Produced by Bryan Ness and the Online Distributed
Proofreading Team at http://www.pgdp.net









               THE SOCIAL DIRECTION OF HUMAN EVOLUTION




               THE SOCIAL DIRECTION OF HUMAN EVOLUTION

                AN OUTLINE OF THE SCIENCE OF EUGENICS


                                  BY

                         WILLIAM E. KELLICOTT
                PROFESSOR OF BIOLOGY, GOUCHER COLLEGE


                            [Illustration]


                         NEW YORK AND LONDON
                       D. APPLETON AND COMPANY
                                 1919


                         COPYRIGHT, 1911, BY
                       D. APPLETON AND COMPANY


               Printed in the United States of America




                               PREFACE


This small volume is based upon three lectures on Eugenics delivered
at Oberlin College in April, 1910. In preparing them for publication
many extensions and a few additions have been made in order to present
the subject more adequately and to include some very recent results of
eugenic investigation.

Few subjects have come into deserved prominence more rapidly than has
Eugenics. Biologists, social workers, thoughtful students and
observers of human life everywhere, have felt the growing necessity
for some kind of action leading to what are now recognized as eugenic
ends. Hitherto the lack of guiding principles has left us in the dark
as to where to take hold and what methods to pursue. To-day, however,
progress in the human phases of biological science clearly gives us
clews regarding modes of attack upon many of the fundamental problems
of human life and social improvement and progress, and suggests
concrete methods of work.

The present essay does not represent an original contribution to the
subject of Eugenics. It is not a complete statement of the facts and
foundations of Eugenics in any particular. It is rather an attempt to
state briefly and suggestively, in simple, matter-of-fact terms the
present status of this science. While Eugenics is a social topic in
practice, in its fundamentals, in its theory, it is biological. It is
therefore necessary that the subject be approached primarily from the
biological point of view and with some familiarity with biological
methods and results. The control of human evolution--physical, mental,
moral--is a serious subject of supremest importance and gravest
consequents. It must be considered without excitement--thoughtfully,
not emotionally.

It is hardly necessary to add that no one can speak of the subject of
Eugenics without feeling the immensity of his debt to Sir Francis
Galton and to Professor Karl Pearson. From the writings of these
pioneers I have drawn heavily in this essay. The recent summary of the
Whethams, and Davenport's valuable essay on Eugenics have also served
as the sources of quotation.

                                                            W. E. K.
  Baltimore, Md., November, 1910.




                               CONTENTS


                                                                 PAGE
    I.--THE SOURCES AND AIMS OF THE SCIENCE OF EUGENICS            3
   II.--THE BIOLOGICAL FOUNDATIONS OF EUGENICS                    49
  III.--HUMAN HEREDITY AND THE EUGENIC PROGRAM                   133




                        LIST OF ILLUSTRATIONS


  FIG.                                                          PAGE
   1.--Increase of population in the United States and the
        principal countries of Europe from 1800 to 1900           26
   2.--Relative and absolute numbers of prisoners in the
        United States from 1850 to 1904                           30
   3.--Recorded measurements of the stature of 1052 mothers       57
   4.--Model to illustrate the law of probability or "chance"     59
   5.--Plinth to illustrate the difference between variability
        (fluctuation) and variation (mutation)                    64
   6.--Curves illustrating the relation between the pure
        line and the species or other large group                 67
   7.--Diagram showing the course of color heredity in
        the Andalusian fowl                                       83
   8.--Diagram showing the course of color heredity in
        the guinea-pig                                            85
   9.--Diagram illustrating the relation of the germ cells
        in a simple case of Mendelian heredity                    92
  10.--Diagram illustrating the phenomenon of regression         107
  11.--Diagrams showing the relation between order of
        birth and incidence of pathological defect               125
  12.--Coefficients of heredity of physical and psychical
        characters in school children                            144
  13.--Family history showing brachydactylism. Farabee's data    151
  14.--Family history showing polydactylism                      155
  15.--Mother and daughters showing "split hand" _Facing_        156
  16.--Two family histories showing "split foot" _Facing_        158
  17.--Family history showing congenital cataract                159
  18.--Family history showing a form of night blindness          161
  19.--Family history showing a form of night blindness          163
  20.--Family history showing Huntington's chorea                165
  21.--Family history showing deaf-mutism                        167
  22.--Family history showing feeble-mindedness                  169
  23.--Family history showing angio-neurotic oedema              170
  24.--Family history showing tuberculosis                       171
  25.--Family history showing infertility                        175
  26.--Family history showing ability                            177
  27.--Family history showing ability                            179
  28.--History of three markedly able families                   183
  29.--History of _Die Familie Zero_                             185




                                  I

           THE SOURCES AND AIMS OF THE SCIENCE OF EUGENICS




                                  I

           THE SOURCES AND AIMS OF THE SCIENCE OF EUGENICS

    "Bravas to all impulses sending sane children to the next age!"


Eugenics has been defined as "the science of being well born." In the
words of Sir Francis Galton, who may fairly be claimed as the founder
of this newest of sciences, "Eugenics is the study of the agencies
under social control, that may improve or impair the racial qualities
of future generations, either physically or mentally."

The idea of definitely undertaking to improve the innate
characteristics of the human race has been expressed repeatedly
through centuries--fancifully, seriously, hopefully, and now
scientifically. Since the times of Theognis and of Plato the student
of animate Nature has been aware of the possibility of the degradation
or of the elevation of the human race-characters. The conditions under
which life exists gradually change: the customs and ideals of
societies change rapidly. Times inevitably come when, if we are to
maintain or to advance our racial position, we find it necessary to
change in an adaptive way our attitude toward these changing social
relations and conditions of life. If we neglect to do this we go down
in the racial struggle, as history so clearly and so repeatedly warns
us.

In the opinion of many biologists and sociologists such a time has
now arrived. The suspension of many forms of natural selection in
human society, the currency of the "rabbit theory" of racial
prosperity--based upon the idea of mere numerical increase of the
population, the complacent disregard of the increase of the pauper,
insane, and criminal elements of our population, the dearth of
individuals of high ability--even of competent workmen, all are
resulting in evil and will result disastrously unless deliberately
controlled. It is hoped that this control, though at first conscious,
"artificial," may later become fixed as an element of social custom
and conscience and thus operate automatically and the more
effectively. The result will be not only the restoration of our race
to its original vigor, mental and physical, but further the carrying
on of the race to a surpassing vigor and supremacy.

The aim of Eugenics is the production of a more healthy, more
vigorous, more able humanity. Again in the words of Galton "The aim of
Eugenics is to represent each class ... by its best specimens; that
done to leave them to work out their common civilization in their own
way.... To bring as many influences as can be reasonably employed to
cause the useful classes in the community to contribute more than
their present proportion to the next generation"; and further, we
might add, to cause the useless, vicious classes to contribute to the
next generation less than their present proportion.

With this definition of Eugenics and preliminary statement of its aims
before us we may proceed to a somewhat fuller statement of the facts
within this field. First let us consider the relation of the science
of Eugenics to its parent sciences, biology and sociology, then after
mentioning some of the steps in the development of the present
eugenic movement, we may describe some of the conditions which give us
human beings pause and lead us to appreciate the necessity for a
reconsideration of much that enters into our present social
organization and conduct.

Shortly before the publication of "The Origin of Species," Darwin was
asked by Alfred Russell Wallace whether he proposed to include any
reference to the evolution of man. Darwin's reply was: "You ask
whether I shall discuss man. I think I shall avoid the whole subject,
as so surrounded with prejudices; though I fully admit that it is the
highest and most interesting problem for the naturalist." This
prejudice which Darwin knew would preclude a just consideration of the
subject of man's origin and evolution, grew out of the former and long
current conception of the position occupied by man in the whole scheme
of Nature--of "Man's Place in Nature."

This conception, happily obsolete now among thinkers, though
occasionally seen lurking in out of the way corners shaded from the
light of modern philosophy and science, placed Man and the rest of
the universe in separate categories. Man was one, all the rest
another. It was for Man's benefit or pleasure that the rains
descended, that the corn grew and ripened, that the sun shone, the
birds sang, the landscape was spread before the view. For Man's
warning or punishment the lightning struck, comets appeared, disease
ravaged, insects tormented and destroyed. It was certainly very
natural that Man should regard himself as a thing apart, particularly
since he was able to control and to regulate Nature, and to take
tribute from her so extensively. But the scientist regarded man
differently; from him the world learned to recognize man as an
integral factor in Nature--as one with Nature, possessing the same
structures, performing the same activities, as other animals; subject
to much the same control and with much the same purposes in life and
in Nature as other living things. There is to-day no necessity to
enlarge upon this view. As Ray Lankester puts it: "Man is held to be a
part of Nature; a being, resulting from and driven by the one great
nexus of mechanism which we call Nature."

But the echoes of the older naïve view of Man and his Nature sounded
long after the rational scientific conception had become dominant. It
is not so very long ago that psychology was little more than human
psychology; nor has sociology long since gone outside the purely human
for explanations of the facts of human society. Nowadays, however,
psychology has a firm comparative basis and sociology finds much that
is illuminating and helpful in the purely biological aspects of the
human animal. Very naturally, then, we have had social science
studying man as Man, with a capital M: biological science studying man
as a natural animal.

But now that modern trend of scientific synthesis which has brought
forth a Physical-Chemistry and a Chemical-Physiology and a
Bio-Chemistry, is combining the purely social and the purely
biological studies of man into a new Bio-Sociology. And as one phase
of this new partnership we have the subject of Eugenics--the science
of racial integrity and progress, built upon the overlapping fields of
Biology and Sociology.

We can trace the idea, perhaps better the hope, of Eugenics from the
modern times of ancient Greece. Plato laid stress upon the idea of the
"purification of the State." In his Republic he pointed out that the
quality of the herd or flock could be maintained only by breeding from
the best, consciously selected for that purpose by the shepherd, and
by the destruction of the weaklings; and that when one was concerned
with the quality of his hunting dogs or horses or pet birds, he was
careful to utilize this knowledge. He drew attention to the necessity
in the State for a functionary corresponding to the shepherd to weed
out the undesirables and to prevent them from multiplying their kind.
Plato stated clearly the essential idea of the inheritance of
individual qualities and the danger to the State of a large and
increasing body of degenerates and defectives. He called upon the
legislators to purify the State. But the legislators paid no heed. The
able-bodied and able-minded continued to be sacrificed to the God of
War; the degenerates and defectives--not fit to fight--were the ones
left at home to become parents of the next generation. And to-day
Greece remains an awful warning.

We cannot describe or even enumerate the wrecks of the many plans for
race improvement that are strewn from Plato to our day. Sporadic,
emotional, visionary, often it must be confessed suggested by
possibilities of material gain to the "leader"--they have all passed.
They failed because they were unscientific; because there was
available no solid foundation of determined fact upon which to build.
One need suggest only the Oneida Community, as it was originally
planned, or the Parisian society of _L'Elite_--in both of which the
selection of mates was to be carefully controlled--or some of the
fantasies of Bernard Shaw, to indicate the character of these
failures. Only recently have we become able to suggest the possibility
of race improvement by scientific methods, and only very recently has
the possibility appeared in the light of a necessity, the alternative
being the universal reward of the unsuccessful.

The present eugenic movement may be said to date from 1865 when
Francis Galton showed that mental qualities are inherited just as are
physical qualities, and pointed out that this opened the way to an
improvement of the race in all respects. The data in support of this
pregnant conclusion were included in Galton's work on "Hereditary
Genius" published in 1869, when he again emphasized definitely the
possibility and desirability of improving the natural qualities of the
human race. His suggestions fell upon the stony ground of ignorance
even of the most elementary facts of heredity. The subject was raised
again in his "Inquiries into the Human Faculty" in 1883, and the word
"Eugenics" was then coined. The ground was still non-receptive.

Then followed a period of rapid increase in our knowledge of heredity
in animals and plants and in 1901 Galton returned again to the
subject, this time in a more direct and elaborate way, and his Huxley
Lecture of that year before the Anthropological Institute was upon
"The Possible Improvement of the Human Breed under the Existing
Conditions of Law and Sentiment." This time he received a real
hearing, partly on account of recent disclosures regarding the state
of human society and its trends in Great Britain, chiefly because
there was at last a real scientific basis for such a proposal. In this
lecture, after declaring that the possibility of human race culture is
no longer to be considered an academical or impractical problem,
Galton proceeded to show that we have a sufficient biological
knowledge of man to furnish a working basis. We know of man's
variability and heredity--that some men are worth more than others in
the community, and that individual traits are also family possessions.
This he followed up with definite suggestions as to possible means of
the "augmentation of favored stock."

The then recently organized Sociological Society of London took up the
subject enthusiastically, and in 1904 and 1905 Galton was invited to
deliver addresses before the Society upon this topic. In his first
address he spoke upon "Eugenics: its Definition, Scope, and Aims."
This proved to be a statement of the elementary principles of the
subject--a sort of eugenic creed. Here Galton struck fire. The reading
of his paper was followed by very extended discussion and criticism,
and he received some enthusiastic support. A few of these enthusiastic
supporters brought forth, on the spur of the moment, wonderful,
visionary schemes for eugenic progress; much of the adverse criticism
went wide of the mark; and, on the whole, Galton must have felt that
at least he had demonstrated fully one need for which he had spoken,
that of developing a race of able thinkers. Galton's second address
before the same society the year following was partly directed at some
of this hasty criticism and partly devoted to the setting forth of the
possibly ultimate place of the ideals of race improvement in the
conscience of the community, and to showing how the whole subject is
fraught with "the greatest spiritual dignity and the utmost social
importance."

The subject was now fairly launched. Magazine articles appeared on
"The New National Patriotism," "Breeding Better Men," _et cetera_.
Meanwhile the bio-sociologist settled down to work. And during the
five years that have since passed an immense amount of knowledge has
been gained, and a large number of excellent workers recruited.
Interest in the subject is now general, and its importance recognized
as vital. Karl Pearson, known as a good fighter, is Galton's "beak and
claws," performing for him much the same kind of service that Huxley
performed for Darwin nearly fifty years ago. Galton himself has
established a Eugenics Laboratory under the direction of Professor
Pearson in the Biometric Laboratory of the University of London and
has endowed a Research Fellowship and Research Scholarships. This
laboratory is publishing a series of Memoirs and a series of Lectures
upon eugenic topics. The University of London is publishing, with the
assistance of the Drapers' Company, a series of "Studies in National
Deterioration." A periodical, _The Eugenics Review_, is established
and appearing regularly. A Eugenics Education Society has been founded
to popularize and disseminate the technical information contained in
the memoirs and special papers. England remains the seat of greatest
activity and interest, but much is being done now in this country. In
America the subject is largely under the auspices of the American
Breeders Association, which has organized an extremely efficient
Committee on Eugenics with which a large number of biological and
medical workers are coöperating. This committee has coöperated in the
establishment of a Eugenics Record Office, at Cold Spring Harbor,
under the direction of H. H. Laughlin. Relevant facts are beginning to
pour in from many directions; eugenic ideals are being given practical
expression, and the science is rapidly gaining headway.

It may be asked: "Well, what is it all about; are we as a nation not
doing well--well enough?" Is it not true, as some have suggested, that
this eugenic movement is but one more expression of England's
temporary national hysteria transferred to this country? In answer to
such queries let us state some of the conditions which have suggested
to so many sober thinkers and observers that the time is arriving, has
in fact arrived, when we must begin to think of the future of our
communities and nations and of our race, rather than contentedly to
read of and meditate upon the great achievements of our past, or to
parade with self-satisfied air through our glass houses of Anglo-Saxon
supremacy. Even were we unthreatened, were we amply holding our own,
the mere fact of the possibility of a natural increase of human
capacity would make it a practical subject of the utmost importance.
We may be sure that somewhere a nation will avail itself of such a
possibility as the increase of inherent native talent, physical,
mental, moral, and will tend to become a strong and dominant people.
Why should not _we_ be that people?

It seems that the facts that lead us to think of the future in this
matter are of two quite distinct classes. First, we have a great mass
of data relative to the composition of our societies and to the
changing character of our population, social data of deep significance
when broadly viewed and thoughtfully considered. Second, there are
certain biological considerations, which all apart from existing
social conditions should warn us to be on the lookout. First let us
review briefly some of the latter, some of those biological
considerations which lead us to regard thoughtfully the problem of
the future evolution of man and his societies.

As with other species of animals, each of us comes into the world
equipped with a physical constitution and a few simple fundamental
instincts. But unlike all other animals, the possession of these alone
does not enable us to take and maintain our positions in the community
life. Man's life to-day is subject to a great social heritage which,
unlike his natural heritage, can be realized only as a result of his
own activity and acquisition. Civilized man is the result of Nature
plus Nurture. Civilization has been defined as "the sum of human
contrivances which enable human beings to advance independently of
heredity." The knowledge of fact, historic and scientific, of
literature, of art, of custom, and manner, and all that goes to make
up the culture and education which are the distinctive traits of our
human lives--all this is no possession of ours when we make our first
bow to society. Nor do these things become ours through a simple
process of growth and development while we remain the passive
subjects. All of these things represent the active individual
acquirement of the racial accumulation of tradition and learning--what
the biologist would call the results of modification. Our troubles
begin when we realize that in the acquisition of this load each
generation does not begin where the preceding left off, not at
all--but we begin where our parents did. The first thing we do toward
advancing our places in the world is to absorb what we can of the same
kind of thing our forbears absorbed, learn over again their lessons,
repeat their experiences; and then we proceed straightway to increase
the difficulties for the next generation by writing more books,
discovering more facts, making a little more history, and so it goes:
the load of tradition increases with every successive generation, and
so it has gone since the beginning of man's civilization. It is
declared that the modern schoolboy knows more than did Aristotle. We
cannot resist the inquiry, Has the modern schoolboy better native
ability than had Aristotle? Here is the whole point of this matter;
are we any better endowed mentally now that the amount to be mentally
absorbed and accomplished is so many times greater? Has our capacity
for mental accumulation kept pace with the amount to be accumulated,
and with the necessity for such accumulation as a fitting for human
life of the civilized variety?

Madison Bentley has recently put it nicely in this way. Does talent
grow with knowledge? "May we not suppose that the men and women of
some distant glacial age, who dwelt upon the ice, wore the skin of the
seal, and ate raw fish, had as much brain and as generous a measure of
talent as have their remote descendants who wear sealskins, and eat
ices and caviar?" He continues that we have little or nothing to show
that the hereditary or innate growth of the mind has kept pace with
the growing social heritage; that as regards mental endowment we begin
where our distant ancestors began. The chief difference between us and
them is that we proceed at once to burden ourselves with information
and obligation which for them did not exist. To compass our languages,
sciences, histories, arts, the complicated social, political, moral
régime, we are supplied with virtually the same minds that primitive
man used for his primitive needs. Is it any wonder, he asks, that
"education" is the central problem for our or any other advanced
civilization?

The biologist asks whether it is not high time to look beyond this
artificial bolster of education, to the possibility of actual
improvement of the innate mental abilities of man. The student of
heredity and evolution looking at this problem has two contributions
to make. First, if the mental capabilities of the present race are too
limited, increase them; if our minds are too weak to carry the burdens
which now must be carried, do not give up the task--strengthen the
racial mind. Second, if we should seem to be in danger of developing a
stock which is well fitted and able to carry the load of mental
acquirement and to push on intellectually, but which is at the same
time physically deficient, weak, or sterile, or susceptible to
disease, do not let the intellectual capabilities diminish, but build
up the physical constitution to a higher supporting level. These are
not idle suggestions nor whimsical schemes. The biologist makes them
knowing that these things are possible; not only possible, they must
be accomplished. We are foolishly building our civilization in the
form of an inverted pyramid of individually acquired characteristics.
This structure can be made stable only by supplying a broader basis of
innate ability which can safely carry the load. This is the first
biological warning to sociology.

The second warning we may put in the form in which Ray Lankester in
his "Kingdom of Man" has recently presented it so strikingly and which
we may abstract freely and with some interpolation. "In Nature's
struggle for existence, death ... is the fate of the vanquished, while
the only reward to the victors ... is the permission to reproduce
their kind--to carry on by heredity to another generation, the
specific qualities by which they triumphed." The _origin_ of man,
partly, at any rate, by such a process of natural selection, is one
chapter in his history. Another begins with the development of his
mental qualities, which are of such unprecedented power in Nature.
These qualities so dominate all else in his "living" activities that
they largely cut him off from the general operations of natural
selection. Perhaps the only direction in which natural selection is
the chiefly operative factor in human evolution to-day is in the
development of immunity from infectious disease. Just as man is a new
departure in the unfolding scheme of the world, so his presence and
characteristics lead to new methods of evolution, of survival, and the
like. Knowledge, reason, self-consciousness, will, are new processes
in Nature, and it is these which have largely determined the direction
of man's history. Nature's discipline of death is more or less
successfully resisted by the will of man. Man is Nature's Rebel.
"Where Nature says 'Die'! Man says 'I will live.'" By his wits and his
will man has overcome many of Nature's bounds and difficulties without
changing, as other organisms would, his innate characteristics. Not
only this but man has obtained control of his surroundings and at
every step of his development he has receded farther from the rule of
Nature. Now "he has advanced so far and become so unfitted to the
earlier rule, that to suppose that Man can 'return to Nature' is as
unreasonable as to suppose that an adult animal can return to its
mother's womb."

But at present man puts into operation no real substitute for natural
selection. "The standard raised by the rebel man is not that of
fitness to the conditions proffered by extra-human Nature, but is one
of ideal comfort, prosperity, and conscious joy of life--imposed by
the will of man and involving a control, and in important respects a
subversion, of what were Nature's methods of dealing with life before
she had produced her insurgent son." Progress in the control of Nature
has been going on with enormous rapidity during the last two centuries
particularly--the "nature searchers" have placed almost limitless
power in the hands of men. And yet the builders of society and
governments and nations have failed to profit by this increase in
natural knowledge. In our social and national organization we remain
fixed in the old paths of ignorance. Lankester says: "I speak for
those who would urge the conscious and deliberate assumption of his
kingdom by Man--not as a matter of markets and of increased
opportunity for the cosmopolitan dealers in finance--but as an
absolute duty, the fulfillment of Man's destiny." The purpose of his
essay is "to point out that civilized man has proceeded so far in his
interference with extra-human Nature, has produced for himself and for
the living organisms associated with him such a special state of
things, by his rebellion against natural selection and his defiance of
pre-human dispositions, that he must either go on and acquire firmer
control of the conditions, or perish miserably by the vengeance
certain to fall on the half-hearted meddler in great affairs." Man is
a fighting rebel who at every forward step lays himself open to the
liabilities of greater penalties should his attack prove unsuccessful.
Moreover, while emancipating himself from the destructive and
progressive methods of Nature, man has accumulated a new series of
dangers and difficulties with which he must incessantly contend and
which he must finally control. Man has taken a tremendous
step--created desperate conditions by the exercise of his
will--further control is essential in order that he should escape from
final misery and destruction.

Nor is this idle, academic invective. The biologist knows that this is
true. It is not idle, for man has the means at his command--it is
merely a question of their employment. This, then, is the second
biological warning to sociology and to statecraft.

Now we may return to consider briefly the nature of those social data
which we suggested force us to think seriously of the problem of man's
future.

As a primary datum we may note the increasing population of the
countries of Europe and North America (Fig. 1). The countries whose
population is increasing most rapidly are the United States, Russia,
and the German Empire. We know that one important factor of the
increase in this country is that of immigration, but this is not
sufficient to account for the total. There is continued multiplication
of the native population, and of the immigrant after he is here. We
wish only to point out in connection with this diagram the steady
trend of the population upward, and the fact that obviously somewhere
there must be a limit. This cannot go on without end.

    [Illustration: FIG. 1.--INCREASE OF POPULATION IN THE
    UNITED STATES AND THE PRINCIPAL COUNTRIES OF EUROPE
    FROM 1800 TO 1900 (From "Statistical Atlas," Twelfth
    Census of the United States.)]

An extremely pertinent fact here has been disclosed by Pearson and is
based upon very extensive observations among several different classes
and nations. It is this--that one fourth of the married population of
the present generation produce one half of the next generation. The
death rate and the ratio of unmarried to married being what they are,
this relation may be stated in this way--twelve per cent of all the
individuals born in the last generation produced one half of the
present generation. "This is not only a general law, but it is
practically true for each class in the community." This conclusion is
based upon data from the English, Danish, and Welsh peoples of
professional, domestic, commercial, industrial, and pastoral classes,
and the per cent of married persons found to be producing one half of
each generation varies from twenty-three to twenty-seven with an
average of twenty-five per cent. We must ask at once--what is the
source of this fourth which is contributing double its quota to the
next generation? Is this twenty-five per cent drawn proportionately
from all classes of society or are some groups contributing
relatively more than others? Is there any relation between this
superfertility and the possession of desirable or undesirable
characteristics? We may answer at once--there is a distinct and
positive relation between civic undesirability and high fertility. We
shall return to this subject at the close of the next chapter; only
the bare fact is to be mentioned at this time.

It is a matter of common notice and remark that to-day, in England at
any rate, there is a dearth of youthful ability. It exists in
commerce, science, literature, politics, the bar, the church. We
cannot dismiss as merely fashionable the statements that the able
classes are not replacing themselves, that men of ability are less
able than formerly. Whether or not this is also the condition in
America to-day, we know that it soon will be the condition unless
steps are taken to bring about a positive relation between civic
desirability and ability and the numerical production of offspring.

Let us turn to data of a somewhat different kind. The United States
Census Reports for the decades from 1850 to 1900 (1904) include data
relative to the number of prisoners in this country. The returns for
1904 omitted certain classes previously enumerated so that for
comparative purposes the figures given have to be corrected. On the
corrected basis these reports show that the total number of prisoners
in the United States increased from 6,737 in 1850 to about 100,000 in
1904, while the total population increased during the same time only
from twenty-three to eighty millions (Fig. 2). The ratio of prisoners
to the total population is of course the significant relation here,
and this increased from 29 per 100,000 in 1850 to 125 per 100,000 in
1904. Not all of this increase can be attributed to more rigid
enforcement of the law or raised standards of morality; there is some
reason for thinking that whatever change there has been in these
respects has tended to have the opposite effect. We should note, in
considering such data as these, that the penologist generally assumes
that of the total number of offenders, actually only about ten per
cent are in prison at any one time.

During the last century, in France, many parts of Germany, and in
Spain the increase in criminality was terrifying. In the United
States the number of murders and homicides per million of the entire
population has nearly trebled in the last fifteen years (Fig. 2). The
average for the five years from 1885 to 1889 inclusive was 38.5 per
million, and for the five years from 1902 to 1906 it became 110 per
million.

    [Illustration: FIG. 2.--Relative and absolute numbers of
           prisoners in the United States from 1850 to 1904.

    - - - - Number of prisoners per 100,000 of total population.

    ------- Total number of prisoners (figures to the right are
            to be read as thousands here).

    -.-.-.- Number of murders and homicides per million of the
            total population.]

England's "defective" classes during the 22 years between 1874 and
1896 increased from 5.4 to 11.6 per thousand of the total; that is,
more than doubled in that brief period. Rentoul has collected careful
information regarding the number of insane or mentally defective and
degenerate in Great Britain. In England the number of "officially
certified" insane, which is far less than the actual number, increased
from one to every 319 of the total population, to one to 285, in the
nine years preceding 1905. In Ireland comparison of the years 1851 and
1896--a period of 45 years intervening--shows an increase in the
corresponding ratio from 1:657 to 1:178. The census of 1901 showed in
Great Britain 484,507 mental defectives of all kinds; this is one to
85 of the total population, and probably if the whole truth were known
the ratio would approximate 1:50, according to Rentoul's calculation.
The ratio of known insane just doubled in the decade preceding 1901.
The Scottish Commission reports an increase in insane of 190 per cent
since 1858, the total population increasing meanwhile by only 52 per
cent.

The worst side of these British statistics follows. In 1901, of the
60,000 and more, idiots, imbeciles, and feeble-minded, nearly
19,000--roughly one third--were married and free to multiply;
and as for that matter a great many of those unmarried are known
to have been prolific. In 1901, of the 117,000 lunatics, nearly
47,000--considerably more than one third--were married. 65,700 idiots
and lunatics legally multiplying their kind and worse! Rentoul rightly
says: "The hand that wrecks the cradle wrecks the nation."

In the United States the census of 1880 reported 40,942 insane in
hospitals, and 51,017 not in hospitals--a total of 91,959 known
insane. In 1903 the number in hospitals had increased to 150,151. The
number not in hospitals was not given and cannot be determined
accurately, but it is conservatively estimated as certainly not less
than 30,000, and probably it is far greater than this. In many states
it is known that about one fourth of the insane are not in hospitals.
But taking the total of 180,000 as a conservative figure, the ratio of
known insane in the total population was 225 per 100,000 in 1903 as
compared with 183 per 100,000 in 1880.

The methods of the collection of such data vary in different countries
so that the results are not comparable. In a single country there is
less, though still some, lack of uniformity, so that the exact rate of
increase in the ratio of the insane is still somewhat doubtful.
Moreover, it is doubtless true that some of this apparent increase
results from improved methods in the collection of data, and from more
complete registration of these defectives. But suppose we disregard
entirely the idea of an increase in the ratio of these defectives, the
bare fact of the existence of nearly 200,000 insane in this country is
sufficiently alarming; and it is disgraceful to any nation, because it
is unnecessary. The Superintendent of the Ohio Institution for the
Feeble Minded wrote in 1902: "Unless preventive measures against the
progressive increase of the defective classes are adopted, such a
calamity as the gradual eclipse, slow decay and final disintegration
of our present form of society and government is not only possible,
but probable."

The latest census reports for the United States give data relative to
the dependents and defectives in institutions. The numbers not in
institutions can only be guessed at. But from the available sources we
can gain an approximate conception of the numbers in our country
to-day as follows:--insane and feeble minded, at least 200,000; blind,
100,000; deaf, and deaf and dumb, 100,000; paupers in institutions,
80,000, two thirds of whom have children, and are also physically or
mentally deficient, and to say that one half of the whole number of
paupers are in institutions is to give a ridiculously low estimate;
prisoners, 100,000, and several hundred thousand more that should be
prisoners; juvenile delinquents, 23,000 in institutions; the number
cared for by hospitals, dispensaries, "homes" of various kinds, in the
year 1904 was in excess of 2,000,000. From these figures we get a
rough total of nearly 3,000,000. Must we define a civilized and
enlightened nation as one in which only one person in every thirty can
be classed as defective or dependent?

It is needless to continue descriptions of this kind. The foregoing
are representative data; they are published by the volume. It is
always the same story--rapid increase of the unfit, defective, insane,
criminal; slow increase, even decrease of the fit, normal, or gifted
stocks. It is with such conditions in mind that Whetham writes:
"Although this suppression of the best blood of the country is a new
disease in modern Europe, it is an old story in the history of nations
and has been the prelude to the ruin of states and the decline and
fall of empires."

The ultimate aim of Sociology is doubtless the working out of the laws
according to which stable communities are formed and maintained, and
in which each component individual may enjoy and contribute the
maximum of pleasure and profit. So the primary purpose of Statecraft
is to produce a nation which shall be stable and enduring. This is all
familiar ground. The objects of the nation's immediate activities and
concern, protection from enemy, development of commerce and
manufacture, agriculture, and education, all these are for the real
purpose of establishing and promoting national integrity. No nation
exists long without ideals and traditions, without teachers, artists,
poets, and yet the primary condition of the existence of all these is
a great body of citizens characterized by physical and mental
soundness--vigor and sanity. In searching for guiding principles in
their great endeavors the sociologist and statesman have sought aid
from many sources. But, as Pearson points out, Philosophy has thus far
given no law by the aid of which we can understand how a nation
becomes physically and mentally vigorous. Anthropology has done little
to show wherein exists human fitness as a social organism. Political
Economists object that they are not listened to with respectful
consideration in legislative chambers. History is the favorite hunting
ground of the statesman searching for guidance; but unfortunately
history teaches chiefly by example and analogy, rarely by true
explanation. And just as some gifted persons are able to give an apt
Biblical quotation touching any occurrence whatever, so, many
statesmen can cite some historical analogue which they offer as
evidence for their views, whatever they are. These men are sincere, in
their ignorance of the nature of scientific proof. Finally, although
the Statesman still holds rather aloof, the Sociologist comes now to
the Biologist, inquiring whether by any chance he may be in possession
of data or guiding principles which may be somehow of service in the
building of stable societies. The Biologist does not send him away
without contribution. The Sociologist makes known his needs, the
Biologist displays his possessions, and it is at once evident to both
that they have much in common, and that each is able to supply the
other with some needed wares. Each may learn from the other; and best
of all, the Biologist seems to have information which can be of the
greatest service in their common work of building sound societies.

And the biologist is grateful to the sociologist for reminding him
that he, too, has sacred duties in this direction. He is too often
forgetful that the real aim of his own, as of any science, is to be
useful in real human life. It is pleasing to the biologist to feel
that he is at last in possession of facts of value to the student of
human society, for to him his debt is great. From the sociologist he
has drawn the inspirations which have led to some of his greatest
discoveries. It was Malthus who suggested to Darwin the great
principle of the struggle for existence among men which Darwin so
successfully applied to other organisms, and used so profitably in
building up his great theory of natural selection. It was from the
sociologist that the biologist derived his idea of the physiological
division of labor which has proved so fruitful a conception; and from
the same source he has drawn many of his conceptions of organic
individuality.

We might suggest here some of the topics upon which biology has
information of value in this bio-social field; many of these we shall
discuss later on from our present and special point of view. First of
all come the facts regarding the variability and variation of human
beings, not alone in physical characteristics, but in respect to
psychic traits as well. Here as in all organisms we must distinguish
between true variations and bodily modifications; that is, we must be
careful to make, as far as possible, the biological distinction
between innate and acquired traits, particularly in considering
mental characteristics. Next must come consideration of the facts of
heredity. This is undoubtedly the field of greatest importance to the
Eugenist; facts of no other kind are of equal significance in
determining the course of eugenic practice. We now have a fairly
extensive working basis here from which to discuss heredity in man.
The various phases of human selection should be noticed, in particular
that known as selective fertility or differential fertility in
different social groups or classes. Another evolutionary factor of
importance here is that of "isolation" in the many and varied forms
which it assumes in human society, especially those which result from
assortative and preferential mating, and from the operation of social
convention, restrictions in marriage, and the like.

Before discussing any of these subjects let us offer here just a word
of caution to the enthusiast. The results gained in one field of
science cannot be transferred _in toto_ to another field and there be
found to fit. Biology has learned much from Physics and Chemistry, but
the biological applications of the laws of these sciences must be
carried out with the greatest care. Such transference has often been
premature and attended by results retardative to progress in the field
of Biology. Any formula borrowed from one science and applied in
another must be rigorously tested under the new conditions. The
indiscriminating application of biological laws in the field of
sociology may result in confusion and retardation in the progress of
both sciences, or at any rate in their practical applications. As
Thomson points out in writing on this topic, human society is not only
a complex of individual activities of a strictly biological character,
but also and further it involves an integration and regulation of
those activities which are not yet, at least, susceptible of concrete
biological analysis. Thomson says: "The biological ideal of a
healthful, self-sustaining, evolving human breed is as fundamental as
the social ideal of a harmoniously integrated society is supreme." The
great danger here lies in forgetting the fundamental and general
character of the biological principles. The ideals of biology and
sociology need not coincide, often they do not, but they must not
conflict. In practice Eugenics must be largely a social matter; but in
its theory, its fundamentals, it must be largely biological.

The coming together of biology and sociology, and their common search
for guiding principles in their common endeavor is likely to have
results of several kinds. It is likely to bring out more clearly than
has yet been done the distinction, in human life and society, between
that which is fundamentally biological or animal, and that which is
distinctly social. Such information will prove of especial value later
when the time comes for the suggestion and carrying out of a definite
eugenic program, when the time comes for the real eugenic organization
of society. And further the close _rapprochement_ of the two subjects
will doubtless result in mutual aid and suggestion in the development
of each subject in its own stricter field, outside the limits of their
common meeting ground.

Before bringing this introductory chapter to a conclusion we should
suggest one further caution which must be borne in mind. There may at
times seem to be suggestions of antagonism between the biological and
the social conceptions of what is eugenic and what is not. Much of
this apparent discord will disappear if we recognize that after all
the overlapping areas of the two subjects which have fused into the
subject of Eugenics are relatively small portions of either whole
subject. Sociology has for one of its aims, perhaps its chief aim, the
improvement of the present condition of society. The sociologist is
interested in the improvement of social conditions to-day and
to-morrow. He wants to improve housing conditions, food and milk
supplies, to reduce the curses of alcoholism, poverty, and crime, to
take the children out of the factory and their mothers out of the
sweatshop and put them into schools or under humane conditions of
labor. And so on through a long list. The biologist or Eugenist is of
course heartily with the sociologist in these endeavors, but as a
human being, not as a biologist or Eugenist. For the Eugenist is, as
such, by deliberate assumption and definition, directly interested in
only such conditions as affect the innate characteristics of the
race, conditions which may not have direct reference to the present
generation at all, but to the next and to future generations. As a
Eugenist he is not concerned with factory legislation, alcoholism, or
play grounds, unless it can be shown that there is a relation between
these things and the innate mental and physical properties of the
race. If there is such a relation, of improvement or impairment, these
are eugenic topics; if there is no such relation they are purely
social topics, and the Eugenist does not deal with them, not because
they are not worth dealing with, but because they are then by
definition outside his field. In the end the Eugenist hopes, with the
Sociologist, to accomplish these social betterments, but he believes
that these will come as by-products in the process of innate racial
improvement--improvement in the inherent, physical, mental, and moral
qualities of the human kind, and that accomplished in this way the
results will be more stable and permanent than any accomplished by
attacking the problems as such and separately, largely leaving out of
account the real and fundamental cause--bad human protoplasm.

Eugenics is not offered as a universal cure for social ills: no single
cure exists. But the Eugenist believes that no other single factor in
determining social conditions and practices approaches in importance
that of racial structural integrity and sanity. The Eugenist would
oppose only those social activities, if such there be, that conflict
with his ideal of genuine, progressive, human evolution. The main
question which the Eugenist would raise here is largely that of the
economy of effort--whether it were not better by concentrating upon a
few activities, known to give permanent results, once for all to end
an intolerable social condition, rather than to attempt the Sisyphean
task.

In conclusion let us quote a few sentences from Francis Galton.
"Charity refers to the individual; Statesmanship to the nation;
Eugenics cares for both.... I take Eugenics very seriously, feeling
that its principles ought to become one of the dominant motives in a
civilized nation, much as if they were one of its religious tenets....
Man is gifted with pity and other kindly feelings; he has also the
power of preventing many kinds of suffering. I conceive it to fall
well within his province to replace Natural Selection by other
processes that are more merciful and not less effective. This is
precisely the aim of Eugenics. Its first object is to check the birth
rate of the Unfit instead of allowing them to come into being, though
doomed in large numbers to perish prematurely. The second object is
the improvement of the race by furthering the productivity of the Fit,
by early marriages and the healthful rearing of their children.
Natural Selection rests upon excessive production and wholesale
destruction; Eugenics on bringing no more individuals into the world
than can be properly cared for, and those only of the best stock."




                                  II

                THE BIOLOGICAL FOUNDATIONS OF EUGENICS




                                  II

                THE BIOLOGICAL FOUNDATIONS OF EUGENICS

    "The gist of histories and statistics as far back as the
    records reach, is in you this hour,..."


We must now proceed to consider briefly and with only the necessary
detail the modes of application of certain biological principles and
data in this special field of Eugenics. First of all a clear
understanding of the basic ideas of variability and heredity must be
had as a primary condition of an appreciation of their significance
for the subject before us.

Like any other organism a human being is a bundle of characteristics,
physical and psychical. Each person has a definite stature and span,
possesses fingers and toes, a head, eyes, ears, hair of a certain
color, and so on through a long list of physical traits. Physiological
characteristics has he also, such as muscular strength, resistance to
fatigue or to disease of many kinds, digestive and assimilative
powers, a rate of heart beat, a blood pressure, an habitual gait,
posture, a characteristic way of clasping the hands or of twirling
the thumbs--and so almost _ad infinitum_. He also possesses
certain physiological traits more closely related with the action
of the central nervous system--keenness of vision, or hearing,
or smell, memory, vivacity, cheerfulness, self-assertiveness,
self-consciousness, reasoning power, determination, and the like.

There is a period during the existence of each human being when he
does not seem to possess these traits or anything resembling them. For
at the beginning of his existence as a new and separate creature,
every individual, among the groups of higher organisms, has the form
of a single organic cell--the germ. This germ may be, as it is in man,
of microscopic dimensions, and it always shows a comparatively slight
degree of differentiation of structure. Moreover, the parts and organs
of the germ bear no actual or visible resemblance at all to the organs
and parts of the organism into which the germ rapidly develops. In
other words, in the germ of an organism we have a structure, partly
material, partly dynamic, the components of which in some way
represent the adult characteristics without resembling them. During
the period of the development of the individual, that is to say,
during its "ontogeny," these characteristics of the germ become
expressed in their final or adult form.

For our purpose it is not necessary to inquire precisely how it is
that the structure of the germ can thus represent or determine the
structures growing out of it. It must suffice to see that somehow the
characteristics of the germ lead to the formation or development of
other characters, and these in turn to still others until at last a
period of comparative changelessness is reached, when we say that
development is completed. It is important to recognize, however, that
this development is fundamentally a process of reaction, the reaction
between the germ and its surrounding conditions. The characteristics
of the adult organism are _determined_ primarily by the structure of
the germ; they _appear_ gradually and successively, as the growing
organism reacts to its environing conditions.

An adult organism is continually doing certain things--performing
certain movements, producing certain secretions, undergoing a great
variety of physical and chemical changes. Just what the organism does
at any given moment is in reality determined by two groups of factors:
first, it depends, obviously, upon the structure of the organism
acting, upon the organs it has to act with, and upon the precise
condition of these organs and of the whole individual; and second, it
depends upon the nature of those conditions outside of and affecting
the organism which lead it to act at all. Either group of factors
taken alone will not lead to any activity; activity of an organism
must be a reaction between organismal structure and environing
conditions--an irritable substance and stimuli to activity. And the
character or quality of an act is affected by circumstances within
either set of factors.

In much the same way the germ acts, and its action is similarly a
reaction between the structure of the germ and its environing
conditions. The germ reacts by producing certain parts,
differentiating certain structures, in short, by developing. The
normal activities or reactions of the adult organism we call in
general its "behavior." The normal activities or reactions of the germ
and embryo we call "development"; the normal behavior of the germ is
development. And in the latter, as well as in the former, changes in
either set of factors lead to changes in the nature of the result of
their interaction, i. e., to changes in the characteristics actually
appearing as the result of development.

In their fully developed state some of the traits or characteristics
of organisms are single, simple, fundamental characters, not
analyzable into more elementary factors. Such are the number of
fingers, or of joints in the fingers, absence of pigments of several
kinds from the eyes or hair, presence of cataract, _et cetera_. These
so-called "unit characters" are roughly analogous to the chemical
elements which may, as units, be combined and recombined in diverse
ways, but which always maintain their integrity as elements although
different combinations produce wholes that are unlike. Each unit
character in the adult is the result of a series of reactions between
the environing conditions of development and a germinal structural
unit, as yet hypothetical and provisionally called the "determiner,"
which in some way not yet understood represents this adult trait.

On the other hand, there are many of these things which we call
characteristics which seem to be composite, capable of being analyzed
or factored into a group of simpler components or unit characters.
Such apparently are stature, span, resistance to fatigue, and probably
most psychic traits. Each of these complexes results apparently from a
series of reactions between the conditions of development and a group
of hypothetical germinal determiners that tend to be associated within
the germ.

The presence or absence of a determiner in a germ is thus the primary
cause of the corresponding presence or absence of a certain
characteristic in the adult organism.

But whatever the essential nature of the characteristic in this
respect, whether simple or complex, we know further that every
organismal characteristic is subject to variation. In any group of
human individuals, for example, we can find persons of different
stature, different weight, with fingers of different length and form,
with heads of different size and shape, hair and eyes of different
shades, different blood pressures, pulse rates, digestive
possibilities, different degrees of determination, cheerfulness,
alertness, and so forth. This fact of variation is not limited to the
comparison of the individuals of a given group or generation among
themselves, but successive generations considered as the units of
comparison show the same sort of thing. And further successive broods
from the same parents exhibit this same phenomenon of variation when
compared with one another. Variation is a universal fact--not only
among organic things but in the inorganic world as well. The variation
which any company of persons shows in stature is paralleled by the
variation in the diameter of the grains in a handful of sand, or of
the drops in a rainstorm.

When we examine the phenomena of variation carefully we find that
they are of two quite distinct categories. The first kind of
variation, that which we most frequently think of as "variation,"
should properly be termed _variability_. Differences of this type are
small _fluctuations_ in any and every character, centering about an
average or mean, which is itself fairly definite and fixed--less
subject to variation in different groups or through successive
generations. For example, if we measure by inches the stature of a
thousand or more persons chosen at random we find that they may vary
from fifty-four to seventy-six inches; the most frequent heights might
be about sixty-nine and sixty-four inches among the men and women
respectively. The results of such a measurement may be expressed
graphically as in Figure 3, which is an expression of the measurement
of 1,052 mothers. The measurement of almost any characteristic in a
large group of any organisms usually gives a result of the kind
figured. The most significant fact here is that this normal
variability exhibited by the traits of living organisms follows
closely the laws of chance or probability. That is to say, the number
of individuals occurring in any class which has a certain deviation
above or below the average, is directly related to, or dependent upon
(in mathematical terms, "is a function of"), the extent of the
deviation of the value of that class from the average of the whole
group. The significance of this is that the precise fluctuation which
we find in any individual is the result of the operation of a large
number of causes or factors, each contributing slightly and variably
to the total result.

    [Illustration: FIG. 3.--Recorded measurements of the stature
    of 1,052 mothers. The height of each rectangle is
    proportional to the number of individuals of each given
    height. The curve connecting the tops of the rectangles is
    the normal frequency curve. The most frequent height is
    between 62 and 63 inches. Average height--62.5 inches.
    Standard deviation, 2.39 inches. Coefficient of variability,
    3.8 (2.39 = 3.8+ % of 62.5 inches). (From Pearson.)]

Many of the most important facts about variability can be illustrated
by a simple model such as that suggested by Galton. This is a
modification of the familiar bagatelle board, covered with glass and
arranged as shown in Fig. 4. A funnel-shaped container at the top of
the board is filled with peas or similar objects (Fig. 4, _A_). Below
this is a regular series of obstacles symmetrically arranged, and
below these, at the bottom of the board, is a row of vertical
compartments also arranged symmetrically with reference to the chief
axis of the whole system. If we allow the peas to escape from the
bottom of the container and to fall among the obstacles into the
compartments below we find that their distribution there follows
certain laws capable of precise mathematical description, so that it
might be predicted with fair accuracy (Fig. 4, _B_). The middle
compartment will receive the most; the compartments next the middle
somewhat fewer; those farther from the middle still fewer; and the end
compartments fewest. If we connect the top of each column of peas by a
curved line we get just such a curve as that given by the stature
measurements above (Fig. 3), i. e., the normal frequency curve. A
curve of the same essential character would result from plotting the
dimensions of a thousand cobblestones, the deviations from the
bull's-eye in a target-shooting contest, or by plotting the
variability of any organismal character--whether it be the stature or
strength of men, the spread of sparrows' wings, the number of rays on
scallop shells, or of ray-flowers of daisies.

    [Illustration: FIG. 4.--Model to illustrate the law of
    probability or "chance." Description in the text. _A_, Peas
    held in container at top of board. _B_, Peas after having
    fallen through the obstructions into the vertical
    compartments below. The curve connecting the tops of the
    columns of peas is the normal probability curve.]

With this model we may illustrate many other essential facts about
variability which must be borne in mind when approaching the problems
of Eugenics. Before we allow the peas to fall we know quite definitely
what the general distribution of them all will be, but we do not know
at all the future position of any single pea. Of this we can speak
only in terms of probability; the chances are very high that it will
fall in one of the three middle compartments, very low that it will be
in one of the extreme compartments. But the chances are equal,
whatever they are, that it will fall above or below the average or
middle position. We see then that in any group there are many more
individuals near the average, i. e., mediocre, than there are in the
classes removed from the average and the farther the remove of a class
from the average the smaller the number of individuals in that class.
Yet all the individuals belong to the same whole group. This leads to
the very important fact that _an individual may belong to a group
without representing it fairly_. The average individuals are the most
representative. But in order to get a correct idea of the whole group
we must know, first, to what _extent_ deviations occur in each
direction, above and below the group average, and, second, the average
_amount_ by which each individual of the group deviates from this
group average. That is, we must know the amount of variability as well
as the extent of the greatest divergence from the average. The best
measure of the amount of variability exhibited by any group of objects
or organisms is not the simple average or mean of all the individual
deviations from the average of the group; it is the square root of the
mean squared deviations from the group average. This is called the
_index_ of variability or "standard deviation." In order to make
possible the comparison of the variabilities of characteristics
measured in unlike units, such as weight and stature, this index must
be converted into an equivalent abstract quantity. This is done by
reducing the index of variability to per cents of the group average,
giving what is called the _coefficient_ of variability. Thus, for
example, in stature the index of variability (standard deviation) of
certain classes of men is approximately 2.7 inches; that is, in a
large group of men the amount of individual variation from the average
height of 69 inches amounts to 2.7 inches. This gives an abstract
_coefficient_ of about 4.0 per cent, for 2.7 equals 3.9 per cent of
69. Similarly the index of variability of the weight of a group of
university students has been found to be about 16.5 pounds; the
average weight is about 153 pounds, and the coefficient of
variability is therefore about 10.8 per cent (16.5 equals 10.78 per
cent of 153). Although pounds and inches may not be compared, these
two abstract coefficients may be, and we may say that men are more
than twice as variable in weight as in stature.

Turning now to variation of the second type we find what are
ordinarily called _mutations_, or differences quite properly termed
_variations_, in a strict sense, as distinguished from the preceding
fluctuations or variability phenomena. Mutations or variations are
abrupt changes of the average or type condition to a new condition or
value which then becomes a new center of fluctuating variability. The
difference between variability and variation may be illustrated
through an analogy suggested by Galton (Fig. 5). A polygonal plinth,
or better a polyhedron, resting upon one face is easily tipped
slightly back and forth, but after slight disturbance it always
returns to its first position of stable equilibrium. Each face of the
plinth or polyhedron represents an organismal characteristic; these
slight backward and forward movements represent fluctuations, always
centering about the average condition. An unusually hard push sends
the plinth over upon another face in which it has a new position of
stability; this represents true variation or mutation. In this new
position it is again stable, may again be rocked back and forth
showing fluctuations about its new average position.

    [Illustration: FIG. 5.--Plinth to illustrate the difference
    between variability (fluctuation) and variation (mutation).]

The essential difference between true variation and fluctuation or
variability of an extreme nature, is with reference to the inheritance
of such divergence. In the second generation the offspring of extreme
variates or fluctuations have not the same average as their own
parents but an average much nearer that of the whole group to which
their parents belonged; the average stature of the children of
unusually short or tall parents is respectively greater or less than
that of their own parents--that is, is nearer the average of the whole
group of parents, provided the shortness or tallness of the parents is
a fluctuation. When the shortness or tallness is a true variation or
mutational character, offspring have approximately the same average
stature as their immediate parents, although the children of course
show fluctuation in height so that some are slightly above and others
slightly below the parental height.

Mutations may occur through the addition or the subtraction of single
characters of the simple or unit type. Such are the variations from
brown or blue eyes to albino, five fingers to six, and the like. These
are the familiar "sports" of the horticulturalist and breeder. They
are of the greatest value in evolution, for it seems quite likely that
it is only through the permanent racial fixation of these mutations
that permanent changes in the characters of a breed may be effected,
i. e., evolution occurs primarily through mutation.

In connection with the general subject of variation we should mention
briefly certain aspects of the recent work of Johannsen and Jennings,
showing that many organic specific groups or "species," whose
characters, when measured accurately give what is called a normal
variability curve similar to that of stature illustrated in Fig. 3,
are not really homogeneous groups of fluctuating individuals as the
curves would indicate superficially, but that each gross group or
species is actually composed of a blend of a number of smaller groups,
each with its own average and fluctuating variability. It is only when
these are taken all together as a lump that they fuse into a single
and apparently simple curve.

For example, the curve shown in Fig. 6, A, which is approximately that
of a normal distribution, in some cases might be shown by
experimentation to consist in reality of several truly distinct
elements, say three for purposes of illustration, as shown in Fig. 6,
B. Each of these sub-groups has its own average and its own amount
and extent of variability (fluctuation) and it is only by adding them
together that we get the larger group. Each of these elementary groups
is called a "pure line," which is defined as a group of organisms, all
of which are the progeny of a single individual. The characteristics
of each pure line remain stable through successive generations, each
about its own average; and it is chiefly this fact that enables us to
identify the different lines. Transition from the condition of one
pure line to another occurs only as a mutation. At present the theory
of the pure line is strictly applicable only to organisms reproducing
asexually or to self-fertilizing forms where the group observed is
actually composed of the progeny of a single organism. It is hardly
possible to say as yet whether or not this extremely important theory
is essentially applicable to the human species or any species where
two organisms are involved in the establishment of a race or line, but
there are some indications of a circumstantial nature that it is thus
applicable in its essentials and so modified as to include this fact
of biparental inheritance.

    [Illustration: FIG. 6.--Curves illustrating the relation
    between the pure line and the species or other large group.
    _A_, a "species" curve composed of three pure lines. _B_,
    the separate elements of the larger curve each with its own
    average and variability.]

With this bare skeleton of the subject of variation before us let us
see how facts of this kind may have any significance for the subject
of Eugenics, any bearing upon the possibility of racial improvement.
When any of the varying human traits, and they all vary, is measured
carefully and the results tabulated we find that they give us a curve
approximating the normal frequency curve, such as we have described
above and illustrated in Fig. 3. The coefficients of variability of a
great many human traits are known and a few representative
coefficients are given in Table I. This type of variability is given
then, by measurements of physical characteristics of all kinds, and,
what is of greater importance, physiological traits, including mental
and moral characteristics, so far as they can be measured by present
methods, vary in just the same way. Annual individual earnings give us
a curve closely similar to that of a normal frequency curve with an
approximate minimum limiting value. Even the tabulation of citizens
according to their social standing or "civic worth" gives the same
sort of thing. This has been brought out nicely in Galton's discussion
of Booth's classification of the population of London.

                            TABLE I

     _Coefficients of Variability of Certain Human Traits_

        Adult Stature                       3.6 to  4.0
        Length at Birth                     5.8 to  6.5
        Length of Limb Bones                4.5 to  5.5
        Cephalic Index                      3.7 to  4.8
        Skull Capacity                      7.0 to  8.0
        Weight (University Students)       10.0 to 11.0
        Weight at Birth                    14.2 to 15.7
        Weight of Brain                     7.0 to 10.6
        Weight of Heart                    17.4 to 20.7
        Weight of Liver                    14.3 to 22.2
        Weight of Kidney                   16.8 to 22.5
        Lung Capacity                      16.6 to 20.4
        Squeeze of Hand                    13.4 to 21.4
        Strength of Pull                   15.0 to 22.6
        Swiftness of Blow                  17.1 to 19.4
        Dermal Sensitivity                 35.7 to 45.7
        Keenness of Eyesight               28.7 to 34.7

It is not so easy to answer the question whether mutations or true
variations are occurring frequently in the human species. Usually it
is impossible to distinguish between an extreme fluctuation and a true
variation without experimental test and the observation of the
behavior of the varying trait through several generations. In most
instances this has been impossible with human beings. From collateral
evidence it seems quite probable that man is mutating with
considerable frequency, especially with respect to psychic traits.

The evolution of the race could be directed more easily and permanent
results attained more rapidly through taking advantage of valuable
mutations than in any other way. A race truly desiring to progress
would foster carefully anything resembling mutation in a favorable
direction. As a matter of fact, however, our social custom leads us to
look with disfavor upon most youthful traits that seem unusual or out
of the ordinary. It would be difficult to devise a system of
"education" which could more effectively repress than does our own the
development of unusual mental traits. In this connection "abnormal" or
"eccentric" may often mean a mutation in a profitable direction, a
getting away from the average of mediocrity in the direction of
improvement.

It is clear that we have the raw materials for race improvement. There
are some individuals with more and some with less than the average in
any respect--physical, mental, moral. The average of a whole social
group can be shifted by subtraction at one end or addition at the
other, or more easily and more effectively by both together. In order
to raise the general average of the value of any of these traits it
is not necessary to strive to exceed the known maximum value in any
respect. The study of the "pure line," as mentioned above, shows that
this may for a long time remain impossible, or at any rate difficult,
pending the appearance of a mutation in a favorable direction. We can,
however, raise the general average of physical strength or of mental
or moral ability by increasing the relative number of individuals in
the upper groups or by diminishing the number in the lower groups,
most easily of course and most effectively by doing both of these
things. By increasing the numbers composing the lines which form the
upper elements of a social group we not only add immensely to the
total value of the group but we do actually change somewhat the
general average. On the other hand numerical increase in the lines in
the lower part of the group will actually lower the average of the
whole, though it does not actually affect the number of individuals in
the more able and valuable classes.

Another consideration is of great importance here. The average is
affected only slightly by the change of individuals from class to
class near the average. But the shifting of even one or two per cent
of the individuals into or out of extreme positions has a very marked
effect upon the character of the total group and upon the average. In
the life of the State the character of the general average of the
citizens is of the greatest importance, and comparatively small
deviations in the average of civic worth may mean much as regards the
history of a democracy. Of course the average individuals in a social
group may not be those of greatest influence; even when taken all
together they may not determine the trend of the life of the society;
but that does not alter the essential fact that the condition of the
average of the population is of very great moment to a democratic
state.

Many of our social endeavors to-day serve in effect to raise
individuals from one of the lower groups up to or toward the average.
Millions of dollars and an incalculable amount of time and energy are
spent annually in striving to accomplish this kind of result. How
immeasurably greater would be the benefit to society if the same
amount of energy and money were spent in moving individuals from the
middle classes on up toward the higher. In the development of our
societies we need to use every possible means to carry individuals
from positions near the average to positions above the average, and
the farther this remove is above the average both in its starting
point and its stopping point, the better for the social group.
Elevation from mediocrity to superiority has far greater effect upon
the social constitution than has elevation from inferiority to
mediocrity.

As the Whethams have written recently: "Of late years, the duty of the
State to support the falling and fallen has been so much emphasized
that its still more important duty to the able and competent has been
obscured. Yet it is they who are the real national asset of worth, and
it is essential to secure that their action should not be hampered,
and their value sterilized, by the jealousy and obstruction of the
social failures, and of others whom pity for the failures has blinded.
Mankind has been shrewdly divided into those who do things and those
who must get out of the way while things are being done, and if the
latter class do not recognize their true function in life, they
themselves will suffer the most. The incompetent have to be supported
partially or wholly by the competent, and, even for their own good,
it would be worth while for the incompetent to encourage the freedom
of action and the preponderant reproduction of the abler and more
successful stocks. It is only where such stocks abound that the nation
is able to support and carry along the heavy load of incompetence kept
alive by modern civilization."

In discussing the general subject of variation and variability in
this connection, we must take always into account the biological
distinction between variation and functional modification, between
innate and acquired traits. Only the former are of real and primary
value in evolution. The distinction is familiar and we cannot dwell
upon it here; but it is of particular importance in dealing with
social improvement and we shall return to it in the next chapter.
Many "social variations" are in reality not variations at all, but
modifications; although these may be of the greatest value to the
individual modified, they are artificial things without permanent
value to the race. So many of the distinguishing personal traits are
the results of nurture rather than of nature. They represent the
result of the incidence of special factors in the environment. It is
extremely difficult and at times impossible to distinguish between
variations and modifications in adult characters, but in general the
distinction is usually clear upon careful analysis.

The changing of the innate characters of the human race is a slow
process, depending chiefly upon the advantage taken of the appearance
of real mutational variations. On the other hand, it is comparatively
easy to improve the condition of the individual by improving his
environing conditions--cleaning him, educating him, leading him to
higher ideals in his physical and mental and moral life. But as this
is easy, so it is impermanent. All this is modificational and has no
influence upon the stock. This is not opposed by the Eugenist; it
simply is no part of his province, for its effect is not racial. By
releasing a deforming pressure it may permit the individual to come
back to his real structurally determined condition, but the
structural condition itself is not thus affected. It is temporary and
must be done over with each generation, or on account of the
unfortunate habit of "backsliding," even at intervals shorter than
that of a generation.

       *       *       *       *       *

Let us now turn to another phase of our subject and consider the
biological methods of the description and measurement of heredity, as
a preliminary to our next chapter in which we shall discuss the
bearings of the facts of human heredity upon the possibility of the
formation of a permanently improved human breed.

The fact of heredity is one of the most familiar and patent things
about organisms. "Do men gather grapes of thorns or figs of thistles?"
For we may define heredity as the fact of general resemblance between
parent and offspring. This simple definition is disappointing to many
persons. "Heredity" is so often supposed popularly to refer only to
some occasional, striking, and unusual similarity within a family
respecting certain traits or peculiarities. Very often the idea of
heredity seems shrouded in mystery: it is some uncanny relation which
explains peculiarities and helps the novelist out of difficulties, but
is itself inexplicable. In truth, however, the fact that a boy, like
his father, has a head and a heart and hands and feet, physical traits
characteristic of the human species, that he begins to walk and talk
and shave at about the same age as his father did--all this is the
fact of heredity. The fact that guinea pigs produce guinea pigs and
not rabbits is the fact of heredity. Often it is true that this
resemblance is strikingly particular. All know of family traits; we
may have our father's eyes or nose, our mother's hair or disposition,
a grandfather's determination or a grandmother's patience. But these
particular individual resemblances are no more and no less
illustrations of heredity than the fact that on the whole children are
more like their parents than like other human beings.

The subject of heredity is of supreme importance in the practice of
Eugenics. The facts of no other department of biological inquiry are
of equal value, and at the same time there is probably no biological
subject regarding which there is so much misunderstanding. Of the
many phases of this extremely fascinating subject there are chiefly
two with which we are particularly concerned as Eugenists. These are
the questions: first, how completely are all the distinguishing traits
of either or both parents represented in the offspring; and, second,
how completely is each trait inherited that is inherited at all? In
other words, what we are chiefly interested to know, as bearing upon
the subject in hand, is whether all or only some of the
characteristics of our parents are heritable, and whether the
offspring show each inherited trait with the same intensity shown in
the parent, or more, or less.

One of the leading British students of heredity has said that no one
should undertake the study of this subject unless he can instantly
detect and explain the fallacy involved in the familiar conundrum,
"Why do white sheep eat more than black ones?" It is perhaps the
elasticity of our language that makes possible the mental confusion
involved in this question, but yet it is certainly true that we do
tend to confuse individual and statistical statements. We must
remember, in connection with this subject particularly, that an
individual may belong to a group without representing it, and that
within a group there are many more individuals with average than with
exceptional characteristics. The mediocre is common, the extremes are
rare. And yet an unusual individual may really be an outlying member
of a normal group.

In describing the facts of hereditary resemblance between successive
generations two formulas are available. One deals ostensibly with the
individual--the Mendelian formula: the other deals with the group--the
statistical formula. It seems entirely probable that these are not
formulas for describing two essentially different processes or forms
of heredity, but that in reality these are two ways of describing the
same facts seen from two different points of view. The Mendelian
formula regards each individual separately and describes its heredity
thus. The statistical formula regards the whole group as the unit and
considers the individual not as such, but as one of the crowd,
concerning which statements can be made only in terms of averages and
probabilities; black sheep and white. Of these two formulas the
Mendelian is obviously of much the greater importance on account of
its more exact, more particular character; its greater definiteness
gives it a value in the treatment of eugenic problems that statistical
statements must inherently lack. While much has been written of late
regarding the Mendelian formula of heredity, we shall find it
profitable to repeat here its general outlines and to recall a few of
the essential features of this important law that we shall make much
use of later.

Let us have a concrete illustration. One of the simplest cases is that
of the heredity of color in the Andalusian fowl which has been so
clearly described by Bateson. There are two established color
varieties of this fowl, one with a great deal of black and one that is
white with some black markings or "splashes"; for convenience we may
refer to these as the black and white varieties respectively. Each of
these breeds true by itself. Black mated with black produce none but
black offspring, white mated with white produce none but white
offspring. Crossing black and white, however, results in the
production of fowls with a sort of grayish color, called "blue" by the
fancier, though in reality it is a fine mixture of black and white. At
first sight we seem to have a gray hybrid race through the mixture of
the black and the white races. Not so: for if we continue to breed
successive generations from these blue hybrid fowls we get three
differently colored forms. Some will be blue like the parents, some
black like one grandparent, some white like the other grandparent. Not
only this but we get certain definite proportions among these three
classes of descendants. Of the total number of the immediate offspring
of the hybrid blues, approximately one half will be blue like the
parents, approximately one fourth black, and one fourth white like
each of the grandparents. Now comes the most important fact of all.
These blacks, bred together produce only blacks, the whites similarly
produce only whites; the blues, on the other hand, when bred together
produce progeny sorting into the same original classes and in the same
proportions as were produced by the blues of the original hybrid
generation. Their blacks and whites each breed true, their blues
repeat the history of the preceding blues. No race of the hybrid
character can be established: blues always produce blacks and whites,
as well as blues. A summary of this history in graphic and
diagrammatic form is given in Fig. 7.

    [Illustration: FIG. 7.--Diagram showing the course of color
    heredity in the Andalusian fowl, in which one color does not
    completely dominate another. _P_, parental generation. The
    offspring of this cross constitute _F1_, the first filial
    or hybrid generation. _F2_, the second filial generation.
    Bottom row, third filial generation.]

This law of heredity was first discovered about forty-five years ago
by Gregor Mendel, working with peas in the garden of the Augustinian
monastery in Brünn, Austria. His work curiously failed to arouse the
interest of contemporary scientists and his results were soon
completely lost sight of. The independent rediscovery of Mendel's
formulas of heredity, about ten years ago, was probably the most
important event in the history of biology and evolution since the
publication of "The Origin of Species."

In most cases of Mendelian heredity the progeny are less easily
classified than in the case above, because the hybrid individuals
resemble one or the other of the parents, quite or very closely. For
instance the crossing of the black and white varieties of guinea pigs
gives hybrids that are all black like one parent. That is, when the
black and white characters are brought together these do not appear to
blend into a gray or "blue," as in the case of the Andalusian fowl,
but one character alone appears; the black seems to cover up or wipe
out the white. This illustrates the frequent phenomenon of
_dominance_; one of the two contrasting characters, in this case the
black color is said to dominate over the other and the two traits are
described as _dominant_ and _recessive_ respectively. Fig. 8 gives a
graphic representation of the history of such a cross. When the black
looking hybrids are crossed together the progeny fall into but two
groups, one resembling each of the grandparental forms. Three fourths
of the progeny now resemble superficially the hybrid form and at the
same time one of the grandparents--the dominating black form, while
the remaining fourth resembles the other white grandparent. However,
we know that the black three fourths do not in reality constitute a
homogeneous class but that this includes two distinct groups; one
group of one fourth of the whole number of progeny (i. e., one third
of all the blacks) are truly black like their black grandparents and
in successive generations will, if bred together, produce none but
blacks of the same character, i. e., pure blacks: the remaining two
fourths of the whole number of progeny (two thirds of all the blacks)
in this generation are actually hybrids and in the next generation, if
bred together, will give the same proportions of the two colors as
were found in the whole of the present generation, i. e., three
fourths black, one fourth white. Of these the whites always produce
whites, the blacks always produce blacks and whites in the approximate
proportions of 3:1; a certain proportion of these--one third (one
fourth of the whole generation) always remain blacks, the other two
thirds (one half of the whole generation) again produce blacks and
whites. In such cases as this where the phenomenon of dominance
appears, and this is the usual course of events, it is impossible to
say which individuals _are_ the hybrids. Only after their progeny are
studied can we say which _were_ the hybrids.

    [Illustration: FIG. 8.--Diagram showing the course of color
    heredity in the guinea pig, in which one color (black)
    completely dominates another (white). Reference letters as
    in Fig. 7.]

In the crossing of the black and white Andalusian fowls described
above the phenomenon of dominance does not appear; when the two color
characters are brought into a single individual neither appears alone,
neither overcomes nor is overcome by the other. In the crossing of the
black and white guinea pigs dominance is complete; when the two color
characters are brought into a single individual only one color
appears, the second becomes recessive, that is, it remains present as
we know from the later history of such hybrids, but it is not visibly
indicated. Besides the Andalusian fowls there are known several other
instances of the absence of dominance and there are many cases where
dominance is incomplete, i. e., where one character merely tends to
dominate the other. And in a few instances dominance is irregular,
i. e., sometimes one character dominates, at other times or under
other circumstances it does not, as with certain forms of the comb or
the feathering of the legs in the common fowl, or with the presence of
an extra toe in the domestic cat, the rabbit, and guinea pig. And
even in those cases where dominance is said to be complete the trained
eye of the breeder can frequently distinguish between the hybrid and
the pure bred dominant individuals. The phenomenon of dominance,
therefore, is not an essential of the Mendelian theory although it is
a frequent, we may say usual, relation.

It does not come within our province to attempt an explanation of this
formula of heredity by describing some of the more fundamental
conditions upon which it depends. In fact, no complete explanation is
yet possible, although several explanatory hypotheses have been
suggested. We may outline briefly that which seems the most
satisfactory in that it serves to account for most of the facts in
Mendelian heredity in a comparatively simple manner. The germ of an
organism, we have seen, somehow contains dispositions of materials
which primarily determine the characteristics of the organism
developed from that germ. To these dispositions or configurations the
term of "determiners" has been applied. In a pure variety like the
black Andalusians, all the germ cells of each fowl are alike in
having this determiner for black color. When two such fowls are mated
together their descendants will result from the fusion of two germ
cells, _each_ containing the determiner for black color; that is, the
germ of the new individual comes to have a double determiner, one from
each parent, for this trait. In the white variety all the germ cells
are alike in _lacking_ this determiner; blackness is entirely absent
and all their descendants are formed from germ cells entirely without
black determiners. When the single germ cell of a black fowl with its
single black determiner is fertilized by a germ cell from a white fowl
without any determiner for black the resulting hybrid has a color
produced by only a single determiner, that from the black parent, and
in this case the blackness is not as fully expressed because produced
by only this single determiner and the fowl appears gray or "blue";
that is, the black produced by a single determiner is in this case not
as black as that produced by the double determiner. Now of course this
hybrid fowl forms germ cells containing determiners for color, but
these cells, instead of being all alike and with semi-black
determiners corresponding with the semi-black characteristics of the
individual, are of two different kinds--some are like those of each of
the grandparents which fused to give origin to the parent forms, and
these are formed in approximately equal numbers--one half with the
black determiner, one half without it. When two such fowls are bred
together the chances are equal for certain combinations of germ cells;
the chances are equal that the "black" or "white" germ cell of the one
individual shall meet and conjugate with the "black" or "white" germ
cell of the other individual. The result may be expressed
algebraically as follows, using the letters _B_ and _W_ to indicate
respectively germ cells with and without the black color determiner.

  Germ cells of first parent                      _B_ + _W_
  Germ cells of second parent                     _B_ + _W_
                                                -------------
                                                _BB_ + _BW_
                                                       _BW_ + _WW_
                                                  -----------------
  Combinations in the germ of the offspring  _1BB_ + _2BW_ + _1WW_

That is, one fourth are pure black (_BB_), one fourth pure white
(_WW_), and the remaining half are hybrids, black and white (_BW_).
The pure blacks again form germ cells, all possessing the determiner
for blackness; the pure whites form germ cells all lacking the
determiner for blackness; the hybrid blues produce again equal numbers
of germ cells possessing and lacking the determiner for blackness. The
relation of the germ cells and the organisms forming them and
developing from them is shown in the diagram in Fig. 9.

In the more common cases where the phenomenon of dominance appears, as
in the guinea pig, this is explained by saying that here a single
determiner for blackness is somehow sufficient to produce the color.
In such cases the black color observed may result either from a single
(_BW_) or from a double (_BB_) black determiner in the germ which
forms the organism. Only when the black determiner is entirely absent
(_WW_) does the white color appear in the developed organism and the
individual is then said to exhibit the recessive characteristic.

    [Illustration: FIG. 9.--Diagram illustrating the relation of
    the germ cells in a simple case of Mendelian heredity, such
    as that of color as shown in Figs. 7 and 8. The spaces
    between the large circles represent the bodies of the
    individuals while the small circles within each represent the
    germ cells formed by those individuals. _P_, parental
    generation; each individual forms a single kind of germ
    cells. _G. F1_, germs of the first filial or hybrid
    generation, each composed of two different kinds of germ
    cells, one from each parent. _F1_, individuals of the first
    filial or hybrid generation, developed from _G. F1_. Each
    member of this generation forms two kinds of germ cells in
    approximately equal numbers. _G. C. F1_, germ cells of _F1_,
    showing possible combinations resulting from the mating of
    two members of _F1_. Each of these combinations occurs with
    equal probability. _G. F2_, germs of second filial generation
    resulting from the above random combinations. _F2_,
    individuals of second filial generation. Each now forms germ
    cells like those which constituted its own germ.]

Another possible type of mating is that between a member of a pure
race, either dominant or recessive, and a hybrid individual. This form
of mating is very common in some of the pedigrees that we shall
examine later. The results of such a mating, first between a hybrid
and a recessive individual can be most easily described by considering
a cross between black and white forms and expressing the result
algebraically.

  Germ cells of first parent (white or recessive)  _W_ + _W_
  Germ cells of second parent (hybrid)             _B_ + _W_
                                                 -------------
                                                  _BW_ + _BW_
                                                         _WW_ + _WW_
                                                 ---------------------
                                                     _2BW_ + _2WW_

That is, returning to the example of the Andalusian fowls, the progeny
will be one half hybrid blues and one half whites--no black at all.
If the cross had been between black hybrid guinea pigs and white
recessive specimens the result would have been half hybrid blacks and
half pure whites.

Or supposing the mating to have occurred between the pure dominant
(black) and the hybrid the result would have been, in the fowls half
pure black and half hybrid blue; in the guinea pig all the progeny
would have been black, half pure blacks and half hybrid blacks.

  Germ cells of first parent (black or dominant)   _B_ + _B_
  Germ cells of second parent (hybrid)             _B_ + _W_
                                                 -------------
                                                  _BB_ + _BB_
                                                         _BW_ + _BW_
                                                ----------------------
                                                     _2BB_ + _2BW_

In the case of the guinea pigs, although the progeny all look alike
(black) their history would show that they were fundamentally unlike,
for if crossed with white again the result would be the production of
all black looking guinea pigs from the cross with the _BB_ forms, and
half black and half white from the _BW_ cross.

On account of the fact of variation every individual is in a certain
sense a hybrid. One's two parents have the species characters in
common but there are certain distinctive traits that hybridize and
follow Mendel's law of heredity. By no means is it to be understood
that all individual distinctive traits follow this rule in heredity.
Many individual characteristics are what we have learned to call
fluctuations--small deviations above or below an average condition of
a group. Such differences play no part in Mendelian heredity. Other
characteristics may be bodily modifications resulting from the direct
reaction between the body tissues and the environing conditions; such
traits would not be represented in the organization of the germ cells
and consequently would not be inherited at all. At present it seems
that the only characteristics that "Mendelize" are those known as
"unit characters." Such characters seem to have their origin in real
variations or mutations and though each may show fluctuations, these
fluctuations in themselves are not hereditary.

This conception of the unit character is an extremely important
element in the whole Mendelian theory and it has extended beyond the
field of heredity and led to a radical change in our notions of what
an organism really is. It is, of course, true in a sense that an
organism is a unit, an organism is one thing; but at the same time it
is true that an organism is fundamentally a collection of units, of
structural and functional characteristics which are really separable
things. A few of these units were mentioned in the first pages of this
chapter and others are mentioned on a later page. They serve as the
building blocks of organisms: individuals of the same species may be
made up of similar combinations or of different combinations. One unit
or a group of units may be taken out and replaced by others.

From the standpoint of heredity, and particularly from our eugenic
point of view, the most important results of the unit composition of
the organism lie in the fact that these units remain units throughout
successive generations and throughout successive and varying
combinations, whatever their associations may be from generation to
generation. It is a fact of the greatest eugenic significance that a
pure bred individual may be produced by a hybrid mated either with a
pure bred or with another hybrid; and that the pure bred resulting
will be just as pure bred as any. "Pure bred" now means pure bred with
respect to certain traits only. An individual may be pure bred in
certain of its characteristics, hybrid in others. Practically there is
no such thing as an individual which is either pure bred or hybrid in
_all_ its traits. One of the chief contributions, then, of Mendelism
to the subjects of Heredity and Eugenics is this--that a pure bred may
be derived from a hybrid in one generation: the pure bred produced by
a long series of hybrid individuals is just as pure as the pure bred
which has never had a hybrid in its ancestry. Another important
consequent is, that among the offspring of the same parents some
individuals may be pure bred and others hybrid. Community of parentage
does not necessarily denote community of characteristics among the
offspring. Yet by knowing the ancestry for one or two generations we
can know the qualities of the individual. Guesswork is eliminated and
the importance of the qualities of the individual is enormously
emphasized. It is necessary only to suggest the social and eugenic
significance of such facts relating to characteristics that are of
social or racial importance.

We shall have occasion in the next chapter to enumerate some of the
human unit characters whose heredity has been traced and which have
been found to Mendelize, but we may mention here a few Mendelizing
units in other organisms in order to give some idea of the kind of
character which behaves as a unit and of the range of the forms which
have been found to show Mendelian phenomena in their heredity. Among
the higher animals one might mention the absence of horns in cattle
and sheep; the "waltzing" habit of mice and the pacing gait of the
horse; length of hair and smoothness of coat in the rabbit and guinea
pig; presence of an extra toe in the cat, guinea pig, rabbit, fowl;
length of tail in the cat; and in the common fowl such characters as
the shape and size of the comb, presence of a crest or a "muff," a
high nostril, rumplessness, feathering of the legs, "frizzling" of the
feathers, certain characters of the voice, and a tendency to brood.
Among plants may be mentioned such characters as dwarfness in garden
peas, sweet peas, and some kinds of beans; smoothness or prickliness
of stem in the jimson weed and crowfoot; leaf characters in a great
variety of plants; in the cotton plant a half dozen characters have
been found to Mendelize; seed characters such as form and amount of
starch, sugar, or gluten; flat or hooded standard in the sweet pea;
annual or biennial habit in the henbane; susceptibility to a rust
disease in wheat. We should not fail to mention that scores of color
characters are known to Mendelize, such as hair or coat color and eye
color in animals and the colors of flowers, stems, seeds, seed-coats,
etc., in plants. The list of Mendelizing traits in different organisms
now extends into the hundreds and is increasing almost weekly.

Before leaving the subject of Mendelism we should say that the
phenomena, as described above in the Andalusian fowl and guinea pig,
are among the simplest known. And while such simple formulas serve to
describe the phenomena of heredity in a large number of instances, yet
in a great many other cases the descriptive formulas are more
complicated. We cannot in this place describe any of these
complications. For a full discussion of these and of the whole subject
of Mendelism the interested reader is referred to Professor Bateson's
work on "Mendel's Principles of Heredity" (1909). It must suffice to
say here that in color heredity, for example, such ratios as 9:3:4 or
12:3:1 in the second filial generation instead of the more frequent
1:2:1 or 3:1 are explainable upon essentially the same relations as
these simpler and more typical ratios. And further, many less usual
Mendelian phenomena, which we cannot undertake to describe here,
are associated with what the specialist technically terms "sex
limitation," "gametic coupling," and the like.

It is often said that the Mendelian formula has a very limited
applicability to human heredity. This is probably true if we consider
carefully the grammatical tense in which this statement is made. And
yet it is almost certainly true that heredity in man is to be
described by this law. This apparent paradox is easily explained. The
only characters whose history in heredity follows this formula are the
unit characters. A complex trait is not heritable, as a whole, but its
components behave in heredity as the separate units. It is perfectly
well known that we are deeply ignorant regarding this phase of human
structure. Our ignorance here is not the necessary kind, however, it
is merely due to the newness of the subject--we have not had time to
find out. How can we say that a complex trait is or is not inherited
according to some form of Mendel's law when we do not know the nature
of the units of which it is composed? We can make no statements about
the Mendelian inheritance of such a trait until it is factored into
its units. A considerable number of human characteristics are really
known to be heritable according to this formula, enough so that
several general rules of human heredity have been formulated. But it
is also quite within the range of possibility that some traits really
do not follow this law, although it cannot yet be said definitely
that this is or is not the case. On the whole, then, we cannot, for
the next few years, expect too much from the application of Mendel's
laws to human heredity, however much this is to be regretted.

Shall we then decline to say anything about the heredity of the great
bulk of human characteristics? By no means: we have seen that in our
bagatelle board we talk very definitely about the distribution of all
the peas, though only about the probable history of one pea. Mendel's
law deals with individual inheritance. When we cannot apply this
formula we have left still the possibility of talking about human
heredity in the group as a whole. That is to say, we have left the
opportunity of describing heredity by the statistical methods, with
the crowd, not the individual, as the unit. Since we are forced into
extensive use of this formula by our present and temporary ignorance
of the applicability of Mendel's rule we must get a clear notion of
how the statistical method is applied in this matter.

The method is the same as that employed by the statistician in
measuring the relatedness of any two series of varying phenomena. If
two quantities or characteristics are so related that fluctuations in
the one are accompanied in a regular manner by fluctuations in the
other, the two quantities or characters are said to be correlated. For
instance, the temperature and the rate of growth of sprouting beans
are related in such a way that increase in the former is accompanied
in a regular way by increase in the latter; or the width and height of
the head, or the total stature and the length of the femur similarly
vary regularly together so that they are said to be correlated to a
certain extent which can be measured. This correlation may result from
the fact that one condition is a cause, either direct or indirect, of
the other; or there may be no such causal relation between the two
phenomena, both resulting more or less independently from a common
antecedent condition or cause.

This phenomenon of correlation is not limited among organisms to the
comparison of two or more different characters in a single series of
individuals; it is applicable also to the comparison of two series of
individuals with respect to the same characteristic. Thus we may
compare the stature of a series of fathers with the same measurement
in their sons. It is this form of correlation with which we are
particularly to deal here. While it is not necessary to understand
just how this subject is dealt with by the statistician we should know
one or two of the elementary principles involved, in order to
appreciate the statistical form of many statements about heredity.

The stature of men may be said to vary usually between limits of 62
and 76 inches, the average height being about 69 inches. In the
complete absence of heredity in stature we should find that fathers of
any given height, say 62 or 63 or 76 inches would have sons of no
particular height but of all heights with an average of 69 inches, the
same as in the whole group. Or if stature were completely heritable
from one generation to the next the _total generations being the units
compared_, then 62 or 63 or 76 inch fathers would have respectively
sons all 62, 63, and 76 inches tall. When we examine the actual
details of the resemblance we find, as a matter of fact, that neither
of these possibilities is actually realized. What we do find is that
fathers below or above the average height have sons whose average
height is also below or above the general average but not so far below
or above the general average as were the fathers. If we measured a
large number of pairs of fathers and sons with respect to stature we
should find each generation with a variability such as that
illustrated in Fig. 3 of the stature of mothers, the limits here,
however, being about 62 and 76 inches. But if we measured all the sons
of 62-inch fathers they would be found to vary say from 62 to only 69
inches, averaging about 66 inches. Similarly 63-inch fathers would
have sons from 62 to 70 inches tall, averaging about 66.5 inches, or
76-inch fathers might have sons from 69 to 76 inches in height,
averaging about 72 inches, and so on for fathers of all heights. In
general, then, we may say that fathers with a characteristic of a
certain plus or minus deviation from the average of the whole group
have sons who on the whole deviate in the same direction but less
widely than the fathers, although the fact of variability comes in so
that some few of the sons deviate as widely as, or even more widely
than, the fathers, others deviate less widely than the fathers from
the average of the whole group. This is the general and very important
statistical fact of _regression_.

The phenomenon of regression may be made somewhat clearer by the aid
of a simple diagram--Fig. 10. Here are plotted first the heights, by
inches, of a group of fathers, giving the series of dots joined by the
diagonal _AB_. Next are plotted the average heights of the sons of
each class of fathers: 62-inch fathers give 66-inch sons, 63-inch
fathers 66.5-inch sons, 64-inch fathers 67-inch sons, and so for all
the classes of fathers. These dots are then joined by the line _EF_.
This is the _regression line_. Had it been the case that there was no
regression in stature the different classes of fathers would have had
sons averaging just the same as themselves and the line representing
the heights of the sons would have coincided with the line _AB_. Or if
regression had been complete the fathers of any class would have had
sons averaging about 69 inches--just the same as the average of the
whole group--and the line representing their heights would have had
the position of _CD_ in the diagram. As a matter of fact, however,
neither of these possibilities is actually realized and the regression
line _EF_ is approximated in an actual series of data. A similar
relation has been found for many characters other than stature.

    [Illustration: FIG. 10.--Diagram illustrating the phenomenon
    of regression. Explanation in text.]

The fact of regression is of considerable importance for the theory of
evolution as well as for the subject of Eugenics when describing the
phenomena of heredity in this statistical manner in whole groups
without paying attention to particular individuals. Regression is
found in all characteristics observed in this way, psychic as well as
purely physical. "The father [i. e., fathers] with a great excess of
the character contributes [contribute] sons with an excess, but a less
excess of it; the father [fathers] with a great defect of the
character contributes [contribute] sons with a defect, but less defect
of it."

Now, whatever the actual extent of this regression is in a group we
need to know how uniformly it occurs for all the classes of different
deviations from the general average, that is, we need to know whether
the extreme groups regress to the same relative extent as do those
nearer the general average; and, further, we need to know how nearly
the sons of fathers of any certain height are grouped about their own
average. In other words, we should know, first, whether the regression
of the sons of 62 and 76 or 67 and 71 inch fathers is proportionately
the same in each case, and, second, to what extent the sons of 62-inch
fathers vary, whether they vary as do the fathers of 62-inch sons, and
so for each group. This kind of information we get by calculating what
is called the _coefficient of heredity_. The calculation of this
coefficient is a complicated process which it is unnecessary to
describe here. It must suffice to say that a numerical coefficient can
readily be determined, which will express the average closeness and
regularity of the relationship between all the plus and minus
deviations from the group average in fathers and the corresponding
plus and minus deviations from the group average of their sons with
respect to a given characteristic. This coefficient of heredity may
vary between 0.0 and 1.0. When it is 0.0 there is, on the whole, no
regularity in the relationship, i. e., no heredity; when it is 1.0
there is, on the whole, complete regularity, i. e., heredity is
complete. Neither of these values is ever actually found in
determining coefficients of heredity in the parental relation; these
are usually between 0.3 and 0.5. It should be emphasized again that
this comparison is between whole groups and not between individuals,
and that it fails to allow for the distinction between fluctuations
and true variations. And, further, it should be noted that the
information derived from such a coefficient is defective in that it
takes into account only the relationship between the son and one
parent; the maternal relation is just as important but this has to be
determined separately. There is no satisfactory method of determining
the relation between children and both parents at the same time.

The coefficient of heredity is, therefore, an abstract numerical value
which gives us a fairly precise estimate as to the probable closeness
of the relation between deviations from the group average of any
character in two groups of relatives. The coefficient of _correlation_
is, in general, a measure of the relation between two different
characteristics or conditions in a single group of individuals. The
method of its determination and its limiting values are the same as
for the coefficient of heredity.

By experience the coefficients of heredity and correlation in general
are found to have the following significance:

  0.00-      no relation.
  0.00-0.10--no significant relation.
  0.10-0.25--low; relation slight though appreciable.
  0.25-0.50--moderate; relation considerable.
  0.50-0.75--high; relation marked.
  0.75-0.90--very high; relation very marked.
  0.90-1.00--nearly complete.
       1.00--complete relation.

One further point remains to be considered, which applies not so much
to coefficients of heredity as to coefficients of correlation in
general, i. e., to the relatedness of two different characters or
series of events in a single group of cases or individuals. This is
that coefficients of correlation may be either positive or negative.
That is, the real limits of the value of the coefficient are plus one
and minus one. The example given above of stature of fathers and sons
gives a positive coefficient. Whenever the deviation from the average
of one group is accompanied in the second group by a deviation in the
same direction, the coefficient is positive. A negative correlation
means that deviation from the average in a given direction in the
first group is accompanied in the second group by a deviation in the
opposite direction. If we imagine that as one measurement increased
above its average a second related measurement decreased below its
average the correlation in such a case would be negative. For
instance, if we measured the relation between the number of berry
pickers employed and the quantity of berries remaining unpicked, in a
number of different fields we would get a negative correlation
coefficient. Some organisms are formed in such a way that increase in
one dimension, such as length, is associated with decrease in another,
such as breadth; measurement of the relatedness of these dimensions
would give a coefficient of correlation that might be very high,
indicating a considerable relation in the deviations, but it would be
negative. In an instance of negative correlation the relation is that
of "the more the fewer." As we shall see presently, a negative
correlation may be just as important and significant as a positive
correlation.

The application of the principles of heredity to our subject of
Eugenics is of such great importance that it is reserved for separate
consideration in the next chapter. We may, therefore, devote the
remainder of this chapter to the consideration of data of another
kind, which are commonly treated by this same method of determining
correlation coefficients between two sets of varying phenomena in
order to determine whether there is any actual relation between them
or not. This will serve to illustrate the use of this method.

We shall turn then to the subject of differential or selective
fertility in human beings and consider its relation to Eugenics. As a
starting point we may take the self-evident statement that a group of
organisms will tend to maintain constant characteristics through
successive generations only when all parts of the group are equally
fertile. If exceptional fertility is associated with the presence or
absence of any characteristic the number of individuals with or
without that trait will either increase or diminish in successive
generations, and the character of the distribution of the group as a
whole will gradually become altered, the average moving in the
direction of the more fertile group. Or if infertility is so
associated, then the average of the whole group moves away from that
condition. Eugenically, then, we should ask whether in human society
there is at present any such association of superfertility or
infertility with desirable or undesirable traits. It is obviously the
aim of Eugenics to bring about an association of a high degree of
fertility with desirable traits and a low degree of fertility with
undesirable characteristics.

First, let us look at certain data gathered relative to the size of
the family in both normal and pathological stocks (Table II). In order
that a stock or family should just maintain its numbers undiminished
through successive generations and under average conditions, at least
four children should be born to each marriage that has any children at
all.

                               TABLE II

     _Fertility in Pathological and Normal Stocks._ (From Pearson)

                                       NATURE OF MARRIAGE.    NO. IN
                           AUTHORITY. (Reproductive period.)  FAMILY.

  Deaf-mutes, England      Schuster      Probably complete      6.2
  Deaf-mutes, America      Schuster      Probably complete      6.1
  Tuberculous stock        Pearson       Probably complete      5.7
  Albinotic stock          Pearson       Probably complete      5.9
  Insane stock             Heron         Probably complete      6.0
  Edinburgh degenerates    Eugenics Lab  Incomplete             6.1
  London mentally
    defective              Eugenics Lab  Incomplete             7.0
  Manchester mentally
    defective              Eugenics Lab  Incomplete             6.3
  Criminals                Goring        Completed              6.6
  English middle class     Pearson       15 years at least,
                                           begun before 35      6.4
  Family records--normals  Pearson       Completed              5.3
  English intellectual
    class                  Pearson       Completed              4.7
  Working class N.S.W.     Powys         Completed              5.3
  Danish professional
    class                  Westergaard   15 years at least      5.2
  Danish working class     Westergaard   25 years at least      5.3
  Edinburgh normal
    artisan                Eugenics Lab  Incomplete             5.9
  London normal artisan    Eugenics Lab  Incomplete             5.1
  American graduates       Harvard       Completed              2.0
  English intellectuals    Webb          Said to be complete    1.5

    All childless marriages are excluded except in the last two
    cases. Inclusion of such marriages usually reduces the
    average by 0.5 to 1.0 child.

The table given shows clearly what stocks are maintaining, what
increasing, and what diminishing their numbers.

This subject has been investigated recently in a rather extensive way
by David Heron, for the London population. Heron concentrated his
attention upon the relation of fertility in man to social status. He
used as indices to social status such marks as the relative number of
professional men in a community, or the relative number of servants
employed, or of lowest type of male laborers, or of pawnbrokers; also
the amount of child employment pauperism, overcrowding in the home,
tuberculosis, and pauper lunacy. Twenty-seven metropolitan boroughs of
London were canvassed on these bases, which are certainly significant,
though not infallible, indices to the character of a community. His
results are shown in the briefest possible form in Table III.

                              TABLE III

  _Correlation of the Birth Rate with Social and Physical Characters
                 of London Population._ (From Heron.)

                                                 CORRELATION
                                                 COEFFICIENT.
  With number of males engaged in professions           -.78
  With female domestics per 100 females                 -.80
  With female domestics per 100 families                -.76
  With general laborers per 1,000 males                 +.52
  With pawnbrokers and general dealers per 1,000 males  +.62
  With children employed, ages 10 to 14                 +.66
  With persons living more than two in a room           +.70
  With infants under one year dying per 1,000 births    +.50
  With deaths from pulmonary tuberculosis per 100,000
    inhabitants                                         +.59
  With total number of paupers per 1,000 inhabitants    +.20
  With number of lunatic paupers per 1,000 inhabitants  +.34

This table gives the results of the calculation of coefficients of
correlation between the birth rates and the conditions enumerated. We
may just recall that this coefficient is a measure of the regularity
with which the changes in two varying conditions or phenomena are
associated: and further that a coefficient of 1.0 indicates perfectly
regular association, 0.75 a very high degree of regularity. The first
line of the table then, for example, means that when these
twenty-seven districts were sorted out, first, with reference to the
number of professional men dwelling in them, and then with reference
to their respective birth rates, there was found a very high degree of
regularity (coefficient of correlation = -.78) in the association of
these two conditions--birth rate and number of professional men. Here
is a very close relation, _but_, the sign of the coefficient is
_negative_. The significance of this negative sign is that among the
communities studied those where the number of professional men is the
larger show always, at the same time, the lower birth rates. Coming to
the second line of the table, it seems fair to assume that the number
of servants employed in a district in proportion to the total number
of residents or families there, gives a fairly though not wholly
satisfactory indication of the social character of the community.
Measurement of the actual relation between the proportional number of
servants employed in a community and the birth rate in that community,
gave practically the same result as in the case of the number of
professional men. The more servants employed in a district the lower
its birth rate. Two methods of measuring this relation gave
essentially the same result; comparison of the birth rate with the
ratio of domestics, first to the number of families, second to the
number of females, gave -.76 and -.80 respectively--very high
coefficients and both negative.

But the sign changes and becomes positive when we come to other
comparisons. When we count the relative number of pawnbrokers and
general dealers, of "general laborers" (that is, men without a trade
and without regularity of occupation and employment), of employed
children between the ages of ten and fourteen, of persons living more
than two in a room, when we consider the infant death rate, the death
rate from pulmonary tuberculosis, and the relative number of
paupers,--then we find the signs of the coefficients are all positive,
and on the average the coefficients are more than 0.50--a moderate to
high degree of regularity of the relation. The districts characterized
by the larger numbers of such individuals or by higher death rates of
these kinds, are at the same time the districts where the birth rates
are the higher.

In a word, then, Heron found that the greater the number of
professional men, or of servants employed in a community, the lower
the birth rate--a very high degree of negative correlation. On the
other hand, the more pawnbrokers, child laborers, pauper lunatics,
the more overcrowding and tuberculosis, the higher the birth rate--a
high degree of positive correlation. Little doubt here as to which
elements of the city are making the greater contributions to the next
generation. There may be some doubt, however, so let us consider two
possible qualifications of these results. First, is not the death rate
also higher among these least desirable classes? Yes, it is. Is it not
enough higher to compensate for the difference in the birth rates, so
that after all the least desirable classes are not more than replacing
themselves? No, it is not. After calculating the effect of the
differential death rate among these different social groups it still
remains true that the _net_ fertility of the undesirables is greater
than the _net_ fertility of the desirables: the worst classes are in
reality more than replacing themselves numerically in such
communities; the most valuable classes are not even replacing
themselves. Second, is not this the same condition that has always
existed in these districts? Why any cause for supposing that this is
going to bring new results to this society? Has not such a condition
always been present and always been compensated for somehow?
Fortunately, Heron is able to compare with these data of 1901 similar
data for 1851, and is able to show that every one of these relations
has changed in sign since that date--in fifty years. The significance
of this change in sign is probably clear. It means here that in London
sixty years ago there was a high degree of regularity in the relation
such that the more professional men and well-to-do families the
community contained, the higher the birth rate; that ten years ago
this had all become changed so that the more of these desirable
families found in a district the lower is the birth rate. It means
that sixty years ago the relation was such that the more undesirables
numbered in a district, the lower its birth rate; ten years ago the
more undesirables, the higher the birth rate, and the coefficients of
1901 are unusually high, indicating great closeness and regularity in
this relation. Heron is further able to show that as regards number of
servants employed, professional men, general laborers, and
pawnbrokers in a district, the intensity of the relationship has
_doubled_, besides changing in sign, in the period observed. It is not
necessary to review the history of this change nor to discuss the
causes involved, but it is necessary to take into account for the
immediate future the fact of the change.

Sidney Webb has recently published an account of the birth-rate
investigations undertaken by the Fabian Society with a view to
determine the causes leading to the rapidly falling birth rate in
England. During the decade previous to 1901 the number of children in
London actually diminished by about 5,000, while the total population
increased by about 300,000. As far as they bear upon this phase of the
subject his results fully confirm these we have been considering. The
falling off is chiefly in the upper and middle classes, in the classes
of thrift and independence, and it has occurred chiefly during the
last fifty years. Webb cannot find that this is due to any physical
deterioration in these classes; it is due to a conscious and
deliberate limitation of the size of the family for what are thought
prudential and economic reasons.

An actual reduction in the number of children may not be an unmixed
evil. A falling birth rate may be a good sign. This is partly a
question for the political economist. "Suicide" may be a socially
fortunate end for some strains. But when, in either a rising or a
falling birth rate, we find a differential or selective relation, then
the subject is eugenic. If the higher birth rate is among the socially
valuable elements of each different class the Eugenist can only
approve; to bring about such a relation is one of his aims. What we
really find, however, is the undesirable elements increasing with the
greatest rapidity, the better elements not even holding their own.

One further aspect of the result of the smaller family remains to be
considered. Are the various members of a single family approximately
similar in their characteristics or are the earlier born more or less
likely to be particularly gifted or particularly liable to disease or
abnormal condition? Or is there no rule at all in this matter? There
is much evidence that the incidence of pathological defect falls
heaviest upon the earlier members of a family. Consider, for example,
the presence of tuberculosis. We should ask, in families of two or
more, are the tubercular members, if any, as likely to be the second
born or third or tenth as to be the first born? The data are tabulated
in Fig. 11, _A_. The distribution of family sizes being what it is in
the number of families investigated and tabulated, we should expect
that there would be about 65 tubercular first born, 60 tubercular
second born, and so forth, on the basis of its average frequency in
the whole community, provided the chances are equal that any member of
the family should be affected with tuberculosis. What we actually
find, however, is that 112 first born are affected, about 80 second
born, and after that no relation between order of birth and
susceptibility to tuberculosis. That is, susceptibility to
tuberculosis is double the normal among first born children. The same
thing is true for gross mental defect. Fig. 11, _B_, shows that the
ratio of observed to expected insane first born children is about 4 to
3. Such a relation has long been known to criminologists and
frequently commented upon. Fig. 11, _C_, gives a definite expression
to the facts here. Whereas, in the number of families observed about
56 criminal first born were to be expected, the number actually found
is about 120; for the second born the corresponding numbers are about
54 and 78, and after that no marked relation is found between order of
birth and criminality. For albinism (Fig. 11, _D_) the expected and
observed numbers among first born are about 185 and 265, second born
165 and 190, and thereafter no definite relation. It remains to be
seen whether a similar relation holds for the unusually able and
valuable members of a family; something has been said on both sides
here, but there are available at present no data sufficiently exact to
be worthy of consideration.

    [Illustration: FIG. 11.--Diagrams showing the relation
    between order of birth and incidence of pathological defect.
    (From Pearson).]

We have here a result that has very important bearings upon the value
to the race of the large family and of the danger of the small family.
The small family of one, two, or three children contributes on the
average much more than its share of pathological and defective
persons. No matter just now what the causes are, they seem to be more
or less beyond remedy. The result for the future, however, must be
reckoned with. This relation has important bearings upon the custom of
primogeniture as well as upon the eugenic values of the large family.

In conclusion let us give a few sentences only slightly modified from
Pearson's "Grammar of Science." The subject of differential fertility
is not only vitally important for the theory of evolution, but it is
crucial for the stability of civilized societies. If the type of
maximum fertility is not identical with the type fittest to survive in
a given environment, then only intensive selection can keep the
community stable. If natural selection be suspended there results a
progressive change; the most fertile, whoever they are, tend to
multiply at an increasing rate. In our modern societies natural
selection has been to some extent suspended; what test have we then of
the identity of the most fertile and the most fit? It wants but very
few generations to carry the type from the fit to the unfit. The
aristocracy of the intellectual and artizan classes are not equally
fertile with the mediocre and least valuable portions of those
classes and of society as a whole. Hence if the professional and
intellectual classes are to be maintained in due proportions they must
be recruited from below. This is much more serious than would appear
at first sight. The upper middle class is the backbone of a nation,
supplying its thinkers, leaders, and organizers. This class is not a
mushroom growth, but the result of a long process of selecting the
abler and fitter members of society. The middle classes produce
relatively to the working classes a vastly greater proportion of
ability; _it is not want of education, it is the want of stock which
is at the basis of this difference_. A healthy society would have its
maximum of fertility in this class and recruit the artizan class from
the middle class rather than _vice versa_. But what do we actually
find? A growing decrease in the birth rate of the middle and upper
classes; a strong movement for restraint of fertility, and limitation
of the family, touching only the intellectual classes and the
aristocracy of the hand workers! Restraint and limitation may be most
social and at the same time most eugenic if they begin in the first
place to check the fertility of the unfit; but if they start at the
wrong end of society they are worse than useless, they are nationally
disastrous in their effects. The dearth of ability at a time of crisis
is the worst ill that can happen to a people. Sitting quietly at home,
a nation may degenerate and collapse, simply because it has given full
play to selective reproduction and not bred from its best. From the
standpoint of the patriot, no less than from that of the evolutionist
and Eugenist, differential fertility is momentous; we must
unreservedly condemn all movements for restraint of fertility which do
not discriminate between the fertility of the physically and mentally
fit and that of the unfit. Our social instincts have reduced to a
minimum the natural elimination of the socially dangerous elements;
they must now lead us consciously to provide against the worst effects
of differential fertility--a survival of the most fertile, when the
most fertile are not the socially fittest.

The subject before us illustrates the direct bearing of science upon
moral conduct and upon statecraft. The scientific study of man is not
merely a passive intellectual viewing of nature. It teaches us the art
of living, of building up stable and dominant nations, and it is of no
greater importance for the scientist in his laboratory, than for the
statesman in council and the philanthropist in society.




                                 III

                HUMAN HEREDITY AND THE EUGENIC PROGRAM




                                 III

                HUMAN HEREDITY AND THE EUGENIC PROGRAM

  "A breed whose proof is in time and deeds;
  What we are, we are--nativity is answer enough to objections."


A few years ago official recognition was taken of the disturbing fact
that the annual wheat yield of Great Britain was grossly deficient in
both quantity and quality. In 1900 The National Association of British
and Irish Millers, with almost unprecedented sagacity, raised a fund
to provide for a series of experiments under the direction of a
competent biologist, in order to discover if possible some means of
restoring the former yield and quality of the native wheats. The story
of the result reads like a romance. The experimenter--Prof. R. H.
Biffen--collected many different varieties of wheat, native and
foreign, each of which had some desirable qualities, and studied their
mode of inheritance. Now, after only a few years of experimentation a
wheat has been produced and is being grown upon a large scale in
which have been united this desirable character of one variety, that
character of another. From each variety has been taken some valuable
trait, and these have all been combined into one variety possessing
the characteristics of a short full head, beardlessness, high gluten
content, immunity to the devastating rust, a strong supporting straw,
and a high yield per acre. A wheat made to order and fulfilling the
"details and specifications" of the growers.

Manitoba and British Columbia opened up whole new lands of the finest
wheat-growing capacity, but the season there is too short for the
ripening of what were the finest varieties. This new specification was
promptly met and the early ripening quality of some inferior variety
was transferred to the varieties showing other highly desirable
qualities, and these countries are now producing enormous quantities
of the finest wheat in the world.

All of this has been made possible by the discovery, mentioned in the
preceding chapter, that many characteristics of organisms are units
and behave as such in heredity; they can be added to races or
subtracted from them almost at will. Pure varieties breeding true can
be established permanently by taking into account the Mendelian laws
of heredity. Similar results have been accomplished in many other
plants and in many animals. A cotton has been produced which combines
early growth, by which it escapes the ravages of the boll weevil, with
the long fiber of the finest Sea Island varieties. Corn of almost any
desired percentage of sugar or starch, within limits, can be produced
to order in a few seasons. The hornless character of certain varieties
of cattle can be transferred to any chosen breed. Sheep have been
produced combining the excellent mutton qualities of one breed with
the hornlessness of another, and with the fine wool qualities of still
a third. And so on from canary birds to draft horses. New races can be
built up to meet almost any demand, with almost any desired
combination of known characters, and these races remain stable.
Possibilities in this direction seem to be limited only by our present
and rapidly lessening ignorance of the facts of Mendelian heredity in
organisms--facts to be had for the looking.

What is man that we should not be mindful of him? Why should we
utilize all this new knowledge, all these immense possibilities of
control and of creation, only for our pigs and cabbages? In this era
of conservation should not our profoundest concern be the conservation
of human protoplasm? "The State has no material resources at all
comparable with its citizens, and no hope of perpetuity except in the
intelligence and integrity of its people." As Saleeby puts it: "There
is no wealth but life; and if the inherent quality of life fails,
neither battle-ships, nor libraries, nor symphonies, nor Free Trade,
nor Tariff Reform, nor anything else will save a nation."

In this work of the creation and establishment of new and valuable
varieties, two essential biological facts are made use of. The raw
materials are furnished by variation--by the fact that there are
individual and racial differences. The means of accomplishing results
are furnished by heredity--the fact that offspring resemble the
parents, not only in generalities, but even in particulars, and
according to certain definite formulas.

And, further, in the formation and establishment of a new race of
plant or animal a conscious and ideal process is involved. The will of
some organism guides the process, carefully doing away with hit and
miss methods, and proceeding as directly as may be possible to an end
_desired_. The facts of variation and heredity are sufficiently
demonstrated for all organisms other than man; are they true of man
also? Have we available the possibilities for the improvement of the
human breed? If not, Eugenics is merely an interesting speculation. We
have mentioned already the facts of variation in man; we undoubtedly
do have the raw materials. What about heredity, and what about the
directive agency? Let us look now at some of the facts of human
heredity and consider some of the possibilities in the way of
directive agencies. Is it going to be possible to breed a stable human
race permanently with or without definite characteristics which now
appear only in certain groups, or sporadically as variations?

At the outset we should say that the knowledge of human heredity is as
yet largely of the statistical sort. We know how a great many
characters are inherited, on the average. The subject of Mendelian
heredity is so new that there has been hardly time to investigate more
than a few human characteristics from this point of view. Certain
conditions add to the difficulties here. First, many, probably most,
of the more important human traits are complexes, not units, and it is
a long and difficult process to analyze them into their units, with
which alone Mendelism deals. Second, in human society we cannot carry
on definite experiments under controlled conditions, directed toward
the solution of some concrete problem in heredity. It is true that
Nature herself is making such experiments constantly, but at random,
and rarely under ideal conditions of what the experimenter calls
control or check. We have first to seek and find them out, and when
they are found we often discover that there are lacking many of the
facts essential to a complete or satisfactory analysis of the facts
displayed. The comparatively small size of the human family sometimes
makes it difficult to get data sufficiently extensive to be really
significant. And the long period that elapses between successive human
generations adds to the difficulty of getting precise information, for
in dealing with the heredity of some traits comparisons must be made
with individuals of the same ages, and the period of observation of a
single observer seldom exceeds the duration of a single generation.
Yet in spite of all these difficulties we have a fairly broad and
exact knowledge of human heredity in respect to some characteristics.

Human heredity involves both physical and psychical characters--both
the body and the mind are concerned. Among other animals little if
anything is known regarding psychic inheritance, but the physical
traits of men are inherited in just the same ways and to the same
degrees as in animals. This degree or intensity of inheritance may be
expressed in coefficients of heredity between the groups of relatives
being compared. To mention a few examples of coefficients for physical
traits we have the following:

  CHARACTER OBSERVED         PARENTAL               FRATERNAL
                            COEFFICIENT            COEFFICIENT
  Stature                  .49-.51 }               .51-.55 }
  Span                     .45     }               .55     }
  Fore Arm                 .42     }  .47          .49     }  .53
  Eye Color                .55     }               .52     }
  Hair Color                                       .57     - Average
  Hair Curliness                                   .52
  Head Measurements-three                          .55     -    "
  Cephalic Index (Ratio between breadth and
    length of cranium)                             .49

We might give many others, but it is unnecessary. Notice that these
parental and fraternal coefficients group about an average value of
about .50 or slightly less. Similar coefficients have been worked out
for other degrees of relationship; thus grandparental coefficients are
about .25.

Stated briefly, in less exact terms, these coefficients mean that,
with respect to such traits as deviate from the group average, the
resemblance of brothers and sisters to each other or of children to
their parents is, on the whole, approximately mid-way between being
complete in its deviation from the average and in not deviating at all
from the average in the direction of the fraternal or parental
characteristic. Grandchildren tend to deviate from the group average
only about one fourth as far as their grandparents. It should be
remembered that these are statistical and not individual statements,
and that as many "exceptions" will be found in the direction of
greater resemblance as in that of lesser resemblance.

One of the present objects of the student of heredity, perhaps his
chief object, is to be able to state the facts of human heredity in
Mendelian terms, reducing many of the complex human traits to their
simpler elements. Some of the chief objections to the use of the
statistical formula of heredity are that apparently it is applicable
only to the fluctuating variabilities of organisms; that it rarely
takes into account the presence of (and therefore the heredity of)
true variations or mutations--and we have seen that it is just these
characters that are of the greatest value in evolution; and that
heredity is after all fundamentally an individual relation which loses
much of its definiteness and significance when we merge the individual
in with a crowd. To some these seem fatal objections to any use of the
statistical formula and it is certainly true that they greatly limit
its value. But for the present at least the statistical statement of
certain facts of heredity is still useful in this bio-social field. We
may therefore use the statistical formulas of heredity as a kind of
temporary expedient, enabling us to make statements regarding
inheritance of certain characters in the group or class, pending the
time when we shall be able to give the facts a more precise and more
"final" expression in Mendelian formulas. Many human traits are indeed
already known to Mendelize. Most of these are, however, "abnormal"
traits or pathological conditions; we are still in the dark regarding
the actually Mendelian or non-Mendelian inheritance of most of man's
normal characteristics. We might enumerate the following Mendelizing
human characters--eye color, color blindness, hair color and
curliness, albinism (absence of pigment), brachydactylism (two joints
instead of three in fingers and toes), syndactylism (union of certain
fingers and toes), polydactylism (one or more additional fingers or
toes in each hand or foot), keratosis (unusually thick and horny
skin), hæmophilia (lack of clotting property in the blood),
nightblindness (ability to see only in strong light--a retinal defect
usually), certain forms of deaf mutism and cataract, imbecility,
Huntington's chorea (a form of dementia).

In observing Mendelian heredity we should bear in mind that a given
character may be due either to the presence or to the absence of a
"determiner" in the germ. Long hair such as is characteristic of many
"Angora" varieties of the guinea pig and cat, for example, is believed
to be due to the absence of a determiner which stops its growth. Blue
eyes are due to the absence of a brown pigment determiner, _et
cetera_. The presence or absence in the offspring of such characters
as we know do Mendelize can be predicted when we know the parental
history for two generations.

Turning now to the inheritance of mental traits and including, of
course, moral traits here as well, we find that we are almost entirely
limited to the statistical statement of results. Pearson found upon
examining data from a large number of school children, brothers and
sisters, that the coefficients of heredity between them were the same
as for their physical traits. His results are summarized in Figure 12.
The physical traits measured were, in the order plotted in the
figure--health, eye color, hair color, hair curliness, cephalic index
(ratio between breadth and length of cranium), head length, head
breadth, head height. These gave an average of .54 in brothers, .53 in
sisters, and .51 in brothers and sisters. The psychical traits in
order were--vivacity, assertiveness, introspection, popularity,
conscientiousness, temper, ability, handwriting. The corresponding
averages were .52, .51, .52.

    [Illustration: FIG. 12.--Coefficients of heredity of physical
    and psychical characters in school children. Characters
    enumerated in text. (From Pearson.)]

Galton's pioneer works on "Hereditary Genius," "English Men of
Science," and "Natural Inheritance" showed with great clearness the
fact of mental and moral heredity. Wood's recent extensive study of
"Mental and Moral Heredity in Royalty" shows the same thing, although
not all the results of these investigations are given in mathematical
form. Little can be said regarding Mendelian heredity of mental traits
because the psychologist has not yet told us how to analyze even the
common and simpler psychic characters into their fundamental units;
since we do not know what the mental hereditary units are, obviously
we cannot work with them. Much of our knowledge in this field does not
permit of very accurate summary, though pointing indisputably to the
fact of mental inheritance in spite of the very great influences of
training and education, environment and tradition, in moulding the
mental and moral characteristics--influences with much greater effect
here than in connection with physical characters.

Galton studied the parentage of 207 Fellows of the Royal Society, a
Fellowship which is a real mark of distinction. He assumed that one
per cent of the individuals represented by the class from which his
observations were drawn, that is the higher intellectual classes,
might be expected to be "noteworthy": among the general population the
average is really about one in 4,000 or one fortieth of one per cent.
On the one per cent basis Galton found that Fellows of the Royal
Society had noteworthy fathers with 24 times the frequency to be
expected in the absence of heredity; noteworthy brothers with 31 times
the expected frequency; noteworthy grandfathers 12 times; and so on
through various grades of relationship.

Schuster examined the class lists of Oxford covering a period of 92
years and found that first honor men had 36 per cent first or second
honor fathers; second honor men had 32 per cent first or second honor
fathers; ordinary degree men 14 per cent first or second honor
fathers. These percentages are far in excess of that to be
expected--perhaps 0.5 per cent--on the assumption that ability is not
inherited. Schuster also determined the coefficients of heredity
between fathers and sons as regards intellectual ability, the evidence
being class marks in Oxford and Harrow; these he found to be about .3
for the parental relation and .4 for the fraternal. The intensity of
heredity in many forms of insanity has been determined and this runs
up much higher--.57 parental and .50 fraternal.

It is clear I take it, that the fact of human heredity does not
concern only physical traits but extends to psychical traits as well,
and with about the same intensity. This fact has been found true also
for still less analyzable characters such as length of life, fertility
or infertility and the like, and again about the same intensity of
resemblance is found.

Human heredity is a fact then just as human variability is a fact. We
have truly the raw materials and the means for racial improvement. The
ability to direct the evolution of the human race makes this our
supremest duty.

The facts of human heredity can more easily be brought home to us by
the examination of some actual pedigrees and family histories. We may
look at a few representative cases which will serve to bring out some
additional aspects of the significance to society of the demonstrated
fact of heredity. In the examination of single family histories we
should remember that a single pedigree may not accurately illustrate a
general law of heredity--again, an individual case may belong to a
group of cases without representing them fairly. Even in observing
illustrations of Mendel's laws allowance has to be made for the
variability due to "chance" meetings of germ cells. It is only when
large numbers of individuals are observed that the typical Mendelian
fractions and ratios can be strictly observed. It must be borne in
mind then that the histories given below illustrate the nature of the
facts of heredity rather than the laws of heredity. Some special
cautions in the interpretation of certain pedigrees will be suggested
in particular cases. Many of the figures are taken from the extremely
valuable "Treasury of Human Inheritance," now being published by the
Eugenics Laboratory of the University of London. In these figures and
some others a uniform series of symbols is used. Successive horizontal
lines designated by Roman numerals indicate generations; within a
single generation the individuals are numbered consecutively simply
for purposes of reference. The meaning of the more common symbols is
as shown in Table IV. We may first consider a few pedigrees showing
the heredity of physical abnormalities or defects.

                              TABLE IV.

  _Symbols used in Pedigrees. As adopted by the Galton Eugenics
                             Laboratory._

  [Symbol] Male and female respectively, not possessing the trait
           under consideration.
  [Symbol] Male and female possessing the trait under consideration.
  [Symbol] Unknown sex--normal or affected.
  [Symbol] Trait incompletely developed.
  [Symbol] Neither presence nor absence of trait can be affirmed.
  [Symbol] With a deformity or disease of special character which
           may possibly be associated with that under consideration.
  [Symbol] Twins.
  [Symbol] Indicates number of children.
  [Symbol] Marriage.
  [Symbol] Number of children unknown.
  [Symbol] Number and character of children unknown.
  _S. P._  _Sine prole._ (No offspring.)

Fig. 13 illustrates a family history where brachydactylism (an
abnormality of the digits commonly called shortfingeredness, due to
the lack of one joint in each digit) is present and frequently
associated with dwarfism. We may describe this case rather fully
because it illustrates nicely the heredity of a trait according to the
Mendelian formula. The parentage of the affected female (II, 1) who
started this line is uncertain. The marriage was with a normal male
whose parentage is unknown but evidently normal. This pair produced 11
children, the character of 8 of whom is known; 4 were affected, 4
unaffected, a Mendelian ratio resulting from the mating of a normal
with a hybrid individual, the observed character dominating (i. e.,
the abnormality appearing in the hybrid individuals). According to
Mendelian laws, the normal offspring of affected hybrids when mated
with normals should produce all normal offspring; this result is shown
clearly through generations IV-VI, where no affected individuals are
produced by two normal parents, although one or two of the
grandparents were affected. Marriage of a normal person with one
affected parent is fit because this individual is wholly without
germinal determiners for this character. Marriage between a normal and
an affected person is unfit (or it would be if the observed character
were a serious defect) because approximately one half their offspring
will be affected like the one parent. Thus in IV, 7-21, we see 12
children from one such marriage, 7 of whom are affected, 5 unaffected.
All of the 11 children of the 5 unaffected are normal, while of the 16
children of the affected persons, all of whom that married at all
married normal individuals, 9 were affected, 7 unaffected. Similar
relations are found in generation VI, where the 9 affected persons in
V married normals, producing 33 children, 15 of whom were affected, 18
unaffected. Taking all the offspring of marriages between unaffected
and affected (hybrid) persons through the four generations III-VI, we
find 35 affected and 33 unaffected, with the condition of 3 unknown.
There is no instance in this pedigree of the marriage of two affected
persons, but such a marriage would be highly unfit (again in the case
of a serious defect) because we know that all their offspring would be
affected. Mating of two unaffected persons, even though each had one
affected parent, would be fit because the offspring would all be
unaffected, barring the possibility of a new variation or mutation to
this character, which would be extremely unlikely. Such a pedigree as
this illustrates very well how a knowledge of Mendelian heredity may
be of the greatest value practically, in determining the fitness or
unfitness of marriages in families where an abnormality or defect is
known to occur. The course of the inheritance here illustrates the
simplest form of Mendelism. We have already indicated that there are
many other forms which we have not described and which we cannot
undertake to describe here on account of their complexity; in such
cases, however, it is still possible to predict with fair accuracy
the characters of the offspring of parents whose history is known for
one or two generations.

    [Illustration: FIG. 13.--Family history showing
    brachydactylism. Farabee's data. (From "Treasury of Human
    Inheritance.")]

The defect we have just been considering is dominant. Many defects are
recessive, i. e., transmitted though not exhibited by a hybrid
individual. Viewed from the standpoint of the character of the
offspring, mating with such a person would be unfit only when both
persons were similarly recessives. Such a chance similarity would be
likely only in cases of blood relationship. Here lies the scientific
basis for many of the legal restrictions against cousin marriage or
the marriage of closer relatives, for here, although both persons may
appear normal, the chances for latent ills appearing in the progeny in
a pure and permanently fixed condition are greatly increased. Of
course the same relation holds for characteristics which are not
defects but really valuable traits. Marriage of cousins possessing
valuable characters, whether apparent or not, might be allowed or
encouraged as a means of rendering permanent a rare and valuable
family trait which might otherwise be much less likely to become an
established characteristic. Some discrimination should be exercised
in the control, legal or otherwise, of such marriages.

    [Illustration: FIG. 14.--Family history showing
    polydactylism. (From "Treasury of Human Inheritance.")]

Fig. 14 gives a brief pedigree of a family in which polydactylism
occurs. This is a condition in which one or more additional or
supernumerary fingers or toes are present in the extremities. The
Mendelian character of the heredity of this defect is less clear than
in the preceding, yet there are many indications that this is really
an illustration of a complex Mendelian formula. Probably if the
parentage of the individuals marrying into this family were known we
should be able to give a complete formula. At any rate the pedigree
illustrates the unfit character of the matings with affected persons,
for in no instance has such a marriage resulted in the production of
fewer than one half affected offspring.

Fig. 15 illustrates a form of what is known as "split hand" or
"lobster claw," where certain digits may be absent in the hands and
feet. In this case all the digits are absent except the fifth. This is
frequently associated with syndactylism or the fusion of the remaining
digits into one or two groups. When present this usually affects all
four extremities. Two pedigrees of this defect are illustrated in Fig.
16. Here again we have a defect whose inheritance follows quite
closely the Mendelian formula, although the character of the matings
is not fully known; it is unnecessary to describe the details--the
histories speak for themselves.

    [Illustration: FIG. 15.--Mother and two daughters showing
    "split hand." (From Pearson.)]

Fig. 17 illustrates a pedigree of congenital cataract. This history is
less satisfactory because the matings are given in only three
instances. It is known from other data that this defect follows simple
Mendelian laws. Normal individuals produce only normals, while
affected persons produce one half or all affected offspring according
to the character of the mating.

Fig. 18 illustrates the heredity of another defect of the eye called
night blindness. This is a retinal defect, the affected being able to
see only in strong illumination. The particular form of the disease in
this family resulted in total blindness later in life. Little is known
definitely concerning the character of the matings; no mating is known
to have been with an affected person and some are known to have been
with unaffected. Of the 42 descendants of the first affected person
only 6 are known to have been unaffected. Can there be any doubt
regarding the unfitness of these matings? In generation III a single
mating led to a family of 10 children _all_ affected by this serious
defect, rendering them dependents.

One of the most complete pedigrees of a defect on record is given in
condensed form in Fig. 19. This summarizes the extraordinarily
complete data of Nettleship covering nine, and in one branch ten,
consecutive generations. The defect is another form of night blindness
as it existed in a French family. The inheritance is obviously
Mendelian: no affected persons are produced by unaffected parents,
although their own brothers or sisters or one parent may have been
affected. The pedigree gives the history of 2,040 persons, all
descended from one affected individual. Of these 135 were known to
have been affected, and all were children of affected parentage. Of
the total number of progeny of affected persons mated with normals,
130 were reported as affected and 242 as unaffected.

    [Illustration: FIG. 16.--Two family histories showing split
    foot. (From "Treasury of Human Inheritance.")]

We may consider next the hereditary history of some forms of nervous
defect, the exact nature of the causes of which can be less definitely
stated than in all of the preceding instances of defect. Fig. 20 gives
a brief history of the heredity of Huntington's chorea--a form of
insanity which here resulted in the death of all but one of the
affected persons in the first four generations; the fifth generation
is the present and is incomplete. Although the matings were with
normals in every case, yet in four of the eight marriages all of the
offspring were affected. From one affected male 23 affected persons
descended in four generations and their multiplication is still going
on. There can be no doubt as to the unfitness of marriage into such a
family.

    [Illustration: FIG. 18.--Family history showing a form of
    night blindness. Character of matings incompletely known.
    (Data from Bordley.)]

A very complete family history showing deaf-mutism is given in Fig.
21. It cannot be said that in every case here the defect is innate,
i. e., hereditary, and it is not known that the cause of the defect
was the same in every family concerned, for deaf-mutism may result
from several different causes. In most cases in this history, however,
the defect behaves like a Mendelian dominant. In certain other cases
it is clearly known to follow the Mendelian formula. Such pedigrees
as this show how dangerous it is to marry into a family in which this
defect exists.

    [Illustration: FIG. 19.--Family history showing a form of
    night blindness. (Condensed form of Nettleship's data.)]

Goddard has recently published several family histories showing
feeble-mindedness. One of the most significant of these--significant
both socially and eugenically--is summarized here in Fig. 22. Of this
Goddard writes: "Here we have a feeble-minded woman [IV, 3] who has
had three husbands (including one 'who was not her husband'), and the
result has been nothing but feeble-minded children. The story may be
told as follows:

"This woman was a handsome girl, apparently having inherited some
refinement from her mother, although her father was a feeble-minded,
alcoholic brute. Somewhere about the age of seventeen or eighteen she
went out to do housework in a family in one of the towns of this State
[New Jersey]. She soon became the mother of an illegitimate child. It
was born in an almshouse to which she fled after she had been
discharged from the home where she had been at work. After this,
charitably disposed people tried to do what they could for her, giving
her a home for herself and her child in return for the work which she
could do. However, she soon appeared in the same condition. An effort
was then made to discover the father of this second child, and when he
was found to be a drunken, feeble-minded epileptic living in the
neighborhood, in order to save the legitimacy of the child, her
friends [_sic_] saw to it that a marriage ceremony took place. Later
another feeble-minded child was born to them. Then the whole family
secured a home with an unmarried farmer in the neighborhood. They
lived there together until another child was forthcoming which the
husband refused to own. When, finally, the farmer acknowledged this
child to be his, the same good friends [_sic_] interfered, went into
the courts and procured a divorce from the husband, and had the woman
married to the father of the expected fourth child. This proved to be
feeble-minded, and they have had four other feeble-minded children,
making eight in all, born of this woman. There have also been one
child stillborn and one miscarriage.

"As will be seen from the chart, this woman had four feeble-minded
brothers and sisters [IV, 6, 10, 15, 16]. These are all married and
have children. The older of the two sisters had a child by her own
father, when she was thirteen years old. The child died at about six
years of age. This woman has since married. The two brothers have each
at least one child of whose mental condition nothing is known. The
other sister married a feeble-minded man and had three children. Two
of these are feeble-minded and the other died in infancy. There were
six other brothers and sisters that died in infancy."

    [Illustration: FIG. 20.--Family history showing Huntington's
    chorea. Last generation incomplete. (Data from Hamilton.)]

The paternal ancestry of this unfortunate woman is hardly less
interesting, as may be seen from the diagram. All told, this family
history, as far as it is known, includes 59 persons; the mental
character of 12 of these is unknown; 10 died in infancy or before
their characteristics were known; of the remaining 37, 30 were
feeble-minded.

    [Illustration: FIG. 21.--Family history showing deaf-mutism.
    (From "Treasury of Human Inheritance.")]

Turning now to defects of other kinds, an interesting history is
illustrated in Fig. 23. Here a single individual fatally affected with
angio-neurotic oedema gave rise, in four completed generations, to
113 persons, 43 of whom were affected. In 11 this disease was the
direct cause of death. The Mendelian character of the heredity here
can be neither asserted nor denied. In generations II-V matings
between normal and affected gave 42 affected and 35 unaffected
offspring.

Fig. 24 gives a brief family history showing pulmonary tuberculosis.
In the history given susceptibility to this disease behaves as a
Mendelian dominant. We cannot as yet say whether this is or is not a
general rule. In describing the heredity of diseases primarily due to
infection, one or two important cautions must be observed. Of course
the source of the infection cannot be "hereditary," and apparently it
is only in comparatively few instances that infection occurs during
fetal life. To some infections certain persons are susceptible, others
are not; some when susceptible are capable of developing immunity,
others are not. When an infection is of such character and prevalence
that practically all persons in approximately similar environments of
a given character are infected, susceptibility or the power of
developing immunity will determine whether or not an individual will
exhibit the disease caused by the infective agent. Practically all
persons living in the denser communities are infected with
tuberculosis; those who are susceptible and incapable of developing
immunity succumb, the insusceptible and those developing immunity do
not. These conditions are heritable; but in speaking of the heredity
of such a disease as tuberculosis it should be clear that the heredity
concerned is really that of susceptibility and the power of developing
immunity. Yet the person who is really susceptible can, by taking
sufficient precaution, escape serious infection, and thus the result
for that person would be the same as if he were insusceptible, but his
offspring would have to take similar precautions if they were to
escape the disease.

    [Illustration: FIG. 22. Family history showing
    feeble-mindedness. Data from Goddard. _A_, alcoholic; _d.i._,
    died in infancy; _E_, epileptic; _ill._, illegitimate; _in._,
    incest; *, same individual as _III_, 6; _n.m._, not married;
    _S_, sexual pervert; _T_, tuberculous.]

    [Illustration: FIG. 23.--Family history showing
    angio-neurotic oedema. (From "Treasury of Human
    Inheritance.")]

    [Illustration: FIG. 24.--Family history showing tuberculosis.
    (Data from Klebs, after Whetham in "Treasury of Human
    Inheritance.")]

We cannot speak of heredity in connection with diseases to which all
are susceptible and incapable of developing immunity. The presence or
absence of such a disease is determined solely by the presence or
absence of infection. Many physical and mental defects result from
infection as the primary cause. If the infection is one to which all
exposed are susceptible and incapable of developing immunity we cannot
speak of the defect as in any way hereditary; if the infection is one
to which some are susceptible, others not, to which some can develop
immunity, others cannot, then we may speak of the defect as
hereditary. Thus certain forms of blindness or insanity are due
primarily to gonorrheal or syphilitic infection, insusceptibility to
which is rare or unknown. Such defects cannot be considered as
affording evidence of heredity though they reappear in successive
generations.

In general the subject of the heredity of immunity and susceptibility
forms one of the most important eugenic aspects of this whole subject.
In a few cases it is known that immunity or insusceptibility to
specific forms of infection is a unit character which follows
Mendelian laws in heredity. It can be added to races or subtracted
from them and pure bred immune races built up. So far this has not
been demonstrated for man. There is some circumstantial evidence that
immunity to specific forms of infection has been a great, although
hitherto neglected, factor in man's evolution, and even in the history
of his civilization and conquest. It is at once obvious that here is a
great field for the common labor of the students of heredity and of
medicine and of Eugenics.

Fig. 25 illustrates a family history of infertility. This is
apparently hereditary, but before that could be asserted definitely to
be so here or in any similar case, we should know that the infertility
were not the result of an infection to which immunity is rare or
unknown. That infertility is really hereditary in this instance is
indicated, first, by the fact that the person marked A later, by a
second marriage into fertile stock, had a large family, and second, by
the fact that the individual B and his child by marriage into fertile
stocks produced in the last generation again a large family and so
saved this whole family from extinction.

    [Illustration: FIG. 25.--Family history showing infertility.
    (From Whetham.)]

Before leaving the subject of the heredity of the kinds of traits we
have been using as illustrations, we should add just a word. It is
often objected that one cannot properly speak of the heredity of such
general things as "insanity" or "deaf-mutism" or "blindness" or "heart
disease," because each of these includes a great variety of specific
forms of these disorders which cannot strictly, medically, be
compared. But the student of heredity replies that when he speaks of
the heredity of insanity or heart disease, that is often just what
he means. He means that often no particular form of these defects is
necessarily strictly heritable as such, but that in a family there may
be a general instability of nervous system or circulatory system,
which may take any one of several possible specific forms, the form
actually appearing depending upon particular conditions which are
frequently environmental and beyond determination. In some cases
specific forms of disorder are actually heritable as such.

Such an inclusive thing as "ability" may depend upon many different
specific conditions. Yet there are families in which persons of
exceptional ability are unusually frequent. The fact that persons of
ability are more frequent in certain families than in the general
population of the same social class and with about the same
opportunity for the demonstration of inherent ability, gives evidence
of its heredity, although we may not be able to summarize the facts
under any particular law but must adhere to their statistical
expression.

    [Illustration: FIG. 26.--Family history showing ability.
    (From Whetham.)]

Figs. 26 and 27 illustrate two such pedigrees of ability. In each of
these histories there is also a line of "unsoundness" the descent of
which it is interesting to trace. It is instructive to compare here
the progeny of matings of different kinds. In generation IV of Fig.
26, the 9th and 10th persons are brother and sister. The sister was of
considerable ability and married into a family of ability, producing 8
offspring, 5 of whom were able. The brother was a "normal" person and
married a similar individual, producing 10 "normal" children. It would
be interesting to know the details regarding these two large families
of cousins. Another interesting comparison is found in this pedigree.
The four able brothers in generation III, coming from a stock of
demonstrated ability, married women of undemonstrated ability and all
told had 13 children (IV) of whom only 3 showed ability and all of
these were in a single family. In this family of the fourth brother
two of the able members married into able families, and among their 11
children (second and fifth families in generation V) 8 showed ability;
the third able member of this family, however, married as her uncles
had, a person not known as able, and none of their 6 children showed
unusual ability (sixth family in generation V). Fig. 27 affords other
illustrations of this same kind. Thus in generation III the 5th and
7th persons are able cousins of able parentage. The former married a
normal and 1 of their 5 children showed ability; the latter married a
person of ability and 5 of their 8 children showed ability. In both
pedigrees the "careers" of those in the last generation are partly
incomplete.

    [Illustration: FIG. 27.--Family history showing ability.
    Paternal ancestry of family shown in Fig. 26. (From
    Whetham.)]

In discussing pedigrees of ability it should be borne in mind that the
larger proportion of able males as compared with females is hardly
significant for the study of heredity; it may merely reflect the
unfortunate fact that women have not had the same opportunity to
demonstrate inherent ability as have men; or it may evidence the still
more unfortunate fact that the distinguished achievements of able
women have not been socially recognized as such and recorded as they
have been for the other sex.

Fig. 28 gives an interesting, though abbreviated, pedigree of three
very able and well-known families. In this history only persons whose
ability is in science are marked as able. Charles Darwin is the third
individual in the third generation. His cousin, Francis Galton, the
founder of Eugenics, is the next to the last person in the same
generation.

Many similar cases of the unusual frequency of individuals of musical
or religious ability in certain families have been published by Galton
and are well known. "As long as ability marries ability, a large
proportion of able offspring is a certainty, and ability is a more
valuable heirloom in a family than mere material wealth, which,
moreover, will follow ability sooner or later."

We might contrast with such families as have been recorded in the
three preceding figures some well-known families at the other pole of
society. As an interesting example we have the family described by
Poellmann. This was established by two daughters of a woman drunkard
who in five or six generations produced all told 834 descendants. The
histories of 709 of these are known. Of the 709, 107 were of
illegitimate birth; 64 were inmates of almshouses; 162 were
professional beggars; 164 were prostitutes and 17 procurers; 76 had
served sentences in prison aggregating 116 years; 7 were condemned for
murder. This family is still a fertile one and the cost to the State,
i. e., the taxpayers, already a million and a quarter dollars, is
still increasing.

    [Illustration: FIG. 28.--History (condensed and incomplete)
    of three markedly able families. (From Whetham.)]

One of the best known families of this type is the so-called "Jukes"
family of New York State so carefully investigated by Dugdale. This
family is traced from the five daughters of a lazy and irresponsible
fisherman born in 1720. In five generations this family numbered about
1,200 persons, including nearly 200 who married into it. The histories
of 540 of these are well known and about 500 more are partly known.
This family history was easier to follow than are some others because
there was very little marriage with the foreign-born--"a distinctively
American family." Of these 1,200 idle, ignorant, lewd, vicious,
pauper, diseased, imbecile, insane, and criminal specimens of
humanity, about 300 died in infancy. Of the remaining 900, 310 were
professional paupers in almshouses a total of 2,300 years (at whose
expense?); 440 were physically wrecked by their own diseased
wickedness; more than half of the women were prostitutes; 130 were
convicted criminals; 60 were habitual thieves; 7 were murderers. Not
one had even a common school education. Only 20 learned a trade, and
10 of these learned it in State prison! They have cost the State over
a million and a quarter dollars, and the cost is still going on. Who
pays this bill? What right had an intelligent and humane society to
allow these poor unfortunates to be born into the kind of lives they
had to lead, not by choice but by the disadvantage of birth? Darwin
wrote long ago "... except in the case of man himself, hardly anyone
is so ignorant as to allow his worst animals to breed."

    [Illustration: FIG. 29.--History of _Die Familie Zero_.
    (Condensed from Jörger's data, partly after Davenport.)]

Probably the most complete family history of this kind ever worked out
is that of the "Familie Zero"--a Swiss family whose pedigree has been
recently unraveled in a splendid manner by Jörger. In the seventeenth
century this family divided into three lines; two of these have ever
since remained valued and highly respected families, while the third
has descended to the depths. This third line was established by a
man who was himself the result of two generations of intermarriage,
the second tainted with insanity. He was of roving disposition, and in
the Valla Fontana found an Italian vagrant wife of vicious character.
Their son inherited fully his parental traits and himself married a
member of a German vagabond family--Marcus, known to this day as a
vagabond family. This marriage sealed the fate of their hundreds of
descendants. This pair had seven children, all characterized by
vagabondage, thievery, drunkenness, mental and physical defect, and
immorality. Their history for the three succeeding generations is
incompletely summarized in Fig. 29. In 1905, 190 members of this
family were known to be living, and probably many living are unknown
on account of illegitimate birth.

In 1861 a sympathetic and charitable priest attempted to save from
their obvious fate many of these "Zero" children and others who
resided in and near his village, by placing them in industrious and
respectable families to be reared under more favorable auspices. The
attempt failed utterly, for every one of the "Zero" children either
ran away or was enticed away by his relatives.

The blame for such an atrocity as this family or the Jukes does not
rest with these persons themselves; it must be placed squarely upon
the shoulders and consciences of the intelligent members of society
who have permitted these predetermined degenerates to be brought into
the world, and who are to-day taking no broadly sympathetic view of
their treatment by exercising preventive measures. _Laissez faire?_

At the risk of easing the conscience, let us finally return to the
other side of society and look at a summarized statement of the
Edwards Family given by Boies and drawn from Winship's account of the
descendants of Jonathan Edwards. "1,394 of his descendants were
identified in 1900, of whom 295 were college graduates; 13 presidents
of our greatest colleges; 65 professors in colleges, besides many
principals of other important educational institutions; 60 physicians,
many of whom were eminent; 100 and more clergymen, missionaries, or
theological professors; 75 were officers in the army and navy; 60
prominent authors and writers, by whom 135 books of merit were
written and published and 18 important periodicals edited; 33 American
States and several foreign countries, and 92 American cities and many
foreign cities, have profited by the beneficent influence of their
eminent activity; 100 and more were lawyers, of whom one was our most
eminent professor of law; 30 were judges; 80 held public office, of
whom one was Vice President of the United States; 3 were United States
Senators; several were governors, members of Congress, framers of
State constitutions, mayors of cities, and ministers to foreign
courts; one was president of the Pacific Mail Steamship Company; 15
railroads, many banks, insurance companies, and large industrial
enterprises have been indebted to their management. Almost if not
every department of social progress and of the public weal has felt
the impulse of this healthy and long-lived family. It is not known
that any one of them was ever convicted of crime."

The serious consideration of bodies of facts like those contained in
some of these pedigrees leads every thoughtful and sympathetic, every
humanely minded, human being to ask--What _can_ we _do_ about it? The
display of such conditions stimulates us to measures of relief. It is
greatly to be regretted that the honest desire to do good often leads
to the performance of ill-considered or unconsidered acts which may
result in positive injury to the constitution of society, or at any
rate at best merely in the amelioration of the immediate situation
without reference to ultimate profit or penalty, or to the necessity
for interminable amelioration. Such relief leaves out of account the
fact that modifications are not heritable--not permanent, practically
without effect in the long run. "Good intentions" have a certain
well-known value as paving material, but not as building material.

The science of Eugenics includes not only the study of the data in
this field, but further the formulation of definite courses of
procedure; but it insists that these be based upon scientific
principles and not upon emotional states. Philanthropic relief has
become a serious business--is becoming a science. Eugenics is a
science and it aims to put the human race upon such a level that the
need for philanthropic relief will be less and continually less. We
shall then be able to devote more of the resources of our time and
money and energy to the production of permanent results. The Eugenist
pleads in this work for more sympathetic consideration of the problems
of relief--for a sympathy which is wider, which transcends the
individual person and reaches the social group, even the nation or
race. For just as a society is something more than the sum of its
individual parts when taken separately, so the consideration of all
the component individuals of a society taken separately and by
themselves, results in something less than social consideration. Again
"Charity refers to the individual; Statesmanship to the nation;
Eugenics cares for both."

       *       *       *       *       *

What, then, does the Eugenist propose to do? What is the eugenic
program? Eugenics is not an academic matter--not an armchair science.
It is intensely practical--so very practical, indeed, that the
Eugenist hesitates to make many suggestions of a definite nature
looking directly and immediately toward specific action. Something
must precede action. The Eugenist has been ridiculed as one
responsible for the absurd schemes proposed in his name, perhaps
seriously, by the unscientific but well-intentioned sympathizer. Many
persons have been led to object to what they believed to be a eugenic
program which is not a eugenic program at all. Thus the willingness of
some to offer adverse criticism of the subject and its aims has grown
largely out of a common misconception of the matter and has led Galton
to say, "As in most other cases of novel views, the wrongheadedness of
objectors to Eugenics has been curious." As a scientist the Eugenist
realizes clearly and fully that his new science is in a very early
stage of its development. It is just entering upon what are the first
stages in the history of any science, namely, the periods of the
formulation of elementary ideas and the collection of facts. There are
certain groups of facts, however, of glaring significance and
undoubted meaning, and upon these as a basis the Eugenist already has
a few, a very few, concrete suggestions for eugenic practice. In
conclusion, then, we may outline tentatively and briefly a
conservative eugenic program somewhat as follows:

First of all there must be an extensive collection of exact data--of
the facts regarding all the varied aspects of racial history and
evolution. These facts must be collected with great care and under the
strictest scientific conditions. In this matter particularly must we
"desert verbal discussion for statistical facts." Figures can't lie,
but liars can figure. What we need first of all is the accumulation of
masses of cold, hard facts, uncolored by any point of view, untinged
by any propaganda: facts regarding the net fertility of all classes;
facts regarding the racial effects of all sorts of environmental and
occupational conditions; facts regarding variability and variation in
the race; facts regarding human heredity of normal and pathological
conditions, of physical and psychical traits. We have merely scratched
the surface of the great masses of such data to be had for the
looking. As Davenport has recently put it in his valuable essay on
"Eugenics"--

"While the acquisition of new data is desirable, much can be done by
studying the extant records of institutions. The amount of such data
is enormous. They lie hidden in records of our numerous charity
organizations, our 42 institutions for the feeble-minded, our 115
schools and homes for the deaf and blind, our 350 hospitals for the
insane, our 1,200 refuge homes, our 1,300 prisons, our 1,500 hospitals
and our 2,500 almshouses. Our great insurance companies and our
college gymnasiums have tens of thousands of records of the characters
of human blood lines. These records should be studied, their
hereditary data sifted out and ... placed in their proper relations"
that we may learn of "the great strains of human protoplasm that are
coursing through the country." Thus shall we learn "not only the
method of heredity of human characteristics but we shall identify
those lines which supply our families of great men: ... We shall also
learn whence come our 300,000 insane and feeble-minded, our 160,000
blind or deaf, the 2,000,000 that are annually cared for by our
hospitals and Homes, our 80,000 prisoners and the thousands of
criminals that are not in prison, and our 100,000 paupers in
almshouses and out.

"This three or four per cent of our population is a fearful drag on
our civilization. Shall we as an intelligent people, proud of our
control of nature in other respects, do nothing but vote more taxes or
be satisfied with the great gifts and bequests that philanthropists
have made for the support of the delinquent, defective, and dependent
classes? Shall we not rather take the steps that scientific study
dictates as necessary to dry up the springs that feed the torrent of
defective and degenerate protoplasm?

"Greater tasks than those contemplated in the broadest scheme of the
Eugenics committee have been carried out in this country. If only one
half of one per cent of the 30 million dollars annually spent on
hospitals, 20 millions on insane asylums, 20 millions for almshouses,
13 millions on prisons, and 5 millions on the feeble-minded, deaf and
blind were spent on the study of the bad germ plasm that makes
necessary the annual expenditure of nearly 100 millions in the care of
its produce we might hope to learn just how it is being reproduced and
the best way to diminish its further spread. A _new_ plague that
rendered four per cent of our population, chiefly at the most
productive age, not only incompetent, but a burden costing 100
million dollars yearly to support, would instantly attract universal
attention, and millions would be forthcoming for its study as they
have been for the study of cancer. But we have become so used to
crime, disease and degeneracy that we take them as necessary evils.
That they were, in the world's ignorance, is granted. That they must
remain so, is denied."

Of course one should not jump from this to the conclusion that the
fact of heredity is responsible for all of this defect. Disease is so
often the result of infections to which none is immune, and defect is
frequently the result of such disease. Warbasse has recently stated
that "At least one fourth of our public institutions for caring for
defectives is made necessary by venereal disease." Doubtless an
appreciable share of this fourth is the result of hereditary
tendencies, the expression of which gives the opportunity for such
infection. Here as elsewhere no single factor accounts for all of the
facts, although when, as the result of the increase of knowledge, we
shall become able to make more definite statements, we no doubt shall
find that heredity is the most important single factor in the
disgraceful prevalence of crime, disease, and defect in our
communities: indeed this is practically demonstrated to-day. These are
questions of the most fundamental importance in our national
life-history: our only "hope of perpetuity" lies in the right solution
of such problems. And the crying need is for facts, always more facts.

The Galton Laboratory for Eugenics is already doing much in this
direction and is publishing in the "Treasury of Human Inheritance"
scores of human pedigrees. An agency is already in operation in this
country. The American Breeders Association has appointed a Committee
and Sub-Committees under highly competent leaders for the collection
of exact data of human heredity upon a large scale. There is
opportunity for everyone to help in this work in connection with the
Eugenics Record Office already referred to.

The second great element in the eugenic program is Research. It is not
enough to collect the known facts; new facts must be forthcoming. We
cannot, perhaps, undertake definite experiments upon human evolution,
but we can and must take advantage of the wealth of experiment which
Nature is carrying out around us and before our eyes could we but
learn to read her results. We need to know more about the process of
differential fertility, of human variability, of the effects of
Nurture as well as of the conditions of Nature.

We do know pretty well the effects, upon the individual, of training,
education, good and ill housing conditions and conditions of labor, of
disease, alcoholism, underfeeding. We need now to know, not to guess
at, the effects of these things upon the race, upon human stock. A
mere beginning has been made here in the way of a scientific treatment
of this question, although many persons have their minds already made
up, firmly and fully, as to the "effects of the environment." But all
that we have guessed here may be wrong.

The discussion of this subject is filled with pitfalls. The common
form of the query as to which is of the greater importance, "heredity
or environment," in determining individual characteristics betrays a
completely erroneous view of what heredity is, and of the organism's
relation to its environment. The living organism reacts to its
environment at every stage of its existence, whether as an egg, an
embryo, or an adult. In this reaction both factors are essential, the
environment as essential as the organism. The result of this continued
reaction is the development on the part of the organism of certain
physiological processes and structural conditions or characteristics.
The nature of these resulting states, depending upon the two
factors--organism and environment--can be changed by altering either
factor. In general, organisms develop under pretty much the same
conditions as their parents and general ancestry did, and their
germinal substances are directly continuous, and therefore very
similar. Consequently, primary organic structure and environing
conditions of development being alike through successive generations,
the results of their interaction are alike. This alikeness is
heredity--the fact of similarity between parent and offspring. The
usually indefinite question as to the effect of the environment
ordinarily has a real meaning however, and this is, or should be,
whether the alteration of particular elements of the environment, the
presence of special, unusual factors which cannot be said to be
"normally" present--whether these produce any effect upon the organism
which is truly heritable.

This is in reality the old question of the "inheritance of acquired
characteristics," or, in a word, of modifications--a question which
has been debated heatedly and at length. And as in many similar
instances the number of essays and the length and heat of the debate
have been inversely as the number and clearness of the pertinent
facts. The large majority of biologists have long felt that the great
bulk of the evidence was on one side, namely, that acquired traits
were not heritable. At the same time they have recognized the
difficulty of explaining certain apparently demonstrated contradictory
facts. Some recent experimental work has largely cleared away the
theoretical difficulties in this field, and the present status of the
old and really fundamental question may be stated as follows: External
conditions--climate, temperature, moisture, nutritional conditions,
results of unusual activity, and the like--incidences of the
environment, undoubtedly produce effects upon the structure and
behavior of the organism, but these effects must be clearly grouped
into two distinct classes.

In the first place the effect of "external" conditions may be to bring
about a reaction between the _bodily_ parts affected and the
environing conditions. Here the body alone is modified and not the
germinal substance for the next generation within this body. Such
responses to environing conditions do not affect nor involve the
structure of the germ, and are therefore unrepresented in that series
of reactions that result in the production of an individual of the
next generation. In this class are found most of the instances of
"functional modification" or acquired characteristics. In this
category belong most of the stock illustrations--from the blacksmith's
arm and the pianist's fingers, to the giraffe's neck and the fox's
cunning. Here also belong the results of training and education; we
can train and educate brain cells but not germ cells.

It is characteristic of most of these bodily reactions to external
conditions that they are adaptive; that is, when a body reacts to
such a condition it does so by undergoing a change which makes the
organism better fitted to the new condition--better able to exist. The
increased keenness of vision, the strengthened muscle, the thickened
fur--all such changes meet new or unusual demands in such a way that
the organism has better chances of survival than it would have had
unmodified.

But in the second place there are certain environmental circumstances
which do affect the structure of the germinal substance within the
body of an organism. An unusually high temperature acting at a certain
period in the life-history may bring about a change in the color of
insects which is heritable--i. e., racial; but such a change results
from the action of temperature upon the germ directly and not alone
upon the body, which then itself affects the germ. It is essential to
recognize that in all such cases it is not the structural change in
the body that affects the germ, but it is the external condition
itself that affects the germ directly. This is not the half of a hair;
it is an extremely important and significant difference. The effects
of this kind of action are not visible until the generation following
that acted upon. They become expressed in the bodies of the organisms
developed from the affected germs.

It is characteristic of such changes as these that they may not,
usually do not, have an adaptive relation to the condition bringing
about the change. There is no correspondence between the bodily and
the germinal modifications resulting from the action of the same
condition. Furthermore, there seems to be no adaptive relation between
the general character of the germinal disturbance and the
environmental disturbance. Rarely some of the organismal characters
resulting from such germinal modification may be in the direction of
greater adaptedness; usually they are neutral or in the direction of
utter unfitness.

But such effects are heritable, whatever their nature with respect to
adaptedness, and it becomes therefore very important to find out what
are the conditions that may thus disturb the normal structure of the
germ. Little more than a beginning has been made here and practically
nothing can be said definitely with reference to the human organism
in this respect. Enough is known, however, to make it clear that it is
only rarely indeed that external conditions can thus affect the
germinal structure. In most cases the effects of the incidence of
environment are purely bodily. A most fruitful field for eugenic
investigation is open here.

One of the first problems to be attacked from this point of view is
that of the racial (i. e., heritable) effects of such poisons as
alcohol. It is frequently said, for instance, that some of the effects
of alcoholism are the weakened, epileptic, or feeble-minded conditions
of the offspring, who are also particularly liable to disease and
infection. It can hardly be said that this is as yet thoroughly
demonstrated. On account of the importance of this question we might
call specific attention to some recent investigations of the problem
of the racial influence of alcohol. The effects of alcohol upon the
individual are fairly well known, although still a matter for debate
in some quarters. But this is not as important eugenically as the
possible effect upon the offspring of the use and abuse of alcohol by
the parents. An investigation has been carried on recently through
the Galton Laboratory for National Eugenics directed toward
ascertaining the precise relation between alcoholism in parents and
the height, weight, general health, and intelligence of their
children. It was found to be perfectly true that alcoholism and
tuberculosis show a high degree of association; but considering the
nondrinking members of the same community just the same high frequency
of tuberculosis was found. And the presence of alcoholism among
parents was found to be practically without effect upon the height and
weight of their offspring. "These results are certainly startling and
rather upset one's preconceived ideas, but it is perhaps a consolation
that to the obvious and visible miseries of the children arising from
drink, lowered intelligence and physique are not added."

The difficulties surrounding investigation and the interpretation of
the results of investigation in this particular field are evidenced by
the fact that these results have been adversely criticised, on the one
hand, because "alcoholism" was taken to mean the continued moderate
use of alcohol, and on the other because "alcoholism" was taken to
mean only the occasional excessive abuse of alcohol. Much of the
confusion surrounding the discussion of the racial effects of alcohol
grows out of the underlying confusion of statistical and individual
statements. It may be left open, then, whether this result from the
Galton Laboratory is clearly demonstrated and whether the basis of
investigation was sufficiently broad to make the facts of general
applicability.

The frequent association between alcoholism and certain forms of
insanity is sometimes taken as evidence of a racial effect. Here again
we find the question really left open when we appeal to facts taken in
large numbers. In a few cases it seems to have been demonstrated that
saturation of the bodily tissues with alcohol affects directly the
structure of the germ cells formed at that time, and that this effect
is seen in physical and mental disturbances of the offspring derived
from such germ cells, and thus becomes hereditary or racial. But these
results, like those mentioned above, need confirmation. The impairment
of the child _in utero_ through maternal overindulgence in alcohol
would not necessarily denote any corresponding germinal (i. e.,
racial) effect.

It is often the case that alcoholic excess, like other forms of
excess, may be an indication of a lack of complete mental balance or
sanity, sure to have become expressed in some form. The lack of
balance in the offspring of such persons is a simple case of heredity
and not the result of the parental use of alcohol. The alcoholism of
the parent was a result, an indication, and not a cause. There may be
instances of the direct action of external conditions upon the germ,
and in a very true sense the body is a part of the external
environment of the germ, but to say that such an action has been
demonstrated for alcohol is premature. It should be easily possible to
get real evidence upon this and similar questions. But at present it
is safest to leave the whole question of the racial effects of alcohol
entirely open pending more and better evidence.

To summarize, then, we may say that the evidence for an inherited
effect of the misuse of alcohol is not as clear as one might wish; it
may be true. There is the greatest need for the careful scientific
investigation of this and allied problems. Much of the evidence here
is not of the kind that can be used to prove things--it consists
largely of the demonstration of the fact of association rather than of
causation. In order to show that a changed environment has produced a
change in the innate characters of the organisms affected it must be
demonstrated that the organismal change continues to be inherited
after the environment has again become what it was originally, and as
yet this has not been done. Indeed when tested in this way it is found
that a permanently heritable alteration can thus be produced only
rarely and by environmental changes of the most profound character.

Research in another direction is greatly needed. We should examine and
reëxamine current as well as proposed social practices and reforms
from the racial point of view. We should know before going much
farther whether the extensive social improvements that are annually
effected are to any considerable degree racially permanent. We should
investigate not only the racial effects of the unfavorable social
conditions themselves, but also the racial effects of the measures
directed toward the relief of such conditions. It is conceivable that
measures of relief may be practically without permanent effect or even
racially detrimental. It would seem that the social worker and
philanthropist should welcome any biologically fundamental truths
touching these questions, and yet it is curiously true that there are
some such persons who seem to prefer not to know the whole truth here,
perhaps because they fear it may disclose the unwelcome fact that much
of their effort has resulted in amelioration rather than in
correction. It should be remembered that simple relief is well worth
while, even though often without resulting racial benefit. When it is
not actually detrimental racially, relief is an economic, social, and
moral duty. The Eugenist, by disclosing the fact that racial effects
can actually be accomplished, enlarges rather than diminishes the
opportunities for relief and his knowledge should be welcomed and use
made of it.

Heretofore the social point of view has been practically the only
point of view in much of this work, and the result is that usually
following when action is based upon half-truth. David Starr Jordan
says: "Charity creates the misery she tries to relieve; she never
relieves half the misery she creates," and he goes on to say that
_unwise_ charity is responsible for half the pauperism of the world;
that it is the duty of charity to remove the _causes_ of weakness and
suffering and equally to see that weakness and suffering are not
needlessly perpetuated. In this connection the following quotation
from Elderton is apt: "... the influence of the parental environmental
factor on the welfare of children is ... at present and has been in
the past the chief direction of legislative and philanthropic attack
on social evils. Degeneracy of every form has been attributed to
poverty, bad housing, unhealthy trades, drinking, industrial
occupation of women, and other direct or indirect environmental
influences on offspring. If we could by education, by legislation, or
by social effort change the environmental conditions, would the race
at once rise to a markedly higher standard of physique and mentality?
Much, if not the whole battle for social reform, has been based on the
assumption that this question was obviously to be answered in the
affirmative. No direct investigation has really ever been made of the
intensity of the influence of environment on man. To modify the
obviously repellent was the immediate instinct of the more gently
nurtured and controlling social class. Was this direction of social
reform really capable of effecting any substantial change? Nay, by
lessening the selective death rate, may it not have contributed to
emphasizing the very evils it was intended to lessen? These are the
problems which occur to the eugenist and call for investigation and,
if possible, settlement.... It is conceivable that the relation
between children's physique, for example, and parental occupation is
an indirect result of the inheritance of physique and a correlation
between parents' physique and their occupation. In other words, what
we are attributing to environment may be a secondary influence of
heredity itself. A weakling may have no option but to follow an
unhealthy trade, a man is a tailor or shoemaker, because he has not
the physique for smith or navvy. His offspring may be physically
inferior because he is a weakling and not because he follows an
unhealthy trade. Clearly, to solve our problem, we must know if there
be any correlation between the same character in the parent as we are
observing in the child and the environment we are correlating with the
child's character. Unfortunately data enabling us to determine the
relationship of any mental or physical character of the parent with
the environment which is supposed to influence the child is rarely
forthcoming."

Just to suggest one further train of thought, we might point out that
several movements apparently of high social value have been attended
by a curious and largely unforeseen back action. Thus the enforcement
of certain forms of Employer's Liability laws has led to
discrimination against married persons by large employers of labor and
a premium thus put upon nonmarriage. The result of Child Labor
legislation has been in some cases an enormous rise in the death rate
of young children among the classes concerned, indicating that the
children receive less care, now that they have ceased to be a
prospective family asset and have become chiefly a burden for many
years. In other cases the result has been so serious a limitation in
the birth rate that communities are dying out and factories are
closing for want of sufficient help. Such problems are not only social
but economic and eugenic, and they cannot be seen squarely from any
single point of view. It is doubtless shocking to the cultured mind
that the chief reason for bringing children into the world should be
their economic value as contributors to the family income. But in
reality does this point of view differ fundamentally from that very
commonly taken of the value of a large family except in the nature of
the standard by which their value is measured? May there not be a
difference of opinion as to whether children are better or worse off
when brought up with some degree of care to be employed under humane
conditions of labor, than when left uncared for to die in large
proportions of disease and neglect?

Finally, studies in heredity, whether on man or on other animals or on
plants, are sure to be of value here because we know that the
fundamental processes of heredity are the same in all organisms. Above
all, the Eugenist needs to know more of Mendelian heredity in man.
The facts of heredity stated in the statistical form of averages and
coefficients do not affect the man in the street materially--he rather
enjoys taking chances. An extensive eugenic practice can be
established only when we can say definitely what the individual or
family inheritance will be in a given instance--not what it will be
with such and such a degree of probability, although that probability
be high. We may not be such a long way off from this ideal, which is
an essential for the inauguration of eugenic practice upon a large
scale. For the Eugenist this is the richest field for investigation
and one which is certain to yield large results.

The Eugenist's demand for more facts will doubtless become an
important factor in the progress of biological science. The practical
application of the knowledge of heredity in the production of
domesticated or cultivated varieties of animals and plants is becoming
annually more extensive; and with the recognition of the possibility
of the application of this knowledge to the control of the evolution
of man himself, will come a rapid increase in biological knowledge
and in the earnestness of the student of heredity. And at the same
time another result may be that the science of biology shall come to
be appraised publicly more nearly at its real value. The biological
worker knows that his science comes into contact with human life at
every point, that a knowledge of the fundamental principles of the
science of life cannot fail to enrich, enlighten, and ennoble the life
of every human being. But the community does not yet realize this, to
its own great loss. Is it not possible that the Eugenist, finding his
fundamentals in biology, by emphasizing the facts of the possibility
and the necessity of controlling human evolution, may be able to bring
to society a vital sense of the importance of this science with a
directness and a vividness which the bacteriologist and hygienist have
not been able thus far to realize? Is it even too much to hope that
the idea that the "humanities" include only the study of man's
comparatively recent past, may now more rapidly give place to a
broader conception which shall include not only the whole of man's
past, but the study of his future as well? Could any ideal be more
vitally, more profoundly human or more worthy of study and devotion,
than this of the production of a race of men, clean and sound in mind
and body? Be that as it may, the development of this bio-social field
can scarcely fail to stimulate strongly the treatment of all social
problems with a strictly scientific method. Nothing less than exact
methods, and results exactly stated, will satisfy the genuine and
really valuable social student of the near future. As one recent
writer has feelingly put it: "We have had essays enough."

Eugenic practice for the immediate future is the third part of our
program. Must we wait until more data are collected, more facts
uncovered, before we undertake any definite proposals for eugenic
procedure? Although this is the most difficult aspect of the subject,
largely through lack of a sufficiently broad fact-basis, yet we are
certainly in possession of enough information to make plain a few
necessary steps. Most of the concrete proposals directed toward the
reduction of the undesirables and the increase of the desirables have
been visionary, impractical, or too limited in their view-point.
Above all, they have been open to the objection that they have gone
too far in the direction of that zone which separates the two classes.
It should be said again that most of these proposals have been those
of the amateur enthusiast, not of the seriously scientific Eugenist;
they have grown out of that common habit of "getting far from the
facts and philosophizing about them."

As Pearson points out, we must start from three fundamental biological
ideas. First, "That the relative weight of nature and nurture must not
_a priori_ be assumed but must be scientifically measured; and thus
far our experience is that nature dominates nurture, and that
inheritance is more vital than environment." Second, "That there
exists no demonstrable inheritance of acquired characters. Environment
modifies the bodily characters of the existing generation, but does
not [often] modify the germ plasms from which the next generation
springs. At most, environment can provide a selection of which germ
plasms among the many provided shall be potential and which shall
remain latent." Third, "That all human qualities are inherited in a
marked and probably equal degree." "If these ideas represent the
substantial truth, you will see how the whole function of the eugenist
is theoretically simplified. He cannot hope by nurture and by
education to create new germinal types. He can only hope by selective
environment to obtain the types most conducive to racial welfare and
to national progress. If we see this point clearly and grasp it to the
full, what a flood of light it sheds on half the schemes for the
amelioration of the people.... The widely prevalent notion that
bettered environment and improved education mean a _progressive_
evolution of humanity is found to be without any satisfactory
scientific basis. Improved conditions of life mean better health for
the existing population; greater educational facilities mean greater
capacity for finding and using existing ability; they do not connote
that the next generation will be either physically or mentally better
than its parents. Selection of parentage is the sole effective process
known to science by which a race can continuously progress. The rise
and fall of nations are in truth summed up in the maintenance or
cessation of that process of selection. Where the battle is to the
capable and thrifty, where the dull and idle have no chance to
propagate their kind, there the nation will progress, even if the land
be sterile, the environment unfriendly and educational facilities
small."

As a concrete example of a most commendable eugenic practice we should
mention the sterilization of certain classes of criminal and insane as
it is now practiced in the States of Indiana and Connecticut. For the
last four years (since March, 1907) the laws of Indiana have permitted
the performance of the operation of vasectomy upon "confirmed
criminals, idiots, rapists, and imbeciles" after rigid scrutiny of all
the mental and physical conditions of the individual case and upon the
concurrent judgment of three competent and impartial persons. The
title and significant parts of the text of this law are as follows:

    _An Act_, entitled, An Act to prevent procreation of
    confirmed criminals, idiots, imbeciles, and
    rapists--providing that superintendents, or boards of
    managers, of institutions where such persons are confined
    shall have the authority, and are empowered to appoint a
    committee of experts, consisting of two physicians, to
    examine into the mental condition of such inmates.

    _Whereas_, Heredity plays a most important part in the
    transmission of crime, idiocy, and imbecility;

    _Therefore_, Be it enacted by the General Assembly of the
    State of Indiana, That on and after the passage of this act
    it shall be compulsory for each and every institution in the
    State, entrusted with the care of confirmed criminals,
    idiots, rapists, and imbeciles, to appoint upon its staff, in
    addition to the regular institutional physician, two (2)
    skilled surgeons of recognized ability, whose duty it shall
    be, in conjunction with the chief physician of the
    institution, to examine the mental and physical condition of
    such inmates as are recommended by the institutional
    physician and board of managers. If, in the judgment of this
    committee of experts and the board of managers, procreation
    is inadvisable, and there is no probability of improvement of
    the mental and physical condition of the inmate, it shall be
    lawful for the surgeons to perform such operation for the
    prevention of procreation as shall be decided safest and most
    effective. But this operation shall not be performed except
    in cases that have been pronounced unimprovable: Provided,
    That in no case shall the consultation fee be more than three
    (3) dollars to each expert, to be paid out of the funds
    appropriated for the maintenance of such institution.

This operation of vasectomy, sometimes known as "Rentoul's operation,"
consists, in the male, in the removal of a small portion of each sperm
duct; the individual is thus rendered sterile in a completely
effective and permanent way. At the same time there are none of the
harmful effects, either physical or mental, such as usually follow the
better known forms of sterilization which are in reality
asexualization rather than sterilization. Vasectomy is a simple
"office" operation occupying only a few minutes and requiring at the
most the application of only a local anæsthetic, such as cocaine; and
there are no disturbing nor even inconvenient after effects. In the
female the corresponding operation of oöphorotomy consists in removing
a small portion of each Fallopian tube. In Indiana nearly a thousand
persons have already been successfully treated, many upon their own
request--a circumstance entirely unforeseen. Similar laws have been
passed in Oregon and Connecticut, and are being carefully considered
in several other States.

In order that the exact nature of such proposals may be better known
generally we may give here also the text of the Connecticut law which
is somewhat more inclusive and more flexible than that of Indiana. The
Connecticut Statute, enacted in August, 1909, is as follows:

    _An Act_, concerning operations for the Prevention of
    Procreation.--Be it enacted by the Senate and House of
    Representatives in General Assembly convened:

    _Section 1._ The directors of the State prison and the
    superintendents of State hospitals for the insane at
    Middletown and Norwich are hereby authorized and directed to
    appoint for each of said institutions, respectively, two
    skilled surgeons, who, in conjunction with the physician or
    surgeon in charge at each of said institutions, shall examine
    such persons as are reported to them by the warden,
    superintendent, or the physician or surgeon in charge, to be
    persons by whom procreation would be inadvisable.

    Such board shall examine the physical and mental condition of
    such persons, and their record and family history so far as
    the same can be ascertained, and if in the judgment of the
    majority of said board, procreation by any such person would
    produce children with an inherited tendency to crime,
    insanity, feeble-mindedness, idiocy, or imbecility, and there
    is no probability that the condition of any such person so
    examined will improve to such an extent as to render
    procreation by such person advisable, or, if the physical and
    mental condition of any such person will be substantially
    improved thereby, then the said board shall appoint one of
    its members to perform the operation of vasectomy or
    oöphorectomy, as the case may be, upon such person. Such
    operation shall be performed in a safe and humane manner, and
    the board making such examination, and the surgeon performing
    such operation, shall receive from the State such
    compensation, for services rendered, as the warden of the
    State prison or the superintendent of either of such
    hospitals shall deem reasonable.

    _Section 2._ Except as authorized by this Act, every person
    who shall perform, encourage, assist in, or otherwise promote
    the performance of either of the operations described in
    Section 1 of this Act, for the purpose of destroying the
    power to procreate the human species; or any person who shall
    knowingly permit either of such operations to be performed
    upon such person--unless the same be a medical
    necessity--shall be fined not more than one thousand dollars,
    or imprisoned in the State prison not more than five years,
    or both.

These States are to be commended in the highest possible terms for
their enlightened action in this direction. Who can say how many
families of Jukes and Zeros have already been inhibited by this simple
and humane means? "Could such a law be enforced in the whole United
States, less than four generations would eliminate nine tenths of the
crime, insanity and sickness of the present generation in our land.
Asylums, prisons and hospitals would decrease, and the problems of the
unemployed, the indigent old, and the hopelessly degenerate would
cease to trouble civilization."

And yet probably for years to come those mental states and conditions
of servitude graciously termed "conservatism" will continue to insure
an undiminished horde of these unfortunates. The situation here is
interestingly analogous to that in connection with certain of the
infectious diseases. Concerning the eradication of typhoid fever, to
mention a single concrete example, competent authorities declare that
we now possess all of the information necessary to make typhoid fever
as obsolete in civilized communities as is cholera or smallpox. "The
average third-year medical student knows enough about typhoid fever to
be able to stamp it out if he were endowed with absolute power."
"Typhoid fever has passed beyond the catalogue of diseases; it is a
crime." Our knowledge of the causes of many of the conditions leading
to gross physical and mental defect and criminality has progressed
already to such a point that we could if we would eradicate them in
large proportion from our civilization. The great horde of defectives,
once in the world, have the right to live and to enjoy as best they
may whatever freedom is compatible with the lives and freedom of the
other members of society. They have not the right to produce and
reproduce more of their kind for a too generous and too blindly
"charitable" society to contend against. The greater crime consists
in allowing the hereditary criminal to be born.

A well-known British alienist, Tredgold, after pointing out that the
duty of medical science is to fight and relieve disease in every shape
and form, adds: "That if social science does not keep pace with
medical science in this matter the end will be national disaster. In
other words, I would lay it down as a general principle that as soon
as a nation reaches that stage of civilization in which medical
knowledge and humanitarian sentiment operate to prolong the existence
of the unfit, then it becomes imperative upon that nation to devise
such social laws as will insure that these unfit do not propagate
their kind.

"For, mark you, it is not as if these degenerates mated solely amongst
themselves. Were that so, it is possible that, even in spite of the
physician, the accumulated morbidity would become so powerful as to
work out its own salvation by bringing about the sterility and
extinction of its victims. The danger lies in the fact that these
degenerates mate with the _healthy_ members of the community and
thereby constantly drag fresh blood into the vortex of disease and
lower the general vigour of the nation."

Such a practice as vasectomy then represents nicely the eugenic aim of
allowing the individual, who is himself never to be blamed for his
hereditary constitution, the greatest possible personal freedom and
liberty, of allowing full play of sympathy for the individual, and at
the same time of exercising the greatest sympathy to society in
prohibiting the hereditary criminal from procreating a long line of
descendants endowed as badly as he himself was through no fault of his
own, but through the gross neglect of society.

Another quotation from Pearson: "To-day we feed our criminals up, and
we feed up our insane, we let both out of the prison or asylum
'reformed' or 'cured,' as the case may be, only after a few months to
return to State supervision, leaving behind them the germs of a new
generation of deteriorants. The average number of crimes due to the
convicts in his Majesty's prisons to-day is ten apiece. We cannot
reform the criminal, nor cure the insane from the standpoint of
heredity; the taint varies not with their mental or moral conduct.
These are the products of the somatic cells; the disease lies deeper
in their germinal constitution. Education for the criminal, fresh air
for the tuberculous, rest and food for the neurotic--these are
excellent, they may bring control, sound lungs, and sanity to the
individual; but they will not save the offspring from the need of like
treatment, nor from the danger of collapse when the time of strain
comes. They cannot make a nation sound in mind and body, they merely
screen degeneracy behind a throng of arrested degenerates. Our highly
developed human sympathy will no longer allow us to watch the State
purify itself by the aid of crude natural selection. We see pain and
suffering only to relieve it, without inquiry as to the moral
character of the sufferer or as to his national or racial value. And
this is right--no man is responsible for his own being; and nature and
nurture, over which he had no control, have made him the being he is,
good or evil. But here science steps in, crying: Let the reprieve be
accepted, but next remind the social conscience of its duty to the
race ... let there be no heritage if you would build up and preserve a
virile and efficient people. Here, I hold, we reach the kernel of the
truth which the science of eugenics has at present revealed."

It is also a part of eugenic practice to oppose vigorously and
unmistakably any social practice leading to the reduction in the
reproductivity of the desirable and valuable elements of society.
There is to be included here for censure a long list of customs and
practices, from the enforced celibacy of the Church to the horror of
horrors--warfare. A moment's reflection will suggest many
reprehensible practices of this kind more or less current in certain
classes or communities. The requirement of nonmarriage on the part of
women teachers--persons of tested and demonstrated ability, is a very
general practice of decidedly noneugenic character. In Great Britain
more than 75,000 nurses, all of whom must have passed physical
examination, are cut off from reproduction by the same requirement of
nonmarriage. Many less striking but all too common practices have the
final effect of forbidding marriage to the healthy, physically or
mentally capable, helpful, classes. "Help wanted. Must be
unencumbered."

More vigorously and more unmistakably does the Eugenist discourage
anything that leads to matings of the unfit and, above all, to their
reproduction. Many countries, from Servia to the Argentine Republic,
have statutes forbidding the marriage of the insane, idiots, deaf and
dumb, certain classes of criminals, and persons afflicted with certain
contagious diseases. It is to be hoped that these laws are enforced
with greater effectiveness than that with which our own less stringent
laws of similar character are administered. After all, it is the
reproduction of these persons that should be limited, and among many
of these classes the fact of nonmarriage would provide not the
slightest barrier to reproduction.

It is unfortunately true, but true none the less, that there are
current forms of so-called philanthropy which, by relieving defective
parents of the care of their defective offspring, thus encourage them
in the production of more defective offspring; and so the flames are
fed. Relief is the smallest part of the problem. Any condition which
leads to the multiplication of the innately defective and dependent
classes must be sternly opposed. No matter how benign the guise of any
form of relief or charity, if it encourages or permits even indirectly
the free reproduction of these classes, it must be resolutely opposed
and soon abandoned. "It is not enough to preach with horror and
indignation against normal parents who restrict their families. Equal
reprobation should be the lot of those who, with inherited insanity,
feeble-mindedness, or disease, bring children into the world to
perpetuate their infirmities. It should not be overlooked that the
realization of the power of limiting the birth rate, while it has
produced untold harm, when applied blindly and in accordance with
individual caprice, may become an instrument for good if it extends to
the worst stocks, while the better stocks once more undertake their
natural duties."

Practical Eugenics need not be limited to its philanthropic and
legislative aspects. There are other social mechanisms which could be
used to encourage the multiplication of the fitter, abler families.
In Munich, under the enlightened leadership of Dr. Alfred Ploetz, a
society for the study and promotion of social and racial hygiene
(Internationale Gesellschaft für Rassen-Hygiene) has made a most
excellent and significant beginning. This society is doing much not
only to collect data and investigate scientifically problems within
its field, but also to spread widely the facts of racial integrity.
Its members agree, among other things, to undergo thorough medical
examination prior to marriage as to their fitness for that state and
agree to abstain from marriage, or at least from parenthood, if found
to be unfit.

Much can be done by suggestion and suasion regarding the choice of
mates and the rearing of large families. When one touches upon this
subject he is pretty likely to be met with the objection that the
selection of mates is so largely an impulsive, emotional affair that
it is quite beyond control. "Marriages," they say, "are made in
heaven." But when we consider the number that can scarcely be said to
be completed there the statement seems open to some question. As a
matter of fact, it is perfectly clear, as Galton, Ellis, and others
have shown, that all peoples, from the Kaffir and the Dyak to the
Hindu and the modern European or American, are surrounded with
restrictions in marriage often of the greatest stringency. And yet,
since these are matters of established social custom, even of
religious observance, we submit almost without knowing it.

That results can be really accomplished in this direction and by this
method is clearly shown by the history of the Jewish people, and by
the Roman Catholics, among whom there are distinctly fewer divorces
and childless marriages than among Protestants. In many countries and
communities the organized Church still exercises an immense influence
over the whole subject of marriage: the Church could easily become a
powerful factor in eugenic practice. Such a control can and should be
given eugenic direction by the establishment of a more discriminative
attitude, looking toward a reduction in the reproductivity of the
dependent or defective as well as to the increased reproductivity of
the valuable and able. In all of the discussion of "race suicide" and
the value to the State of the large family, how seldom do we hear any
mention of quality! To plan the organization and conduct of a State
without regulating and controlling the quality of its membership is
like adopting plans and elevations for a costly building without
making any specifications as to materials.

In concrete eugenic practice it seems probable that most can be
accomplished for the present by striving to limit the multiplication
of the undesirable, dependent, or dangerous elements of the social
group. There can be less uncertainty here. The social organization has
already marked certain kinds of individuals as unfit and unworthy,
whose liberty must be limited in many directions for the social
welfare. This aspect of the matter can be put upon a dollars and cents
basis very clearly, and this is apparently the only relation that
affects a good many people. Why should the able and worthy and thrifty
members of society be compelled to pay, as they are in this country
alone, $100,000,000 annually, not to mention the vast sums voluntarily
contributed toward "charitable" purposes, for the support of the
criminal and pauper and defective classes who themselves contribute
nothing of value and whose very existence is evidence of criminal
disregard of the right of every individual to be well born, into a
healthy and sane life? The only answer, if it be an answer,
is--because the competent are willing to foot the bill. Millions for
tribute but not one cent for defense. And yet a penny's worth of
defense outweighs a million's worth of cure.

In the practice of Eugenics the greatest caution must be exercised.
All eugenic practice must be tested by the most careful and
scrutinizing scientific methods. Mendelian heredity gives a different
answer from Job's to his own query: "Who can bring a clean thing out
of an unclean?" It also makes clear how it may often happen that it
needs but three generations to go from Fifth Avenue to the Bowery, and
back again. Many so-called criminals may be anachronisms, some only
modificationally bad. But there are many cases, many practices,
regarding which there can be no doubt: the Eugenist says, treat these,
and let the doubtful cases alone until as a result of the increase of
knowledge there is no doubt. And while it is easy to say that we
_believe_ the criminal or the insane are the products of a wrong
environment, it is also easy to say that we believe they are not. What
the Eugenist demands is _knowledge_, then belief, and action based
thereon.

Finally, the eugenic program calls for the spread of the facts, far
and wide, through all classes of society. Bring forcibly before the
people the facts of human heredity. Teach them to understand the force
of the eugenic ideal of good breeding. "The prevalent opinion that
almost anybody is good enough to marry is chiefly due to the fact that
in this case, cause and effect, marriage and the feebleness of
offspring, are so distant from each other that the near-sighted eye
does not distinctly perceive the connection between them." By
education we must produce first of all a thoughtfulness in the
community regarding the racial responsibilities of marriage and
reproduction. Human beings are frequently rational creatures; placing
before them clear and truthful ideas regarding fit and unfit matings
cannot fail of an ultimate effect. "The virtue of repetition, the
summation of suggestion, which sells pills and pickles, which makes
Free Trade or Tariff Reform a national issue, this force operating as
a slight but persistent influence when linked to eugenic proposals
will in a few years' time make these proposals a living force to the
common man." By talking and teaching, in season and out, the community
will be compelled to think on these things; they will be forced into
the public conscience and the pressure of public opinion will rise for
the eugenic and against the noneugenic ideals of mating and the
rearing of families. And the rest will come in due season and more
effective and permanent results will follow than are likely to come
from any amount of premature legislation. As Galton writes: "The
enlightenment of the individual is a necessary preamble to practical
Eugenics, but social opinion by praise or blame constantly influences
individual conduct." "Public opinion is commonly far in advance of
private morality, because society as a whole keenly appreciates acts
that tend to its advantage, and condemns those that do not. It
applauds acts of heroism that perhaps not one of the applauders would
be disposed to emulate." "The first and main point is to secure the
general intellectual acceptance of Eugenics as a hopeful and most
important study. Then let its principles work into the heart of the
nation, who will gradually give practical effect to them in ways that
we may not wholly foresee."

In this educational part of the eugenic program, and particularly in
the encouragement of research directed toward the solution of eugenic
problems and the establishment of eugenic practices, there lies one of
the greatest opportunities ever opened to the philanthropist. The
genuine philanthropist is he who would at this moment make possible
the rapid solution of many of the still baffling problems of human
heredity and who would help to spread and teach the gospel of true
racial integrity. But while it has been easy to interest
philanthropists in the relief of social disorders, few can be
interested in the causes at work which make the necessity for relief
seem so imperative.

The patient unraveler of the Jukes family history has said, "I am
informed that $28,000 was raised in two days to purchase a rare
collection of antique jewelry and bronze recently discovered in
classic ground forty feet below the _débris_. I do not hear of
as many pence being offered to fathom the _débris_ of our
civilization--however rich the yield!" Possibly one reason for this
neglect or omission has heretofore been the lack of evidence that real
results could be accomplished in this field. Now that it is so obvious
that we have a real foundation of fact from which to work we may
expect soon some degree of recognition of the supreme importance of
the need for investigation in subjects allied to Eugenics, and of
devotion to eugenic aims.

"Whether or no the importance of the issues at stake comes to be
recognized fully by the nation at large, individuals and families have
it in their power to act on the knowledge they have acquired.... When
once more the importance of good birth comes to be recognized in a new
sense, ... it will be understood to be more important to marry into a
family with a good hereditary record of physical, mental, and moral
qualities than it ever has been considered to be allied to one with
sixteen quarterings." "Families in which good and noble qualities of
mind and body have become hereditary form a natural aristocracy, and,
if such families take pride in recording their pedigrees, marry among
themselves, and establish a predominant fertility, they can assure
success and position to the majority of their descendants in any
political future. They can become the guardians and trustees of a
sound inborn heritage, which, incorruptible and undefiled, they can
preserve in purity and vigour throughout whatever period of ignorance
and decay may be in store for the nation at large. Neglect to hand on
undimmed the priceless germinal qualities which such families possess,
can be regarded only as the betrayal of a sacred trust....

"We look, then, for a day in the near future, when, in some circles at
any rate, a comparison of scientific pedigrees will replace, or at all
events precede, the discussion of settlements in the preliminaries to
a marriage; when birth and good-breeding (in its wide sense),
character and ability will be the qualities most prized in the choice
of mates; when a bad ancestral strain likely to reappear in
succeeding generations will suppress an incipient passion as
effectually as it is now cured by a deficiency of education or a
superfluity of accent." (Whetham.)

As matters are at present it is all too often the case that marriage
is _followed_ by the disclosure or discovery of a family history of
sterility, or criminality, or insanity. In a truly enlightened society
the failure to make known such conditions in the antecedents to a
marriage will be regarded as evidence of the greatest moral obliquity,
if not of criminal misdemeanor.

The wise and honored founder of Eugenics looks forward to the
inclusion of eugenic ideals as a factor in religion. "Eugenics,"
Galton writes, "strengthens the sense of social duty in so many
important particulars that the conclusions derived from its study
ought to find a welcome home in every tolerant religion." "Eugenic
belief extends the function of philanthropy to future generations; it
renders its action more pervading than hitherto, by dealing with
families and societies in their entirety; and it enforces the
importance of the marriage covenant, by directing serious attention to
the probable quality of the future offspring. It strongly forbids all
forms of sentimental charity that are harmful to the race, while it
eagerly seeks opportunity for acts of personal kindness as some
equivalent to the loss of what it forbids. It brings the tie of
kinship into prominence, and strongly encourages love and interest in
family and race. In brief, eugenics is a virile creed, full of
hopefulness, and appealing to many of the noblest feelings of our
nature."

And Whetham adds: "Hitherto the development of our race has been
unconscious, and we have been allowed no responsibility for its right
course. Now, in the fulness of time ... we are treated as children no
more, and the conscious fashioning of the human race is given into our
hands. Let us put away childish things, stand up with open eyes, and
face our responsibilities."




                                INDEX




                                INDEX


  Ability, heredity of, 146, 147.
    heredity and pedigrees of, 176-181.

  Acquired characteristics, relation of, to heredity, 199-207.

  Adaptedness, 200-202.

  Albinism, and order of birth, 125, 126.
    heredity of, 142.

  Alcoholism, heritable effects of, 203-207.

  American Breeders' Association, 15, 196.

  Andalusian fowl, heredity of color in, 81-83.

  Angio-neurotic oedema, pedigree of, 168, 170.

  Aristotle, 18.


  Bagatelle board, to illustrate variability, 58-60.

  Bateson, William, 81, 100.

  Bentley, Madison, quoted, 19.

  Biffen, R. H., 133.

  Biology, and Sociology, 8, 35-45.
    eugenic applications of, 38-40, 49 _et seq._

  Biometric Laboratory, 14.

  Bio-Sociology, 8.

  Birth rate, and social status, 116-123.
    decreasing, in England, 122.

  Boies, abstract of Winship's data of Edwards family, 187, 188.

  Booth, classification of London population, 70.

  Brachydactylism, heredity of, 142.
    pedigree of, 150-153.


  Cataract, heredity of, 143.
    pedigree of, 157, 159.

  Cephalic index, heredity of, 140, 144.

  Chance, law of, 56-58.

  Child labor laws, effect of, 211, 212.

  Chorea, Huntington's, heredity of, 143.
    pedigree of, 160, 165.

  Church, influence and opportunities of, 231.

  Civic worth, variability of, 70.

  Coefficient of correlation, 110, 111.

  Coefficient of correlation
    between birth rate and  social status, 117.
    positive and negative, 111-113.
    significance of, 111.

  Coefficient of heredity, 109.
    human, 140.

  Coefficient of variability, 62, 63.
    human, 69.

  Color blindness, heredity of, 142.

  Connecticut, vasectomy statute of, 220-222.

  Conservation of human protoplasm, 136.

  Correlation, 103, 104.
    coefficient of, 110, 111.
    social status and birth rate, 116-123.

  Cousin marriage, regulation of, 154, 155.

  Criminality, and order of birth, 125, 126.
    increase in, 29.


  Darwin, pedigree of, 181, 183.
    quoted, 6, 184.

  Data, need for and collection of, 192.

  Davenport, quoted, 192-195.

  Deaf, United States census of, 34.

  Deaf and dumb, United States census of, 34.

  Deaf-mutism, heredity of, 143.

  Deaf-mutism, pedigree of, 160, 167.

  Defect, and order of birth, 123-126.

  Defectives, number of, in Great Britain, 31.
    United States census of, 34.

  Dependents, United States census of, 34.

  Determiners, absence of, 143.
    in germ, 54.
    in Mendelian heredity, 88-95.

  Development of the individual, 51.
    as a form of reaction, 52, 53.

  _Die Familie Zero_, 184-187.

  Differential fertility, 113-121.

  Dominance, in Mendelian heredity, 84.
    irregular and incomplete, 87.

  Dominant characteristics, 85.

  Drapers' Company, 14.

  Dugdale, account of "Jukes" family, 182-184.
    quoted, 236, 237.


  Education, 20, 71.
    heritable effects of, 200.

  Edwards, Jonathan, descendants of, 187, 188.

  Elderton, quoted, 209-211.

  Employer's liability laws, effects of, 211.

  England, falling birth rate in, 122.
    number of defectives in, 31, 32.

  Environment, effects of, 197-207.

  Eugenics, aims of, 5, 42-45, 114, 123.
    as a factor in religion, 239, 240.
    definition of, 3.
    encouragement of ideals of, 234-240.
    history of, 10-13.
    objections to, 191.
    practice of, 215-234.
    program of, 189-240.

  Eugenics Committee of American Breeders' Association, 15, 196.

  Eugenics Education Society, 14.

  Eugenics Laboratory, 14.

  Eugenics Record Office, 15.

  _Eugenics Review_, 14.

  External conditions, effects of, 199-203.

  Eye color, heredity of, 140, 142, 143.


  Fabian Society, 122.

  _Familie Zero_, 184-187.

  Family histories. _See_ Pedigrees.

  Feeble-minded, in Great Britain, 32.
    in United States, 34.

  Feeble-mindedness, pedigree of, 162-169.

  Fellows of the Royal Society, mental heredity in, 145, 146.

  Fertility, and social status, 116-123.
    differential (selective), 113, 121.
    in normal and pathological stocks, 115.
    of various classes, 120, 121.

  Fluctuation, 56.

  Forearm, heredity in length of, 140.

  Fowl, color heredity in Andalusian, 81-83.

  Functional modification, non-inheritance of, 199-207.


  Galton, Sir Francis, illustrations of variability, 58, 63.
    in history of Eugenics, 9-13.
    on mental heredity, 144-146.
    pedigree of, 181-183.
    quoted, 5, 44, 45, 236, 239, 240.

  Gametic coupling, 100.

  Germ, relation of, to adult structure, 50.

  Germ cells, relation of, to Mendel's law, 88-94.

  Goddard, account of feeble-minded family, 162-169.

  Great Britain, number of defectives, etc., 31, 32.

  Greece, 9, 10.

  Guinea-pig, heredity of color in, 84-87.


  Hæmophilia, heredity of, 143.

  Hair color and curliness, heredity of, 140, 142.

  Harrow, mental heredity in students of, 147.

  Head measurements, heredity of, 140.

  Heredity, coefficient of, 109, 140.
    definition of, 77.
    human, 137-188.
    Mendelian formula of, 80-102.
      in human traits, 142.
    need for studies in, 212, 213.
    of acquired characters (modifications), 199-207.
    psychic characters, 143-147.
    relation of, to Eugenics, 78, 79.
    statistical formula of, 80, 102-113.

  Heron, David,
    birth rate, and net fertility of social classes, 116, 119-121.

  Homicides, number of, in United States, 30.

  Huntington's chorea, heredity of, 143.
    pedigree of, 160, 165.


  Idiots, statistics of, 32.

  Imbeciles, statistics of, 32.

  Imbecility, heredity of, 143.

  Immunity, relation of, to heredity of disease, 168-173.

  Index of variability, 62.

  Indiana, vasectomy statute of, 218, 219.

  Infection, heredity of, diseases and defects due to, 168-173.

  Infertility, pedigree of, 174, 175.

  Inheritance. _See_ Heredity.

  Insane, statistics of, 31-34.

  Insanity, and order of birth, 124-126.
    associated with alcoholism, 205, 206.

  _Internationale Gesellschaft für Rassen-Hygiene_, 230.


  Jennings, 66.

  Johannsen, 66.

  Jordan, David Starr, quoted, 209.

  Jörger, _Die Familie Zero_, 184-187.

  "Jukes" family, 182-184.


  Keratosis, heredity of, 142.


  Lankester, Sir E. Ray, "Kingdom of Man," 21-24.
    quoted, 7.

  _L'Elite_, 10.

  Lobster claw, heredity of, 155.
    pedigree of, 155, 157.

  London, number of children in, 122.
    university of, 14.


  Man's place in Nature, 6, 7.

  Marriage, antecedents to, 238, 239.
    restrictions in, 228-232.

  Mediocrity, 61.

  Mendel, Gregor, 83, 84.

  Mendelian formula of heredity, 80-102.

  Mendelism and eugenic practice, 97, 233.

  Mendel's law, and unit characters, 95-99.
    characteristics inherited according to, 98, 99.
      human, 142, 143.
    complications of, 100.
    present limitations of, 100-102.

  Mental ability, pedigrees of, 176-181.

  Mental defect, heredity of, 147, 160, 165, 162-169.

  Mental traits, heredity of, 143-147.

  Models, illustrating variability and variation, 59, 63-64.

  Murders, number of, 30.

  Mutation, 63-66.


  National Association of British and Irish Millers, 133.

  Natural selection, 21-23, 45.

  Nettleship, pedigree of night blindness, 158-163.

  Night blindness, heredity of, 143.
    pedigrees of, 157, 158, 161, 163.

  Normal frequency curve, 56-60.

  Nurture, 17, 76.


  Oedema, pedigree of angio-neurotic, 168-170.

  Ohio Institution for the Feeble-Minded, superintendent quoted, 33.

  Oneida community, 10.

  Ontogeny, 51.

  Oöphorectomy (oöphorotomy), 218-222.

  Order of birth and pathological defect, 123-126.

  Oxford, mental heredity in graduates of, 146, 147.


  Paupers, United States census of, 34.

  Pearson, Karl, 14, 27, 36.
    heredity in school children, 143, 144.
    quoted, 127-130, 216-218, 225-227.

  Pedigrees of ability, 176-181.

  Pedigrees of angio-neurotic oedema, 168, 170.
    of brachydactylism, 150-153.
    of cataract, 157, 159.
    of deaf-mutism, 160, 167.
    of feeble-mindedness, 162-169.
    of Huntington's chorea, 160, 165.
    of infertility, 174, 175.
    of lobster claw or split hand, 155-157.
    of night blindness, 157-163.
    of polydactylism, 155, 156.
    of tuberculosis, 168-171.

  Plato, 3, 9.

  Ploetz, Dr. Alfred, 230.

  Poellman, family described by, 181.

  Polydactylism, heredity of, 142.
    pedigree of, 155, 156.

  Population, of Europe and North America, 25, 26.

  Practice of Eugenics, 192-240.

  Prisoners, number of, in United States, 29, 30.

  Probability, law of, 56-59.

  Pure bred, 97.

  Pure line, 67, 72.


  Recessive characteristics, 85.

  Regression, 105-108.

  Regression line, 106, 107.

  Rentoul, statistics of defectives, 31.

  Rentoul's operation, 218-222.

  Research, in the eugenic program, and need for, 196-215.

  Restrictions in marriage, 154, 155, 230, 231.

  Royal Society, mental heredity in Fellows of, 145, 146.


  School children, heredity in, 143, 144.

  Schuster, on mental heredity, 146, 147.

  Scottish Commission, statistics of insane, 31.

  Selective fertility, 113-122.

  Sex limited heredity, 100.

  Size of family, 114, 115.
    and relative proportion of defectives, 126.

  Social practices, investigation of, 207-212.
    opposed to Eugenics, 227, 228.

  Social status, and birth rate, 116-123.

  Social variation, 75.

  Society for social and racial hygiene (Munich), 230.

  Sociological Society, 12.

  Sociology, aims of, 35, 42.
    and Biology, 8, 35-45.

  Span, heredity of, 140.

  Species, relation of, to pure line, 66.

  Split hand. _See_ Lobster claw.

  Sports, 65.

  Standard deviation, 62.

  Statistical formula of heredity, 80, 81, 102-113.

  Stature, heredity of, 140.
    of mothers, 56, 57.

  Sterilization, eugenic value of, 222-225.
    statutes permitting, 218-223.

  "Studies in National Deterioration," 14.

  Symbols used in pedigrees, 149.

  Syndactylism, heredity of, 142.


  Theognis, 3.

  Thomson, 40.

  "Treasury of Human Inheritance," 196.
    symbols used by, 148-150.

  Tredgold, quoted, 224, 225.

  Tuberculosis, and order of birth, 124, 125.
    associated with alcoholism, 204.
    pedigree of pulmonary, 168, 171.

  Typhoid fever, eradication of, 223.


  Unit characters, 53.
    list of, 98, 99.

  Unit characters, relation of, to Mendel's law, 95-99.

  United States Census Reports, statistics of defectives, etc., 28-34.

  University of London, 14.


  Variability, 56-63.
    measure (coefficient) of, 61-63.
    of human traits, 69, 70.

  Variation, 55-70.
    and modification, 75.
    application of, in Eugenics, 70-77.
    distinguished from variability, 63, 64.

  Vasectomy, 218-225.
    Connecticut statute permitting, 220-222.
    Indiana statute permitting, 218, 219.


  Wallace, Alfred Russell, 6.

  Warbasse, quoted, 195.

  Webb, Sidney, 122.

  Wheat, new varieties of, 133, 134.

  Whetham, quoted, 35, 74, 75, 229, 237-239, 240.

  Winship, data regarding Edwards family, 187, 188.

  Woods, heredity in royalty, 145.


  _Zero, Die Familie_, 184-187.




                         TRANSCRIBER'S NOTES


1. Passages in italics are surrounded by _underscores_.

2. Illustration captions are indicated by =caption=.

3. Images and tables have been moved from the middle of a paragraph to
the closest paragraph break.

4. Figure 17 is missing from the scanned pages even though there is no
break in the continuity of page numbers.

5. The word oedema uses an oe ligature in the original.

6. The following misprints have been corrected:
      "stattistical" corrected to "statistical" (page 81)
      Removed stray bracket in "second parent)" (page 93)
      Added period at end of abbreviation "N.S.W" (page 115)
      "conditons" corrected to "conditions" (page 245)

7. Other than the corrections listed above, printer's inconsistencies
in spelling, punctuation, hyphenation, and ligature usage have been
retained.