Europe, Hadrosaurus in America.

[71] Megalosaurus in Europe, Dryptosaurus in America.

[72] Testudo Græca.

[73] Testudo talenlata.

[74] The parts of the joints which flatten out in the tortoise are seen
at _sp_ in the lizard and snake, pp. 103, 111.

[75] Testudinea.

[76] Terrapins.

[77] Emyx and Trionys.

[78] Chelydra serpentina.

[79] Chelonia midas.

[80] Chelonia imbricata.

[81] Zootoca vivipara.

[82] Ophisaurus ventralis.

[83] Anguis fragilis.

[84] Natrix torquata.

[85] Naja.

[86] Crotalus.

[87] Naja tripudians.

[88] _Ichthyopsida_--_ichthys_, fish; _opsis_, appearance.

[89] _Sauropsida_--_sauros_, lizard; _opsis_, appearance.

[90] Archœopteryx, see picture-heading, Chapter VII.

[91] See picture-heading of this chapter.

[92] _Ichthyornis_, fish-bird.

[93] _Hesperornis._

[94] Some chamæleons and geckos also have air-tubes passing from the
lungs into the body, and the crocodile’s skull is full of air-cells;
but the two phenomena are not connected as in birds, and other parts of
the skeleton or of the skin-covering, being heavy, have a counteracting
effect.

[95] This third eyelid is a fold on the inner side of the eye; some
reptiles and amphibians have it, and so have the marsupials and many of
the higher animals.

[96] Struthio camelus.

[97] Dinornidæ, of which Dinornis, a still more ancient form, must have
been ten feet high.

[98] This beautiful effect may be seen from below when the guillemots
are fed in any of the public aquariums.

[99] Talegallus.

[100] Megapodidæ or large-footed birds.

[101] Partridges, quails, and some others are exceptions, and pair.

[102] Columba migratoria.

[103] Gecinus viridis.

[104] Alcedo ispida.

[105] The Indian and Chinese edible-nest Swiftlets (Collocalia), make
their nests entirely of this saliva, and they are eaten by the natives.

[106] Troglodytes parvulus.

[107] Orthotomus sutorius.

[108] _Marsupium_, a pouch.

[109] Ornithorhynchus paradoxus.

[110] Echidna hystrix.

[111] Professor Owen has described a reptile from the Trias of Africa,
and Professor Cope another from the Permian of Texas, both having
characters closely resembling the Platypus.

[112] This argument, which can only be stated very roughly here, must
not be supposed to rest merely on the quadrate bone, though this is the
easiest point to illustrate popularly. I am deeply indebted to Mr. W.
Kitchen Parker for a whole flood of light thrown on these early forms,
and only regret that I have neither skill nor space to do justice to
his graphic illustration of a subject of which he is pre-eminently
master.

[113] Diprotodont.

[114] The only exceptions to this are a tooth and a piece of a tusk of
one of the ancient elephants, lately found in Australia, showing that
a few straggling forms of mammalia probably reached that country in
Tertiary times.

[115] Macropus giganteus.

[116] Hypsiprymnus penicillatus.

[117] Dendrolagus.

[118] Phascolomys.

[119] Dasyurus.

[120] Thylacinus.

[121] Didelphis.

[122] Cholœpus.

[123] Mymecophaga.

[124] Dasypus.

[125] Megatherium.

[126] Glyptodon.

[127] Myrmecophaga jubata.

[128] Tamandua.

[129] For a few of these forms see the picture-heading, p. 209.

[130] Coryphodon.

[131] Paleotherium and Anoplotherium.

[132] Xiphodon.

[133] Eohippus.

[134] Hyænarctos.

[135] Cynodon.

[136] Hyænodon and others.

[137] Arctocyon.

[138] Cynomys.

[139] Spalacidæ.

[140] Geomyidæ.

[141] Myogale Pyrenaica.

[142] Castor fiber.

[143] Potamogale.

[144] Myogale.

[145] Soledon and one of the Shrews.

[146] Pteromys Petaurista.

[147] Galeopithecus volans.

[148] Tupaia.

[149] Chiroptera.

[150] Pteropus vulgaris.

[151] The Magot, Macacusinuus.

[152] Naturalists now class monkeys under the order “Primates” (or
highest forms), together with man, and they have given up the term
Quadrumana, or four-handed, because, although the feet grasp like
hands, they are _true feet_. Nevertheless, this term is very useful;
and, if properly understood, expresses the grasping power of the four
feet characteristic of the group.

[153] Platyrrhine monkeys, from _Platus_ broad, _rhines_ nostrils.

[154] Except the marmosets, which have a peculiar dentition of their
own.

[155] Catarrhine monkeys; _kata_ downward, _rhines_ nostrils.

[156] See Parkyns’ _Life in Abyssinia_.

[157] Hylobates, or walker in the woods.

[158] Malay: _Orang_ man, _utan_ forest.

[159] The Dinocerata of the Middle Eocene of America. These gigantic
extinct animals, with tusks and horns, but very small brains, are
believed by Professor Marsh to have connected the two groups the
elephants and the hoofed animals among the early milk-givers.

[160] Anoplotherium; for this form and others, see p. 256.

[161] Paleotherium.

[162] Eohippus.

[163] Xiphodon.

[164] See picture heading.

[165] See picture heading.

[166] See p. 213, and picture heading, p. 209.

[167] The genealogy of the horse is so important, that it may be well
to give a table of the seven principal stages, though transitions are
known even between these.

       Period.           In         Front      Hind    No. of     In
                       America.     Toes.      Toes.   Teeth.   Europe.

     {Recent            --  }        1           1              Equus.}
  7. {  and                 }    ---------   ---------   40           }
     {Upper Pliocene   Equus}    2 splints   2 splints          Equus.}

                                     1           1
  6. Upper Pliocene  Pliohippus  ---------   ---------   42      --
                                 2 splints   2 splints

                                  1 large     1 large
  5. Lower Pliocene  Protohippus  -------     -------    44   Hipparion.
                                  2 small     2 small

  4. Upper Miocene   Miohippus       3           3       44  Anchitherium.

                                     3
  3. Lower Miocene   Mesohippus   --------       3       44      --
                                  1 splint

  2. Upper Eocene    Orohippus       4           3       44      --

                                     4
  1. Lower Eocene    Eohippus     --------       3       44      --
                                  1 splint


[168] See table, above.

[169] Cameleopardalis.

[170] See heading of chapter.

[171] Compare this with the Deer with the one-spiked antler in the
picture heading.

[172] In the African elephant; in the Indian they are smaller, and the
female has none.

[173] Mustelus.

[174] Herpestes.

[175] Canis lupus.

[176] These are united in one family, the _Canidæ_ or Dog family; but
this name is unfortunate, as there are no original wild dogs, only
those which have run wild from man. Dogs are now almost certainly shown
to be descended from wolves and jackals.

[177] Thalassarctos (ursus) maritimus.

[178] Trichechus rosmarus.

[179] Plantigrade.

[180] Enhydra marina.

[181] Pinnipedia.

[182] Otariidæ (_ous_, _otos_, an ear), eared Seals.

[183] Callorhinus (Otaria) ursinus.

[184] Phoca vitulina.

[185] Hence their name _Sirenia_, a curious name for voiceless animals.

[186] Cetacea--_cete_, a whale.

[187] Megaptera.

[188] Phocæna communis.

[189] Orca gladiator.

[190] Picture heading, Chap. II.

[191] Picture heading, Chap. IV.

[192] Picture heading, Chap. VIII.

[193] Picture heading, Chap. VI.

[194] _Ibid._ Chap. VII.

[195] Sauropsida.

[196] Picture heading, Chap. III.

[197] Picture heading, Chap. V.

[198] Picture heading, Chap. IX.

[199] Picture Heading, Chap. X.

[200] Chapter XI., Europe in the Age of Ice.

[201] From “A Legend of a Stone Axe,” a clever and suggestive poem in
the _New Quarterly_, April 1879. The text is slightly altered.

[202] _Animal Intelligence_, Romanes, p. 261.




INDEX.

_References printed in Italics are to Figures in the Text._


  _Aard-vark, or Cape ant-eater_, 202;
    habits of, 203.

  Adjutant bird killing the cobra, 121;
    _with its feet flat_, 128.

  Æpyornis of Madagascar, 140.

  Affection in animals, 348–352.

  Africa, _aard-vark and pangolin of_, 202;
    darting birds of, 168;
    isolation of, in ancient times, 340;
    wild animals of, 275.

  Air-bladder, uses and hindrances of an, 53;
    of fish, use of, 26;
    of minnow, 25;
    of mud-fish, 55.

  _Air-breathers, home of the early_, 70.

  Air-breathing fish, 34.

  Air-sacs in bones of birds, 135.

  Alaska, sea-otters of, 301.

  Albatross, habits of the, 146;
    _home of the_, 147.

  Aldabra, tortoises of, 101.

  Aleutian Isles, sea-lions of the, 306, 310.

  Alligators acting as scavengers, 109.

  Alytes, a frog-father carrying strings of eggs, 87.

  Amazons, manatees in the, 316;
    monkeys of the, 246;
    mud-fish of the, 33.

  Amblystoma, air-breathing form of axolotl, 81.

  America, absence of wild hogs in North, 263;
    beaver communities of, 229;
    earliest forms of horse come from, 265;
    jaguar and puma of, 292;
    passenger pigeons of, 162;
    _ant-bear of_, 200;
    characters of monkeys of, 245;
    sturgeon in rivers of, 32;
    songless perching-birds of, 169;
    stags with single antlers in, 273.

  American and Australian colonists, argument drawn from, 131.

  Ammocœtes, history of, 18;
    _larva of lamprey_, 16.

  Amphibia, ancestors of the mammalia, 191;
    large ancient, 82–84;
    wonderful metamorphosis of, 335.

  Amphibian, true meaning of the term, 77, 81.

  _Amphioxus lanceolatus_, 11.

  Ancestors of the higher milk-givers, 213.

  _Angling-fish_, _Lophius piscatorius_, 59.

  Animals, affection and devotion in, 348–352;
    combination for defence among, 350;
    narrow range of lower, 2;
    which have taken to the water, 300;
    living with early man in England, 343.

  _Anoplotherium_, 209;
    one of the ancestors of hogs and rhinoceroses, 213, 261.

  Ant, limit of powers of the, 6.

  _Ant-bear of South America_, 200;
    habits and strength of, 204.

  Antelopes, range of, 274;
    setting sentinels, 269.

  Antlers, gradual development of, 273.

  _Apteryx, or Kiwi_, 140;
    structure and habits of, 139.

  Aquatic mammalia, 300.

  Archæopteryx, or ancient winged bird, 129, 131;
    _restoration of_, 153.

  _Arctocyon_, 209;
    ancestor of carnivores, 213.

  Arm, modifications of the, 347.

  Armadilloes, with plates like a crocodile, 204;
    _figured_, 200.

  _Ascidian, growth of an_, 14.

  _Ass, skeleton of a wild_, 266.

  Australia, bats and mice in, 230;
    duck-billed platypus of, 187;
    isolation of, 340;
    mud-fish of, 33;
    why the home of marsupials, 185.

  _Australian marsupials_, 193.

  Australian and American colonists, argument drawn from, 131.

  _Axolotl and amblystoma_, 80.

  Axolotl, metamorphosis of, into amblystoma, 81.

  Aye-aye, habits of the, 245;
    _figured_, 244.


  _Babirusa, a double-tusked hog_, 262.

  Baboon, fetching a young one, 250;
    structure and habits of, 249.

  Backbone, first start of a, 12;
    of the minnow, 24.

  Backboned division, 3;
    advantage of skeleton in the, 7;
    lowest form of the, 10–15.

  Badgers, small carnivores, 281.

  Bandicoots, marsupial rabbit-rats, 195.

  Bangsrings, insect-eaters, 232.

  Barbets, climbing birds, 165.

  Basking shark, 28.

  _Bat, flying_, 220;
    long-eared, 236;
    _skeleton of a_, 233;
    _walking_, 235.

  Bats, structure and habits of, 233–237;
    affection for young, 238;
    enemies of, 236;
    _fruit-, in Mauritius_, 238;
    the only true flying milk-givers, 232–237;
    self-guiding power of, 234;
    vast masses in caves, 236.

  Bear, hug of the, 295;
    grizzly, an animal feeder, 295;
    _Polar_, 294;
    food of, 293;
    habits of, 296.

  Bears, largely vegetarian, 293;
    walk flat-footed, 294.

  _Beaver_, 227;
    structure and habits of the, 228.

  Beaver-meadows, 229.

  Beckles cited, 212.

  Bee-eaters of Africa, 168.

  _Beryx, a deep-sea fish_, 43, 47, 50.

  Bichir of the Nile, 33.

  Bird, the structure of a, 124–129.

  Bird-life as a whole, 179.

  Birds, _ancient_, 123, 153;
    with jointed tails, 130;
    with teeth, 130;
    arose not direct from reptiles but from a common ancient stock, 131;
    avoiding winter by migration, 348;
    climbing, 162;
    dangers of land, 154–156;
    darting, 167;
    feet of perching, 155;
    ground, 156;
    _a group of wading_, 149;
    growth of feathers of, 133;
    habits of scratching, 156;
    linked in structure to reptiles, 129;
    love-time of the, 124;
    lungs of, 135;
    migrations of, 142, 151, 155, 177;
    mound-building, 158;
    nest-building, 170;
    origin of, 337;
    perching, 168;
    of prey, 174;
    range of, 136;
    rise from ground to perching, 159;
    running, 136–140;
    sea, 142;
    singing, 168;
    songless, 169;
    structure of water-, 141;
    third eyelid of, 136;
    throat of singing, 169;
    wading, 148;
    warmer-blooded than man, 135;
    wingless, 139.

  Bisons, protecting a young one, 269;
    the only ruminants of America, 274.

  Blennies, walking-fish, 57.

  _Blue shark_, _Carcharias glaucus_, 29.

  _Boa constrictor of America_, 115;
    manner of seizing and devouring prey, 117.

  Boar, defences of the wild, 260.

  “Bombay Duck” a phosphorescent fish, 48;
    _figured_, _see frontispiece_.

  Bone at tip of mole’s nose, 224.

  Bonito, a fish without air-bladder, 53.

  Bony fish, agility of, 44;
    or modern fish, 27;
    _early forms of_, 43;
    origin of, 45;
    rise and spread of, 43;
    structure of, 45.

  Bony pike of North America, 33.

  Box-tortoises closing their shell, 101.

  Brazil, monkeys of, 246.

  Breast-bone, flat in running birds, 136;
    keeled of flying birds, 124.

  Breathing apparatus of birds, 135;
    of bony fish, 45;
    of frog, 75, 76;
    of lamprey, 17;
    of lancelet, 12;
    of marsupials, 192;
    of minnow, 23;
    of mud-fish, 34;
    of seals, 308;
    of shark, 30;
    of the snake, 113;
    of sturgeon, 32;
    of tadpole, 73, 74;
    of tortoise, 95;
    of whales, 321.

  British Museums, specimens in, 32, 34.

  _Brush-turkeys and their mounds_, 158.

  _Buffalo cow defending her calf_, 274.

  Buzzard killing a viper, 120.


  Cæcilians, nearest type to Labyrinthodonts, 84;
    worm-like amphibians, 82.

  Calf-fish or amia, 33.

  California, sea-otters of, 301.

  Californian gray whale in ice, 330;
    killed by a shoal of grampuses, 325.

  _Camel_, 270;
    the only ruminant with upper front teeth, 270.

  Capybaras of South America, 215.

  _Carapace of tortoise_, 98.

  Carnivora, or flesh-feeders, 257, 259;
    ancestors of the, 213;
    the smaller, 280.

  Carnivorous marsupials, 196.

  Carp family, 65.

  _Cartilaginous fish_, 31–42.

  Cassowary of New Guinea, 139.

  Cat-fish, 65.

  Cat less tamable than dog, 287.

  Cave-lion in England, 343.

  _Celebes, double-tusked hog of_, 262.

  _Ceratodus or “Barramunda,”_ 34;
    a descendant of ancient fish, 39.

  Chalk Period, extinction of reptiles in the, 211.

  _Chamæleon_, 105;
    structure and habits of, 106, 107.

  Chauliodus, a deep-sea fish, 47;
    _figured_, _see frontispiece_.

  Chauvin, Marie von, cited, 81.

  Chimæra between sharks and sturgeons, 41.

  Chimpanzee, home of the, 253.

  Chinchillas of South America, 225.

  Circulation of blood in frog, 76.

  _Clavelina, larval form of_, 14.

  _Claws, retractile of felines_, 289.

  Climbing birds, paired toes of the, 163;
    build in tree-holes, 164.

  Clinging fish, 51, 57, 58.

  Coal-forests, amphibians of the, 82.

  Coast fish, 57.

  Cobra, enemies of the, 121.

  _Cobra di Capello_, 118.

  Cold blood, the cause of, in the frog, 76.

  Cold-blooded life in reptiles, 90;
    cold-blooded vertebrates, 24.

  Colours, protective, 347.

  _Colugo, a flying insect-eater_, 231.

  Conger eels, 49.

  Conodonts, probably lamprey’s teeth, 19.

  Cope, Prof., cited, 212, 190.

  _Cormorant, figured_, 144.

  Coryphæna or dorado, 53.

  Cow chewing the cud, 259.

  Cranes, migrations of, 152.

  Creation a gradual change, 336.

  Creepers, 172.

  Creative power, ever silent working of the, 336;
    high conception of the, 345.

  _Crocodile_, 108;
    care for her young, 110;
    habits and structure of the, 108.

  Crop of pigeons, 161.

  Crustaceans, huge, in time of early fish, 37.

  Cuckoo, sometimes builds a nest, 166.

  Cud, chewing the, 259.

  Cumberland, Mr., on vitality of ant-bear, 205.

  Curlews, wading birds, 148.

  Cyclostomata, round-mouthed fishes, 16.


  Dace, 65.

  Dactylopterus, or flying gurnards, 55.

  Darwin, on blood-sucking bats, 237;
    on Galapagos tortoises, 101;
    on evolution, 345.

  D’Azara on ant-bear, 205.

  Deep-sea fish, 47–50;
    rising at night, 50.

  Deer, growth of antlers of, 271;
    range of, 273.

  Depth at which fish live, 49.

  _Desman_, 226.

  Devotion in animals, 348–352.

  Dingo dog, probably brought to Australia, 194.

  Dinichthys, a huge Devonian fish, 40.

  Dinocerata, ancestors of elephants and hoofed animals, 260.

  Dinornis, extinct wingless bird, 140.

  Dipper, or water-ouzel, 172.

  Dipterus, a large ancient fish, 39.

  Disk of the Remora, 52.

  Dodo, flat-breasted pigeon, 161.

  Dog, descended from wolves and jackals, 286.

  Dogfish, 28.

  Dolphins travel in shoals, 323.

  _Dorado pursuing flying-fish_, 54.

  Doras, a land-travelling fish, 66.

  _Dromatherium, jaw of_, 183.

  Duck, structure of the, 141.

  _Duck-billed platypus and its home_, 188;
    the lowest type of milk-giver, 188.

  Dugong, a tusked sea-cow, 314.

  Dunlins, wading-birds, 148.


  _Eagle bringing food to its young_, 175.

  Eared-seals, history of the, 310.

  _Echidna_, 188;
    a low milk-giver, 190.

  Edentata, low and antiquated forms, 201;
    former history of, 201.

  Eels and eel-fares, 66.

  Efts, huge, of olden times, 82;
    or newts of our ponds, 78.

  Egg-birth, dangers of, 184.

  Eggs, of the crocodile, 110;
    of fish carried in the father’s mouth, 65;
    of frogs, 71;
    of ostriches cracked by the father, 139;
    of fish, modes of transport of, 66;
    of shark, 28, 42;
    of snake, 116.

  Eider-duck, range of the, 142.

  Elastic band in front of snake’s jaw, 111.

  Elephant, affinity to rodents, 276;
    _the Indian_, 277;
    intelligence of the, 278;
    structure of the, 276–279;
    tooth and tusk of, found in Australia, 194;
    -seal, 314.

  Emus, pairing birds, 139.

  Enamel-scaled fish, 33.

  _Eohippus_, 209;
    ancestor of the horse, 213, 261.

  _Europe in the age of ice_, 299.

  Evolution, of sympathy and self-sacrifice, 352;
    taught by Darwin, 345.

  _Exocœtus, the flying-fish_, 54.

  Eyelid, third, in reptiles and birds, 109, 136.

  Eyelids, absence of, distinguishes snakes from legless lizards, 110.


  Falcon, swooping of the, 176.

  _Fangs of poisonous snakes_, 119.

  Feather, number of threads in an eagle’s, 133.

  Feathers of birds, their growth and importance, 133, 134.

  Feet, grasping of perching birds, 155.

  Felines, highest type of flesh-feeder, 290;
    kill by a blow, 288;
    retractile claws of, 289.

  Fins of the minnow, 24.

  Fish, affection shown by, 69;
    age of the gristly, 333;
    air-bladder of, 25;
    ancient forms of, 33, 37–42;
    blind, of Kentucky caves, 68;
    come to the coast to spawn, 57;
    deep-sea, 47–50;
    lowest type of, 11;
    limbs of, 25;
    mammals which imitate, 318;
    muscular power of, 24;
    ocean home of the, 21;
    of the old or gristly type, 27;
    parental care in, 349;
    skeletons of deep-sea, 49;
    small ancient, 20, 34–42;
    varieties of modern, 46;
    weapons of, 29, 40, 42, 48, 52, 58, 59, 64, 68.

  _Fishing frog, Lophius_, 59.

  Fish-life, general sketch of, 67.

  Fish-lizards of olden times, 92.

  _Flamingo, half-way between waders and swimmers_, 150.

  Flat-fish, structure of, 61.

  Flint tools of early man, 343.

  Flying-fish, 53–55.

  Flying-gurnards, 55.

  Food of land-birds, 155.

  Fowls and their relations, 157.

  Fox, a solitary hunter, 285;
    range of the, 286.

  France, tree-frogs of, 87.

  Freshwater fish, 65.

  Frigate-bird, perches on trees, 148.

  Frog, a recent form of amphibian, 84;
    carrying young in a pouch, 87;
    carrying eggs and tadpoles, 87;
    _metamorphosis of the_, 72–76;
    lungs of, 76;
    more nearly allied to fish than reptiles, 129;
    mouth and tongue of, 77;
    respiring skin of, 77;
    spawn described, 71;
    _tree-, of New Guinea_, 86.

  _Fruit-bats_, 238.

  Fur-seals, history of, 310.


  Gadow, Dr., on number of threads in an eagle’s feather, 133.

  Galagos or lemurs of Africa, 243.

  Galapagos, tortoises of, 101.

  _Galeopithecus or Colugo_, 231.

  Gaudry cited, 212.

  Gautier, M., on snake poison, 119.

  _Gecko or wall lizard_, 105.

  Geese, range of wild, 142.

  Geography, changes in physical, 340.

  Germany, beaver communities in, 229.

  Gibbons, or long-armed apes, 251.

  Gibraltar, monkeys on the rock of, 241.

  Gills of Axolotl, 80;
    of bony fish, 45;
    of embryo shark, 73;
    of the minnow, 22;
    of proteus, 79;
    of sea-horse, 63;
    of shark, 30;
    of sturgeon, 32;
    of tadpole, 73.

  Giraffes, structure of, 271.

  Glacial Period, 342.

  Glass-snake of America, 107.

  Globe-fish, 55.

  Glyptodons, ancient armadilloes, 202, 208.

  Goats and sheep, range of, 274.

  Gobies, clinging by the throat, 58.

  Golden age of amphibia, 83;
    of ancient fish, 40;
    of reptiles, 92.

  Gorilla, _at home_, 254;
    driving out elephant, 251;
    structure and habits of, 253.

  Grampus, a flesh-feeding whale, 325.

  Gray, Capt., on whalebone, 329.

  _Greek tortoise_, 96;
    killed by birds, 101.

  Greenland whale, traces of hind limbs in the, 318.

  Gristly skeleton of shark, 31.

  Ground-birds, 156–161;
    generally polygamous, 161.

  Ground-pigeons of New Guinea, 161.

  Grouse are ground-nesters, 156.

  Gudgeon, 65.

  Guillemots, _homes of the_, 144;
    silvery bubbles on, 143.

  _Gulls and their homes_, 144.

  Günther, Dr., on deep-sea fish, 49.

  Gurnards walking, 57.


  Haddock, destroyed by hags, 18.

  Haddon, Prof., A.C., drawings by, 11, 14, 23.

  Hadrosaurus, 93.

  Hags or borers, 16, 18.

  Hang-nests of America, 173.

  Harpodon, a deep-sea fish, 47;
    _figured_, _see frontispiece_.

  Harvest-mouse and shrew compared, 218.

  Hawksbill turtle, tortoise-shell of, 97.

  Hearing apparatus of herrings, 56.

  Heart, of amphibia and reptiles, 74, 76, 96;
    of birds, 135;
    of fishes, 23;
    of frog, three-chambered, 76;
    of tadpole, two-chambered, 74;
    three-chambered, of tortoise, 96.

  _Hedgehog_, 220;
    structure and habits of, 220.

  Herbivora, ancestors of the, 213;
    advantage of struggle for existence to the, 282;
    defences of the, 259;
    large stomachs of, 258;
    structure of the, 258;
    uniting for defence, 350;
    wide range of, 257.

  Heron, strokes of wing of, 134;
    a tree-building wader, 152;
    grasping foot of the, 152.

  Herrings probably call to each other, 56;
    their habits and structure, 56.

  Hesperornis, 130;
    _figured_, 123.

  Heterocercal tails, 30.

  _Hippocampus or sea-horse_, 63.

  Hippopotamus, defences of the, 263;
    former range of the, 263;
    in glacial beds, 342.

  Hissing of a snake, how caused, 113.

  Hogs, early types without tusks, 260;
    various kinds of, 263.

  Homocercal tails, 30.

  Hoofs as defences, 260.

  Horns, absence of, in early forms, 260;
    as defences, 260;
    permanent, of buffaloes, 273.

  Horse, ancestors of the, 213, 261;
    genealogy of the, 267;
    mouth of the, 259;
    no true wild living, 265;
    structure of the, 259, 266.

  Horses unite for protection, 268.

  Howler-monkeys, 246.

  Humming-birds, lovely nests of, 167.

  _Humpback whale suckling her young_, 319.

  Huxley on Ichthyopsida and Sauropsida, 129.

  Hyæna, in glacial times of England, 342;
    teeth and claws of the, 290.


  Ice, covering Northern Europe, 342.

  Ichneumon, killing the cobra, 121;
    _the Egyptian_, 281.

  Ichthyodorulites of the Silurian, 38.

  Ichthyopsida, fish and amphibia, 129.

  Ichthyornis, 130;
    _figured_, 123.

  _Ichthyosaurus_, 89, 92.

  Iguanas or tree-lizards, 106.

  _Iguanodon_, 89, 93.

  Imperfect-toothed animals, or Edentata, early history of, 201.

  _Insect-eater, skull and teeth of_, 217.

  _Insect-eaters, a group of_, 220;
    small-sized animals, 215;
    and rodents compared, 239;
    absent from South America, 230.

  Instincts, interest of in theory of development, 347.

  Invertebrata and their limits, 4–6, 9.

  Isinglass from sturgeon, 32.


  Jacamars of America, 168.

  Jackals, hunting in packs, 285;
    ancestors of the dog, 286.

  Jaguar, feeding on tortoise, 100;
    habits and range of the, 292;
    and ant-bear, 205.

  Japan, gigantic salamander of, 78;
    monkeys in, 241.

  Jaw, movement of, in flesh-feeders, 289;
    in vegetable-feeders, 259;
    _of snake_, 119;
    distensible, 114.

  Jerboas of Africa, 225.

  Jumping shrews, 225.


  Kangaroo-rats, 195.

  _Kangaroos_, 193;
    strength of, 194.

  Kentucky caves, blind fish of, 68.

  _Kaola, or native bear of Australia_, 193, 195.

  Killer-whale, voracity of the, 325.

  _Kingfisher_, 166;
    a darting bird, 167.

  “King of the Herrings,” 41.

  Knob, on bird’s beak for shell-breaking, 143;
    on nose of baby platypus, 190.


  Labyrinthodonts, age of, 337;
    of the coal-forests, 84.

  Lakes, fish-eggs carried to, 66.

  Lamprey, _and young_, 16;
    breathing organ of, 17;
    teeth of, 17, 19, 37;
    metamorphosis of the, 19.

  Lampris luna, sun-fish, 53.

  _Lancelet, structure of the_, 11.

  Land-birds, their enemies and difficulties, 154–156.

  Lark, nest of the, 170.

  Legs, of a bird, construction of, 127;
    vestiges of, in snakes, 110.

  Leidy cited, 212.

  Lemming, strange migrations of, 225.

  _Lemurs_, 244;
    position and habits of, 243.

  Lepidosteus or bony pike, 33.

  Life, gradual development of, 4.

  Light-giving deep-sea fishes, 47.

  Lion fighting with a buffalo, 274;
    formerly in England, 291;
    habits and range of the, 291.

  Lizard, _skeleton of a_, 103;
    structure and habits of, 104;
    can live in unhealthy places, 104;
    flying, 106;
    legless and snake-like, 107.

  London, hippopotamus bones under, 263.

  Lories, the lemurs of India, 243.

  Love, gradual development of parental, 348–350;
    a reigning law of life, 353.

  Lumpsucker clinging to rock, 58.

  Lungs, of frog, 76;
    of the snake, 113.


  Machairodus or sabre-toothed tiger, 291;
    _figured_, 333.

  Mackerel going in to spawn, 55.

  Madagascar, true lemurs of, 243.

  Magpie’s nest, 170.

  Mammalia or milk-givers, divisions of the, 182;
    distribution of, 340;
    aquatic, 300;
    extinction of large, 341;
    sudden appearance of higher, 211.

  Mammoth, the hairy, 279.

  Man, after Glacial Period, 343;
    _among animals now extinct_, 333;
    exterminating wild animals, 344.

  _Manatee or sea-cow grazing_, 315;
    relationship of, 303.

  Mandrill, the lowest baboon, 250.

  _Manis or pangolin_, 202;
    structure and habits of, 203.

  Marmosets, monkeys of South America, 245.

  Marmot, a burrowing rodent, 225.

  Marsh, Prof., his collection of reptile remains, 339;
    cited, 212;
    on Dinocerata, 260.

  Marsupials, jaws of earliest known, 183;
    breathing of infant, 192;
    of Australia, past history of the, 185;
    early appearance of, 337;
    playing the part of higher animals, 196;
    structure and habits of, 192–199.

  Mastodon, a four-tusked elephant, 279;
    _figured_, 256.

  Megalosaurus, 93;
    _figured_, 89.

  Megapodes, mound-building birds, 159.

  Megatheria, huge ancient ground-sloths, 202, 206, 208.

  Metamorphosis of the frog, 73–76.

  Mexico, iguanas of, 106.

  _Microlestes, tooth of_, 183.

  Migration, of birds, 142, 151, 155, 177, 348;
    of lemmings, 225.

  Milk-givers are viviparous, 185;
    earliest origin of, 191;
    extinction of large, 341;
    _home of the early_, 181;
    sudden appearance of higher, 211;
    taking to the water, 300.

  Miller’s thumbs, 65.

  Minnow, breathing apparatus of the, 22;
    _inner and outer structure of the_, 23–26;
    intelligence of, 26;
    spinal cord of, 23, 26.

  _Moa of New Zealand_, 140.

  _Mole_, 220;
    enemies of the, 224;
    structure and habits of, 223.

  Mole-rats, burrowing rodents, 226.

  Monitors of Africa, 105.

  _Monkeys_, 247;
    advantage of tree-life to, 251;
    almost confined to hot countries, 241;
    grasping hands and feet of, 241;
    intelligence of, 248;
    origin of, 240;
    of America, 245;
    of the Old World, characters of, 248.

  Monk-fish, 41.

  Moor-hen, intelligence of the, 151.

  Mosasaurus, 92;
    _figured_, 89.

  Motmots of America, 168.

  _Mound-building birds_, 158.

  Mucous scales of fish, 23, 27.

  Mud-fish and their breathing, 33.

  Mud-tortoises, 102.

  Mullets, feeding, 57.

  Musquash, a swimming rodent, 227.

  Myrmecobius, an insect-eating marsupial, 195;
    like the ancient marsupials, 198.


  _“Native Devil” or Dasyurus_, 197.

  Nervous system of vertebrata, 8.

  _Nest of the common wren_, 171;
    _of duck-billed platypus_, 188.

  Nest-building birds, 168–173;
    gradual progress of, 156, 160, 165, 167, 170, 173.

  Nests, edible, of China swiftlet, 167;
    inland, of wading birds, 151.

  _Newts_, 78.

  New Zealand, _wingless birds of_, 140.

  Nightjar hunting for prey, 167.

  Nile, _crocodile of the_, 108;
    mud-fish of the, 33.

  Norway, lemmings of, 225.

  Nostrils of fish, 27.

  Notochord of the lancelet, 12.

  Nototrema frog, with a pouch for young, 87.

  Nuthatch, a climber among perchers, 172.


  _Opossums_, 200;
    habits of, 198;
    why surviving in South America, 197–199:
    their relation to Australian marsupials, 198.

  Orangutan or mias, 252.

  Orca or grampus, a flesh-feeding whale, 325.

  Ornithorhynchus, _and its home_, 188;
    _bill and feet of_, 189;
    structure of the, 190;
    the lowest milk-giver, 191.

  Osprey, the sea-eagle, 177.

  Ostrich _at full speed_, 137;
    structure and habits of, 138.

  Otter, common, 301;
    _sea-_, 302.

  Owen, Prof., on a reptile like platypus, 190;
    on advantage of pouch to marsupials, 193.

  Owl, adapted for night-hunting, 176.

  Owl-monkeys, 246.

  Oystercatchers, wading birds, 148.


  Paddle-fins of mud-fish, 35, 38.

  _Paleotherium_, 209;
    one of the ancestors of tapirs and rhinoceroses, 213, 261.

  Pallas cited, 11.

  Pangolins, structure and habits of, 203.

  Paraguay, rheas of, 139.

  Parker, Prof. Kitchen, on evolution, 191;
    on origin of mammalia, 191.

  Parkyn, Mr., on baboons, 249.

  Parrots, using beak in climbing, 165.

  Partridges, ground-nesters, 156.

  Peccaries of South America, 263.

  Peewit or lapwing, 148.

  Pelican, perches on trees, 148.

  _Penguin, home of the_, 147;
    swimming wings of the, 146.

  Perch, climbing, 66.

  Perching birds, 168–173;
    aquatic bird among, 172;
    bird of prey among, 172;
    climbers among, 172;
    darters among, 172;
    ground-feeders among, 170.

  Petrel, home of the stormy, 145.

  _Phalanger, a flying_, 193, 195.

  Pheasants, ground-nesters, 156.

  Phosphorescent, fish, 47, 48;
    fluid, 50.

  Pigeons, beginners in nest-building, 160;
    crop of, 161;
    passenger, 162.

  Pike, 65.

  Pilot-fish accompanying shark, 52.

  Pipistrelle the common bat, 236.

  Plates, horny, in duck’s bill, 142;
    in bill of Ornithorhynchus, 188;
    in mouth of whale, 328;
    under the snake’s body, used in walking, 112.

  Platypus, 188;
    knob on nose of baby, 190.

  Plesiosaurus, 92;
    _figured_, 89.

  Plovers, wading birds, 148;
    dragging the wing, 151.

  Pocket-mice of North America, 215.

  Poison of snakes a concentration of a substance found in ordinary
        saliva, 119.

  Poisonous snakes, 117–121.

  Polar bear, walrus fighting the, 309.

  Polypterus or bichir, 33.

  _Porcupine_, 221;
    structure and habits of, 222;
    tree, 222.

  _Porpoise_, 323;
    good type of whales, 324.

  Pouch-bearers, see Marsupials.

  Pouched-rats, burrowing rodents, 226.

  Prairie-dogs, burrowing rodents, 225.

  Protective, colours, 347;
    smells in animals, 347.

  Proteus of Carniola caverns, 79.

  Protopterus of the Nile, 33.

  Protorosaurus earliest known reptile, 91.

  Ptarmigan, white plumage of, 157.

  Pterodactyls or flying reptiles, 93;
    _figured_, 89.

  Pterygotus and early fish, 37;
    _figured_, 20.

  Puff-birds of America, 168.

  Puffin Island, sea-birds of, 142.

  _Puffins_, 144;
    laying eggs in cliff-holes, 142.

  Puma, range and habits of the, 292.

  Pythons crushing their prey, 117.


  Quadrate bone, absent in milk-givers, 191;
    giving a wide gape to the snake, 114;
    _in bird_, 126;
    _in lizard_, 103;
    _in snake_, 111.

  Quadrumana, use of term, 242.

  Quails, scratching birds, 157.

  Queensland, _Ceratodus of_, 34.


  Rats, intelligence of, 230.

  Rattlesnake feeding on “Prairie dogs,” 225;
    horny plates of the, 118;
    _jaw of the_, 119.

  Rays, manner of feeding of, 42.

  _Red deer with branching antlers_, 272.

  _Remora carried by shark_, 51.

  Reptiles, abound in warm countries, 90;
    age of the great, 339;
    care for their young, 122;
    disappearance of ancient, 94, 211;
    flying, of olden times, 93;
    huge, of ancient times, 91, 94;
    _in their palmy days_, 89;
    lay their eggs on land, 90;
    linked in structure with birds, 129;
    modern, 94–122.

  Rheas, three-toed ostriches, 139.

  Rhinoceros, absence of upper teeth in, 265;
    horn made of matted hair, 264;
    embedded in ice, 265.

  Rhytinas in Behring’s Straits, 316.

  Ribbon fish, 49.

  Ribs of lizard, 97, 103;
    of snake, used in walking, 112;
    of tortoise, forming the shell, 99.

  River-fish, 46, 64.

  River-tortoises, 101.

  Roach, 65.

  _Rodent, skull of_, 217;
    teeth of, 216.

  Rodents or gnawers, 215;
    affinity of elephants to, 276;
    generally small and weak, 215;
    _a group of_, 221;
    and insect-eaters compared, 239.

  Rollers, darting birds of the East, 168.

  Rooks, nests of, 170.

  Rorqual, short whalebones of, 326.

  Rough hound, 28.

  Round-mouthed fishes, 16.

  Ruminants, characters of the, 259;
    wide spread of, 269.

  Running birds, 136–140.

  Russia, sturgeon in, 32.


  Salamander, gigantic, of Japan, 78;
    black, viviparous, 81.

  Salamandra atra, viviparous, 81.

  Salmon going up river to spawn, 64.

  Sandpipers, wading birds, 148.

  Sauropsida, birds and lizards, 129.

  Scales of bony fish and mud-fish, 45;
    of fish, 27;
    of snakes embedded in the skin, 111.

  Scaly lizard is viviparous, 105.

  Scoresby, on walrus killing narwhal, 309;
    on whale-mothers defending their young, 330;
    on whale spouting, 321.

  Sea, chief home of fish, 46.

  Sea-birds, 142–150;
    _a group of_, 144.

  Sea-cows, relationship of, 303;
    their structure and habits, 315.

  _Sea-horse, a fish_, 63.

  Sea-lion, _and common seal_, 306;
    _skeleton of a_, 304;
    structure of, 305;
    range of, 306.

  Sea-lions on the Aleutian Isles, 310;
    _fighting for wives_, 311.

  Seals, breathing apparatus of, 308;
    how adapted for a sea-life, 307;
    on English coasts, 303;
    origin of, 303;
    structure and range of, 313, 314.

  Seal-skin, how prepared, 308.

  Sea-otter, structure of the, 301.

  _Sea-squirt, growth of a_, 14.

  Sea-squirts, anomalous position of, 15.

  Sea-tortoises coming on land to lay eggs, 102.

  Secretary bird killing poisonous snakes, 121.

  Self-sacrifice, a law of life, 352.

  Sentinels placed by animals, 269.

  Shark _carrying remora_, 51;
    accompanied by pilot-fish, 52;
    eggs, 28, 42;
    external gills of embryo, 73.

  Sharks, history of the, 41;
    their structure, 28–30.

  Sheat-fish, fathers carrying eggs in the mouth, 65.

  Sheep and goats, range of, 274.

  Shell of tortoise, how formed, 98.

  Shields of the crocodile, 108.

  Shrike, a perching bird of prey, 172.

  Shrew and harvest-mouse compared, 218.

  Silver Pit, soles living in the, 63.

  Siren, a gill-breather, 80.

  Sirenia, name for sea-cows, 315.

  Skates, flat bodies of, 41;
    purse-eggs of, 42.

  _Skeleton, of bat_, 233;
    _bird_, 126;
    _wild ass_, 266;
    _lizard_, 103;
    _sea-lion_, 304;
    _snake_, 111;
    _tortoise_, 98;
    _whale_, 318.

  Skeletons of deep-sea fish, 49.

  _Skulls of rodent and insectivore_, 217.

  Skye, walrus seen off, 310.

  Slime on fish causing phosphorescence, 50.

  _Sloths hanging from a tree_, 200;
    structure and habits of, 206.

  Slowworm, a legless lizard, 107.

  Smooth hound, 28.

  Snake, affection in a, 349;
    casting its skin, 116;
    _common ringed_, 113;
    cup and ball joints of the, 112, 114;
    eggs, 116;
    enemies of the, 117;
    food of the common, 116;
    mode of swallowing prey, 114;
    _skeleton of a_, 111;
    coiling round prey, 117;
    nature of poison of, 119;
    poisonous sea-, 121.

  Snapping turtle, 101.

  Sole, history of its growth, 62;
    _young and old_, 61.

  Song of birds, how caused, 169.

  _Sparrow_, 125;
   _skeleton of_, 126.

  Spawning of lampreys, 18.

  Spermaceti in head of whale, 326.

  _Sperm whale_, 327;
    its structure and habits, 325;
    taking breath, 322.

  Spider monkeys, 246.

  Spinal cord, of lamprey, 17;
    of the lancelet, 12;
    of shark, 30;
    of vertebrata, 9.

  Spines, of hedgehog and porcupine, 222;
    of sharks, 29, 38.

  Spinous processes, of lizard, 103;
    of snake, 111;
    of tortoise, 98.

  Squirrels, enemies of the, 231;
    _flying_, 231;
    tree-loving rodents, 230.

  Stickleback father defending the young, 65.

  _Sticklebacks and their nest_, 65.

  Sting-rays, 42.

  Stomias, a deep-sea fish, 48.

  Storks, migrations of, 151.

  Struggle for existence, developing sympathy, 351;
    improving the herbivora, 282.

  Sturgeon _entering a river_, 31;
    first appearance of the, 41;
    _head and mouth of_, 32;
    structure of, 32.

  _Sucking-fish or remora_, 51.

  Sun-fish with large air-bladder, 53.

  Surinam toad, carrying young in hollows of the skin, 87.

  Swallow, a darter among the perchers, 172.

  Swans, range of wild, 142.

  Swifts, darting birds, 167;
    in East build nests with saliva, 167.

  Sword-fish, Xiphias, 55.


  Tadpole, _life and changes of_, 72–76;
    of salamandra atra, 81;
    summary of changes in the, 335.

  _Taguan or flying squirrel_, 231.

  Tail, jointed, of ancient land-bird, 130;
    of minnow, 24;
    homocercal and heterocercal, 30;
    of bony fish, 45;
    of sharks and sturgeon, 30.

  _Tailor bird’s nest_, 173.

  Tallegallus, mound-building birds, 158.

  Tapirs, past and present range of, 264.

  _Tasmanian marsupials_, 197.

  Teeth as defences, 260;
    in jaws of ancient birds, 130;
    of American monkeys, 246;
    of Old World monkeys, 248;
    of ancient type of fish, 35, 38, 39;
    of lamprey, 17, 19, 37;
    of rodents and insect-eaters, 217;
    of snake used in holding, 115;
    of snake are its poison fangs, 119.

  Tenrecs of Madagascar, 216.

  Termites, ant-bear feeding on, 205.

  _Tern, black-winged_, 144.

  Terrapins or box-tortoises, 101.

  _Testudo Græca_, 96.

  Thresher-shark, 28.

  Thrush, nest of the song-, 170.

  Thuringian lizard, earliest reptile, 91.

  _Tiger_, 287;
    _claws of the_, 289;
    _man fighting the sabre-toothed_, 333, 343;
    range and habits of the, 292;
    sabre-toothed, 290;
    structure of the, 288.

  _Tiger wolf or Thylacinus_, 197.

  Tinamous, a group between running birds and ground birds, 156.

  Toad, habits of the, 85.

  Todies of America, 168.

  Toe-thumbs in opossums, dormouse and monkey, 242.

  Tongue of frog, 77;
    of snake a harmless organ of touch, 112, 118, 119;
    of the woodpecker, 164.

  Torpedo-fish, 42.

  Tortoise, _back of a young_, 99;
    _Greek_, 96;
    structure and habits of, 95–100.

  Tortoises, gigantic land, 101;
    mud and sea, 102.

  Tortoise-shell, 97.

  Toucans, climbing-birds, 165.

  Tree-frogs, 86, 87.

  Trilobites with the early fish, 37.

  Trunk of the elephant, 277.

  Tunny, a fish without air-bladder, 53.

  Turkeys, scratching birds, 157.

  Turnstones, wading birds, 148.

  Turtles, 101, 102.

  Tusks, as weapons, 260, 263;
    of the elephant, 276;
    wanting in early forms, 260.


  Uneven-toed animals, origin of, 265.

  Ungulata, or hoofed animals, 257.


  Vampires in South America, 237.

  Vegetable-feeders, _see_ Herbivora.

  Vertebrata, advantages of the, 7;
    spinal cord of the, 9.

  Viper, _common English_, 121;
    killed by the buzzard, 120.

  Viscacha of South America, 225.

  Vultures, scavengers of the earth, 174.


  _Wading birds, a group of_, 149.

  Walking fish, 57.

  Wallace, Mr. A. R., bitten by bats, 237;
    on colugo, 232;
    on mound-building birds, 159;
    on orangutan, 252;
    on separation of Australasia, 186.

  _Walrus_, 294;
    structure, home, and habits of the, 309.

  Wart-hogs of Africa, 263.

  Water-birds, _the earliest known_, 123;
    structure of, 141.

  Water-mole, 188.

  Water-ouzel or dipper, 172.

  Water-rat and water-shrew, 219.

  _Weasel, a small flesh-feeder_, 280.

  Weevers, spined fish, 58.

  Whale, breathing apparatus of, 321;
    _skeleton of whalebone_, 318;
    _suckling her young_, 319;
    ancient origin of, 303;
    a warm-blooded mammal, 317;
    kept warm by blubber, 320;
    long life of, 331;
    parasites on, 331.

  Whalebone, nature of, 328.

  Whiskers of tiger are feelers, 289.

  White animal tints in winter, 347.

  Wild duck, strokes of wing of, 134.

  Wing, rapid strokes of a bird’s, 134;
    structure of a bird’s, 127.

  Wing-feathers, hooklets on, 133.

  Wings of a bat, how formed, 233.

  Wolf, affection of a, 286;
    ancestor of the dog, 286;
    _dog-like form and teeth of_, 283;
    structure of, 284;
    the only social tribe of carnivora, 286.

  _Wombat_, 197;
    a marsupial, 195.

  _Woodpecker, the great green_, 163;
    tongue of, 164.

  _Wood-pigeon on her nest_, 160.

  _Woolly monkey and child_, 247.

  Worm, compared to the lancelet, 13.

  _Wren, common, nest of_, 171.

  Wryneck, 172.


  _Xiphodon_, 210;
    ancestor of the antlered animals, 213;
    ancestor of ruminants, 261.


  Yapock, 300.


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Transcriber’s Notes


Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed. Inconsistent capitalization has been retained.

Simple typographical errors were corrected; unbalanced quotation
marks were remedied when the change was obvious, and otherwise left
unbalanced.

Illustrations in this eBook have been positioned between paragraphs
and outside quotations. In versions of this eBook that support
hyperlinks, the page references in the List of Illustrations lead to
the corresponding illustrations.

The first illustration is the cover.

The index was not checked for proper alphabetization or correct page
references.

Footnotes, originally at the bottoms of the pages on which they were
referenced, have been collected, sequentially renumbered, and placed at
the end of the main text, just before the Index.