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DARWINISM AND HUMAN LIFE

DARWINISM AND
HUMAN LIFE

THE SOUTH AFRICAN LECTURES FOR 1909

BY

J. ARTHUR THOMSON, M.A.

Regius Professor of Natural History in the University of Aberdeen

AUTHOR OF ‘‘THE STUDY OF ANIMAL LIFE,” ‘' THE SCIENCE OF LIFE,”

‘OUTLINES OF ZOOLOGY,” ‘‘THE NATURAL HISTORY OF THE YEAR,”

‘(THE PROGRESS OF SCIENCE IN THE CENTURY,” ‘' HERBERT SPENCER,”

“HEREDITY,” “THE BIBLE OF NATURE,” ETO.; JOINT AUTHOR OF
‘(THE EVOLUTION OF SEX,”

NEW YORK
HENRY HOLT AND COMPANY
LONDON: ANDREW MELROSE

PRINTED BY
HAZELL, WATSON AND VINEY, LD.
LONDON AND AYLESBURY,
ENGLAND,

DEDICATION

This short course of lectures on a great theme is a centenary

tribute to Charles Darwin, but I wish also to ask the many

friends who made me no stranger in their country—men and

women of diverse opinions, at one however in their evolu-

tionist outlook and in their good-will—to lay it on the

threshold of United South Africa. Quod bonum, felix
faustumque sit /

PREFACE

In 1908 the Lecture Committee of the South
African Association for the Advancement of Science
did me the honour of inviting me to give the
“South African Lectures” for 1909, and sug-
gested that, in view of Darwin’s Centenary, the
subject of the course should be Darwinism. It
was the chief aim of the lectures to explain the
gist of Darwinism—what problems Darwin set
himself to solve, and what solutions he arrived
at, and to indicate what progress has been made
as regards the problems of Organic Evolution
since Darwin’s day—what has been added to
Darwinism, what, if anything, has been taken
away, and, especially, what is now being recon-
sidered. An endeavour—necessarily straitened by
the limits of the course—was also made to suggest
how Darwinism touches everyday life, in farm and
garden, in city and empire.

CONTENTS

CHAPTER I

WHAT WE OWE TO DARWIN

Biographical—Darwin’s Books—The Naturalist’s Problems—The
first Question: What is This ?—The second Question: How does
This work ?—The third Question: Whence is This ?—The fourth
Question: How have Present-day Organisms come to be as they
are ?—Manifoldness of Darwin’s Services—The Web of Life—The
Struggle for Existence—Variability of Living Creatures—Natural
Selection—Vindication of the Evolution Idea—The Evolution
Theory, a Modal Interpretation—Darwin’s Argument—Comparison
of Evolution Formula and Gravitation Formula—The Descent and
the Ascent of Man—Liberation of Intelligence—Ideal of Scientific
Mood and Method—Characteristics of Scientific Mood: Passion and
Reverence for Facts—Scientific Caution—Clearness of Vision—
Sense of Interrelations—Darwin’s Method of Working—Darwin on
his own Success—Darwin’s Achievements—Co-operating Influences
—Particular Reasons for Darwin’s Success . . + pp. 3-42

CHAPTER II

THE WEB OF LIFE

Correlation of Organisms as well as Correlation of Organs—What
the Metaphor of “ The Web of Life ’’ suggests—Dependence of Living
Creatures upon their Surroundings—Nutritive Chains—Nexus

ix

x CONTENTS

between Mud and Clear Thinking—Correlation between Catches of
Mackerel and Amount of Spring Sunshine—Nuitritive Chains in the
Deep Sea—Dependence of one Organism on another for the Con-
tinuance of the Species—Darwin’s Instance of the Connection
between Cats and Clover—Scattering of Seeds—Interrelations
between Freshwater Mussels and Fishes—Life-histories of Parasites
—Far-reaching Influence of Certain Animals: Earthworms—Ter-
mites, or White Ants—The Hand of Life upon the Earth—Practical
Importance of a Realisation of the Web of Life . » pp. 45-65

CHAPTER III
THE STRUGGLE FOR EXISTENCE

The Idea not so Simple as it seems—The Anthropomorphism of
the Idea—Different Forms of the Struggle for Existence—Struggle
for Existence in the Plant World—Illustration of the Complexity
of the Struggle for Existence—Reasons for the Struggle for Existence
—Results of the Struggle for Existence—Breadth of the Darwinian
Concept of the Struggle for Existence—The other Side of the
Struggle for Existence—Mutual Aid—Application of the Concept
to Human Life . ° . * ‘ * . »- pp. 69-94

CHAPTER IV
THE RAW MATERIALS OF PROGRESS

Organic Progress Primarily depends on Variability—Darwin’s
Position—Progress since Darwin’s Day in Regard to Variation—
Variations more Abundant than even Darwin supposed—Proportion
between Frequency and Amount of Variations—Correlation of
Variations—Brusque Variations more Frequent than was formerly
supposed—Discontinuous Variations—Mutations—Darwin’s Posi-
tion in Regard to Mutations—Origin of Variations—Germinal
Selection—Variational Stimuli—Modifications or Acquired Charac-
ters—Indirect Importance of Modifications—Modification-Species—
Individual Plasticity—Relation to Human Life « pp. 97-126

CONTENTS xi

CHAPTER V

FACTS OF INHERITANCE

Progress during the Darwinian Era—Demonstration of Heritable
Qualities—Heredity, u Term for the Genetic Relation between
Successive Generations—Appreciation of Distinction between
Nature and Nurture—The Idea of the Continuity of Generations—
Critical Attitude in Regard to Various Conclusions—Mendelism—
Methods of Studying Heredity—Microscopical Study of the Germ-
cells—Statistical Study: Filial Regression—Galton’s Law of
Ancestral Inheritance—Experimental Study—Pairing of Similar
Pure-bred Forms—Blending—Particulate Inheritance—Exclusive
Inheritance—Reversion—New Departures—Mendelian Inheritance
—Unit Characters—The Case of Andalusian Fowls—Waltzing Mice
—Occurrence of Mendelian Inheritance—Practical Importance of
Mendelism—Much Progress but Great Uncertainty—Transmission
of Acquired Characters—Disease—Facts and Possibilities—A
Striking Case—Logical Position of the Question—Cases where
the Theory of Modification-inheritance is Inapplicable—Im-
portance of Environment and Function Remains—Selection and
Stimulus—Indirect Importance of Modifications—Practical Im-
port of the Question as to the Transmission of Acquired
Characters—Inheritance of Moral Character—Three General
Conclusions . . . : . : - pp. 129-177

CHAPTER VI

SELECTION : ORGANIC AND SOCIAL

Influence of Malthus—Darwin’s Position—The Theory stated—
The Theory of Natural Selection to be tested as an Interpretative
Formula—Illustrations of Natural Selection—Objections and
Criticisms—Adaptations—Changes since Darwin’s Day—Evidences
of Natural Selection—Lessening the Burden of the Theory—Sexual
Selection—Isolation—Gradual Diminution of Natural Selection in

aoe CONTENTS

i

Ee between the Human Race and the Animal
World—Some Natural Selection remains—The Dilemma of Civilisa-
tion—The extreme laissez-faire Position—Social Surgery—How far
is Social Selection compensating for Diminished Natural Selection?—
Reversed Selection in Human Society—Summary of the Argument—
Constructive Suggestions—Selection of Eutopias—Selection of
Healthful Occupations—Eugenic Selection. - pp. 181-237

REPRESENTATIVE BOOKS ON DARWINISM . pp. 241-245

CHAPTER I
WHAT WE OWE TO DARWIN

CHAPTER I

WHAT WE OWE TO DARWIN

Biographical—Darwin’s Books—The Naturalist’s Problems—The
first Question: What is This ?—The second Question: How
does This work ?—The third Question: Whence is This ?
—tThe fourth Question: How have Present-day Organisms
come to be as they are ?—Manifoldness of Darwin’s Services
—The Web of Life—The Struggle for Existence—Variability
of Living Creatures—Natural Selection—Vindication of the
Evolution Idea—The Evolution Theory, a Model Interpreta-
.tion—Darwin’s Argument—Comparison of Evolution Formula
and Gravitation Formula—The Descent and the Ascent of
Man—Liberation of Intelligence—Ideal of Scientific Mood
and Method—Characteristics of Scientific Mood: Passion and
Reverence for Facts—Scientifie Caution—Clearness of Vision
—Sense of Interrelations—Darwin’s Method of Working—
Darwin on his own Success—Darwin’s Achievements—Co-
operating Influences—Particular Reasons for Darwin’s Success.

BroGRAPHicaL.—Charles Darwin, the greatest natu-
ralist who has yet lived, was born at Shrewsbury
on February 12, 1809, on the same day as Abraham
Lincoln. Indeed the year was one of remarkable
children, for it saw the birth of Tennyson and
Gladstone, of Chopin and Mendelssohn, of Mrs.
Browning and Fanny Kemble, of Edgar Allan
Poe and John Hill Burton, of Edward Fitzgerald
and Oliver Wendell Holmes, and many more. We
shall not compare Darwin with any of the
illustrious personalities whom we have named,
for the comparison of incommensurables is always
unprofitable; but without exaggeration, which
3

4 DARWINISM AND HUMAN LIFE

should be absent from scientific discourse, it may
be said that no other man of science has influenced
the framework of human thought as Darwin has
done. We propose, first of all, to recall very briefly
the leading facts of his life.

Darwin’s inheritance must have given him a
scientific bent. His grandfather, Erasmus Darwin,
the author of “ Zoonomia ” (1794) was a thoughtful
evolutionist; his father, Robert Waring Darwin;
also a physician, had an unusually keen faculty
of observation; his mother was a daughter of
Josiah Wedgwood, the founder of the famous
pottery works; and it may be further noted that
Sir Francis Galton is Darwin’s cousin. . In addi-
tion to actual inheritance, there was another
influence which would tend to direct Darwin’s
mind towards science, namely, the scientific atmo-
sphere and tradition of his home.

As a boy Darwin was strong and active; he
was fond of open-air life, and he made nothing
of the classical school to which he was sent. In
1825 he went with his brother to Edinburgh with
the purpose of studying medicine; but he found
the lectures “intolerably dull” and made little
of them. He got to know several naturalists,
however, and made his first discovery—in regard
to the development of the sea-mat (Flustra). After
two sessions at Edinburgh he went to Cambridge
with the vague view of becoming a clergyman ; but
of this period he writes: ‘‘ During the three years
which I spent at Cambridge my time was wasted,
so far as academical studies were concerned, as
completely as at Edinburgh and at school.”

During his stay at Cambridge he kept up his
boyish beetle-collecting and indulged his fondness

WHAT WE OWE TO DARWIN 5

for riding and shooting. He came under the
influence of Professor Henslow, the botanist, who
advised him to read Lyell’s “Principles of
Geology,” and was instrumental in sending him
off on the Beagle.

Of the Beagle voyage, which extended for five
years (1831-6), mainly spent along the coasts of
South America, Darwin says: “ This was by far the
most important event in my life, and has deter-
mined my whole career.” He learned to work
hard, he accumulated a wealth of impressions, and
he had time to think. On one of his land journeys
over the Pampas he was struck by the resemblances
between living and extinct forms, and wrote: “ This
wonderful relationship in the same continent
between the dead and the living will, I do not
doubt, hereafter throw more light on the appearance
of organic beings on our earth, and their dis-
appearance from it, than any other class of facts.”
The savage character of the natives at Tierra del
Fuego and the individuality of the fauna on the
various Galapagos islands were seed-impressions
which afterwards bore fruit in thought.

For six years after returning from the Beagle
voyage, Darwin worked in London at his collections,
especially at the geological specimens. He pub-
lished his “‘ Naturalist’s Voyage ” in 1839, and in
the same year married his cousin, Emma Wedg-
wood. As his health had not been good after his
return from the Beagle, he left London in 1842,
and settled in a country house at Down. There
in quiet industry, badly hampered by ill health,
he spent the rest of his life. He died on April 19,
1882, one of the great Immortals among men.

Darwin’s Books.—The forty years at Down

6 DARWINISM AND HUMAN LIFE

were punctuated by the completion of book after
book—the “ milestones of my life,” as he called
them; and it may be useful to note that Darwin
recognised three stages in his career as a biologist:
(1) the mere collector at Cambridge; (2) the
collector and observer on the Beagle voyage (to
which he thought he owed “ the first real training
and education ” of his mind); and (8) the trained
naturalist after his eight years’ work on barnacles.

His books may be arranged in three groups:

(a) The early zoological and geological studies,
e.g. “ Zoology and Geology of the Beagle ” (1840-
46), “ Coral Reefs” (1842), “Monograph on the
Cirripedia ” (1846-54). Although the book on
Earthworms was not published till 1881, it was
begun more than forty years before, and may be
included in the first series.

(b) The series of evolutionary volumes: “ The
Origin of Species” (1859); “ Variation of Ani-
mals and Plants under Domestication” (1868) ;
“ Descent of Man” (1871); “ Expression of the
Emotions ” (1872).

(c) The botanical books—largely influenced by
evolutionary ideas: “ Fertilisation of Orchids ”
(1862); ‘‘Movements and Habits of Climbing
Plants ” (1875); “ Insectivorous Plants ’ (1875) ;
“Cross and Self-fertilisation in Plants” (1876) ;
“The Different Forms of Flowers in Plants of the
same Species ” (1877) ; ‘‘ The Power of Movement
in Plants” (1880).

Tue NaTuRALISsT’s PRoBLEMS.—It may be useful
to inquire into the aims and methods of naturalists
in general, if we are rightly to appreciate the
services rendered by the greatest of them all. The
problems appear at first sight to be numerous and

WHAT WE OWE TO DARWIN 7

varied, but, from a certain distance, we see that
naturalists ask only four questions: What is this
living creature? How does it work? Whence
has it arisen? How has it come to be as it
is? Darwin asked each of these questions, but,
after serving his apprenticeship in answering the
first three—for he was anatomist, physiologist,
and paleontologist in turn—he settled down to
the fourth—the question of questions—How have
living creatures come to be as they are ?

The Question What is This?—The naturalist’s
first question—however learnedly he may phrase
it—is one of the child’s first questions, asked long
before it can speak: “ What is this?” In how
many different tones—of fear, of awe, of wonder,
of inquisitiveness—has this question been asked
since man and science began! Was it not
Aristotle’s question when a new specimen was
brought to him? Was it not the question of
the naturalist on the Challenger when the dredge
came up? Is it not the question on the lips of
every teacher and student of natural history
to-day ?—What is this? It is a “simple ques-
tion,’ but how hard to answer, as we press it
further and further home, from external features
to internal structure, from organs to tissues, from
tissues to cells, as we put one lens after another in
front of our own, as we call to our aid all sorts
of devices—scalpel and forceps, razor and micro-
tome, fixative and stain! “ What is this,” we
say, “in itself and in all its parts ? what is this by
itself and when compared with its fellows and
kindred 2’, and our answer broadens and deepens
till it furnishes the raw materials of the science of
morphology,

8 DARWINISM AND HUMAN LIFE

The Question How does This work?—But close
upon the first question—What is this ? there rises a
second—How does this work? It is equally natural
and necessary, and throughout the progressive
periods in the history of biology the two questions
have never been far apart. They have evolved
together especially during the last hundred years,
prompting one another to a more and more pene-
trating inquisitiveness. The key-word of the one
is structure, or organisation ; of the other function,
or activity. The creature which our first question
killed and picked to pieces has to be put together
again and made to work. What does it do? how
does it do it? how does it go? how does it keep
a-going ? how does it set other creatures like itself
a-going ? how long can it go? how does it cease
from going? In other words, how does the
organism feel and move? how does it grow and
multiply ? how does it waste, recover itself, and
finally, in most cases, die? Above all, what
is the secret of its activity and of its power of
effective response to the order of nature? These
are some of the physiological problems which
recall Clerk Maxwell’s boyish question—‘“ What is
the go of this—the particular go of this?”

The Question Whence is This ?—A third question
is—Whence is this? and, though it is probably
as ancient as the others, the answering of it is
distinctly modern. It is really a double question,
for we may inquire into the development—the
becoming—of the individual, and we may in-
quire into the history of the race to which the
individual belongs. We may study the child-
animal in its cradle—the bee-grub in the comb,
the embryo skate in its mermaid’s purse, the

WHAT WE OWE TO DARWIN 9

chick within the egg-shell—and the answer to the
question—Whence came this individual animal
as a whole and in each of its parts ? is embryology.
On the other hand, we may study the history of
the race as it is hidden in the strange graveyards
of the buried past, the fossil-bearing rocks, and
the answer to the question—Whence came this
race? is paleontology.

The Question How have Present-day Organisms
come to be as they are?—There remains a fourth
question, also ancient, but since Darwin’s day
asked with a new hopefulness—How have these
living creatures come to be as they are? They have
had a history—a slow racial evolution—as surely
as they have an individual development. We
have got a firm grasp of the modal theory—that
the present is the child of the past, but the causal
theory is still being evolved. The idea of evolution
is the most potent thought-economising formula
which the world has yet known, but as to the
factors in evolution we are still only inquiring.
What are the originative and what the directive
factors ¢ How has the raw material of progress,
which we call variation, been made available
throughout the countless ages ? and how has’ this
raw material been fashioned to shape and use 2

MANIFOLDNEsSsS OF DaRwin’s SeRvices.— What
do we owe to Darwin? It is the meed of greatness
to receive manifold tribute. For how many diverse
reasons has Shakespeare the world’s homage! A
great life-work is like a great picture ; this character
appeals to me and that to you. So some say that
what we most owe to Darwin is our evolutionist out-
look, while others emphasise the idea of selection,
and others the demonstration that the problems

10 DARWINISM AND HUMAN LIFE

of heredity and variation are amenable to
scientific analysis, and others that he first clearly
showed the affiliation of man to the rest of creation.
The fact is that Darwin focussed so many ideas
that were previously dim; and made so many old
facts new, and gave us keys to so many doors, that
it is a matter of opinion which of his services was
greatest. This, at least, is certain: that, when
we have thought for an hour of what we owe to
Darwin, we shall not have discovered how much
that is. For his intellectual legacy is still earning
interest and increasing our wealth. His leaven
will go on fermenting till the whole is leavened.
Then it will be time for a new yeast.

(I) THe Wes or Lire.—What do we owe to
Darwin? We give precedence to Darwin’s picture
of “The Web of Life,” the service that appeals
most to the naturalist, to whom the conception is
absolutely fundamental. It lies below the idea of
the Struggle for Existence, and therefore below the
idea of Natural Selection. It is a fact of life which
will remain, however theories may change. It
is a fine idea to dream over and to work with.

What is meant by Darwin’s picture of the Web
of Life, and where did he paint it? We find it
in all his works—a luminous background—the
idea of linkages in nature, the idea of the corre-
lation of organisms. Cats have to do with the
clover crop, Darwin says, and earthworms with
the world’s bread supply. If there is an orchid in
Madagascar with a spur eleven inches long, Darwin
prophesies that there is a moth with a proboscis
of equal length. No bird falls to the ground
without sending a throb through a wide circle, for
Darwin rears eighty seedlings from a single clod

WHAT WE OWE TO DARWIN 11

taken from a bird’s foot. Long nutritive chains
bind the bracken on the hill-side to the brain
of the proprietor—if he is fond of eating trout.
The patent-leather shoes on his feet connect him
with the melancholy slaughter of seals, while
his ivory-backed toilet-brushes implicate him in
the passing of the elephant. There is a ceaseless
circulation of matter and energy. All things
flow. Influence passes from A. to Z., though
Z. is quite unaware of A. What ripples spread
and spread from the introduction of rabbits into
Australia, or of sparrows into the United States,
or of the mongoose into Jamaica! What abso-
lutely essential connections there are between
cutting down trees and a plague of insects, between
birds and seed-scattering, between sunlight and
the catches of mackerel !

Take an instance from “The Origin of Species ” :
“Tf certain insectivorous birds were to decrease
in Paraguay, the parasitic insects would probably
increase; and this would lessen the number of
navel-frequenting flies—then cattle and horses
would become feral, and this would certainly
greatly alter (as indeed I have observed in parts of
South America) the vegetation ; this, again, would
largely affect the insects ; and this, as we have just
seen in Staffordshire, the insectivorous birds, and
so onwards in ever-increasing circles of complexity.”

(II) Toe StruceLe ror Existence.—What do
we owe to Darwin? In the second place, we may
rank his realisation of “the struggle for exist-
ence.” From Aristotle to Lucretius, from Buffon
to Robert Chambers, there had been allusion to
the struggle for existence in nature, and every one
knows, for instance, haw it recurs repeatedly in

12 DARWINISM AND HUMAN LIFE

Tennyson’s “In Memoriam,” which was written
before “ The Origin of Species.” The poet speaks
of Nature “ red in tooth and claw with ravine ”’ ;
“so careless of the single life”; “of fifty,” or
(as he afterwards suggested) “of myriad seeds
she often brings but one to bear.” But itis certain
that no one before Darwin realised the length
and breadth, the height and depth, of the struggle
for existence. His realisation of it is “ bigger”
than that of most of his successors. Darwin
recognised the struggle between Fellows, the
struggle between Foes, and the struggle be-:
tween Living Creatures and the Physical Forces.
(a4) There is cannibalism in the cradle in the
egg-capsules of the buckie and the dog-whelk ;
locust may eat locust when the worst comes to
the worst; stag may fight to the death with
stag in the forest clearing; certain mountain-
varieties of sheep will starve out other mountain-
varieties; the sister seedlings compete together
in the plot: that is Struggle between Fellows. We
may extend this category of competition between
individuals of the same species to include com-
petition between individuals of nearly related
species, though what is involved in the step should
be carefully noticed. If we make the extension,
however, we include Darwin’s well-known case
of brown rat versus black rat. The other illus-
trations he gave concerned two kinds of thrush,
two kinds of swallow, two kinds of cockroach, and
two kinds of charlock. (B) Secondly, the world
is full of competition and struggle between living
creatures not nearly related to one another—
between fox and hare, between stoat and rabbit,
between mongoose and snake, and so on, end-

WHAT WE OWE TO DARWIN 13

lessly: that is Struggle between Foes. The foes
do not need to be well matched. Alfred Russel
Wallace has recently told us of a pair of blue tits,
with a large family, who worked for sixteen hours
a day at midsummer, and it was estimated that
they captured in that time about two thousand
caterpillars and grubs. A locust-bird at work is
another good instance of a one-sided struggle.
Nor do the foes need to compete directly—it will
suffice if both seek the same food, the same locality,
the same anything. (c) Darwin recognised a
third great mode of the struggle for existence
when he spoke, for instance, of a plant on the
edge of the desert struggling for life against the
drought, and of the birds struggling against the
winter. This is the Struggle with Fate.

As a number of illustrious living naturalists
persist in maintaining that what Darwin mainly
thought of was the struggle between near kin—
for room in the nest, for food at the platter,
for foothold on the rock, and so on, we must
remember Darwin’s emphatic statement that he
used the term “in a large and metaphorical
sense.” He speaks of two “canine animals”
struggling with each other in a time of dearth;
of mistletoe versus mistletoe on the same branch ;
of mistletoe versus other fruit-bearing plants ;
of a plant on the edge of the desert in days of
drought ; and then says, “ In these several senses,
which pass into each other, I use, for convenience’
sake, the general term of Struggle for Existence.”
The fact is that the “struggle for existence ” is a
formula-phrase including all the reactions and
endeavours of living creatures in face of difficulties
and limitations.

14 DARWINISM AND HUMAN LIFE

(III) Vartapiuity or Livinc Creatures.—What
do we owe to Darwin? A vivid presentation of
the idea of variability, or organic flux. There had
been, of course, transformists before his day, but
either they had not the idea very clearly in their
own minds or they failed in making it convincing
to others. So it was that Darwin had to make
way against the general conviction of contemporary
naturalists that species were fixed. In 1844 he
wrote to Hooker: “I am almost convinced .. .
that species are not (it is like confessing a murder)
immutable.” The idea seems to have suggested
itself more than once on the Beagle voyage; for
instance, when he found fossils in Argentina very
like living forms and yet different.

In forming his impression of the variability of
living creatures Darwin depended on what has
taken place in domestication and cultivation,
on the experience gained in his systematic work
that specific characters are far from being constant,
and that so-called varieties often link species to
species. A species is a group of similar individuals
of common descent, capable of pairing together,
and breeding more or less true. It may be repre-
sented by a constellation of dots, densest towards
the centre (which means that the great majority
are very like one another) and thinning out to-
wards the periphery where the variants extend
as outliers in different directions. When we
begin to study a corner of the zoological sky it
seems to be covered with very distinct constella-
tions, and it is all clear; but in many cases deeper
study shows that one constellation is connected
with another by outliers, and that there is con-
tinual flux.

WHAT WE OWE TO DARWIN 15

Darwin recognised the occurrence of structural
changes directly due to changed surroundings
and changed habits, which he called “ definite
variations,” which are now usually called modi-
fications, or “acquired characters”; and he believed
that these were, in some cases, transmitted. This
is the characteristic Lamarckian position. But the
raw materials of progress which Darwin chiefly
relied on were what he called the ‘‘ numerous, suc-
cessive, slight, favourable variations ” (“ Origin of
Species,” p. 421). He also took account of “sudden
and considerable deviations of structure ”—“ single
or occasional variations,” as he called them; but
he very deliberately refrained from attaching
importance to such leaps and bounds, thinking
that they had no staying power in inheritance.
As to the causes of the inborn variations in living
creatures, Darwin had no light, and, with his
characteristic candour, said so.

(IV) Naturat SELEcTION.—What do we owe
to Darwin? The theory of Natural Selection,
which his magnanimous fellow-worker, Alfred
Russel Wallace, independently stated at the same
time (1858), and of which there had been a few
previous suggestions of a more or less vague de-
scription. It was here that Darwin’s originality
was greatest, for he revealed the many different
forms—often very subtle—which Natural Selection
takes, and, with the insight of a disciplined scientific
imagination, he realised what a mighty engine of
progress it has been and is. His theory is simple
and admits of brief statement. We can under-
stand Huxley’s remark: “‘ How extremely stupid
not to have thought of that!”

(1) Variability is a fact of life. The members of

16 DARWINISM AND HUMAN LIFE

a family or of a species are not born alike: some
have qualities which give them a little advantage
both as to hunger and as to love; others are
relatively handicapped. We may not understand
their origin, but we know that useful variations
occur.

(2) A struggle for existence is also a fact of
life—a struggle for existence in an _ intricate
web of interrelations. It operates whenever there
is disturbance of equilibrium or clashing of inter-
ests, whenever the living creature makes effective
responses to the limitations closing in upon it.

(3) In certain forms of the struggle for existence
the relatively less fit forms are eliminated, which
does not necessarily mean that they come at
once to a violent end, but often simply that they
die before the average time and are less successful
than their neighbours as regards their offspring.
The result is that the relatively more fit tend
to survive, and to become the majority. The fit-
ness may refer to the whole constitution, or to a
particular character.

(4) As many variations are transmitted from
generation to generation, and may, through the
pairing of similar or suitable mates, be gradually
increased in amount, the eliminative or selective
process, if discriminate, consistent, and sustained,
will work towards the establishment of new
adaptations and new species. Natural Selection is
Nature’s process of singling and sifting for parent-
hood by the discriminate elimination of the relatively
less fit to the given conditions.

Take, in the meantime, just one illustration.
In Dublin Bay there is a sandy island, about
120 years old. It is frequented by a light-coloured

WHAT WE OWE TO DARWIN 17

variety of mouse which burrows in the sand.
It seems reasonable to interpret the prevalence
of this inconspicuous sand-coloured variety as
due to the elimination of the ordinary darker
mice by birds of prey.

Wallace asks the interesting question: Why,
after many had failed, did Darwin and he find
the same solution of the riddle of progress, namely,
in Natural Selection? He points out that they
had certain experiences in common: (1) as ardent
beetle-hunters from their youth up, they were both
accustomed to study minute details and varieties,
and they thus had a trained eye for individualities ;
(2)*they both had a speculative turn of mind, and
were fond of trying solutions ; (3) they both enjoyed
the wealth of impressions that travel gives, and the
boon of solitude and quiet in which to “ attend
their minds unto” the problem that “ haunted ”
them; and (4) both had read Malthus. Perhaps
one might add that both had realised the selective
processes implied in the keen competitive con-
ditions of their time.

(V) Vrnpication or THE EvoLuTIoN IpEa.—
What do we owe to Darwin? The first successful
vindication of the evolution idea. It was not
his own, nor was he its first champion, yet we
always, and rightly, think of Darwin and the
Doctrine of Descent together. He made it current
coin of the intellectual realm. He made the
nations “ think in terms of evolution.”

The central idea of evolution is that the present
is the child of the past and the parent of the
future. It is the idea of progressive change from
phase to phase without loss of continuity. A
process of Becoming leads to a new phase of

2

18 DARWINISM AND HUMAN LIFE

Being—whether in solar systems or in social
institutions or in living creatures. But in the
first the continuity is sustained in identity of
substance, in the second by tradition and social
registration, and in the third by the hereditary
linkage of successive generations.

_ “ Stated concretely, in regard to living creatures,
the general doctrine of descent suggests, as we
all know, that the plants and animals now around
us are the results of natural processes working
throughout the ages; that the forms we see are
the lineal descendants of ancestors on the whole
somewhat simpler, that these are descended from
yet simpler forms, and so on backward, till “we
lose our clue in the unknown—but doubtless
momentous—vital events of pre-Cambrian ages,
or, in other words, in the thick mist of life’s
beginnings.” *

* As in the development of a fugue,” Samuel
Butler says, ‘‘ where, when the subject and counter-
subject have been announced, there must thence-
forth be nothing new, and yet all must be new,
so throughout organic nature—which is a fugue
developed to great length from a very simple
subject—everything is linked on to and grows ©
out of that which comes next to it in order.”

The evolution idea is not only essentially simple,
it is also very ancient. It is as old as Aristotle—
and older. It is perhaps as old as clear thinking,
which we may date from the unknown time when
man discovered the year, with its marvellous
object-lesson of recurrent sequences, and realised
that his race had a history. Whatever may have

1 “ The Study of Animal Life,” by J. Arthur Thomson. (Murray,
London.)

WHAT WE OWE TO DARWIN 19

‘been its origin, the idea was familiar to several
of the ancient Greek philosophers, as it was to
Hume and Kant; it fired the imagination of
Lucretius and linked him to Goethe; it persisted
through the ages of other than scientific pre-
occupation; it became a concrete theory of the
transformation of species in the hands of the
pioneers of modern biology—such as Buffon,
Lamarck, Erasmus Darwin, and Treviranus; and
it became current intellectual coin when Charles
Darwin, Alfred Russel Wallace, Herbert Spencer,
Huxley, and Haeckel, with united but varied
achievements, won the conviction of most thought-
ful men.

Tue EvotutTion THEoRY A Mopat INTERPRE-
TATION.—It must be carefully noted that the
general idea of organic evolution is a modal inter-
pretation of the history of the animate world. It
suggests the mode by which organisms have come
to be as they are. It says that the mode is scien-
tifically decipherable, and is comparable to what
we see going on in the origin of new breeds of
pigeons or new varieties of wheat. But what
other view is there? We do not know of any
other scientific view, and the only alternative is
to maintain that the mode of origin of the various
kinds of living creatures is undecipherable scien-
tifically, and cannot be formulated except in
transcendental terms, such as Creation. The
general view when Darwin published the “ Origin
of Species” was Creationist, or, if the naturalist
fought shy of such words, the Linnean dogma
of the Fixity of Species was accepted and the
question of origin was regarded as hopeless.

Much will be gained if we clearly understand

20 DARWINISM AND HUMAN LIFE

that the theory of evolution suggests a modal
interpretation within the scientific universe of
discourse, while the other view gives up even
the possibility of scientific re-description, and
suggests a transcendental formula as alone possible.
It is quite certain that there is no manner of
use in pitting a scientific formula against a trans-
cendental one: that always means a false anti-
thesis and intellectual fog. They are incom-
mensurables. The true antithesis is between a
scientific interpretation and maintaining that it
is impossible to give one.

There is an intricate, beautiful, rational pattern
before us in nature: are we to think of it as woven,
thread by thread, by invisible hands in a way
past finding out scientifically; or was there so
much mind put into the original institution of
things—an apparently simple loom—that thence-
forth the web has been worked out automatically
in a manner that admits of scientific formulation ?
When we finally discover that the doctrine of
descent and all the theories of evolution do not
fundamentally explain what they formulate,’ we

1 This expresses the common view that science is re-description
in “simpler terms’’—which, however, are not themselves “ ex-
plained.” In regard to complexities such as development and
behaviour we formulate sequences, but we cannot flatter ourselves
that our notations are more than symbols of the realities. In
his “L’Evolution Créatrice,” Prof. Henri Bergson states this
position (which he does not hold) in the following sentence:
“Ce n’est plus la réalité méme, dit-elle, qu’elle recomposera, mais
seulement une imitation du réel, ou plutét, une image symbolique ;
Pessence des choses nous échappe et nous échappera toujours, nous
nous mouvons parmi des relations, labsolu n’est pas de notre
ressort, arrétons-nous devant l'Inconnaissable.” For an exposition
of this scientific position see “ The Bible of Nature,” by J. Arthur
Thomson (1908).

WHAT WE OWE TO DARWIN 21

shall be able, perhaps, to return to the transcen-
dental formula with intelligence.

In regard to the proposition that science offers
not explanations but formulations, it is important
to bear in mind (1) that the biologist, for instance,
postulates simple living creatures with which
to start his story of evolution; (2) that he also
takes for granted throughout the organism’s
power of varying and trading with time; (3)
that he does not account, as yet, for the “ big
lifts * in the process of evolution, or for the direc-
tion in which the tree has grown (vertically, so
to speak, as well as horizontally)—a direction
which gives the whole process greater significance ;
and (4) that the biologist’s causal equation is not
like those of mechanics, where causa aequat effectum.
Bergson distinguishes (a) a cause acting par
wmpulsion, as when one billiard-ball strikes an-
other (where the quantity and quality of the
effect vary with the quantity and quality of
the cause); (5) a cause acting par délanchement,
as when a spark makes the powder explode (where
the invariable effect has no relation to the quantity
and quality of the cause); and (c) a cause acting
par déroulement, as when the spring which
works the gramophone unrolls the tune on the
cylinder (where the quantity of the effect is pro-
portionate to the quantity of the cause). In the
first case only does the cause explain the effect,
but living is not such an effect.

Darwin’s ArcuMENT.—What did Darwin really
do in regard to the general doctrine of organic
evolution? He showed that it rationalises our
whole outlook. He took a wide sweep of things
as they are and showed that they admit of evo-

22 DARWINISM AND HUMAN LIFE

lutionist interpretation. There are no locks which
its key does not fit. As there is often misunder-
standing in regard to the so-called “ evidences of
evolution,” we must note that Darwin’s magistral
work was not of the nature of an induction leading
up to the doctrine of descent as its conclusion.
It was a deductive vindication of the doctrine
that he gave us—“a cumulative justification
showing how well the formula fits a vast series of
facts.” We cannot agree with the statement
that Darwin proved in 1859 what Lamarck had
only suggested fifty years before,’ for there is no
logical proof of the doctrine of descent. It must
be allowed, however, that Darwin’s illustrations—
what some would call his cumulative evidence—
were so carefully chosen that they left few openings
for effective criticism. The basis of fact which
the formula was shown to fit was solid, broad, and
representative.

(a) Darwin pointed to the evolution which is
going on in domesticated animals, such as sheep
and cattle, and in cultivated plants, such as
cabbages and apples, and used the argument: If
Man has been instrumental in fixing all these
varieties in a short time, what may not Nature
have effected in a very long time? This line of
argument has been greatly strengthened of recent
years by cases like De Vries’s mutations of the
Evening Primrose (Ginothera lamarckiana).

(b) There is significance in the broad fact that
it is possible to arrange the animal kingdom in
a provisional genealogical tree, showing stages
in progressive organisation from lower to higher

1 Lamarck’s “‘ Philosophie Zoologique” was published in 1809,
when Darwin was born.

WHAT WE OWE TO DARWIN 23

forms. When we take a particular group of
animals it is often possible to draw that branch
of the genealogical tree with a firmer hand, for
it is the mutual relations of the large series which
are so difficult. From the actual classification of
organisms, from the peculiar way in which the
categories are related one within the other—
species, genera, families, orders, classes—we get
an impression of affiliation which we do not get
from a classification of rocks or other inanimate
objects.

(c) Darwin attached great importance to the
anatomical evidence of adherence to general type
in spite of the most manifold diversity in external
form. If we take, for instance, a series of fore-
limbs among Vertebrates—the arm of a frog, the
paddle of a turtle, the wing of a bird, the fore-leg
of a horse, the flipper of a whale, the wing of a
bat, the arm of man—we find a detailed homology
not only as regards the bones, but as regards
muscles, nerves, and blood-vessels. It is difficult
to suggest any interpretation except that the
resemblance is due to relationship. As Darwin
said: ‘‘ How inexplicable is the similar pattern
of the hand of a man,. the foot of a dog, the wing
of a bat, the flipper of a seal, on the doctrine of
independent acts of creation! How simply ex-
plained on the principle of the natural selection
of successive slight variations in the diverging
descendants from a single progenitor ! ”

(d) Darwin made a good case out of rudi-
mentary or vestigial organs—the dwindling remains
of structures which were presumably well developed
in ancestral forms. Cetaceans have no visible
hind-limbs, but many show relatively small ves-

24 DARWINISM AND HUMAN LIFE

tiges buried deep below the surface. The whale-
bone whale has two sets of teeth which never cut
the gum, their place being taken by baleen plates.
The New Zealand Kiwi has minute traces of wings,
the limbless slow-worm has a rudimentary pectoral
girdle, man has scores of vestiges, such as the
third eyelid or the ear-moving muscles. Darwin
compared these vestiges to the unsounded letters
in many words, such as the “o” in leopard,
the “b” in doubt, the “g” in reign, which are
quite functionless, but tell us something about
the history of the words.

(e) It is a simple but eloquent fact that the
geological record in the fossil-bearing rocks shows
the gradual appearance of higher and_ higher
forms. At a certain stage in the history of the
earth all the animals were Invertebrates; then
fishes appeared, then amphibians, then reptiles,
then birds and mammals. As the ages have
passed, life has been slowly creeping upwards.
The rock-record corresponds in its sequences
with those deducible from comparative anatomy
and embryology.

Furthermore, the rock-record reveals quite a
number of connecting links, such as Archaopteryz,
the oldest known bird, which has some distinctly
reptilian features, and a larger number of generalised
types, such as Phenacodus, one of the ancestors
of the horse lineage, which bind together several
subsequently specialised families, or even orders.

In certain cases, where fossils have been ob-
tained from successive strata, the paleontological
series is wonderfully complete, and the various
stages in the evolution of tooth, or limb, or shell
appear like the stages in individual development,

WHAT WE OWE TO DARWIN 25

Thus there is convincing completeness in the
series uniting various species of the freshwater
snails, Paludina and Planorbis, and various types
of Ammonites. In the same way the remarkable
series of fossil horses, elephants, and crocodiles,
are either records of pedigree or conundrums.

(f) The development of the individual is often
in some measure interpretable as a condensed
recapitulation of the presumed racial evolution.
The individual, as Prof. Milnes Marshall said,
climbs up its own genealogical tree. Ontogeny
tends to recapitulate phylogeny, especially as
regards the stages passed through by a particular
organ, such as the brain or the heart. In their
early stages there is a remarkable resemblance
between the embryos of the higher Vertebrates :
they seem, as it were, to travel for some distance
along the same road before they diverge on their
several paths. Gill-slits occur in the development
of the embryos of reptiles, birds, and mammals,
although they have no respiratory significance and
are not of any use at all except that one seems to
become the Eustachian tube connecting the ear
with the back of the mouth. The young tadpole
of the frog is fish-like in many details, eg. as
regards the heart and circulation. The very
unsymmetrical flat fishes, such as flounder and
sole, pass through a symmetrical stage. In Fritz
Miiller’s “ Facts for Darwin” the recapitulation
idea was applied in detail to Crustaceans, and it
seems impossible to understand the often very
circuitous development unless it has an historical
significance.

(g) The facts of geographical distribution in
past and present suggest the gradual dispersal of

26 DARWINISM AND HUMAN LIFE

races from centres where they had their original
headquarters. Peculiar cases, such as the present-
day distribution of Camelide, or the fauna of
Australia, or the population of oceanic islands,
readily admit of evolutionist interpretations.

We have not given prominence to the so-called
evidences of evolution, partly because they have
been stated so often—eg. by Romanes and by
Milnes Marshall—partly because none of the so-
called evidence is in itself demonstrative in the
strict sense. All that is shown is that the formula
fits a wide and representative series of facts, and
enables us to think of them in a clear and rapid
way. What can be securely said is this, that all
biological facts can be used as evidence of evolution
if we know enough about them, and there are no
biological facts which are inconsistent with it,
so far as we know.

Comparison OF EvoLuTiIon FoRMULA AND
GRAVITATION FormuLa.—Let us compare the
evolution theory with one of the great physical
generalisations—the gravitation formula. Both
are simple in statement, both are wide as the
world in their applicability. We are aware of
no facts contradictory to either. Furthermore,
they are alike in this, that neither proposes any
ultimate explanation, that both are examples
of intellectual shorthand, of thought-economising,
descriptive formule. We do not know why
one body attracts another in the manner which
Newton formulated; we do not know why
life should have its power of slowly creeping
upwards. It has been pointed out that, just as
Newton started with gravitation as a big funda-
mental fact, so Darwin started from variation,

WHAT WE OWE TO DARWIN 27

and that both left their fundamental assumption
from experience unexplained.

But there is this difference between the gravi-
tation formula and the evolution idea, that the
experimental vindication of the first is easy,
while that of the second is, to say the least, ex-
tremely difficult. Whether we study the apples
falling in the orchard or the planets in their courses,
we can continually confirm the accuracy of the
gravitation formula, to which two centuries have
not added anything essential, from which two
centuries have taken nothing away.

But the evolution doctrine does not rest on a
foundation of this sort. Like wisdom, it is justified
of its children—by half a century’s using—and
to speak of proving it is to misunderstand it.

Before passing from the general idea of organic
evolution we must point out that it is no mere
doctrine of the schools, but an important human
asset—of practical and emotional, as well as of
intellectual value. In accepting the evolution
idea we lose no small part of its virtue if we do
not visualise it, if we do not, in some measure,
image the relative simplicity of life’s beginnings
and the long pageant that has passed in gorgeous
procession over the earth for millions of years ;
if we do not understand that evolution is going
on still and that it includes us and our doings in
its sweep.'

‘1 Emile Ferriére illustrates the theory of organic evolution
very clearly by drawing a parallel between species and languages.

A language may have many varieties, just as a species often
has. In both cases there is evidence of slow transformation and
of demonstrable pedigrees. Changes may be observed in actual

occurrence alike in languages and in organisms. It is possible
in both to distinguish changes arising from within (intrinsic varia-

28 DARWINISM AND HUMAN LIFE

(VI) Taz Descent anp Ascent oF Man.— |
What do we owe to Darwin? A recognition of .
man’s solidarity with the rest of creation, of his
affiliation to a Simian stock. In the cumulative
argument of the “Descent of Man,” Darwin
disclosed the rock whence he was hewn and the
pit whence he was digged, showing, not exactly
that “ man sprang from a monkey,” as the vulgar
idea is, but that man and anthropoid apes are
collateral branches from a common Primate stock
which remains hidden in obscurity.

Darwin gave details of the all-pervading simi-
litude of structure between man and the anthropoid
apes, to which the researches of recent years
have added such striking items as a sameness
in blood-reaction to Friedenthal’s test. He showed
how we carry about with us a museum of relics
indicative of our ancestry—a museum whose
catalogue now amounts, according to Wiedersheim,
to about a hundred items. The anatomical re-
semblances between adult man and adult apes
are associated with even closer resemblances in
the embryos, and gain additional significance
when we take into account the scanty skeletal
remains of primitive man, the lower races of
men, and the occurrence of almost sub-human
types occasionally born in times of distress.
The affiliation applies to mind as well as
body, for there is an ever-growing mass of

tions) from changes imposed from without (extrinsic modifications).
Young stages of a language show embryonic features, just as
languages that have been evolving for centuries show: vestigial
structures, such as the familiar unsounded letters in words. There
are fossil languages, just as there are fossil species. Both in
languages and in species we can recognise the operation of selective
processes and the effect of isolation,

‘WHAT WE OWE TO DARWIN 29

facts relating to peculiar psychoses in child and
adult which we must recognise as vestigial and
recapitulatory.'

Those who feel a repugnance to the Darwinian
conclusion that man is descended from a humble
Simian ancestry should remember the marvellous
ascent in each individual lifetime. Neither the
dignity nor the value of a result is affected by
the historical conditions of its becoming. And
if man is separated off by reason (or the power of
conceptual inference), by morality (or the habit
of controlling his conduct in reference to ideals),
by the possession of true language or Logos, and
by other qualities distinctively human, then we
must increase our respect for, and see more in,
that brute creation which contained the potenti-
ality of all. For it is a fundamental idea of
evolution that there is nothing in the end which
is not also in the beginning.

(VII) Liszration or INTELLIGENCE.—What do
we owe to Darwin? A great liberation of the in-
telligence. Like Abraham Lincoln, who was born
on the same day in the same year, Darwin worked
for freedom, though perhaps without ever thinking
of it. As Prof. H. E. Crampton has said:
“The ‘ Origin of Species’ has proved a veritable
Magna Charta of intellectual liberties, for, as
no other single document before or since, it has
released the thoughts of men from the trammels
of unreasoned conservatism and dogmatism.”
Speaking of his first impressions of the “ Origin

1 Prof. Stanley Hall gives, as an illustration, “the new psychology
of crime and criminals, who are so shot through, body and soul,
with atavisms that only the early history of the race can explain
them.”

30 DARWINISM AND HUMAN LIFE

of Species,” Sir Francis Galton has told us that
his dominant feeling was one of freedom.

For one must remember that Darwin attacked
a whole series of problems which, for most of
his contemporaries, were either insoluble mysteries
or a preserve for transcendental interpretation.
“ Evolution,” Prof. Bateson says, “is a process
of variation and heredity. The older writers,
though they had some vague idea that it must
be so, did not study variation and heredity.
Darwin did, and so begat, not a theory, but a
science.” He showed that the deeper mysteries
of life were in a measure accessible to the scientific
method. He won freedom for the application of
the evolution formula to man as well as to other
creatures, and not only to his body, but to his
emotions and behaviour. He was one of the
founders of genetic psychology, which, though
still hardly above the ground, is destined to
make for the growing freedom of the human
spirit. We mean not merely intellectual freedom
from obscurity, but a practical freedom as well;
for in regard to the mind, as well as the body,
Darwin set a-going a kind of inquiry into individual
development and racial evolution, into variation
and heredity, which promises to give us a firmer
control of life. We are only beginning to realise
that the truth which is in Darwinism shares with
all truth the power of making us free.

Darwin gave men confidence in the interpre-
tative value of the evolution formula, which
makes the present less obscure by throwing on
it the light of the past, and every one knows how
the interpretation has been applied to mind,

1 “ Darwin and Modern Science,” (1909), p. 88

WHAT WE OWE TO DARWIN 31

to morals, to language, to art, to customs, to
religion. Even the evolution theory has had
its evolution, and is still, happily, being evolved.

Of the wide diffusion of the evolutionary way
of looking at things which Darwin justified, we
give a single example, as a diagram as it were.
After the disaster of Kéniggratz the Austrian
Parliament met to consider what steps should
be taken for the re-consolidation of the monarchy,
and a distinguished member of the Upper House
began a famous speech with the words, “ The first
thing we have to consider is: Is Charles Darwin
right, or is he not ? ”—“ and upon the rightness of
Darwin’s theory it was gravely proposed to re-
construct the Austrian monarchy.” !

Darwin once expressed satisfaction that he
had not been permitted to become a “ specialist” ;
it is hardly too much to say that there is no
specialism in natural science which he has left
unaffected by his influence.

(VIII) IpEat oF Screntiric Moop anp Meruop.
—What do we owe to Darwin? An ideal of
the scientific mood and of scientific workmanship.
As it will be a long time before Science weeps, like
Alexander, having no more worlds to conquer,
perhaps this ideal is not the least of Darwin’s
legacies. If we can follow Darwin in the spirit,
not necessarily in the letter, we shall not go far
astray. As Prof. T. H. Morgan finely says:
“Tt is the spirit of Darwinism, not its formula,
that we proclaim as our best heritage.” For
this reason, and because the scientific spirit is a
big fact in modern life, let us consider the features

1 See Sir Archibald Geikie’s Speech at the Darwin-Wallace
Celebration, Linnean Society (July Ist, 1908), p. 53.

32 DARWINISM AND HUMAN LIFE

of the scientific mood, and Darwin’s illustration
of them.

In his stimulating presidential address at the
meeting of the British Association at Dover in
1899, Sir Michael Foster discussed the distinctive
features of the scientific spirit—of which he was
himself a fine embodiment. His answer was that
the features of the fruitful scientific mood are
in the main three—truthfulness, alertness, and
courage. (1) “The seeker after truth must him-
self be truthful—truthful with the truthfulness of
nature.” (2) “He must be alert of mind, ever
on the watch, ready at once to lay hold of Nature’s
hint, however small; to listen to her whisper,
however low.” (3) “ Scientific inquiry has need of
the moral quality of courage—not so much the
courage which helps a man to face a sudden
difficulty, as the courage of steadfast endurance.”
To the objection that truthfulness, alertness, and
courage are virtues belonging to almost every one
who has commanded or deserved success, Sir
Michael answered: “ That is exactly what I
would desire to insist, that men of science have
no peculiar virtues, no special powers. They are
ordinary men, their characters are common, even
commonplace. Science, as Huxley said, is organ-
ised common sense, and men of science are common
men, drilled in the ways of common sense.”

CHARACTERISTICS OF SCIENTIFIC Moop : Passion
AND REVERENCE FoR Facts.—But let us consider
the scientific mood more analytically. The first
characteristic of the scientific mood is a passion
and reverence for facts. Long ago Bacon said:
“We should accustom ourselves to things them-
selves’; and to distinguish between appearance

WHAT WE OWE TO DARWIN 33

and reality is part of the unending business of
science. Faraday said that the scientific investi-
gator should be “not a respecter of persons, but
of things.” It was Huxley who spoke of “that
enthusiasm for truth, that fanaticism of veracity,
which is a greater possession than much learning ;
a nobler gift than the power of increasing know-
ledge.” Darwin was a fine illustration of this
passion for facts; there have been few naturalists
more careful as to data. He began collecting facts
in regard to the work of earthworms when a
young student in Edinburgh, and he published
his fascinating book the year in which he died.
His gardener said: “He moons about in the
garden, and I have seen him stand doing nothing
before a flower ten minutes at a time.”
Screntiric Caution.—Following from the pas-
sion of facts is a second characteristic of the
scientific mood, namely, cautiousness, or distrust
of finality and dogmatism of statement. Prof.
W. K. Brooks says, in his “ Foundations of
Zoology”: “ The hardest of intellectual virtues
is philosophic doubt, and the mental vice to
which we are most prone is our tendency to believe
that lack of evidence for an opinion is a reason
for believing something else. . . . Suspended judg-
ment is the greatest triumph of intellectual dis-
cipline.” As Huxley said: “ The assertion that
outstrips the evidence is not only a blunder but
a crime.” As Karl Pearson says: “ The scientific
man has, above all things, to strive at self-elimina-
tion in his judgments, to provide an argument which
is as true for each individual mind as for his
own.” What a fine temper there is in Darwin’s
statement—“I have steadily endeavoured to

3

34 DARWINISM AND HUMAN LIFE

keep my mind free so as to give up any hypothesis,
however much beloved—and I cannot resist
forming one on every subject—as soon as facts are
shown to be opposed to it.” “I had,” he says,
“during many years followed a golden rule, namely,
that whenever a published fact, a new observation
or thought came across me, which was opposed
to my general results, to make a memorandum
of it without fail, and at once; for I had found,
by experience, that such facts and thoughts were far
more apt to escapefrom the memory than favourable
ones.”’ Let us remember how Darwin opened his first
note-book in 1837, conceived the idea of natural
selection in 1838, sent a sketch of the theory to
Hooker in 1844, read his joint-paper with Wallace
in 1858, and published “ The Origin of Species” in
1859. These dates are eloquent. It is interesting
to notice that Wallace wrote his sketch in a week
—the thought-stream of his fevered brain in spate.

CLEARNESS OF Vision.—A third characteristic
of the scientific mood is dislike of obscurities, of
blurred vision, of fogginess. Ignorance in itself
is no particular reproach, if it is not carried too
far, but it is essential to know when we know
and when we do not. The mole has a strange
half-finished lens, which is physically incapable
of throwing a precise image on the retina. If
there is any image, it must be a blurred tangle
of lines. In our busy lives we tend to acquire
mole-like lenses in regard to particular orders of
facts; we see certain things clearly, others are
blurs; but the scientific mood is in continual
protest against obscurities, insisting upon lucidity.
One of Bacon’s most historically true aphorisms
declares “Truth to emerge sooner from error

WHAT WE OWE TO DARWIN 35

than from confusion.” Now we may claim for
Darwin the quality of definiteness and lucidity.
He was convinced of the efficacy of natural
selection, and his exposition, though rarely elegant,
is always clear. He did not understand how
variations in the direction of fitness arose, and
he said so. His yea was yea, and his nay, nay.

Sense oF InTERRELATIONS.—A fourth charac-
teristic of the scientific mood is a sense of the
interrelations of things. The realisation of Nature
as a great interconnected system is, indeed, one
of the ends of science; to be on the outlook for
interrelations is diagnostic of the scientific mood.
We have seen how Darwin had the vision of the
web of life with pre-eminent vividness.

Darwin’s Metuop or Worxine.—As to Dar-
win’s method of working, he tells us himself three
things: (1) that he had from his earliest youth
a desire to explain things, and that he could not
resist forming an hypothesis on every subject;
(2) that he accumulated large collections of facts
and tried to formulate them in a general law;
- and (3) that he sought to anticipate all possible
objections to his conclusion. In short, he was a
deductive-inductive philosopher.

In speaking of Darwin’s services, Romanes
said: “A true scientific judgment consists in
giving a free rein to speculation on the one hand,
while holding ready the brake of verification with
the other. Now it is just because Darwin did
both these things with so admirable a judgment
that he gave to the world of natural history so
good a lesson as to the most effective way of
driving the chariot of science.”’*

1 “Darwin and After Darwin ”’ (1897), vol. i. p. 7.

36 DARWINISM AND HUMAN LIFE

Prof. Karl Pearson says, in his “ Grammar of
Science,” that the scientific method is marked by
the following features: “ (a) careful and accurate
classification of facts and observation of their
correlation and sequence; (b) the discovery of
scientific laws by aid of the creative imagination ;
and (c) self-criticism and the final touchstone of
equal validity for all normally constituted minds.”
The writer had Darwin as well as Newton in
mind when he framed this useful definition.

DaRWIN ON HIS OwN SuccEss.—-No one who has
read Darwin’s “ Autobiography ” can forget how
he himself deals with the question of his success,
“My success as a man of science, whatever this
may have amounted to, has been determined, as
far as I can judge, by complex and diversified
mental qualities and conditions. Of these, the
most important have been—the love of science,
unbounded patience in long reflecting over any
subject, industry in observing and collecting facts,
and a fair share of invention as well as of common
sense. With such moderate abilities as I possess,
it is truly surprising that I should have influenced
to a considerable extent the belief of scientific
men on some important points.”

Darwin’s ACHIEVEMENTS.—Let us turn from
that humility of greatness once more to the actual
achievement. The idea of organic evolution, older
than Aristotle, slowly developed from the stage
of suggestion to the stage of verification, and
the first convincing verification was Darwin’s;
from being an @ prior: anticipation it has become
a detailed interpretation of nature, and Darwin
is still the chief interpreter ; from being a modal
interpretation of the manner in which living

WHAT WE OWE TO DARWIN 37

creatures have come to be, it has advanced to the
rank of a causal theory, the most convincing part
of which men will never cease to call Darwinism.

In referring to Darwin’s services, Huxley wrote :
“Whatever be the ultimate verdict of posterity
upon this or that opinion which Mr. Darwin pro-
pounded ; whatever adumbrations or anticipations
of his doctrines may be found in the writings of
his predecessors; the broad fact remains that,
since the publication, and by reason of the publica-
tion, of ‘ The Origin of Species ’ the fundamental
conceptions and the aims of students of living
nature have been completely changed. . . . But
the impulse thus given to scientific thought rapidly
spread beyond the ordinarily recognised limits
of biology. Psychology, ethics, cosmology were
stirred to their foundations, and ‘The Origin of
Species’ proved itself the fixed point which the
general doctrine needed in order to move the
world.”

Co-oPERATING INFLUENCES.—To understand how
all this came about we must get beyond the person-
ality of Darwin. We must shake ourselves free
from all creationist appreciations of Darwin and
Darwinism; we must recognise the services of
pioneers who helped to make the time ripe—
notably, for instance, Robert Chambers, whose
work has seldom been adequately appreciated ;
we must inquire into the acceptance of evolutionary
conceptions in regard to other than biological
orders of facts; we must realise how the growing
success of scientific interpretation along other
lines gave confidence to those who refused to
admit that there was any domain from which
science could be excluded as a trespasser; we

38 DARWINISM AND HUMAN LIFE

must take account of the development of philo-
sophical thought—for instance in Herder, Kant,
and Hegel; we should also, if we are wise enough,
consider social changes. In short, we must abandon
the idea that we can understand a great step
like the acceptance of the evolutionist outlook
without getting beyond the individual prophet,
without associating his work with contemporary
evolution in other departments of activity. The
man and the moment must agree, and, as Professor
R. M. Wenley says in this very connection, “ genius
rarely achieves supremacy without the co-operant
‘social mind.’ ”

There is a risk of attaching too much importance
to the force of individual effort on the one hand,
and to the ripening of public opinion on the other.
The storm of opposition roused by the publication
of “The Origin of Species” shows how far the
time was from being ripe. To say, as Samuel
Butler said, “‘ Buffon planted, Hrasmus Darwin and
Lamarck watered, but it was Mr. Darwin who
said ‘ That fruit is ripe’ and shook it into his
lap,” seems to us as wilful a perversion of historical
fact as that other statement by the same ingenious
and often well-advised critic, ‘‘ Darwin was heir to
a discredited truth, and left behind him an ac-
credited fallacy.” Much more accurate is Huxley’s
fine pronouncement’: ‘‘ None have fought better,
and none have been more fortunate, than Charles
Darwin. He found a great truth trodden underfoot,
reviled by bigots, and ridiculed by all the world ; he
lived long enough to see it, chiefly by his own efforts,
irrefragably established in science.” That the time
was far from ripe is shown by Darwin’s foreboding:

1 © Darwiniana,” p. 247.

WHAT WE OWE TO DARWIN 39

“When my notes are published I shall fall infinitely
low in the opinion of all sound naturalists ; so this
is my prospect for the future.” That the time
was far from ripe is well shown in a passage in the
second volume of Buckle’s “ History of Civilisa-
tion,’ which was published two years after “ The
Origin of Species ’’: ‘‘ We are in that predicament
that our facts have outstripped our knowledge,
and are now encumbering its march. The publica-
tions of our scientific institutions, and of our
scientific authors, overflow with minute and
countless details, which perplex the judgment,
and which no memory can retain. In vain do
we demand that they should be generalised and
reduced into order. Instead of that, the heap
continues to swell. We want ideas, and we get
more facts. We hear constantly of what nature
is doing, but we rarely hear of what man is thinking.
Owing to the indefatigable industry of this and
the preceding century, we are in possession of a
huge and incoherent mass of observations, which
have been stored up with great care, but which,
until they are connected by some presiding idea,
will be utterly useless.” And yet one of the
greatest of generalisations, one of the most powerful
of presiding ideas, was awaiting Buckle’s recogni-
tion. It was eminently characteristic of Darwin
that the accumulation of facts was to him not
an end but a means to an end.

ParTIcuLAR REASONS FOR DaRwin’s SuccESS.—
We must grant that the intellectual temper of
the time was changing, that in various departments
men were becoming familiar with the historical
method—the first step to becoming evolutionists,
that the genetic view of nature was insinuating

40 DARWINISM AND HUMAN LIFE

itself like a slow incoming tide in men’s minds,
and that the scientific spirit had ripened since
the days when Cuvier laughed Lamarck out of
court, but we must still ask, more personally, how
it was that Darwin succeeded so well. There are
several answers.

Because, in the first place, he had clear visions—
pensées de la jeunesse, exécutées par Vdge mir—
which a University curriculum had not made
impossible, which the Beagle voyage—a Columbus
voyage that discovered a new world—had made
vivid, which an unrivalled British doggedness
made real—visions of the web of life, of the fountain
of change within the organism, of the struggle for
existence, of discriminate winnowing or selection,
and of the spreading genealogical tree.

Because, in the second place, he put so much
grit into the verification of his visions, forcing
them to the proof in an argument which is, of
its kind—direct demonstration being out of the
question—quite unequalled.

Because, in the third place, he broke down
the opposition which the most scientific had felt
to the seductive modal formula of evolution, by
bringing forward a more plausible theory of the
process than had been previously suggested. Nor
can one forget, since questions of this magnitude
are human and not merely academic, that Darwin
wrote, of his condescension, so that all men could
understand.

As Mr. Arthur Balfour recently said: ‘ Charles
Darwin’s performances have now become part
of the common intellectual inheritance of every
man of education, wherever he lives or whatever
his occupation or trade in life. To him we trace,

WHAT WE OWE TO DARWIN 4]

in the main, the view which has affected, not
merely our ideas of the development of living
organisms, but our ideas upon politics, upon
sociology, ideas which cover the whole domain of
human terrestrial activity. He is the fount and
origin, and he will stand for all time as the man
who has made this great, and, as I think, beneficent
revolution in the mode in which educated men
can see the history, not merely of their own institu-
tions, not merely of their own race, but of
everything which has that unexplained attribute
of life, everything that lives on the surface of
the globe or within the depths of the ocean.” ?

In any case, we must agree with what Huxley
says of Darwin: “It is only by pursuing his
method, by that wonderful single-mindedness,
devotion to truth, readiness to sacrifice all things
for the advance of definite knowledge, that
we can hope to come any nearer than we are
at present to the truths which he struggled to
attain.”

Darwin was no metaphysician; he always kept
very close to earth—which is half the secret of
the persistent strength of his teaching. For this
reason, most appropriately, Prof. R. M. Wenley
ended a very suggestive address* on Darwin by
quoting, in reference to Darwin’s services, the
fine words of a Scottish poet:

Man’s thought is like Anteus, and must be
Touched to the ground of Nature to regain
Fresh force, new impulse, else it would remain
Dead in the grip of strong Authority.

1 Nature, July Ist, 1909.
3 Popular Science Monthly (1909), vol. Ixxiv. p. 395,

42

DARWINISM AND HUMAN LIFE

But, once thereon reset, ’tis like a tree,
Sap-swollen in spring-time: bonds may not restrain;
Nor weight repress; its rootlets rend in twain
Dead stones and walls and rocks resistlessly.
Thine, then, it was to touch dead thoughts to earth,
Till of old dreams sprang new philosophies,
From visions systems, and beneath thy spell
Swiftly uprose, like magic palaces,—
Thyself half-conscious only of thy worth—
Calm priest of a tremendous oracle !

CHAPTER II
THE WEB OF LIFE

43

CHAPTER II

THE WEB OF LIFE

Correlation of Organisms as well as Correlation of Organs—What
the Metaphor of “ The Web of Life” suggests—Dependence of
Living Creatures upon their Surroundings—Nutritive Chains
—Nexus between Mud and Clear Thinking—Correlation
between Catches of Mackerel and Amount of Spring Sunshine
—wNutritive Chains in the Deep Sea—Dependence of one
Organism on another for the Continuance of the Species
—Darwin’s Instance of the Connection between Cats and
Clover—Scattering of Seeds—Interrelations between Fresh-
water Mussels and Fishes—Life-histories of Parasites—Far-
reaching Influence of Certain Animals: Earthworms—Termites,
or White Antsa—The Hand of Life upon the Earth—Practical
Importance of a Realisation of the Web of Life.

NaTURALISTS, in the true sense, who study the
life of living creatures in nature, have always
been distinguished by a keen perception of the
inter-relations of things. Whether we take Gilbert
White as representing the old school, or W. H.
Hudson as ‘representing the new, we get from
their observations the same impression of nature
as a vibrating system, most surely and subtly in-
ter-connected. But it seems just to say that no
naturalist, before or since, has come near Darwin
in his realisation of the web of life, in his clear
vision and picture of the vast system of linkages
that penetrates throughout the animate world.
CoRRELATION OF ORGANISMS AS WELL AS CORRE-
LATION OF OrcANs.—In thinking of a living body
we are accustomed to the idea of the correlation of
45

46 DARWINISM AND HUMAN LIFE

organs. Itis of the very nature of an organism that
there should be mutual dependence among its parts.
The organs are all partners in the business of life,
and if one member changes others also are affected.
This is especially true of certain organs that have
developed and evolved together, and are knit by
close physiological bonds. We know in health
how nerve and muscle, brain and sense-organs,
heart and lungs, are closely bound together in the
bundle of life. We know in disease that a change
in one organ often affects another, and the fact
remains, though the nexus is sometimes mysterious.
The state of our liver may give colour to our whole
intellectual firmament, and a slight ocular de-
rangement may warp a wise man’s philosophy.
The far-reaching importance of a little organ like
the thyroid gland beside the larynx is well known ;
our intellectual as well as our bodily health de-
pends on its soundness. Now, just as there is
a correlation of organs within the body, so there
is a correlation of organisms in that system of
things which we call Nature. In both cases we
are here using the word “correlation ’’ in its deeper
sense—that the various parts are more than
mutually dependent, that they are in some measure
co-ordinated, making larger systems workable.
Wuat THE Merapuor or “THE Wes oF LiFE”
SUGGESTS.—We may use the metaphor “ web of
life’? in two ways. On the one hand, Nature hasa
woven pattern which science seeks to read, each
science following the threads of a particular colour.
There is a warp and woof in this web, which to the
zoologist usually appear as “ hunger ” and “ love.”
There is a changing pattern in the web, becoming
more complex as the ages pass; and this is evo-

THE WEB OF LIFE 47

lution. But the essential idea of a web is that of
interlinking and ramifying. We can never tell
where a thread will lead to. If one be pulled out,
many are loosened. This is true of Nature through
and through.

The phrase “web of life” suggests another
picture—the web of a spider—often an intricate
system, with part delicately bound to part, so that
the whole system is made one. “The quivering
fly entangled in a corner betrays itself throughout
the web; often it is felt rather than seen by the
lurking spinner. So in the substantial fabric of
the world part is bound to part. In wind and
weather, or in the business of our life, we are
daily made aware of results whose first conditions
are very remote; and chains of influence, not
difficult to demonstrate, link man to beast, and
flower to insect. The more we know of our
surroundings the more we realise that nature is
a vast system of linkages, that isolation is im-
possible.” *

DEPENDENCE OF LIVING CREATURES ON THEIR
SurRounDiInes.—We do not know what life in
principle is, but we may describe living as action
and reaction between organisms and their en-
vironment. This is the fundamental relation—
the dependence of living creatures on appropriate
surroundings, and the primary illustrations of
linkages must be found here. The living creatures
are real, just in the same sense as the surroundings
are real; but it is plain that we cannot abstract
the living creatures from their surroundings.
When we try to do this they die—even in our
thought of them, and our biology is only necrology.

1 “The Study of Animal Life,” by J. Arthur Thomson (1890).

48 DARWINISM AND HUMAN LIFE

Huxley compared a living creature to a whirlpool
in a river; it is always changing, yet always
apparently the same; matter and energy stream
in and stream out; the whirlpool has an individu-
ality and a certain unity, yet it is wholly dependent
upon the surrounding currents. One may push
the whirlpool metaphor too far, so as to give a
false simplicity to the facts, for when vital whirl-
pools began to be there also emerged what cannot
be discerned in crystal or dewdrop—the will
to live, a capacity of persistent experience, and
the power of giving rise to other lives. To ignore
this is to attempt a falsely simple natural history.
But what Huxley’s metaphor of the whirlpool
does vividly express is the dependence of living
creatures on their surroundings. We cannot under-
stand either the whirlpool or the trout apart from
the stream.

When we think out this fundamental dependence
upon surroundings, we see, for instance, that all
our supplies of energy, all our powers of every
kind—with our own hands, or by the use of animals,
or by means of machinery—are traceable to the
sun. Or again, it is easy to show that our society
depends fundamentally not on gold, but on iron.
We depend for food on plants and animals, and
through these animals on plants ultimately ;
the plants feed upon air, water, and salts, which,
with the aid of the energy of the sunlight, they
build up into complex organic compounds; they
cannot do this unless the sun shines through a
screen of green pigment called chlorophyll; there
cannot be chlorophyll without iron ; therefore our
whole social framework is founded on 1Ron.

Nutritive Cuains.—Plants feed on their in-

THE WEB OF LIFE 49

animate environment in a direct way that is
impossible to animals, so we pass insensibly from
dependence on surroundings to those nutritive
chains which bind living creatures together in
long series often quaintly suggestive of “ The
House that Jack Built” and similar old rhymes.
We have ceased to wonder at the circulation of
the blood in our body; have we begun to wonder
enough at the ceaseless circulation of matter in
the system of nature? As Heraclitus said, ravra
pet, all things are in flux. “ The rain falls; the
springs are fed; the streams are filled and flow
to the sea; the mist rises from the deep and the
clouds are formed, which break again on the
mountain-side. The plant captures air, water,
and salts, and, with the sun’s aid, builds them up
by vital alchemy into the bread of life, incorporating
this into itself. The animal eats the plant, and a
new incarnation begins. All flesh is grass. The
animal becomes part of another animal, and the
reincarnation continues.” The silver cord of the
bundle of life is loosed, and earth returns to earth.
The microbes of decay break down the dead, and
there is a return to air and water and salts. We
may be sure that nothing real is ever lost; we are
sure that all things flow. Penelope-like, Nature
is continually unravelling her web and making a
fresh start.

NEXUS BETWEEN Mup AND CLEAR THINKING.—
To keep a famous inland fish-pond from giving
out, some boxes of mud and manure were placed
at the sides. Bacteria—the minions of all putre-
faction—worked in the mud and manure, making

1“The Bible of Nature,” by J. Arthur Thomson (1908).
(Scribner, New York. Clark, Edinburgh.)

4

50 DARWINISM AND HUMAN LIFE

food for minute Infusorians, which multiply so
rapidly that there may be a million from one in
a week’s time.. A cataract of Infusorians over-
flowed from box to pond, and the water-fleas and
other small fry gathered at the foot of the fall
and multiplied exceedingly. Thus the fishes were
fed, and, as fish-flesh is said to be good for the
brain, we can trace a nexus from mud to clear
thinking. What was in the mud became part of
the Infusorian, which became part of the Crus-
tacean, which became part of the fish, which
became part of the man. And it is thus that
the world goes round.

CORRELATION BETWEEN CaTCHES OF MACKEREL
AND AMOUNT oF SpRinG SUNLIGHT.—A curious and
most interesting correlation has been discovered
by Dr. E. J. Allen between catches of mackerel
and the amount of sunlight.1 The more sunshine
in May, the more mackerel at Billingsgate. How
does this work out? Mr. G. E. Bullen? shows
that “for the years 1903-1907 there appears to
be a correlation between the number of mackerel
taken during May and the amount of Copepod
plankton, upon which the mackerel feed, taken
in the neighbourhood of the mackerel fishing
grounds during the same month.” Mr. W. J.
Dakin * shows that the food of Copepods consists
largely of the vegetable organisms of the plankton,
such as diatoms, and of Infusorian-like organisms
called Peridinide. But the production -of this
microscopic plankton, the “stock” of the “sea-
soup,” depends partly on the composition of the

1 Journ. Marine Biol. Assoc. (1909), vol. viii. p. 394.
2 Ibid. p. 269.
2 Internat. Revue Hydrobiologie (1908), vol. i.

THE WEB OF LIFE 51

sea-water, partly on the temperature, and partly
on the amount of light available. There seems to
be no correlation between the surface temperature
and the abundance of mackerel, but Dr. Allen has
shown a correspondence between sunshine and
the catches. Thus we see that, if all flesh is grass,
then in the same sense all fish is diatom.

Nutritive Caains In THE Deep Sza.—lIf we
pass from the sunlit open sea to the floor of the
deep sea—that strange, dark, cold, silent, plantless
world—we find carnivorous animal preying upon
carnivorous animal through long series—fish feeds
on fish, fish on crustacean, crustacean on worm,
worm on still smaller fry, and all ultimately depend
on the basal food-supply—the ceaseless shower of
moribund atomies sinking from the surface waters
many miles, it may be, overhead, like the snow-
flakes on a quiet winter day.

DEPENDENCE OF ONE ORGANISM ON ANOTHER
FOR THE CONTINUANCE OF THE SPECIES.—Passing
from “nutritive chains,’ we may select a few
illustrations of the dependence of one creature
upon another for the continuance of its kind.
The crowning instances are to be found in the
interrelations between plants and animals which
secure cross-fertilisation and the distribution of
seeds. To both of these Darwin devoted much
attention, and they were always favourite subjects
with him.

Every one knows that flowering plants and
flower-visiting insects have grown up throughout
long ages together, in alternate influence and
mutual perfecting. They are now fitted to one
another as hand to glove. The insects visit the
flowers for food ; in so doing they carry the fer-

52 DARWINISM AND HUMAN LIFE

tilising golden dust from blossom to blossom, so
that the possible seeds become real seeds.

In 1793 a Berlin naturalist, Christian Konrad
Sprengel, like Darwin in his perception of the
web of life, published a pioneer book entitled
“The Secret of Nature discovered in the Structure
and Fertilisation of Flowers,” in which he showed
that most flowers have nectar which insects
enjoy; that by the insects’ visits pollination is
secured ; that there is no detail of the flower without
its meaning—the colour is a flag to attract the
insect’s eye, conspicuous spots are honey-guides
to the explorers, there are arrangements for keeping
the pollen dry and for dusting it on the insects,
and so on. If Sprengel had only discovered the
utility of the cross-fertilisation, which Darwin
proved experimentally, his work could hardly
have been overlooked for nearly seventy years.
In 1841 it came into Darwin’s hands, and im-
pressed him as being “ full of truth,” although
“with some little nonsense.” In Darwin’s work
Sprengel had his long-delayed reward.

Darwin’s INSTANCE OF THE CONNECTION BE-
TWEEN Cats anbd Ciover.—One of Darwin’s
instances of the web of life—given in connection
with the pollination of flowers—has become
familiar all over the world. It should never
become trite to us and it should never be regarded
as more than a particularly clear illustration of
a general fact. “ Plants and animals, remote in
the scale of nature, are bound together by a web
of complex relations....I have found, from
experiments, that humble-bees are almost indis-
pensable to the fertilisation of the heart’s-ease
(Viola tricolor), for other bees do not visit this

THE WEB OF LIFE 53

flower. I have also found that the visits of bees
are necessary for the fertilisation of some kinds
of clover—thus, 100 heads of red clover (Tri-
folium pratense) produced 27,000 seeds, but the
same number of protected heads produced not a
single seed. Humble-bees alone visit red clover,
as other bees cannot reach the nectar. . . . Hence
we may infer as highly probable that, if the whole
genus of humble-bees became extinct or very
rare in England, the heart’s-ease and red clover
would become very rare, or wholly disappear.”
We know that the red clover imported to New
Zealand did not bear fertile seeds until humble-
bees were also imported. “‘ The number of humble-
bees in any district depends in a great measure
on the number of field-mice, which destroy their
combs and nests; and Colonel Newman, who has
long attended to the’ habits of humble-bees,
believes that more than two-thirds of them are
thus destroyed all over England.” Now the
number of mice is largely dependent, as every
one knows, on the number of cats; and Colonel
Newman says: “ Near villages and small towns
T have found the nests of humble-bees more numer-
ous than elsewhere, which I attribute to the
number of cats that destroy the mice.” Thus we
may say, with Darwin, that next year’s crop of
purple clover is influenced by the number of
humble-bees in the. district, which varies with
the number of field-mice; that is to say, with the
abundance of cats !

ScatrerInc oF SeEeps.—It is a fascinating
chapter of natural history which tells us how
cross-pollination is effected—here by a bee and
there by a butterfly, occasionally by a long-billed

54 DARWINISM AND HUMAN LIFE

humming-bird beautifully poised before the flower
with almost invisibly rapid vibrations of its wings,
and occasionally by a slowly moving snail of
epicure appetite. But not less important is the
part played by animals in the scattering of seeds,
and here again Darwin gives us the classic case
of fourscore seeds germinating out of a ball of
mud from a bird’s foot. From one instance you
may learn all, and see that much of Darwin’s
work has been an eloquent commentary on that
memorable saying about the sparrow that falls
to the ground. Such a simple event literally
sends a throb through surrounding nature; we
can follow its effects a few steps, just as we follow
for a few yards the ripples made when we throw
a stone into a still lake: in neither case can we
doubt that the spreading influences are real,
though they pass beyond our ken.
INTERRELATIONS BETWEEN FRESH-WATER Mus-
SELS AND FisHes.—As a striking illustration of
the inter-linking of different forms of life, we
may take the case of the fresh-water mussels and
their larve. The fertilised eggs develop in the
outer gill-plate of the mother-mussel, and minute °
bivalve larvee, called Glochidia, are formed. The
mussel keeps these within the cradle until a fresh-
water fish—such as the minnow—comes into the
vicinity, and then she sets them free. In a way
that we do not understand, the simple constitution
of the larve is tuned to respond to the presence of
minnows and the like, and with snapping valves
they manage to fix themselves to their host.
After a short period of temporary parasitism, at
the end of which there is a metamorphosis, they
drop off from the fisb into the mud, often far

THE WEB OF LIFE 55

from their birth-place. This is curious enough,
but the idea of linkages becomes incandescent in
the mind when we note that, just as the fresh-water
mussel has young temporarily parasitic on fishes, so
a fresh-water fish, the bitterling (Rhodeus amarus),
has its young temporarily parasitic in the gills
of the mussel.

LIFE-HISTORIES OF ParastrEs.—When we pass
to parasites in a stricter sense we find the most
extraordinary interconnections, the most widely
separated animals often sharing a parasite between
them. Liver-rot, which has repeatedly killed a
million sheep in a year in Britain alone, is due
to a parasite which passes from sheep to water,
from water to water-snail, from water-snail to
grass, from grass to sheep. The tapeworm of the
cat has its bladder-worm stage in the mouse, the
sturdie-worm of the sheep’s brain has its tapeworm
stage in the dog, and similar relations hold for
hundreds of species. The troublesome thread-
worm of human blood (Pilaria sanguints hominis)
is transferred from man to man by the mosquito,
and the guinea-worm, which was probably the
fiery serpent that vexed the Israelites in the
desert, which passes into man in drinking-water,
spends its youth in a minute water-flea, called
by the giant’s name of Cyclops. The import-
ance of tse-tse flies in transmitting the minute
animals which cause sleeping-sickness and allied
diseases is known to all. We have spoken of the
connection between cats and clover, and there
is a not less striking connection between cats
and plague. For it seems to have been shown
in India that the more cats the fewer rats,
and the fewer rats the fewer rat-fleas, which

56 DARWINISM AND HUMAN LIFE

are the agents in passing the plague-germs to
man.

FAR-REACHING INFLUENCE OF CERTAIN ANIMALS :
HaRTHworMs.—We realise the idea of the web
of life in another way when we consider the
far-reaching influence of particular kinds of acti-
vity, the best instance being the work of earth-
worms. In 1777 Gilbert White got at the very
root of the matter. “The most insignificant
insects and reptiles are of much more consequence
and have much more influence in the economy
of nature than the incurious are aware of... .
Karthworms, though in appearance a small and
despicable link in the chain of nature, yet, if
lost, would make a lamentable chasm...
Worms seem to be the great promoters of vege-
tation, which would proceed but lamely without
them, by boring, perforating, and loosening the
soil, and rendering it pervious to rains and the
fibres of plants; by drawing straws and stalks
of leaves and twigs into it; and, most of all,
by throwing up such infinite numbers of lumps
of earth called worm-casts, which, being their
excrement, is a fine manure for grain and grass.
Worms probably provide new soil for hills and
slopes where the rain washes the earth away; and
they affect slopes probably to avoid being flooded.
. . . The earth without worms would soon become
cold, hard-bound, and void of fermentation, and
consequently sterile. ... These hints we think
proper to throw out, in order to set the inquisitive
and discerning at work. A good monograph of
worms would afford much entertainment and
information at the same time, and would open a
large and new field in natural history.”

THE WEB OF LIFE 57

The monograph that Gilbert White wished for
in 1777 was published by Darwin in 1881, the
year before he died—“ the completion,” he said,
“of a short paper read before the Geological
Society more than forty years ago.” With his
characteristic thoroughness and patience he worked
out the part that earthworms have played in the
history of the earth, and proved that they deserve
to be called the most useful animals. By their
burrowing they loosen the earth, making way
for the plant rootlets and the raindrops; by
bruising the soil in their gizzards, they reduce
the particles to more useful, powdery form; by
burying the surface with castings brought up from
beneath, they have been for untold ages ploughers
before the plough, and by burying leaves they
have made a great part of the vegetable mould
over the whole earth. In illustration of the last
point, we may notice that we recently found thir-
teen midribs of the leavesof the rowan, or mountain-
ash, radiating round one hole like the spokes
of a wheel; the withering leaflets had been carried
down, and two were sticking up at the mouth of
the burrow: that meant 91 leaflets to one hole.
Darwin showed that there often are 50,000 (and
there may be 500,000) earthworms in an acre ;
that they often pass ten tons of soil per acre
per annum through their bodies; and that they
often cover the surface at the rate of three inches
in fifteen years. Though our British worms only
pass out about 20 oz. of earth in a year, the weights
thrown up in a year on two separate square yards
which Darwin watched were respectively 6°75 lb.
and 8'387 Ib., which correspond to 143 and 18
tons per acre per annum.

58 DARWINISM AND HUMAN LIFE

We follow the work further and it becomes
evident that the constant exposure of the soil
bacteria on the surface is bound to be important,
on the one hand, in allowing them to be scattered
by wind and rain, on the other in exposing
them to the beneficent action of the sunlight—
which is the most universal, effective, and eco-
nomical of all germicides.

In Yorubaland, on the West Coast of Africa,
Mr. Alvan Millson calculated that about 62,233
tons of subsoil are brought every year to the sur-
face of each square mile, and that every particle
of earth, to the depth of two feet, is brought to
the surface once in twenty-seven years. It need
hardly be added that the district is fertile and
healthy.

Earthworms play their part in the disintegration
of rocks, letting the solvent humus-acids of the
soil down to the buried surface. Their castings
on the hill-slopes are carried down by wind and
rain and go to swell the alluvium of the distant
valleys or the wasted treasures of the sea. The
well-known parallel ledges along the slopes of
grass-clad hills are partly due to earthworm
castings caught on sheep-tracks, and thus we
begin to connect the earthworms not only with
our wheat-supply but with our scenery. Well
may we say, with Darwin: “It may be doubted
whether there are many other animals which have
played so important a part in the history of the
world as have these lowly organised creatures.”
Those who wish to understand Darwinism should
always begin with Darwin’s last book— The
Formation of Vegetable Mould through the Action
of Worms ” (1881). It illustrates the web of life,

THE WEB OF LIFE 59

the idea of which is essential to an understanding
of the struggle for existence and natural selection.
But it also illustrates what Darwin had learned
from Lyell—that great results may be brought
about by the accumulation of infinitesimal items.
As Prof. A. Milnes Marshall said: “The lesson
to be derived from Darwin’s life and work cannot
be better expressed than as the cumulative import-
ance of infinitely little things.”

TERMITES, OR Waite Ants.—Henry Drummond,
in his “ Tropical Africa,” tried to make out a case
for the agricultural importance of termites, or
white ants. It is well known that these old-
fashioned insects have a pruning action in the
forest, destroying dead wood with great rapidity.
Houses and furniture, fences and boxes, as well
as forest-trees, fall under their jaws. In some
places, “if a man lay down to sleep with a wooden
leg, it would be a heap of sawdust in the morning.”
But what of the termites’ agricultural importance ?
The point is that they keep the soil circulating
by constructing earthen tunnels up the sides of
trees and posts and by making huge obelisk-lhke
ant-hills, or termitaries. “ The earth-tubes crumble
to dust, which is scattered by the wind; the rains
lash the forests and soils with fury, and wash off
the loosened grains to swell the alluvium of a
distant valley.” It must be noted, however,
that Drummond did not prove his case with suffi-
cient precision, and there is, as Escherich points
out in his beautiful study of termites,' this difficulty,
that, while the castings of earthworms are soft
and loose, the earth-tubes and constructions of
termites are stony.

1 “Die Termiten.” (Leipzig, 1909.)

60 DARWINISM AND HUMAN LIFE

Escherich does, however, admit that the termites
have some agricultural importance, and he points
out that there are other services to be put to
the credit side of their account. They prune off
wood that has begun to go; they destroy rotting
things, including the bodies of small animals;
they make for cleanliness and health. In some
low-lying tracts, as Silvestri has shown, there are
dry stretches, “termite islands,” which have
been gradually built up from the broken-down
remains of termitaries. Nor should it be forgotten
that the white ants are often used as food. On
the other hand, Escherich does not hesitate to
rank them as among the great hindrances to
the spread of civilisation. They insidiously devour
everything wooden, from the telegraph-post to
the wooden butt of the gun hanging against the
wall, from books in the library to corks in the
cellar. There does not seem sufficiently precise
information in regard to the living plants that
they attack, and no safe general statement can be
made except that their appetite is large and
catholic.

With a centre in earthworms, what a variety of
interests must be included within the radius of
their life and work!—centipedes, birds, moles,
seedlings, man. The same is true of termites,
and two further illustrations may be given. Ob-
servers have reported about thirty different species
of termites with the habit of feeding on fungi
grown within the termitary on specially constructed
mazy beds. The habit is interesting in many ways;
for instance, because the fungi afford a supply of
nitrogenous material which is scarce in the ordinary
diet of wood, and also because a similar habit

THE WEB OF LIFE 61

occurs in the quite unrelated true ants. Finally,
the web is illustrated by the numerous boarders,
mostly beetles, that are found in the termitaries—
not hostile intruders or parasites, but guests which
are fed and cared for apparently for the sake of
a palatable exudation with a pleasant, narcotising
effect on the termites. With a centre in termites,
what a variety of interests must we not include
within the radius of their life and work !—fungi
and trees, beetles and birds, lizards and ant-eaters,
and man more than any.

Tae Hanp or Lire upon THe Eartu.—The
hand of life has been working upon the earth for
untold ages. Take plants, for instance. The sea-
weeds lessen the force of the waves, the lichens
eat into the rocks, the mosses form huge sponges
on the moors which keep the streams flowing
in days of drought. Many little plants are for
ever smoothing away the wrinkles on the earth’s—
their mother’s—face, and they adorn her with
jewels. Others that have formed coal have en-
riched her with ages of entrapped sunlight. The
grass—which began to appear in Tertiary ages—
protects the earth like a garment; the forests
affect rainfall and temper climate, besides sheltering
multitudes of living things, to many of whom every
blow of the axe is a death-knell. No plant, from
bacterium to oak-tree, lives or dies to itself, or
is without its influence upon the earth. So among
animals there are destructive borers and burrowers
and conservative agents, such as the coral-polyps
and the chalk-forming Foraminifera.

PracticaL IMpoRTANCE OF A REALISATION OF
THE Wes oF Lirr.—What has Darwinism to do
with human life? The answer at this stage in

62 DARWINISM AND HUMAN LIFE

our inquiry is clear: we must respect the web
of life if we wish to master Nature. She must
be humoured, not bullied. Emerson included in
his vision of a perfected earth the absence of
spiders, but the absence of spiders—which snare
so many injurious insects—would mean the absence
of much else, man probably included. In a
northern county in Scotland the proprietors were
justly annoyed at the injuries inflicted on young
trees by squirrels, and they formed a squirrel-
club, setting a price on the beautiful rodent’s
head. Perhaps a wiser course would have been to
begin by inquiring what disturbance of the balance
of nature had allowed the squirrels to multiply
so disastrously. But, after a period of squirrel-
slaughter and some jubilation thereat, a cloud
began to rise in the sky. The wood-pigeons were
multiplying worse than ever, and the farmers,
at least, said with no uncertain voice that they
preferred the squirrels. An imperfect recognition
of the web of life had left out of account the
notable fact that squirrels destroy large numbers
of young wood-pigeons.

One of the hopeful symptoms of the last few
years is the reawakening of an interest in woods
and forests. Every one knows how terribly these
have been wasted, and how the disastrous results
have affected rainfall and irrigation, climate and
crops, and even the character of the people. Here
what was once a pleasant stream is now like a
gravelly road, and there the fertile plains are
flooded; here the wind is sweeping away the
soil, and there both beauty and health have
departed. The birds which the woods once
sheltered are driven elsewhere, and the insect-

THE WEB OF LIFE 63

pests are rife among the crops. For “ the cheapest
and most effective insecticides are birds.”

The recognition of consequences—often far-
reaching—grows with us as we work with the
idea of the web of life, as we see in proper
perspective the criminality of those who are
ruthless. President Roosevelt: has declared his
abomination of “the land-skinner ”’—“ the in-
dividual whose idea of developing the country is
to cut every stick of timber of it, and then leave
a barren desert for the home-maker who comes
in after him. That man is a curse, and not a
blessing, to the country. The prop of the country
must be the man who intends so to run his business
that it will be profitable to his children after him.”
Every right-thinking man, and especially those
who have grasped the idea of the web of life,
will say with Roosevelt, “ Z am against the land-
skinner every time.”

It may be said that man must exterminate a
good deal if he is to go on peaceably with his
business, and it will be admitted that there has
never been a strong enthusiasm, humanitarian or
otherwise, against the elimination of rattlesnakes,
and such like. The naturalist’s answer is that
every crusade should be carefully considered on
its own merits, and that every careless and hasty
destruction of life is to be condemned. Even in
regard to snakes killing may be carried too far.
Some creatures are, as it were, on the fringes of the
web, while others occupy a position where many
threads meet. It is scientifically and esthetically
deplorable that birds like the great auk and

1 Quoted by A. H. 8. Lucas in his admirable Presidential Address,
«Proc. Linnean Soc. N.S.W.” (1908), vol. xxxiii. pp. 1-38.

64 DARWINISM AND HUMAN LIFE

mammals like the quagga should have been exter-
minated, but it is practically much more deplorable
that we have lost so many hawks and weasels
and other members of that pertinacious army
whose guerilla warfare keeps hundreds of more
humdrum creatures up to the scratch, and keeps
“vermin” from becoming a plague. Moreover,
it is extremely difficult to tell what may be the
consequences of exterminating any creature—
remote as it may seem from the beaten track of
human affairs. One of the obvious lessons of
Darwinism is that we should be slow to call any
change unimportant. Everything counts, or may
count. A so-called unimportant animal is destroyed
and no immediate ill effects are seen. But who
can tell ?

Very pertinent, for instance, is the question:
What about the parasites that used to complete
their life-history in romantic routine in this ex-
tinguished animal? Have we extinguished the
parasite also? Or is it waiting, with a whip of
scorpions, to chastise mankind for their ignorance
of Darwinism ?

The practical importance of recognising the
web of life has been proved by the heavy penalties
which man has often had to pay for disturbing
the balance of nature, careless of results and
ruthless of beauty, for not admitting that if we
would master Nature we must first understand
her. How much has Australia had to pay for
the introduction of rabbits in 1860, or America
for sparrows? Sometimes the introduction has
been unconscious, and man has only to blame
himself for letting the imtruder take hold, as in
the case of the Phylloxera in France, or of the

THE WEB OF LIFE 65

Colorado Beetle in Ireland. “ Ignorance of nature,”’
Mr. A. H. 8. Lucas says, “is costly. By disturbing
the balance of nature, man has introduced foes
into his own household.” Speaking of Australia,
he says: “ How much is needed for the eradication
of Bathurst Burr, Prickly Pear, Water-hyacinth,
Bramble and Sweetbriar, Codlin Moth, Waxy
Scale, Pear Slug, and Red Spider, owing to care-
lessness or lack of knowledge in early days ? ”?

An obvious moral is that we should be careful
in our introductions of new organisms—man
included—into new surroundings. The primary
consequences may be predictable, but the secondary
and the tertiary consequences—who is sufficient
for these things? We have records of the un-
conscious introduction of rats into Jamaica, where
they became a pest. To destroy them mongooses
were imported, and the rats were soon checked.
But the mongooses, having finished the rats, began
to eat up the poultry and young birds of various
kinds. As this went on the injurious insects and
ticks, that the birds used to eat, began to gain
the ascendant. A recent report—which requires
confirmation—says that the increase of ticks is
making life a burden to the mongooses. Thus a
balance will be again arrived at. There is no
doubt of that, but how much is often unnecessarily
lost by the way!

1 “ Presidential Address, Proc. Linnean Society N.S. Wales”
(1908), vol. xxxiii. pp. 1-38.

CHAPTER III
THE STRUGGLE FOR EXISTENCE

67

CHAPTER ITI

THE STRUGGLE FOR EXISTENCE

The Idea not so Simple as it seems—The Anthropomorphism of
the Idea—Different Forms of the Struggle for Existence—
Struggle for Existence in the Plant World—lIllustration of the
Complexity of the Struggle for Existence—Reasons for the
Struggle for Existence—Results of the Struggle for Existence—
Breadth of the Darwinian Concept of the Struggle for
Existence—The other Side of the Struggle for Existence—
Mutual Aid—Application of the Concept to Human Life.

Tue Ibe NoT so SIMPLE As IT SEEMS.—No evolu-
tionist phrase is more familiar than “ the struggle
for existence,” which has passed into everyday
usage. Yet it is not easy to grasp its full meaning,
or to keep it vividly in mind. “ Nothing is easier,”
Darwin said, “than to admit in words the truth
of the universal struggle for life, or more difficult—
at least I have found it so—than constantly to
bear this conclusion in mind. Yet, unless it be
thoroughly engrained in the mind, the whole
economy of nature, with every fact on distribution,
rarity, abundance, extinction, and variation, will
be dimly seen or quite misunderstood.” *

If a recognition of the “ struggle for existence ”
is essential to a clear outlook on nature, and
if Darwin found difficulty in bearing it constantly
in mind, we must be prepared to take some pains
in trying to get a grasp of the facts which the

1 * The Origin of Species,” p. 49.
69

70 DARWINISM AND HUMAN LIFE

phrase sums up. This is the more desirable since
there is often tyranny in a phrase, especially when
it is misunderstood. Are we sure that we under-
stand what the struggle for existence means ?
Are we clear that it means much more than the
bare words suggest? Do we understand that
the phrase is a biological formula which has at
the same time the misfortune of being an anthro-
pomorphic metaphor ?

From ancient days there had been a recognition
of a struggle in nature—we find the idea expressed
by Aristotle and by Lucretius, and more definitely
by several of the pioneers of modern evolution
theory—but it was Darwin who first realised its
length and breadth, its height and depth, and,
what is more, its dynamic significance.

THE ANTHROPOMORPHISM OF THE IpEzA.—In
trying to understand the past and present of
living creatures naturalists have followed with
some success two very different methods, which
seem opposed to one another, but are rather
complementary. The one method is to inquire
into the material machinery of vital activity, to
throw on the puzzling drama of life the light of
chemistry and physics. This is a sound method
as far as tt goes. The celery is blanched because

1 It is interesting to notice how often Tennyson turns to certain
aspects of the struggle for existence, as when he speaks of Nature
“red in tooth and claw with ravine,” “So careless of the single
life,”’ or in the well-known lines:

“ For life is not as idle ore ;

But iron dug from central gloom,
And heated hot with burning fears,
And dip’t in baths of hissing tears,

And batter’d by the shocks of doom

To shape and use.”

THE STRUGGLE FOR EXISTENCE 71

it is hidden from the light; the child is pale
because, roughly speaking, it has not enough of
iron in its blood. The defect of the method is
that, unless its partiality be borne in mind, it
is apt to give a false simplicity to the facts, for
it is quite certain that we cannot at present re-
describe vital happenings in terms of modern
physics and chemistry—vitalistic as these are.
The old materialism has been found out.

The other method is to read man into the
beasts and even into the flowers of the field, to
interpret the life of animals and plants in terms
of human life. This is also a sound method as
far as tt goes. Its defect is that, verification
being difficult, we are apt to land in fanciful an-
thropomorphism. Perhaps we may say, without
disrespect, that it was in great part Darwin’s
method, just as the other was Spencer’s. Darwin
approached the naturalist’s problem from above,
Spencer from below.

No better illustration of Darwin’s wholesome
anthropomorphism can be found than the cardinal
idea of the struggle for existence. It is an idea
borrowed from human life; it was consciously
suggested to Darwin by reading Malthus; it was
subconsciously suggested by the keen industrial
competition, more striking—because more novel—
in Darwin’s day than in ours. In human life
the phrase “ struggle for existence” is a formula
summing up in three words half the misery and
half the happiness of mankind. It means that
when Nature has said to man “ you must die”
he has always answered back “I will live”! It
means that he has fought with wild beasts and

1 See “ The Kingdom of Man,” by Sir E. Ray Lankester.

72 DARWINISM AND HUMAN LIFE

worsted them or tamed them, that he has sifted
out the wholesome from the poisonous plants, that
cowering and crouching for ages, he has watched
the forces of nature till he has mastered their
secrets, that he has been to his fellows since the
beginning the strangest mixture of self-assertiveness
and sympathy, that he has kept up an age-long
endeavour after well-being—always at his best
when rowing hard against the stream.

The formula, “ struggle for existence,” familiar
in human affairs, was used by Darwin in his
interpretation of organic life, and he showed that
we gain clearness in our outlook on animate
nature if we recognise there, in continual process,
a struggle for existence not merely analogous
to, but fundamentally the same as that which
goes on in human life. He projected on organic
life a sociological idea, and showed that it fitted.
But while he thus vindicated the relevancy and
utility of the sociological idea within the biological
realm, he declared explicitly that the phrase
“struggle for existence”? was meant to be a
shorthand formula, summing up a vast variety
of strife and endeavour, of thrust and parry, of
action and reaction. The idea has been better
realised by naturalists than by the severer labora-
tory specialists. ‘“‘It was certainly no chance,”
Weismann says, “that the struggle for exist-
ence first revealed itself to men who had spent
the greater part of their lives in the open air.”
Similarly, Prof. Poulton suggests that the main
reason why Huxley never appreciated the theory

1 «For words are wise men’s counters—they do but reckon by

them ; but they are the money of fools.” Hobbes, “‘ Leviathan,”
Pt. I. ch. iy,

THE STRUGGLE FOR EXISTENCE — 73

of natural selection was that he had so little of
the naturalist’s mood and experience.

DIFFERENT Forms oF THE STRUGGLE FOR
Existence.—Some of Darwin’s successors have
taken pains to distinguish a great many different
forms of the struggle for existence, and this
kind of analysis is useful in keeping us aware of
the complexities of the process. Darwin himself
does not seem to have cared much for this logical
mapping out and defining; it was enough for
him to insist that the phrase was used “in a
large and metaphorical sense,” and to give full
illustrations of its various modes. For our present
purpose it is enough to follow his example.

(a) Struggle between Fellows.—When the locusts
of a huge swarm have eaten up every green thing
they sometimes turn on one another. This canni-
balism among fellows of the same species—illus-
trated, for instance, among many fishes—is the
most intense form of the struggle for existence.
An eerie struggle occurs between sister embryos
in the egg-capsules of the buckie and the dog-
whelk on the sea-shore: This sort of thing has
its close analogue in what goes on between thick-
sown seedlings of the same kind, which compete
with one another for room and food and light.
The struggle does not need to be direct to be
real—the essential point is that the competitors
seek after the same desiderata of which there is
a limited supply. Whether an adult frog eats
a tadpole of its own kind, or a female spider
her suitor, or coral polyps compete for the same
niche, or rabbits for the same scanty food, the
formula is the same in all cases, and, apart from
chance, the result will be the same—the survival

74 DARWINISM AND HUMAN LIFE

of those fittest for the particular conditions.
The struggle may be for food, or foothold, or
breathing-space, or what is sought after may be
a luxury, as is seen in the wild stampede of the
reindeer when the longing to visit the salt sea-
shore becomes irresistible—many are overthrown
and trampled in the mad rush.

As an instance of keen struggle between nearly
related species, Darwin referred to the combats
of rats. The black rat was in possession of many
European towns before the brown rat crossed
the Volga in 1727; whenever the brown rat
arrived the black rat had to go to the wall. Thus
at the present day there are practically no black
rats in Great Britain. Here the struggle for
existence is again directly competitive. It is
difficult to separate off the struggle for food and
foothold from the struggle for mates, and it seems
clearest to include here the battles of the stags
and the capercailzies, or the extraordinary lek
of the blackcock—showing off their beauty at
sun-rise on the hills.

(b) Struggle between Foes.—In the locust swarm
and in the rats’ combats there is competition
between fellows of the same or nearly related
species, but the struggle for existence includes
much wider antipathies. We see it between foes
of entirely different nature, between carnivores
and herbivores, between birds of prey and small
mammals. In both these cases there may be a
stand-up fight, for instance between wolf and
stag, or between hawk and ermine; but neither
the logic nor the biology of the process is different
when all the fight is on one side. As the lemmings,
which have over-populated the Scandinavian

THE STRUGGLE FOR EXISTENCE 75

valleys, go on the march they are followed by
birds and beasts of prey, which thin their ranks.
Moreover, the competition between species need
not be direct; it will come to the same result
if both types seek after the same things. The
victory will be with the more effective and the
more prolific.

In the same way we pass from the struggle of
similar seedlings in the over-crowded garden-plot
to the struggle of coarser with finer grasses after
a veldt-fire—in many cases apparently ending in
the survival of the coarsest.

(c) Struggle with Fate—Our sweep widens still
further, and we pass beyond the idea of competition
altogether, to cases where the struggle for existence
is between the living organism and the inanimate
conditions of its life—for instance, between birds
and the winter’s cold, between aquatic animals
and changes in the water, between plants and
drought, between plants and frost—in a wide
sense, between Life and Fate.

Tue STRUGGLE FOR EXISTENCE IN THE PLANT
Worip.—We may be saved from taking a narrow
view of the struggle for existence if we emphasise
the fact that the concept must apply to plants
as much as to animals. “It has always pleased
me,” Darwin said, “to exalt plants in the scale
of organised beings,’ and in his books “ The
Power of Movement in Plants,” “ Climbing

1 We cannot here pursue the suggestive idea that, besides struggle
between individuals, there is struggle between groups of individuals
—the latter most notably developed in mankind. Similarly,
working in the other direction, there is struggle between parts
or tissues in the body, between cells in the body, between equiva-
lent germ-cells, and, perhaps, as Weismann pictures, between the
various multiplicate items that make up our inheritance.

76 DARWINISM AND HUMAN LIFE

Plants,” and “Insectivorous Plants,” we find
most interesting evidence that they are not so
sound asleep as is often thought. Among the
insectivorous plants we find actively aggressive,
almost militant, forms, like the well-known Venus
Fly-trap and the Sundew. Do they struggle
less really than the octopus? Has not the Venus
Fly-trap more than a hint of memory? Yet
how impossible to draw the line where aggres-
siveness ceases! We have to include the pas-
sive pitcher-plants and bladderworts. Apart from
actually carnivorous plants there are various
orchids that entrap, or, we may almost say,
visibly resent certain intruding insects, and there
are many common plants that have deep moats
where unwelcome visitors drown, hedges of hairs
where they are entangled, sticky surfaces where
they are limed.

There is no bloodshed among plants, but there
is over-crowding, crushing, starving, smothering,
strangling. Whether we take two lichens—each
a quaint partnership of Alga and Fungus—com-
peting for room to grow on an exposed stone,
or the plants in the meadow, or the weeds in
the sluggard’s garden, or the crowded life of the
jungle, we find clear evidence of competition for
space and light, for food and air. This has been
beautifully expressed by R. L. Stevenson, in his
poem “ The Woodman”:

Thick round me in the teeming mud

Brier and fern strove to the blood:

The hooked liana in his gin

Noosed his reluctant neighbours in:

There the green murderer throve and spread,
Upon his smothering victims fed, ~

THE STRUGGLE FOR EXISTENCE 77

And wantoned on his climbing coil.
Contending roots fought for the soil
Like frightened demons: with despair
Competing branches pushed for air.
Green conqu ors from overhead
Bestrode the bodies of their dead :
The Cesars of the sylvan field,

Unused to fail, foredoomed to yield:
For in the groins of branches, lo!

The cancers of the orchid grow.

Silent, as in the listed ring,

Two chartered wrestlers strain and cling ;
Dumb as by yellow Hooghly’s side
The suffocating captives died ;

So hushed the woodland warfare goes
Unceasing ; and the silent foes
Grapple and smother, strain and clasp
Without a cry, without a gasp.

Here also sound Thy fans, O God,
Here too Thy banners move abroad:
Forest and city, sea and shore,

And the whole earth, Thy threshing-floor !
The drums of war, the drums of peace,
Roll through our cities without cease,
And all the iron halls of life

Ring with the unremitting strife.

But as we continue our illustrations of struggle
among plants we lose the competitive note alto-
gether,—in cases like the desert plant with-
standing exceptional drought, and the northern
plant withstanding unusually keen frost. No one
doubts that extremes of drought and cold, and
the like, press upon the ceaseless endeavour of
even vegetable life, and that the plants answer
back. They do not take every assault lying
down.

ILLUSTRATION OF THE COMPLEXITY OF THE
SrruaeLe FoR Existence.—To convey a broad

78 DARWINISM AND HUMAN LIFE

impression of the struggle for existence we
cannot do better than refer to a graphic picture
drawn by Mr. W. H. Hudson in his charming
“ Naturalist in La Plata.” The summer of 1872-3
in La Plata was rich in sunshine and showers;
there was great wealth of blossom; the humble-
bees were very abundant; and the season was
also very favourable for mice which devoured the
bees. “In autumn the earth so teemed with
mice that one could scarcely walk anywhere
without treading on them; while out of every
hollow weed-stalk lying on the ground dozens
could be shaken.” They were so abundant that
“the dogs subsisted almost exclusively on them ;
the fowls also, from incessantly pursuing and
killing them, became quite rapacious in their
manner ; whilst the sulphur tyrant-birds (Pitangus)
and the Guira Cuckoos preyed on nothing but
mice.” The cats became wild hunters; “ foxes,
weasels, and opossums fared sumptuously ; even
for the common armadillo (Dasypus villosus) it
was a season of affluence.” Countless numbers
of storks and of short-eared owls came to assist
at the general feast. The owls were so numerous
that any evening after sunset Mr. Hudson could
count forty or fifty hovering over the trees about
his house. They became destructive to birds as
well as mice, and although the naturalist shot
many to try to reduce the havoc they were making
among the ovenbirds, the gaps he made were so
rapidly filled that he grew sick of the cruel war
in which he had hopelessly joined. “A singular
circumstance was that the owls began to breed
in the middle of winter.” “By August (1873)
the owls had vanished, and they had, indeed,

THE STRUGGLE FOR EXISTENCE 79

good cause for leaving. The winter had been
one of continued drought; the dry grass and
herbage of the preceding year had been consumed
by the cattle and wild animals, or had turned
to dust, and, with the disappearance of their
food and cover, the mice had ceased to be.” The
cats sneaked back to the houses. “ It was pitiful
to see the little burrowing owls; for these birds,
not having the powerful wings and prescient
instincts of the vagrant Otus brachyotus, were
compelled to face the poverty from which the
others escaped.” They became tame with hunger,
and so reduced as scarcely to be able to fly.

Fine weather, ready cover, and plenty of food
had allowed the mice to multiply beyond measure,
but their enemies had likewise increased. As
the herbage disappeared, multiplication of mice
ceased, and the army of enemies cleared off the
residue so thoroughly that “in spring it was
hard to find a survivor, even in barns and houses.”

This “wave of life” is one of the most in-
structive of biological pictures. It illustrates the
web of life, and the variety of the struggle for
existence. A physical change lets the stream of
life overflow, and, as the flood gathers momentum,
it widens the breach in its banks. One struggle
causes another struggle. Flowers abound, bees
abound, mice abound, cats and owls abound, and
there is struggle amongst all. Diets are changed,
habits are changed, numerical proportions are
changed, and then the season changes and all
is over. The mice are reduced to a minimum
and the wave of life is lost in the sand.

“The fact,” Mr. Hudson says, “that species
tend to increase in a geometrical ratio makes

80 DARWINISM AND HUMAN LIFE

these great and sudden changes frequent in many
regions of the earth; but it is not often they
present themselves so vividly as in the foregoing
instance, for here, scene after scene, is one of
Nature’s silent, passionless tragedies open before
us, countless myriads of highly organised beings
rising into existence only to perish almost im-
mediately, scarcely a hard-pressed remnant re-
maining after the great reaction to continue the
species.”

REASONS FOR THE STRUGGLE FOR EXISTENCE.—
The reasons for the struggle for existence among
animals and plants are fundamentally the same
as those which lie behind our own human struggle
and endeavour. “ Why do the people thus strive
and cry ?”’ Goethe asked, and gave the answer,
“They will have food, they will have children,
and bring them up as well as they can.” So it
is with other living creatures—their twofold,
never-ending business is to care for themselves
and to care for others. It has been said that
hunger and love solve the world’s problems, and
this is true if we take a wide enough view of these
notable words.

(a) One reason for struggle is to be found in the
tendency to over-population. The river of life
is always tending to overflow its banks. Struggle
is the safety-valve against the internal pressure
of rapidly increasing population. Wallace quotes
Kerner to the effect that a common British weed
| (Sisymbrium sophia) often has three-quarters of
a million seeds; if all grew to maturity for only
three years the whole of the land-surface of the
globe would not hold them. An annual plant
with only two seeds would be represented by

THE STRUGGLE FOR EXISTENCE 81

1,048,576 in the twenty-first year. “A bacillus
less than sogoth of an inch in length multiplies,
under normal conditions, at a rate that would
cause the offspring of a single individual to fill
the ocean to the depth of a mile in five days ”
(H. E. Crampton). “The cholera bacillus can
duplicate every twenty minutes, and might thus
in one day become 5,000,000,000,000,000,000,000,
with the weight, according to the calculations of
Cohn, of about 7,366 tons. In a few days, at this
rate, there would be a mass of bacteria as big
as the moon, huge enough to fill the whole ocean ”
(Saleeby).

The slowest breeder among mammals is the
elephant; it is supposed to rear one young one
every ten years, but, as it lives to more than a
hundred, Darwin calculated that in 750 years each
pair would, if all their offspring lived and bred,
be the ancestor of nineteen millions. The lemmings
in the Scandinavian valleys become periodically so
numerous that they eat up every plant, and must
march or starve. The bands become an army which
devastates as it goes, till their problem is solved
in the waves of the Baltic or the North Sea.

A cod has two million eggs, they say ; if these all
developed into cods there would soon be no more
fishing. An oyster may have sixty million eggs,
and the average American yield is sixteen millions.
If all the progeny of one oyster survived and
multiplied, its great-great-grand-children would
number sixty-six with thirty-three noughts after
it, and the heap of shells would be eight times the
size of the world.

Huxley calculated that if the descendants of a
single green-fly all survived and multiplied they

6

82 DARWINISM AND HUMAN LIFE

would, at the end of summer, weigh down the
population of China.

The common house-fly lays eggs in batches of
120 to 150 at a time, and may lay five or six of
these batches during its life—of about three weeks
in very hot weather. At the end of summer, if all
developed, and if there were six generations, the
progeny of a single pair, pressed together into a
solid mass, would occupy a space of something like
a quarter of a million cubic feet, allowing 200,000
flies to a cubit foot. There is no real increase,
hence the mortality must be prodigious.

The intensity of the struggle can be inferred
from the rate of increase. If there is slow multi-
plication and yet no falling off in the number of
adults, there is no keen struggle for existence. If
there is rapid multiplication and yet no increase
in the number of adults, there must be a keen
struggle for existence. It is useful to think. over
the simple equation : the number produced minus
the number eliminated equals the normal number
of adults.

(b) Another reason follows from the pattern of
the web of life—there are nutritive chains, one
organism depending on another for its food-supply.
Indeed, the struggle that strikes us most is that
which follows from the obvious fact that many
animals prefer to be carnivorous. There is a good
deal of the conjugation of the verb “To eat” in
life, and the objection to be eaten is as natural
to some animals as the desire to eat is to others.

(c) A third reason for struggle is to be found
in the irregular changefulness of the physical
environment. Give an animal time, and it may
become marvellously well adapted to its surround-

THE STRUGGLE FOR EXISTENCE 83

ings, as hand to glove; but when the surroundings
change the adaptation is gone. In some cases,
indeed, the living creature is adapted to change
with the changes of its surroundings : turning white
in winter, for instance, like the mountain-hare and
the ptarmigan. But when the outer world changes
wregularly, then the shoe pinches. The living
creature must accept defeat or struggle, and its
struggle may bring it success until a constitutional
variation in the right direction has time to establish
itself.

(d) Another reason for struggle is often over-
looked—namely, the self-assertiveness of the
vigorous animal. The lusty creature tends to be
a hustler. It elbows its way through the crowd,
jostling its neighbours. Even the plant pushes
and obstructs, ensnares and strangles, stings and
kills.

RESULTS OF THE STRUGGLE FOR EXISTENCE.—
There are three chief results of the ubiquitous
struggle for existence.

(A) In the first place, there may be a reduction
in numbers which relieves the pressure of popula-
tion without directly making for progress. Out
of 533 larve of the large garden white butterfly
collected by Prof. Poulton, 422 died from ichneu-
mon grubs: four out of every five—a great
mortality. But since there was no evidence that
the survivors were saved by being the possessors of
some peculiarity which those eliminated lacked, the
thinning had no evolutionary importance. It was
merely fortuitous or indiscriminate elimination.

(B) In the second place, it may be that the
organism is driven, by the pressure of the struggle,
to seek out a new habitat, to choose a more appro-

84 DARWINISM AND HUMAN LIFE

priate environment, or, what comes to the same
thing, to form a new habit. From the beginning,
necessity has been the mother of invention. For
animals, as for man, the exploration of new terri-
tory has been a constantly recurrent result of the
struggle for existence, and one of the most im-
portant. The open-air naturalist is familiar with
the way in which nearly related species fill slightly .
different corners in the same crowded area. It is
interesting, also, to think of the gradual peopling of
strange habitats, such as the abysses of the ocean,
the dark caves, and under the ground; or how
fishes come ashore, and mammals get into the air,
and crabs go up the mountains.

(c) In the third place, there may be discriminate
elimination of the less fit to the given conditions,
and it is this result that has most evolutionary
interest. The black rat’s territory is invaded by
the brown rat, and soon there is only brown rat.
Probably Kropotkin is right in suggesting that
this case is less simple than Darwin supposed, for
the arrival of a second rat made man wake up,
and the weaker species yielded first. But there
is evidence enough to lead us to believe that the
struggle between brown rat and black rat leads
to the rapid extermination of the black. From
this extreme case we find every possible gradation,
till all we can say is that the less fit are slightly
handicapped in the race of life. But if the slight
handicapping tells at all—and tells consistently—
as regards length and vigour of life, or number and
vigour of offspring, then it will serve as a selective
agent.

It is very important to realise that the struggle
for existence may select without rapidly killing off

THE STRUGGLE FOR EXISTENCE — 85

the less fit. If it mean that the less fit have a more
difficult lxfe and do not live so long, if it mean that
they have smaller and less vigorous families, if it
mean that the parents are harassed so that they
cannot give the offspring the best available start,
then it will, in the long run, work out to the same
result as if the less fit had come to a rapid violent
end. The advantageous character that the fit
variant possesses may be of survival-value, although
the absence of it does not mean the sudden death
of the less fit.

The elimination of the less fit may have a con-
servative influence, without resulting in any pro-
gressive change. It may keep the race up to an
established standard. But this is precisely the
same kind of process as that which results in
progressive adaptation, and should not be separated
off. It need hardly be said that when we find a
state of affairs where slackness is tolerated, it
means a temporary resting on the oars. Among
434 toads taken from the same place, Prof. W. E.
Kellicott found 5 per cent. with injuries and 3°68
per cent. with abnormalities, mostly disadvantage-
ous. The conditions of life were peculiarly easy,
there was abundant food, there were few enemies,
there were readily available means of protection
and concealment.

BREADTH OF THE DARWINIAN CONCEPT OF THE
STRUGGLE FOR ExisTeNcE.—There are many au-
thorities who insist that what Darwin particularly
and mainly meant was the struggle between
organisms of the same kind. Thus Weismann’
writes: The “struggle for existence,” which

1 “Darwin and Modern Science.” Edited by A. C. Seward,
Cambridge (1909), p. 20

86 DARWINISM AND HUMAN LIFE

Darwin regarded as taking the place of the human
breeder in free nature, is not a direct struggle be-
tween carnivores and their prey, but is the assumed
competition for survival between individuals of
the same species, of which, on an average, only
those survive to reproduce which have the greatest
power of resistance, whilst the others, less favour-
ably constituted, perish early.” ?

Here, however, as in not a few other instances,
Darwin is broader than many Darwinians. Al-
though one of the sections in chapter iii. of
“The Origin of Species ” is headed “ Struggle for
Life most Severe between Individuals and Varieties
of the same Species,” the evidence given hardly
justifies the title, and, in any case, another section
is headed “ The Term, Struggle for Existence, used
in a Large Sense.” In writing to Hooker in 1856,
he said: “ The slight differences selected, by which
a race or species is at last formed, stand in a far
more important relation to its associates than to
external conditions”; but there are many passages
in “The Origin of Species’ which express the
view that the struggle for existence as the method
of Nature’s sifting includes very much more than
internecine competition between fellows. “I should
premise,” he says, “that I use this term [“ struggle
for existence ”’] in a large and metaphorical sense,
including dependence of one being on another,
and including (which is more important) not only
the life of the individual, but success in leaving
progeny.”

1 The same view is expressed by Haeckel and Ray Lankester,
but I am glad to find that, in his scholarly and judicial “‘ Handbook
of Darwinism,” Prof. L. Plate interprets Darwin’s conclusions

and the state of affairs in nature in much the same way as I have
done.

THE STRUGGLE FOR EXISTENCE 87

The position which we are seeking to define and
defend is this. The concept “ struggle for exist-
ence” is wider than is suggested by the words
taken literally. It is a function of many in-
dependent variables. It expresses the reaction of
lwwing creatures to their limitations and difficulties.
It means that living is rarely drifting, except for
parasites. The physical world is careless of life;
there is an extraordinary abundance of life; the
river is always surging up to its embankments ;
love calls, hunger calls, and there is often no satis-
faction ; there are many critical moments in growth
and development, many risks of falling through
holes in the Mirza bridge; the living creature has
a will of its own—a will to live,—all this, and
more, may be usefully condensed in the formula
“ struggle for existence.”

Our thesis is that we have the struggle for exist-
ence wherever living creatures press up against
limiting conditions ; wherever living creatures, with
their powers of growing and multiplying, thrusting
and parrying, changing and being changed, do in
any way say, “ We will live.”

The living creature is by its very essence asser-
tive. Ifit cannot do anything else it will multiply.
Life is an endeavour; it expands, it intrudes itself,
it protests against limitations. One living creature
presses upon another, competes with another, eats
another. And for all this thrust and parry between
living creatures and ‘their limitations we use the
formula-phrase “struggle for existence.” Surely
Darwin had this broad conception vividly in mind
when he used that strange metaphor: “ Nature
may be compared to a surface on which rest
ten thousand sharp wedges touching each other

88 DARWINISM AND HUMAN LIFE

and driven inward by incessant blows ”—the idea
being that any wedge that was relieved from
blows would at once rise above the rest. But
the comparison to wedges is inadequate; we
have to think of living wedges with a will of
their own—a will to rise, and then we have got
nearer the idea of the struggle for existence.
The same idea is suggested by Darwin’s extra-
ordinary sentence: “It may metaphorically be
said that natural selection is daily and hourly
scrutinising throughout the world the slightest
variations.”

THe OTHER SIDE OF THE STRUGGLE FOR Exist-
ENCE.—If we are right in our wide interpretation
of the concept “struggle for existence,” which
we maintain to be Darwin’s, though many biolo-
gists, such as Sir EH. Ray Lankester, say it is not,
then we can pass in a more logical way than here-
tofore to what has sometimes been called the other
side of the struggle for existence: to a recognition of
the love of mates, parental sacrifice, filial affection,
the kindliness of kindred, gregariousness, sociality,
co-operation, mutual aid, and altruism generally.
These are facts of life, though we may differ as to
the precise psychological terms to be used in
describing them. The business of life, all through,
includes care for others as well as care for self. As
Herbert Spencer says: “If we define altruism as
being all action which, in the normal course of
things, benefits others instead of benefiting self,
then, from the dawn of life, altruism has been no
less essential than egoism. Though primarily it
is dependent on egoism, yet secondarily egoism
is dependent on it.” “‘Self-sacrifice is no less
primordial than self-preservation.” As has been

THE STRUGGLE FOR EXISTENCE = 89

well said: “The purely self-seeking animal has
been found to be a fiction, like that of the
economic man ” (Norman Wilde).

Our position is that, instead of making an anti-
thesis between “ struggle for others ” and “ struggle
for self,” it is clearer to recognise that both may be
included in the rubric of reaction of self-assertive
living creatures against the difficulties and limita-
tions of environing conditions. In many cases a
kin-instinct is as well defined as a self-preservative
instinct, and, in face of difficulties and limita-
tions, a solution may be found along either line
or along both. The world is indeed the abode
of the strong, but it is also the home of many
feeble folk who make up in love what they lack
in strength. .

Mourtvuat A1p.—Kropotkin has done real service
to science by showing, in detail, how much there
is of mutual aid among animals. There are some
genuine societies, where the whole is more than the
sum of its parts and sometimes acts as a unity.
Ants are little people, and all the world is against
them; in facing their limitations—which is what
“ struggle’ means—they have found a solution
in sociability, and they are dreaded by much
stronger insects. Every one knows that some
species of ants go to war. But our outlook on
nature should take its colour not only from the
wartare, but also from the self-subordination which
the whole life of the ant-hill illustrates. In many
species it seems to be a law of the hill that an ant
with a full crop must never refuse to feed a hungry
comrade.

There is something very suggestive in an ob-
servation of Hudson’s in regard to social and

90 DARWINISM AND HUMAN LIFE

sociable animals higher up in the scale, the Vis-
cachas—burrowing rodents of South America.
When the farmer destroys a viscacha burrow and
buries the inhabitants under a heap of earth, other
viscachas, coming from a distance—for village
often visits village—dig out those that are buried
alive. There are thousands of similar facts, which
go to show that there is much more in the animal
world than a Hobbesian warfare—each for himself
and extinction take the hindmost.

Besides animal societies in the stricter sense
there are many flocks and herds—gregarious rather
than social creatures; and what we know of their
mode of life, though it is not nearly so precise as it
ought to be, warrants us in saying that the vul-
garisation of the Darwinian picture of the struggle
for existence is inaccurate. There is an ugly
proverb which says that a wolf is a wolf to other
wolves, but Kipling’s zoology is finer: there’s a
law of the pack which means self-subordination.
We do not associate kites and vultures with fine
feelings, but the Brazilian kite is said to summon
its friends to the feast (when it is big enough), and
one of the strongest vultures is called—not without
good reason—the sociable vulture.

There are instances of co-operation among
animals neither social nor gregarious; thus a dozen
burying beetles may combine to transport a dead
bird to soft ground. Every one knows that little
birds, like wagtails, will combine to drive off a falcon,
and there are many records of the frequent disap-
pointment of birds of prey when they visit the
lake-side crowded with ducks and terns and
plovers. It is quite certain that the battle is not
always to the strong. Another striking fact is the

THE STRUGGLE FOR EXISTENCE 91

social character of migration in the case of many
birds that usually live alone.

Besides sociality, gregariousness, and co-opera-
tion, there are the associations of the pair and the
family, which evidently include much more than
squabbling round the platter. The struggle for
existence includes, as Darwin emphasised, “ suc-
cess in leaving progeny.” Macgillivray found two
thousand feathers in the nest of the long-tailed tit.

It goes without saying that mutual aid pays,
and pays because there is a universal struggle for
existence. Wedo not wish, therefore, to complicate
the issue with psychological questions of egoism
and altruism, self-regarding and other-regarding ;
nor do we wish to make an antithesis between
mutual aid and mutual struggle ; our point is that
within the wide concept of Struggle—or Reaction to
Limitations—there ts included mutual aid, and that
this mode of solution is attended with success—a
success which is more: than survival, for it spells
progress as well. As Kropotkin says: “Mutual
aid leads to mutual confidence, the first condition
for courage, and to individual initiative, the first
condition for intellectual progress.” The intel-
ligence of the social birds, like rooks, parrots, and
cranes, has been the subject of admiration since
natural history began.

Let us get away from mere words and into
contact with facts. Animals get hungry, they
seek their food, they endeavour to catch what often
endeavours not to be caught, they compete with
others who endeavour to catch the same elusive
prey, they have also to keep an eye on those who
are seeking to catch them while they are seeking
to catch something else, and meanwhile they have

92 DARWINISM AND HUMAN LIFE

to struggle to keep their foothold amid the storm
of the careless physical environment. There are
also struggles for mates and for the sake of off-
spring. Which of these endeavours is the struggle
for existence ? Each and all. For the real mean-
ing of the phrase is to be found, not in picturing
this or that kind of struggle or endeavour, but
rather in the general idea of living organisms
asserting themselves against limitations and diffi-
culties, partly no doubt due to their immediate
competitors of the same kin or even family, but
by no means restricted to this.

Our thesis is that progress depends on much
more than a squabble around the platter; that the
struggle for existence is far more than an inter-
necine competition at the margin of subsistence ;
that it includes all the multitudinous efforts for self
and others between the poles of love and hunger ;
that it comprises all the endeavours of mate for
mate, of parent for offspring, of kin for kin, as well
as every detail of self-assertiveness ; that existence
for many an animal means the well-being of a
socially bound or kin-bound organism in a social
milieu ; that egoism is not satisfied until it becomes
altruistic.

APPLICATION OF THE Concept To Human Lire.
—What has the Darwinian conception of the
struggle for existence to do with human life ?

(1) If Nature has any particular word to say
to man that word is Endeavour. All through the
ages we may see Nature’s condemnation of “ the
unlit lamp and the ungirt loin.” Nature is all for
efficiency, and down on slackness.

(2) It has to be admitted, however, that, at
juncture after juncture, Nature offers the alterna-

THE STRUGGLE FOR EXISTENCE 93

tive of parasitism, and there are thousands of living
creatures that have followed this line of least re-
sistance with its reward of adult safety and complete
material well-being, with its nemesis of degeneracy.
To man also this alternative is offered, and it is
not infrequently, in part at least, accepted, both
by lower and by higher stocks, and always with
inevitably attendant dangers. Let us recall Mere-
dith’s verse :

Behold the life of ease, it drifts.

The sharpened life commands its course :
She winnows, winnows roughly, sifts,

To dip her chosen in her source.

Contention is the vital force

Whence pluck they brain,—her prize of gifts.

(3) As among animals, so among men, disturb-
ances of equilibrium and conflict of interests bring
about struggle, and there are always two chief lines
of solution (besides that of partial parasitism).
The one is increased intensity of competition ; the
other is increased combination and mutual aid.
From the biologist’s point of view it is important
to make clear that Nature has rewarded both these
lines of solution with survival, and that the line
of mutual aid and sociality has been especially
justified by psychical progress. We may take it
that, as it has been in the past, survival and pro-
gress will continue to be the rewards of those
nations in which there is not only valour in com-
petition (more and more shifted from the battle-
fields), but the virtue of loyal subordination of
individual to communal interests.

(4) With the spread of civilisation the character
of the struggle for existence among men has

94 DARWINISM AND HUMAN LIFE

greatly changed, becoming less and less literal, less
and less sustained. It is seldom allowed to work
out to a finish, as it does in the animal world. As
this is apt to result in a state of affairs in which
the superior are defrauded of the rewards of superi-
ority and the inferior are not mulcted for their
inferiority—an unnatural state of affairs—it be-
hoves man to secure that the literal struggle for
existence is replaced by an endeavour after
well-being, which will continue in a subtler, more
rational, more humane form the automatic singling
and sifting which goes on in Nature. ~

CHAPTER IV

THE RAW MATERIALS OF
EVOLUTION

CHAPTER IV
THE RAW MATERIALS OF EVOLUTION

Organic Progress Primarily depends on Variability—Darwin’s Posi-
tion—Progress since Darwin’s Day in Regard to Variation—
Variations more Abundant than even Darwin supposed—
Proportion between Frequency and Amount of Variations
—Correlation of Variations—Brusque Variations more Frequent
than was formerly supposed—Discontinuous Variations—
Mutations—Darwin’s Position in Regard to Mutations—Origin
of Variations—Germinal Selection—Variational Stimuli—
Modifications or Acquired Characters—Indirect Importance of
Modifications — Modification-Species — Individual Plasticity—
Relation to Human Life.

Orcantc Progress PRIMARILY DEPENDS ON
VaRIABILITY.—The most difficult problem in bio-
logy—part of the persisting mystery of life itseli—
is the innate changefulness which we often see
manifested in a family, a herd, or a seed-plot, when
we compare one generation with another. Of how
much interest and importance is this changefulness !
for it is among the inborn variations of living
creatures that we find the raw materials of evolu-
tion.

Evolution implies change—change along a defi-
nite line, and it also implies a certain continuity
throughout the change. Individual development,
the growing of the mustard-seed into the greatest
of herbs, the “ minting and coining of the chick
out of the egg,” is progressive change in which the

97 v4

98 DARWINISM AND HUMAN LIFE

continuity is one of personal identity. In organic
evolution the continuity is racial, not individual ;
but, as in development, there is progress in the wide
sense. It may be up or down, for the better or for
the worse, measured by certain standards, but
progress of some sort is implied in the concept of
evolution, and it is with the raw materials of
progress that we are now concerned. The interest
of this inquiry is enhanced by the fact that, through-
out the ages, life has been on the whole slowly
on the upgrade, and that among animals there has
been a gradual emergence of greater control and
more freedom, of a fuller life and higher intelligence.

Darwin’s Postrion.—Darwin started from the
admitted fact of life that offspring are often
innately different from one another and from
their parents. Through his study of species—
which began in his boyish beetle-collecting and
went on to his eight years’ work on barnacles—
he had become aware of the fountain of change
in living creatures, and he strengthened his
impression by patiently accumulating facts in
regard to the variability of domesticated animals
and cultivated plants. In his original 1858 essay,
and in the “ Origin, of Species ” (1859), he recog-
nised two kinds of hereditary variations: (1) large
“single variations,” or “ sports,” which occur
rarely and result in individuals conspicuously
different from the type of the species; and (2),
slight “individual variations,” which are of
frequent occurrence, distinguishing child from
parent, brother from sister, or cousin from cousin.
He was much interested in the large single varia-
tions, such as occurred in the origin of copper-beech
and weeping willow, but—true to the influence

THE RAW MATERIALS OF EVOLUTION 99

of Lyell—he came to the conclusion that the
minute ubiquitous “ individual variations’ were
by far the more important. Fleeming Jenkin,
Professor of Engineering in Edinburgh, pointed
out that single large peculiarities would be likely
to be swamped by inter-crossing, and this criticism
had so much weight with Darwin that he ceased
to attach importance to the larger divergences,
and found his raw material in what he called
“individual variations.” “The more I work,”
he said, “the more I feel convinced it is by the
accumulation of such extremely slight variations
that new species arise.”

In reference to both sports and small variations,
Darwin used the terms “ indefinite” and “ spon-
taneous,” to distinguish them from “ definite
variations,”’ which are now called somatic modifica-
tions—i.e. definite and direct results of environ-
mental or functional changes. Darwin believed
in the occasional transmissibility of these “ definite
variations,’ and in so doing he agreed with
Lamarck, whose work he does not seem to have
adequately appreciated.

PROGRESS SINCE Darwin’s Day In REGARD TO
VariaTion.—While we must still confess, with
Darwin, that in regard to the causes of variation
our ignorance is immense, we have also to recognise
that, in several directions, there is progress to
report. For some time after the publication of
“The Origin of Species” more attention was
given to the directive than to the originative factors
in evolution. The idea of selection fascinated
naturalists, and it was too much the custom simply
to postulate variability to meet the demands of
particular problems. Life is so abundant and

100 DARWINISM AND HUMAN LIFE

so Protean that biologists tended to draw upon
the variability account as if there was no limit
to it, scarce waiting to see whether their cheques
were honoured. A lesson might have been taken
from Darwin’s painstaking study (1868) of varia-
tions in domesticated animals and cultivated
plants, or from Mr. J. A. Allen’s pioneer work
(1871) in measuring American birds, but the
vice of simply postulating variations when they
were wanted for theoretical purpose persisted
and has been wide-spread for fifty years.

In the preface to his “ Materials for the Study
of Variation ” (1894), Bateson wrote: “ We are
continually stopped by such phrases as, ‘ if such
and such a variation then took place and was
favourable,’ or, “we may easily suppose circum-
stances in which such and such a variation, if
it occurred, might be beneficial,’ and the like.
The whole argument is based on such assumptions
as these—assumptions which, were they found
in the arguments of Paley or of Butler, we could
not too scornfully ridicule. . . . If we had before
us the facts of variation there would be a body
of evidence to which, in these matters of doubt,
we could appeal. We should no longer say ‘ J}
variation take place in such a way,’ or ‘If such
a variation were possible’; we should, on the
contrary, be able to say, ‘Since variation does,
or at least may, take place in such a way,’
“Since such and such a variation is possible,’
and we should be expected to quote a case, or
cases, of such occurrence as an observed fact.”

In the most general terms it may be said that
one of the greatest steps of progress in evolution-
lore since Darwin’s day has been the accumulation

THE RAW MATERIALS OF EVOLUTION 101

of accurate data in regard to the variations that
do actually occur. It is a tedious task, but
peremptorily necessary, and already it is having
its reward. The recording and statistical registra-
tion of variations—such as we find in the pages
of the journal called Biometrika—is rapidly helping
us out of the slough of vagueness, in which, to
the physicist’s contempt, biology is so apt to
flounder. Let us try to state some of the general
impressions that we get from the post-Darwinian
study of variation.

(1) Variations more Abundant than even
Darwin supposed.—“ Even Darwin himself,” as
Wallace says, “did not realise how much and
how universally wild species vary’; but one of
the clear results of much patient work of recent
years has been the proof that variations are as
marked among creatures living wild in nature
as they are among those under man’s control.
The fountain of change is even more copious
than was dreamed of.

In commenting on the “ fallacy of the belief
that great variation is much rarer in wild than
in domesticated animals,” Mr. Bateson notes
that “if we examine the variation in the vertebrae
of the sloths, in the teeth of the anthropoid
apes, in the colour of the dog-whelks (Purpura
lapillus), etc., we find a frequency and a range of
variation matched only by the most variable of
domesticated animals.” We get the same im-
pression when we look at a good collection of
cuckoo’s eggs, or of land-snails, or of ruffs, and
so on through a long list.

It is difficult to realise the frequency and amount
of variations unti] one begins to measure and

102 DARWINISM AND HUMAN LIFE

weigh. In 1871 Mr. J. A. Allen measured numerous
individual representatives of some common species
of American birds, and found that, as regards
important points, eg. length of bill and length
of wing, birds of the same sex and season, caught
at the same place, on the same day, showed
numerous variations, often large in amount. “ The
facts of the case,” Mr. Allen says, “show that
variation of from 15 to 20 per cent. in general
size, and an equal degree of variation in the relative
size of different parts, may be ordinarily expected
among specimens of the same species and sex
taken at the same locality, while in some cases
the variation is even greater than this.”

(2) Proportion between Frequency and Amount
of Variations.—Another fact has been made clear
in regard to variations: there is a proportion
between the frequency of a particular change
and the amount of its departure from the mean
of the character in question. In other words,
the variations, when plotted out, show what is
called the Curve of Frequency of Error! In

1 Quetelet (1846) showed that variation followed the law of
frequency of error, the mathematical expression of which was
discovered by Gauss. Sir John Herschel, in illustrating this, took
the case of a rifleman aiming at a target. “It was pointed out
that, irrespective of the skill of the rifleman, the shots, after a
large number of trials, would be aggregated most thickly about
the centre of the target, and would be more and more thinly scat-
tered the farther the distance became from the centre of the target.
The only difference between the targets of a good and of a bad
rifleman is that in the former case the total area which contains
all the shots would be smaller than in the latter case. But in
each case the centre of the area would coincide with the centre
of the target, and the distribution of shots within the area would
be similar. The explanation of this result rests upon the cir-
cumstance that, each time the rifleman takes aim, a number of
factors come into operation, tending to disturb the correctness

THE RAW MATERIALS OF EVOLUTION 103

measurements of 2,600 men, taken at random,
Wallace notes that there is 1 of 4 ft. 8 in. and
lof 6 ft. 8in. ; 12 of 5 ft. and about 12 of 6 ft. 4 in.;
equal numbers at equal distances from the mean
of 5 ft. 8 in.

This tedious work of registering the variations
that occur may lead us right into the heart of
the matter; thus the asymmetry or skewness of
the curve may show us at a glance that the species
is moving in a definite direction as regards the
particular character measured, or the formation
of a double-humped curve may vividly bring
home the fact that the species is dividing into
two sub-species. Thus, by a statistical path, we
are brought face to face with the most vital of
all facts—l’évolution créatrice.

(3) Correlation of Variations.—Another im-
pression which we get from some of the modern
work on variation is, that the living creature

of the alignment of the rifle. But as these factors act with equal
frequency in every direction, it follows that the point of thickest
distribution of the shots will still remain at the centre of the target.
Now, variation is found to follow precisely the same law. If measure-
ments of some character are taken in a large number of individuals,
it is found that there is a mean measurement in the neighbourhood
of which the individuals are most thickly clustered, and that the
further the distance from the mean, the fewer are the individuals
represented. The analogy goes yet farther: for, just as in the
case of the good and bad riflemen, we found the shots to be in
close juxtaposition or more widely scattered, so in the case of
variation, it is found that the divergences from the mean are in
some cases far more accentuated than in other cases; that is to
say, the degree of constancy or variation in different organs is
very different. But in all cases the variation can be represented
by a geometrical curve, the ordinates of which are proportional
to the terms in the expansion of the binomial (a--b). Occasionally
the individuals are found to cluster round two or more points of
thickest distribution, and it is then inferred that they belong to
two or more different races,’"—Hdinburgh Review, Jan. 1909,

104 DARWINISM AND HUMAN LIFE

varies, in many cases, aS a unity, not in this
corner and that—like a machine that is perfected
by the accumulation of little patents,—but through
and through and all at once. As Darwin pointed
out, there is a “correlation of variations.” One
change brings another in its train, and the one
that is for the time most important may evolve
another much more important. Thus a variation
too small in itself to be of value may be carried
over the dead point into effectiveness because it
is physiologically bound up with another variation.

Another aspect of the same idea is that what
seem to be new departures in widely separated
parts of the animal may be really diverse outcrops
of one deep physiological change. We may have
thought of this in connection with some disease
that we have watched: it has very different
expressions in different parts of the body, though
it is due to a single slight derangement in the
normal sequence of chemical events. We may
have thought of the same idea in connection
with sex, where changes apparently confined
to minute and superficial and unconnected parts
may be, as it were, the correlated outcrop of
one deep physiological change.’ It is a familiar
fact that numerous apparently distant and un-
connected changes of adolescence are all funda-
mentally one. Similarly, when an individual plant
or animal varies as a whole, when compared with
its parent, this means that the potential individual,
the germ-cell, has varied as a unity.

(4) Brusque Variations more Frequent than
was formerly supposed.—But the most important

1 “The Evolution of Sex,” by P. Geddes and J. Arthur Thomson,
# Contemporary Science Series ” (1889). Revjsed Edition (1901).

THE RAW MATERIALS OF EVOLUTION 105

general result of the modern study of variability
is the evidence that changes of considerable
amount sometimes occur at a single leap.
These brusque changes are called “discontinuous
variations,” and, in certain cases, “mutations.”
Lamarck said, “Nature is never brusque,” and
we usually look askance at reports of “ Jack-in-
the-Box ” phenomena in nature; but, through the
solid work of Bateson, De Vries, and others, there
is more reason to-day than there was fifty years
ago to believe that organic structure may pass
with seeming abruptness from one position of
organic equilibrium to another.

Discontinuous VaARIATIONS.—In the individual
development of an embryo there is gradual con-
tinuous change from hour to hour, from day to day ;
and if we suppose similar changes to occur, not as
normal stages in the development of one creature,
but as new steps of progress in successive genera-
tions of creatures, we have the individual variations
that Darwin most believed in as furnishing the
raw materials of evolution. But in many a develop-
ment, such as that of a starfish or a butterfly,
there is in a certain sense discontinuity ; there is a
crisis, when the developing creature recommences
on a newtrack; and thissort of change occurring,
not as a normal event in individual development,
but as a new departure in racial evolution, would
be a “ discontinuous variation.” Using Galton’s
simile, we can picture a polyhedron oscillating or
rocking on one of its faces: this would be an
* individual variation,” or fluctuation ; we can also
picture it rolling over to a position of equilibrium
on another face: this would be “ discontinuous
yariation,” or mutation,

106 DARWINISM AND HUMAN LIFE

The greatest contribution in this connection is
Bateson’s work entitled, “ Materials for the Study
of Variation,” which showed that discontinuous
variations of certain kinds are not uncommon.
Abundant evidence is given of “ the existence of
sudden and discontinuous variation ; the existence,
that is to say, of new forms having from their first
beginning more or less of the kind of perfection
that we associate with normality.”

Mutations.—The idea that the Proteus may
leap as well as creep is prominent in the work of
the Dutch botanist De Vries, embodied in his
“‘Mutations-Theorie.” De Vries tells the story, for
instance, of a stock of the evening primrose
(Ginothera lamarckiana), which he found as an
escape in a potato-field near Amsterdam. It was,
as it were, frolicking in its freedom ; “ sporting,” as
we say. Almost all its organs were varying, as
if swayed by a restless, internal tide. It showed
minute fluctuations from generation to generation ;
it showed extraordinary freaks, such as fasciation
and pitcher-forming; it showed hesitancy as to
how long it meant to live, for while most were
biennial, many were annual, and a few were
triennial ; best of all, it showed what seemed like
new species in the making. From this stock De
Vries obtained, in a short time, half a dozen or more
distinct varieties or elementary species, breeding
true generation after generation, He was led to
the important conclusion that “ new varieties are
produced from existing forms by sudden leaps.”

1 It is unfortunate that nothing certain is known as to the origin
of Gnothera lamarckiana, which has been in cultivation for a
long time. It is possible that its “ mutations” result from the
impurity of the stock, As Prof. 8, J, Holmes says, in an interesting

THE RAW MATERIALS OF EVOLUTION 107

The first part of the Dutch botanist’s great work
was published forty-three years after “ The Origin
of Species,” and there are many who regard the
Mutation Theory and Mendelism as the two
greatest steps of progress that have been made in
evolution-lore since 1859. Others, such as Alfred
Russel Wallace, the Nestor of the evolutionist camp,
are very far from sharing this view. In any case
we must try to understand what mutations are and
what their significance may be.

The general idea is that novel characters may
suddenly appear, as it were, full-fledged, with con-
siderable perfectness from the moment of their
emergence, and without intergrades linking them to
the parents. Furthermore, the novel character of
the mutant, if we may use the word, is independently
heritable and does not blend; it can be grafted
intactly on to another stock, or it can be dropped
out as such. Again, mutations are what may be
‘called qualitative, as contrasted with the fluctua-
tions which are quantitative. Thus, some of the
new evening primroses which De Vries got out
of his changeful stock of Ginothera lamarckiana
were very different from the parent type—some had
few branches instead of many, some had small
flowers instead of large, some had quite different
leaves, and so on. Mutations have been recorded
for a number of other plants, such as violets and
shepherd’s purse; but the inquiry is still young.

Among animals in nature we know as yet of few

paper on “ The Categories of Variation ” (American Naturalist (1909),
vol, xliii. p. 277): ‘“ Should it turn out to be derived from a mixture
of two or more forms, the mutation theory would be deprived
of some of its best evidence; but there would still remain a con-

siderable number of mutations from pure ancestry,”

108 DARWINISM AND HUMAN LIFE

sudden emergences of qualitatively new characters,
but several cases have been reported. Thus pink
katydids may abruptly appear among green ones,
and short-winged insects in a long-winged race,
in both cases without intergrades. Mutations are
also described among freshwater fishes and among
meduse.

When we turn, however, to domesticated animals,
where we have greater opportunities of intimate
observation, the case for mutation becomes
stronger. There are sudden negative changes—
the entire dropping out of a character—as seen in
the abrupt appearance of hornless cattle, sheep, and
goats, of hairless dogs and horses, of tailless cats
and dogs. There are also sudden positive changes
—the acquisition of a new character—such as the
appearance of extra digits in poultry and pigs.
Those who have bred birds are familiar with such
sports, which are often striking. There is evidence
in a number of cases that stable and successful
breeds have been established, not by the slow
increase of minute fluctuations, but by getting a
big startin a mutation. In many cases, although
breeding or cultivation has grafted the novelty on to
a strong stock and made it prepotent, it has not
greatly increased the magnitude of the quality
which the original sport exhibited.

Darwin’s Position 1n Recarp to Mutations.
—Though Darwin had not the conception of unit
characters—that is to say, independently heritable
characters which are handed on intact or dropped
out altogether—in its modern clear-cut form, he
was well acquainted with mutations in domesticated
animals and cultivated plants, and he dismissed
most of them as not important, Tn the first place,

THE RAW MATERIALS OF EVOLUTION 109

they seemed to him to partake too much of the
pathological. But we must not hurriedly dismiss
mutations like that of fowls with webbed feet and
no tails as obviously teratological, for most of
them may be matched in nature. If there were
only one specimen of a cross-bill, for instance,
would it not be regarded as a freak which could not
possibly survive in nature? In the second place,
reacting as he was against a catastrophic view of
nature, and looking at things (as he said) through
Lyell’s eyes, Darwin naturally fought shy of
big sudden changes. Moreover, as he said to Asa
Gray: “ There seems to me in almost every case
too much, too complex, and too beautiful adapta-
tion in every structure to believe in its sudden
production.” Finally, he thought that a full-
fledged new character appearing suddenly would
be swamped by intefcrossing.?

The last difficulty, which is the only serious one,
has been removed, for it is characteristic of muta-
tions that, when they arrive, they come to stay,
unless they be eliminated as disadvantageous. In

1 It was characteristic of the Lyellian, or Uniformitarian school
of geologists to explain large results on the principle of slow suc-
cessive increments, accumulating for a very long time.

2 Let us hear what he says in the last edition of “ The Origin
of Species”

“Mr. Mivart is further inclined to believe, and some naturalists
agree with him, that new species manifest themselves * with sudden-
ness and by modifications appearing at once... .’ This con-
clusion, which implies great breaks or discontinuity in the series,
appears to me improbable in the highest degree”’ (p. 201).

“ Although very many species have almost certainly been
produced by steps not greater than those separating fine varieties,
yet it may be maintained that some have been developed in a
different and abrupt manner. Such an admission, however,
ought not to be made without strong evidence being assigned”

(p. 203).

110 DARWINISM AND HUMAN LIFE

other words, a new unit character of a beetle or
of a shepherd’s purse—two experimentally tested
instances—does not blend when its possessor is
crossed. with the original type. It is not swamped
by intercrossing, but reappears in its integrity in
a definite proportion of the succeeding generations.
Already in actual practice in wheat-growing it is
being found that selected single ears breed true,
and that no further selection is needed.

The attractiveness of the mutation theory is so
great that we must be particularly cautious in our
acceptance of it. It would relieve the difficulties
that many naturalists have in believing that the
apparent big lifts and qualitative changes which
the history of organic life implies have arisen by
the natural selection of minute individual fluctua-
tions. It would make more intelligible the dis-
continuity of many species, if we found reason to
believe in their saltatory origin. It need hardly
be said that the origin of the mutation would
remain a mystery, for the mutation theory is not
a theory of mutations. It will be interesting if
evidence accumulate to show that the Proteus
leaps as well as creeps, if future generations look
back to Darwin as the naturalist who saw nature
moving by small steps, while Dr. Vries caught a
glimpse of her dancing !

ORIGIN oF VARIATIONS.—In regard to the difficult
question of the origin of variations, we must not be
impatient to answer until our knowledge of their
nature has greatly increased. We must, still confess,
with Darwin : “ Our ignorance of the laws of varia-
tion is profound. Not in one case out of a hundred
can we pretend to assign any reason why this or
that part has varied.” And again he said:

THE RAW MATERIALS OF EVOLUTION 111

“Tf, as I must think, external characters produce
little direct effect, what the devil determines each
particular variation ? ”

Having made this confession of ignorance, we
venture to discuss the possibilities of answer to a
question which can never be far from any thought-
ful mind.

There are variations and variations. There are
variations that mean nothing more than an aug-
mentation or diminution of an already existing
quality. The hair may be very long or the tail
very short. Or a variation may mean that a
character present in parents and ancestry is absent
from the offspring: the entail has been broken.
An albino expresses such a variation, or a hornless
calf, or a tailless kitten. Or, again, a variation
may be interpretable as a novel arrangement of
characters or qualities which were present in the
ancestry. A piebald pony may serve as a diagram.

Now, in regard to variations of this sort—
which may be described as permutations and
combinations of the already existing unit char-
acters—the modern knowledge of the conditions
of heredity has made it plain that there are many
opportunities for their occurrence before, during,
and after fertilisation. We know that each germ-
cell contains a definite number of stainable bodies,
or chromosomes, which appear to be the bearers
of the heritable qualities. 'We may compare these
to a microscopic pack of cards, and we may say
that there is an extraordinarily elaborate shuffling
before development begins. Half of the pack is
ejected from the egg-cell in what is known as a
“polar body,” and. the number is raised to the
normal again (constant throughout the body of the

112 DARWINISM AND HUMAN LIFE

organism) by the entrance of the fertilising sperma-
tozoon whose chromosomes have also been reduced
by a half. In fertilisation, at the beginning of
each new life, there is an intricacy of combination
that may be likened to the making of a living
mosaic out of parental and ancestral contributions.
It may also be that in the making of the germ-
cells there is a segregation of antithetic qualities,
so that two different kinds of germ-cells result,
corresponding to the two sharply contrasted
parents. It may also be, as Weismann supposes,
that there is a struggle between rival unit-char-
acters in the penetralia of the germ-cells. In
any case, there is abundant opportunity for new
permutations and combinations. There are many
factors which may give the vital kaleidoscope a
twist.

There is, however, another kind of variation,
when novel features appear, which are qualitative
rather than quantitative, substantive rather than
architectural, in kind rather than in degree, and
more than mere rearrangements of previously
expressed unit characters. What can be said as
to their origin ?

Weismann and others have suggested that
the stimulus to germinal variations comes from
the oscillations and changes in the immediate
surroundings of the germ-cells. They get their food-
supply from the body, and that food-supply is
liable to be somewhat variable. It may contain
a poison, for instance, which seriously shakes
the architecture of the germ-plasm at the very
start; but it may also contain some stimulus,
which provokes the living germ to a new de-
parture.

THE RAW MATERIALS OF EVOLUTION 113

Another suggestion, which has some interesting
experimental evidence behind it, is that important
changes in the environment—changes in chemical
composition, heat, light, and electrical conditions,
and so on—may saturate deeply through the
body and stimulate the germ-cell to change. We
shall return to this suggestion later on.

GeRMiInaL SELEcTION.—In his theory of “ gers
minal selection” Weismann has elaborated an
interesting speculation in regard to the roots of
variation. With his characteristic way of following
an idea as far as it will lead him, he has extended
the concepts of struggle and selection to the
primary constituents (or determinants) within
the germ-cell. In consequence of unequal nutrition
these primary constituents are always varying. If
one of them, corresponding, let us say, to a sense-
cell, receives for a considerable time more abundant
food than before, it will grow in proportion, and
if the germ-cell develops into an organism the
sensory cell may be twice as strong as it was in
the parent.

But the strengthened determinant may begin
actively to nourish itself more abundantly—
attracting the food to itself, and in some measure
withdrawing it from its fellow-determinants. In
this way “it may get into a permanent upward
movement, and attain a degree of strength from
which there is no falling back.”

In a similar manner a downward variation of
a determinant may be started by diminished
nutrition, and the weakened determinant will
have less affinity for attracting nutriment because
of its diminished strength. ‘“ If a certain critical
stage of downward progress be passed, even

8

114 DARWINISM AND HUMAN LIFE

favourable conditions of food-supply will no
longer suffice permanently to change the direction
of the variation.”

If, in such a case, the determinant be that of
a useful structure, then the ordinary process of
natural selection will remove the individual; but
if the weakened determinant be that of a useless
organ it will continue getting weaker generation
after generation.

“In most cases the fluctuations will counteract
one another, because the passive streams of
nutriment soon change; but in many cases the
limit from which a return is possible will be passed,
and then the determinants concerned will continue
to vary in the same direction till they attain
positive or negative selection-value. At this stage
personal selection intervenes and sets aside the
variation if it is disadvantageous, or favours—
that is to say, preserves—it if it is advantageous.
But the determinant of a useless organ is un-
influenced by personal selection, and, as experience
shows, it sinks downwards; that is, the organ
that corresponds to it degenerates very slowly
but uninterruptedly till, after what must obviously
be an immense stretch of time, it disappears from
the germ-plasm altogether.” Thus “ germinal
selection supplies the stones out of which personal
selection builds her temples and palaces: adapta-
tions.”’*

The theory is, of course, entirely hypothetical,
dealing as it does with the invisible, but it enables
us to formulate a large number of facts.

VARIATIONAL STimuLI.—Some of the most in-
teresting and striking work of the last dozen years

1 “The Evolution Theory,” by Weismann (1904), vol. ii.

THE RAW MATERIALS OF EVOLUTION 115

must be referred to in connection with the origin
of variations. It has been shown experimentally
that chemical substances in the food of the mother
may be carried on into the offspring. Thus, when
the dye known as Sudan is mixed with the
food of hens, it appears in the yolk of the egg
and eventually in the fatty tissue of the chick.
Perhaps this sort of thing is commoner than is
usually supposed. By changing the temperature
and the food of the caterpillars of Vanessa and
Arctia, Standfuss and Fischer were able to induce,
in the next generation, aberrant characters, which
remained distinct when crossed with the parent
form.

More striking, however, are the experiments
carried on for twelve years by Professor Tower
on beetles of the genus Leptinotarsa, which he
subjected to unusual conditions of temperature
and moisture when the male or female reproductive
organs were at a fixed point in their development.
The result was to induce in the offspring striking
changes, not only in colour and markings, but
also in some details of structure. Sometimes all
the germ-cells seemed to be affected, sometimes
only a fraction of them ; sometimes various changes
resulted from the same treatment; some of the
changes were brusque, others showed intergrades
with the parental conditions; sometimes the
change did not occur until after the lapse of
several generations in the unusual environment ;
there was no reversion to the parental condition.
Of course Tower could not get at the reproductive
organs except through the body, but it should
be noted that the body of the parent was not
changed, and it was only at particular stages

116 DARWINISM AND HUMAN LIFE

that the influence was operative. Here, then, we
have definite evidence of germinal variation
evoked by environmental stimulus.

Very interesting, also, are the experiments of Dr.
C. S. Gager, who exposed the egg-cells and pollen-
cells of Onagra biennis to Radium rays, and found
that plants grown from the seeds produced under
this influence were very different from the parents,
and that the change persisted to the second genera-
tion at least. Here, again, there is proof of heritable
variation induced by environmental stimulus.

Shortly before his death Darwin began to
experiment on the possibility of producing galls
artificially. “‘He imagined to himself wonder-
ful galls caused to appear on the ovaries of
plants, and by these means he thought it possible
that the seed might be influenced, and thus
new varieties arise.”! What Darwin just began
has been carried out with great skill by Prof. |
D. T. MacDougal. “ Among other operations,
solutions of sugar, calcium, potassium, and zinc
were injected by the use of hypodermic syringes
into the developing ovaries of Raimannia, one of
the evening primroses, early in 1905, with the
result that, out of several hundreds of seeds borne
by the treated ovaries, sixteen individuals were
found to be notably atypic, among other char-
acters lacking the trichomes which are so con-
spicuous with the parental form. These reproduced
themselves in the second and third generations,
coming true to the newly-assumed characters.” ?
Similar experiments were made with Mnothera

1 ‘© Life and Letters of Charles Darwin,” vol. ii. p. 517.
2 «The Direct Influence of Environment,” by D. T. Mac-
Dougal, in “ Fifty Years of Darwinism ” (1909).

THE RAW MATERIALS OF EVOLUTION 117

biennts and Penstemon wrightii, and we have
decisive evidence that environmental stimulus
acting directly on the germ-cells may induce
striking variations. This is a very important
result, for it is evident that the germ-cells of
animals may in a similar way be naturally stimu-
lated to vary by chemical changes in the vascular
fluids. ‘With the flowers, as with the beetles, there
were not only losses and augmentations of what
was previously present, but there were distinct
novelties which maintained their distinctness when
crossed with the parental strains.

After we have worked for years along the lines
of these various suggestions that have been offered
as to the causes of variations, we shall be better
able to say how far they account for what we believe
has occurred in the past, and for what we know
to occur at present. Perhaps they will prove
insufficient, and evolutionists will be forced to
recognise that variability is, like growth, a primary
quality of living things, and that “ breeding
true” has arisen secondarily as a restriction.
The relation of genetic continuity between succes-
sive generations is an economical arrangement
which secures relative constancy amid continual
flux, but in spite of this the Proteus continually
asserts itself. Its essence is creative power. It
lives because it changes, it changes because it
lives. From generation to generation there is a
continuous lineage of germ-cells; but just as we
see a youth growing and changing, taking time
into himself and making himself, in some ways,
new by his experience, so it may be that there is a
power of growing and varying inherent in the germ-
cells—as also in the unicellular organisms in the

118 DARWINISM AND HUMAN LIFE

waters—which requires only time and experience
to produce what is new.

MoDIFICATIONS, OR ACQUIRED CHARACTERS.—
We must now ask a very important question. Are
there no other raw materials of evolution besides
those inborn changes which we call variations and
mutations, which we trace back to more or less
mysterious processes occurring in the germinal
material? It is well known that our bodies suffer
change according to what we do ordo not do, and
according to climate and food, and so forth. Does
this sort of change not furnish part of the raw
material of evolution ?

Among the observed differences which mark
man from man, or trout from trout, or buttercup
from buttercup, there are many to which we can-
not apply the word “variation.” For, apart
from constitutional or inborn changes, there are
differences which are impressed upon the body
in the course of life by influences from without,
such as sun-burning in man or colour in trout; or
by use and disuse, such as callosities on the fingers.
These do indeed presuppose a constitution capable
of being changed, but we can relate each to some
definite influence, either of function or of environ-
ment, which has brought about a structural change
transcending the limits of organic elasticity. We
call these modifications, and though they may be
of much importance to the individuals possessing
them, they are not known to be of any direct
importance in the evolution of the race, for the
simple reason that there is no convincing evi-
dence that they can be transmitted. Here the
_ Lamarckians entirely dissent; but they have still
to prove their case.

THE RAW MATERIALS OF EVOLUTION 119

After much discussion most naturalists have
come back to the position of Kant, that life does
not run on a compound interest principle of adding
to the child’s inheritance the individual acquisi-
tions (somatogenic or exogenous modifications)
of the parents. As a matter of fact, we do not
know of any clear case of individual modifications
due to surroundings, education, work, or sloth,
being transmitted in any degree to offspring. That
the parents’ mode of life influences the children
yet unborn is obvious; but the point is, whether the
influence produces a corresponding or representa-
tive effect.

InpirEct Importance oF MopiIFIcaTions.—
Those who find no warrant for accepting the
Lamarckian postulate of the transmissibility of
modifications, do not thereby assert that modifica-
tions are of no importance. Many living creatures
are exceedingly plastic, and their modifiability
sometimes saves them where their variability is
at fault. This idea has been elaborated independ-
ently by Profs: Mark Baldwin, Lloyd Morgan,
and H. F. Osborn, and we venture to quote
Lloyd Morgan’s terse summary :

(1) Variations (V) occur, some of which are in
the direction of increased adaptation (+), others
in the direction of decreased adaptation (-—).
(2) Acquired modifications (M) also occur. Some
of these are in the direction of increased accom-
modation to circumstances (+), while others are in
the direction of diminished accommodation (—).
Four major combinations are—

(a) + V with + M. (c) — Vwith + M:
(6) + V with —- M. (d) — V with — M.

120 DARWINISM AND HUMAN LIFE

Of these (d) must inevitably be eliminated while
(a) are selected. The predominant survival of
(a) entails the survival of the adaptive variations
which are inherited. The contributory acquisi-
tions + M are not inherited; but they are none
the less factors in determining the survival of the
coincident variations.” Lamarckians believe that
useful modifications are in some degree sometimes
transmitted. On the view just sketched the modi-
fications are the screens or nurses of coincident
variations in the same direction.

We can imagine conditions where swarthiness
was a character of life-saving value, where the
possessors of inborn variations in the direction of
swarthiness were favoured, where those who varied
in the direction of increased blondeness were
handicapped. It is readily intelligible that those
who could acquire swarthiness as an individual
somatic modification would also be favoured, and
that the acquired swarthiness might act as a life-
saving screen until constitutional and heritable
swarthiness had time to establish itself.

Furthermore, although modifications may not
be entailed, they may have occasionally important
indirect influences on the offspring. A starved
mother may have a weakly child.

MoDIFICATION-SPECIES.—In the case of animals
and plants which we do not know except in
particular surroundings, it is quite possible that
characters which we credit to inherited nature
may be impressed on every successive generation
by nurture. Especially among the more vegeta-
tive forms of life we find indications, which experi-
ment will some day test, that there are what may
be called “ modification-species,” which differ from

THE RAW MATERIALS OF EVOLUTION 121

nearly related species only because the conditions
of their life are different.

InpivipuaL Prasticiry.—At all events, there
is great interest in individual plasticity, in what
can be effected by changes in nurture. We must
picture the living creature as continually running
the gauntlet of the mechanical, chemical, physical,
and even animate influences that make up its
environment. It passes over a series of anvils,
on each of which the hammers ring a different
tune. Let us take a few illustrations from among
the many.

If the alkalinity of the sea-water be slightly
altered, the egg of a sea-urchin allows itself to be
fertilised by the sperm of a starfish, or of a crinoid,
or of a mollusc (!), producing larve which all take
after the mother.

If the chemical and physical state of the sea-
water be slightly disturbed, artificial partheno-
genesis can be induced in starfish and sea-urchin,
in worm and mollusc.

Sometimes the result of a slight chemical change
is very perplexing, and there are many experiments
at which we look with bated breath. Quaint
abnormal larvee of sea-urchin and frog are obtained
by adding a little lithium to the water, and the
addition of a little magnesium to the sea-water
containing embryos of the fish Fundulus hetero-
clitus induces in a large number of these the de-
velopment of a single Cyclopean eye in place of
the normal two eyes.

A small Crustacean called Gammarus, very
common in fresh water, has the habit of avoiding

1 Charles R. Stockard, in Journal of Experimental Zoology,
February 1909.

122 DARWINISM AND HUMAN LIFE

the light, but add a little acid so that the solution
is no stronger than ;32,5th of one per cent., and
Gammarus swims towards the light.

Remove one or two of the metals from sea-
water, keeping up the alkalinity, and the sea-
urchin egg develops into twins. Raising the
temperature a little often has the same result.

Cold slows growth and development, yet the
population of floating and drifting animals is
denser in the Arctic waters than in the Tropics—
a curious fact which Prof. Loeb explains by showing
that lowering the temperature greatly increases
the duration of life. There are more generations
living at the same time. Lowering the temperature
of the caterpillar box may be followed by curious
aberrations of colour in the moths and butterflies,
especially in the direction of melanism (Standfuss,
Fischer, and others). Prof. Poulton showed that
the caterpillars of the small tortoise-shell, for
instance, are for a short time so sensitive that
those in a white or gilded box have light or
golden pups, while those from the dark box have
dark pupe.

The influence of diet alone might form the subject
of a course.of lectures. Take the simple but very
suggestive fact reported by Marchal that a scale-
insect, Lecanium corn, becomes L. robiniarum when
reared on Robinia pseudoacacia instead of on its
own normal food-plant, though the reverse ex-
periment does not succeed. Or consider one of
the most interesting of recent researches. Mr.
C. W. Beebe’ caused the scarlet tanager (Piranga
erythromelas) and. the bobolink (Dolichonyx oryzi-
vorus) to keep their breeding plumage through

1 American Naturalist (1908), vol. xlii. p. 34.

THE RAW MATERIALS OF EVOLUTION 123

the year by giving them fattening food and keeping
them without much exercise in dim light. Gradual
return to the light and the addition of mealworms
to the menu brought back the spring song, even
in mid-winter. After a year, and at the beginning
of the normal breeding season, individual tanagers
and bobolinks were gradually brought under normal
conditions and activities, and in every case they
moulted from nuptial plumage to nuptial plumage,
the dull colours of the winter season having been
skipped. The inherited constitution determines
what is possible, but there is evidently a large
range of plasticity. We do not know that modifica-
tions are entailed, but we must attach all the more
importance to the influence of the environment in
bringing about individual adjustment, in stimu-
lating variation, and in punctuating developmental
processes.

Reuation TO Human Lire.—-What has all this
discussion regarding fluctuations and variations
and mutations and modifications to do with
human life? It would be easier to answer this
question if we knew more about these changes,
but some practical considerations are obvious.

To begin with, man probably arose by a mutation;
that is to say, by a discontinuous variation of
considerable magnitude. Every one who has known
a genius has in this happy experience some idea of
what is meant by a mutation, though the com-
parison breaks down inasmuch as the quality of
genius is rarely heritable. It is not merely that
the genius has more brains; he has a new pattern
of brains, and a large mutation is a new constitu-
tional pattern. It is likely that man had his
starting-point as a prepotent anthropoid genius,

124 DARWINISM AND HUMAN LIFE

Man’s origin is hidden, and, whatever our ancestry
was, we cannot change it; man’s future is also
hidden, but it will be, in some measure, of our
making. Now, it is evident that some variations
are undesirable: they make their possessor miser-
able, and his neighbours hardly less miserable. We
admit that there is an “ optimism of pathology ” ;
unpromising buds may burst into flowers as fair as
they are unexpected, weaklings bend Titans to their
will, cripples make the world go round, and those of
marred visage teach us what beauty really is; but,
with all the breadth of view that biology will allow,
there are some variations on which the verdict of
history is that they make for retrogression. Every
one wishes these variations to die out.

There are other variations that are unmistakably
desirable—in the direction of fine physique,
artistic skill, keen mental ability, originality,
socialised disposition, and strength of character.
Every one wishes these variations to be widely
distributed.

Inquiry into the history of good animal stocks
shows that steady progress has always rewarded
the mating of nearly related forms, while the
blending of distant and incompatible types seems
often to lead to reversionary mongrels. Here we
have a warning to the thoughtless experimenter
with his own stock.

One of the characteristics that should dis-
tinguish the biologist is an expectancy, an open-
mindedness, a tolerance, even a reverence, with
respect to variations; for these new departures
on the part of the ever-changing organism are the
raw materials of progress, and should be sedulously
guarded. Individuality is often born, often

THE RAW MATERIALS OF EVOLUTION 125

smothered, rarely made. A man with an idio-
syncrasy, who is snubbed as an impossible person,
may be a Moses who might have led us out
of bondage! Captain Fitzroy nearly refused to
take Darwin on the Beagle voyage because of
his nose !

For various reasons biologists take a strong
interest in the play of animals and of children.
Play is no mere safety-valve for overflowing
animal spirits: it is a rehearsal, without responsi-
bilities, of some of the essential activities of adult
life. But itis more: it affords what the Germans
call Abdnderungspielraum—playground for varia-
tions. The playing organisms are the most
educable.

The distinction between variations and modifica-
tions seems sometimes academic and tiresome, but
if we understand it we see it as one of the most
practical of questions. Do the innate changes
in the natural inheritance furnish the whole raw
material of progress, or do the changes in the body
due to peculiarities of nurture furnish some? At
present the scientific answer seems to be, that the
raw material of organic evolution is due to varia-
tions, and in no direct way due to modifications.
How closely this touches human life! There is
social evolution as well as organic evolution, and
social evolution has provided an apparatus whereby
the gains of experience may swell the legacy of
successive generations, although they do not, from
the nature of the case, become part of the germinal
inheritance.

As Lloyd Morgan’ well says: “ The history of

1 «‘ Mental Factors in Evolution,” in “ Darwinism and Modern
Science’ (1909), p. 445.

126 DARWINISM AND HUMAN LIFE

human progress has been mainly the history of
man’s higher educability, the products of which
he has projected on to his environment. This
educability remains, on the average, what it was
a dozen generations ago; but the thought-woven
tapestry of his surroundings is refashioned and
improved by each succeeding generation.”

“Few men have in greater measure enriched the
thought-environment with which it is the aim of
education to bring educable human beings into
vital contact than has Charles Darwin.”

CHAPTER V
FACTS OF INHERITANCE,

127

CHAPTER V
FACTS OF INHERITANCE

Progress during the Darwinian Era—Demonstration of Heritable
Qualities—Heredity, a Term for the Genetic Relation between
Successive Generations—Appreciation of Distinction between
Nature and Nurture—The Idea of the Continuity of Genera-
tions—Critical Attitude in Regard to Various Conclusions—
Mendelism—Methods of Studying Heredity—Microscopical
Study of the Germ-cells—Statistical Study: Filial Regression
—Galton’s Law of Ancestral Inheritance—Experimental Study
—Pairing of Similar Pure-bred Forms—Blending—Particulate
Inheritance—Exclusive Inheritance—Reversion—New Depar-
tures—Mendelian Inheritance—Unit Characters—The Case
of Andalusian Fowls—Waltzing Mice—Occurrence of Mendelian
Inheritance—Practical Importance of Mendelism—Much
Progress but Great Uncertainty—Transmission of Acquired
Characters—Disease—Facts and Possibilities—A Striking Case
—Logical Position of the Question—Cases where the Theory
of Modification-inheritance is Inapplicable—Importance of
Environment and Function Remains—Selection and Stimulus
—Indirect Importance of Modifications—Practical Import of
the Question as to the Transmission of Acquired Characters—
Inheritance of Moral Character—Three General Conclusions.

EVEN in ancient times men pondered over the
resemblances and differences between children and
their parents, and wondered as to the nature of
the bond which links generation to generation ;
but, although a recognition of these problems is
old, the precise study of them is altogether modern,
and may almost be called Darwinian. For it was
largely through Darwin’s influence that the scientific
study of heredity began. “Before and after
Darwin,” Professor Osborn says, “ will always be
129 9

130 DARWINISM AND HUMAN LIFE

the ante et post urbem conditam of biological history”;
so it may be useful to inquire into the advances
that have been made in the study of heredity since
the beginning of Darwin’s day.’

PROGRESS DURING THE DaRwINIAN Era. (1)
Demonstration of Heritable Qualities.—Before 1859
much attention was given to the demonstration
of the general fact of inheritance. In a large
treatise like that of Prosper Lucas (1847) many
hundreds of pages are devoted to proving, what we
now take for granted—that our start in life is no
haphazard affair, but rigorously determined by our
parents and ancestors; that various peculiarities,
important and trivial, useful and disadvantageous,
reappear as part of the inheritance generation
after generation.

This demonstration of heritability is still going
on in reference to particular qualities; thus we
have Prof. Karl Pearson’s evidence in regard to
such subtle qualities as longevity and fecundity,
and his indirect proof that mental qualities illus-
trate the same law of inheritance as bodily qualities.
It is very desirable that more data should be accu-
mulated in regard to the heritability of variations,
whether Darwin’s “ individual variations,” or De
Vries’s “‘ mutations.” On the whole, however, it
may be said that, since Darwin’s day, sufficient
evidence has been gathered to justify us in saying
that any kind of character which appears as an
inborn feature in an organism may be transmitted
to the next generation.

(2) “* Heredity” a Term for the Genetic Rela-

1 See, for a detailed discussion of what is dealt with briefly in
this chapter, the author’s treatise “‘ Heredity” (Murray. London,
1908).

FACTS OF INHERITANCE 131

tion between Successive Generations.—Another step
is, that we are learning not to spell heredity
with a capital “bh.” We no longer think of it
as a power or as a principle, as a fate or as
one of the forces of nature; we study it as a
genetic relation which is sustained by a visible
material basis, as a relation of resemblances and
differences which can be measured and weighed, or
in some way computed. In regard to property
there is a clear distinction between the heir and
the estate which he inherits; but at the beginning
of an individual life there is biologically no such
distinction. The organism and its inheritance are,
to begin with, one and the same. We inherit our-
selves. Thus “heredity” 1s simply a convenient term
for the genetic relation between successive generations,
and inheritance includes all that the organism is, or
has, to start with in virtue of its hereditary relation.
(3) Appreciation of Distinction between “‘ Nature”
and ‘“ Nurture.’—Another step, following on
the last, is that we have begun to realise more
clearly the distinction implied in the words
“nature” and “nurture’”’—a distinction made
by Shakespeare and definitised by Galton. The
fertilised egg-cell contains, in some way which
we cannot picture, the potentiality of a particular
living creature—a tree, a daisy, a horse, a man.
If this inheritance is to be realised there must be
an appropriate environment, supplying food and
oxygen and necessarystimuli of many kinds. With-
out this nurture the inherited nature can achieve
nothing. The development of every character
implies the interaction of the two sets of factors—
the internal organisation and the external environ-
ment. But the surrounding influencesare often very

132. DARWINISM AND HUMAN LIFE

changeful, and the nature of the young organism
may be profoundly modified by them. Thus we
try to distinguish—and it is of enormous practical
as well as theoretical importance—between the
expression of hereditary nature realised in normal
nurture and the individually acquired modifica-
tions which are due to changes or peculiarities in
that nurture. The characters of a newly hatched
chick stepping out of the imprisoning egg-shell are
in the main strictly hereditary ; but they need not
be altogether so, for during the three weeks before
hatching there has been some opportunity for
peculiarities in the environment to leave their
mark on the developing creature. Still more is
this the case with the typical mammalian embryo,
which develops often for many months as a sort of
internal parasite within the mother, in a complex
and variable environment. And as life goes on,
peculiarities due to nurture continue to be super-
imposed on the hereditary qualities, especially
when the creature trades with time, and, by choosing
its own nurture, creates for itself an individuality.

(4) The Idea of the Continuity of Generations.
—Another step is the general acceptance of a
somewhat subtle and yet essentially simple idea,
which may be called the continuity of genera-
tions There is a sense, Galton says, in which
the child is as old as the parent, for when the
parent’s body is developing from the fertilised
ovum a residue of unaltered germinal material is

1 In his address “ Fifty Years of Darwinism,” Prof, Poulton says :
“The greatest change in evolutionary thought since the publication
of the ‘ Origin ’ was wrought, after Darwin’s death, by the appear-
ance of that wonderful and beautiful theory of heredity, which
looks on parents as the elder brother and sister of their children.”

FACTS OF INHERITANCE 133

kept apart to form the reproductive cells, one of
which may become the starting-point of a child.
In many cases, scattered through the animal
kingdom, from worms to fishes, the beginning of the
lineage of germ-cells is demonstrable in very early
stages before the division of labour implied in
building up the body has more than begun. Let us
suppose that the fertilised ovum has certain
qualities, a, b, c,... 2%, y, 2; it divides and re-
divides, and a body is built up; the cells of this
body exhibit division of labour and the structural
side of this, which we call differentiation; they
lose their likeness to the ovum and to the first
results of the cleavage of the ovum. In some of
the body-cells the qualities a, b find predominant
expression ; in others the qualities y, z; and so
on. But if, meanwhile, there be certain germ-
cells which do not differentiate, which retain the
qualities a, 6, c,... x, y, 2 unaltered, these will
be in a position by-and-by to develop into an
organism like that which bears them. Similar
material to start with, similar conditions in which
to develop—therefore, like tends to beget like. To
use Weismann’s words: “In development a part
of the germ-plasm (7.e. the essential germinal
material) contained in the parent egg-cell is not
used up in the construction of the body of the
offspring, but is reserved unchanged for the forma-
tion of the germ-cells of the following generation.”
Thus the parent is rather the trustee of the germ-
plasm than the producer of the child. In a new ,
sense, the child is a ‘ chip of the old block.’ ”

May we think for a moment of a baker who has
a very precious kind of leaven ; he uses part of this
in baking a large loaf; but he so arranges matters,

134. DARWINISM AND HUMAN LIFE

by a curious contrivance, that part of the original
leaven is not mixed up with the dough, but is
carried on unaltered within the loaf, carefully
preserved for use in another baking. Nature is
the baker, the loaf is a body, the leaven is the germ-
plasm, and each baking is a generation.

Picture the long runner of a strawberry, bearing
rooted, flowering plants at intervals: the runner
may represent the continuous line of germ-cells,
the flowering plants are the individuals, and the
relation between them is the relation of genetic
continuity, which we call heredity.

It will be obvious that this concept of germinal
continuity is very different from Darwin’s pro-
visional hypothesis of pangenesis, according to
which the germ-cells have their peculiar virtue of
reproducing like from like because they become
the storehouses of representative gemmules liber-
ated from the various organs of the body. Although
the hypothesis did not at the time obtain favour
and is less acceptable now than ever, it is interesting
to note, as Prof. Strasburger points out, that it in-
cluded the favourite modern idea of invisible units
as the carriers of particular hereditary characters.

(5) Critical Attitude in regard to Various Con-
clustons.—Another change is seen in the critical
attitude which is now taken up in regard to
various sets of facts, or alleged facts, relating to
inheritance, which were once accepted without
question. Thus Darwin said a good deal about
reversion ; but many phenomena labelled “ rever-
sion ” have received a different interpretation, and
some of the leading authorities on heredity have
ceased to use the term. It is difficult to find a
scientific worker who believes in what many

FACTS OF INHERITANCE 135

practical men put money on—the influence of a
previous sire on offspring subsequently borne
by the same mother to a different father. More
serious, however, is the wide-spread scepticism as
to the transmission of individually acquired charac-
ters or modifications.

(6) Mendelism.—But the greatest change that
has come about since Darwin’s day is the most
recent * one—associated with the work of Mendel.
We shall devote some attention to this at a later
stage in our exposition, but it may be noted,
in the meantime, that Mendelian experiment
has afforded evidence that an inheritance often
consists, in part at least, of well-defined, non-
blending “ unit characters.” ‘ By a unit character
in the sense of Mendel’s law we mean any quality
or part of an organism, or assemblage of qualities
or parts, which can be shown to be transmitted
in heredity as a whole and independently of other
qualities or parts.” * The inheritance in a fertilised
egg-cell consists of an assemblage of distinct
ingredients in duplicate, contributed from the
father and from the mother. If both the germ-
cells (egg-cell and sperm-cell) bring in a similar
ingredient when they unite in fertilisation, then
all the germ-cells of the ofispring will have it;
if neither bring it in, then none of the germ-cells
of the offspring will have it. Two blue-eyed
parents (without pigment in the front of the
iris) do not have dark-eyed children. If the

1 We must say recent, for although Mendel died two years after
Darwin and published his great discovery in 1865, his work was lost
sight of till 1900, when Correns, Tschermak, and De Vries were
independently led to a rediscovery of Mendel’s law and to a dis-

covery of his buried memoirs.
2 W. E. Castle, in ‘‘ Fifty Years of Darwinism ” (1909), p. 146,

136 DARWINISM AND HUMAN LIFE

ingredient come in from one side and not from
the other, then, on an average, in half the resulting
germ-cells it will be present, and from half it
will be absent. “ This last phenomenon, which
is called segregation, constitutes the essence of
Mendel’s discovery.”? “In this,” Mr. Punnett
says, “lies the explanation of the facts that
hybrids mated together produce a definite pro-
portion of the pure forms, which subsequently
breed true without ever giving a hint of their
mixed ancestry.”

Metxops oF Stupyine Herepity.—In studying
a difficult problem, such as the weather, there
are three possible lines of attack: we may make
minute researches, eg. on the role of dust in
forming fog; we may make experiments, e.g. on
the change of a cloud into rain, or on the effect
of tree-planting on climate; or we may collect
a multitude of observations of a statistical char-
acter, e.g. a8 to the rainfall in different localities
and at different times of year. These are three
sound methods, which have been worked with
success. They are complementary, not opposed.

Similarly, we may attack the problems of
heredity by the microscopical study of the germ-
cells in which life is continued from generation
to generation, by breeding experiments, and by
the statistical study of the measurable characters
of successive generations.” These three different
methods of attacking the problems of heredity

1 W. Bateson, “ The Methods and Scope of Genetics ” (Cambridge,
1908), p. 15.

2 It is of interest to note that Sir Francis Galton, who may be
taken as the representative of the statistical study, and Gregor

Mendel, who was the pioneer of the experimental study, were born
in the same year (1822),

FACTS OF INHERITANCE 137

seem to be equally valid, and though the generalisa-
tions reached along the different lines do not at
present cohere in a harmonious body of doctrine,
there is no reason to doubt that this will gradually
develop. Let us illustrate some of the results
attained along the three lines.

MroroscoricaL STUDY OF THE GERM-CELLS.—
Most plants and animals are built up of cells
and start in life as fertilised egg-cells, and it
was in a fertilised egg-cell that our own natural
inheritance consisted. A few exceptions may be
made—e.g. for bananas, which have no longer
any seeds; for potatoes, which are multiplied by
cutting; for the drone-bees and summer green-
flies, which have mothers but no fathers; and
for the simple, single-celled organisms which are
themselves comparable to eggs and sperms; but
the exceptions are trivial compared with the
vast majority of living creatures of which it is
certain that each individual life begins as a ferti-
lised egg-cell—the result of the intimate and
orderly union of a spermatozoon and an ovum.

We get a very misleading idea of the ovum, or
ege-cell, when we think, as we always do at first,
of birds’ eggs. For in these familiar objects the
true egg-cell has been dilated by an enormous
quantity of nutritive yolk, on the top of which
a minute drop of nucleated living matter lies
like an inverted watch-glass. Most ova are very
minute cells, often invisible to the naked eye.
The spermatozoon, or male element, which fertilises
the egg, is smaller still ; it is often only zoo/o00 th
of the ovum’s size. In a way that we cannot
picture each of the germ-cells (or gametes) carries a
complete set of hereditary characters. All theory

1388 DARWINISM AND HUMAN LIFE

apart, it is by the minute germ-cells that the
secret of life and the character of each kind of
living creature are sustained from generation to
generation. Within every cell in the body of
an organism there is usually a nucleus, and within
the nucleus a number—a definite number—of
readily stainable rods, or loops, or grains called
chromosomes. Each kind of living creature has
a definite number; thus, there are thirty-two in
man and in the cockroach, twenty-four in mouse
and in lily, twelve in the grasshopper, and two in
a species of threadworm. There is no doubt that
these stainable bodies, or chromosomes (including
less visible bodies associated with them), are very
important. There are many facts pointing to the
conclusion that they are bearers (not perhaps the
exclusive bearers) of specifically different materials
which, in appropriate conditions, will develop into
particular heritable qualities. One of the leaders
of experimental zoology, Dr. Przribram, sums up
a number of remarkable investigations when he
says: “Substances or parts can be actually
demonstrated in the ovum, the removal of which
conditions the absence of definite organs or parts in
the embryo.” Now, while the immature germ-cells
have the same number of chromosomes as the
cells of the body have, the mature germ-cells have
half the normal number. If 8 be the normal
number, the ripe ovum has 4, and the fully formed
spermatozoon has 4, so that when the ovum is
fertilised the normal number is restored. In a
remarkable way, by a kind of cell-division which
occurs only in the maturing germ-cells, the number
of chromosomes is always reduced by a half—
except, indeed, in certain cases of parthenogenesis.

FACTS OF INHERITANCE 139

In this reduction, which means in the case of the
egg the absolute rejection of half of the chromo-
somes (which are carried off by the first polar
body and come to nothing), we see an opportunity
for permutations and combinations among the
items of the inheritance, e.g. for the dropping out
of a character altogether.

Not less important is the visibly demonstrable
fact that sperm and ovum contribute the same
number of chromosomes (except in certain cases
where half of the spermatozoa have an extra
chromosome), and that, when the fertilised egg-
cell divides, each daughter-cell receives the normal
number of chromosomes, half of maternal origin
and half of paternal origin. This has been followed
for several divisions, so that, if the chromosomes
are inheritance-bearers, we have ocular demonstra-
tion of the truth of the prophetic statement which
Huxley made in 1878: “It is conceivable, and
indeed probable, that every part of the adult
contains molecules derived both from the male
and from the female parent; and that, regarded
as a mass of molecules, the entire organism may
be compared to a web of which the warp is
derived from the female and the woof from the
male.” ,

SratisticaL Stupy: Fin1aL REGREssION.—
Darwin’s illustrious cousin, Sir Francis Galton,
has been the leader in the statistical study of
inheritance. He has shown the value of collecting
statistics as to the resemblances and differences
in successive generations, e.g. as regards stature,
-colour of eyes, and intellectual ability, and he
has reached several general inductions which
express the inherent orderliness obtaining even

140 DARWINISM AND HUMAN LIFE

in a domain where occurrences seem as capricious
as those of weather.

It has often been remarked that the children
of extraordinarily gifted parents are sometimes
very ordinary individuals, and that the children
of under-average parents sometimes turn out
surprisingly well, both physically and mentally.
Every one who has looked into the facts of in-
heritance in greater detail, and has compared the
average of qualities in successive generations,
has noticed, in a general way, that there is a
tendency to sustain the same average level from
generation to generation. Even the older in-
quirers, like Lucas, called attention to the fact
that extraordinary qualities in families tend to
wane away, as if there were some mysterious
succession-tax levied on marked deviations from
the average, whether in the way of excellence or
of defect. But we owe to Galton’s careful statisti-
cal work the generalisation known as the Law of
Filial Regression, which has replaced a vague
impression by a definite formula. He has defined
and measured the tendency towards mediocrity,
the tendency to approximate to the mean, or
average, of the stock. We must notice, at the
outset, that this Filial Regression has nothing to
do with reversion or with degeneration, that it
works upwards as well as downwards, forwards
as well as backwards.

The data which Galton utilised were chiefly the
records of family faculties, obtained from about
one hundred and fifty families, and dealing especi-
ally with stature, eye-colour, temper, artistic
faculty, and some forms of disease. These were
supplemented by measurements at Galton’s anthro-

FACTS OF INHERITANCE 141

pometric laboratory, and by observations on
sweet-peas, and to some extent on moths.

Most trustworthy, however, were the data pro-
cured in regard to stature, which, as Galton points
out, is a quality with many advantages as a subject
of investigation. It is nearly constant during
mature life, it is readily and frequently measured
with accuracy, and it does not seem to be of appre-
ciable moment in sexual selection. Its variability,
though small, is normal; that is to say, it is ex-
pressible in the normal curve of the frequency of
error.

As the subject is by no means easy to those
unaccustomed to statistical mquiry, and as we
cannot, within our limits, explain the methods,
it may be most profitable to give a few illustrative
quotations from Galton’s “ Natural Inheritance ”
(1889).

“Tf the word ‘ peculiarity ’ be used to signify
the difference between the amount of any faculty
possessed by a man and the average of that
possessed by the population at large, then the law
of regression may be described as follows. Hach
peculiarity in a man is shared by his kinsmen,
but on the average in a less degree. It is reduced
to a definite fraction of its amount, quite inde-
pendently of what its amount might be. The
fraction differs in different orders of kinship,
becoming smaller as they are more remote”
(p. 194).

“‘ However paradoxical it may appear at first
sight, it is theoretically a necessary fact, and one
that is clearly confirmed by observation, that the
stature of the adult offspring must on the whole be
more mediocre than the stature of their parents ;

142 DARWINISM AND HUMAN LIFE

that is to say, more near to the mean or mid of the
general population” (p. 95).

“ The law of regression tells heavily against the
full hereditary transmission of any gift. Only a
few out of many children would be likely to differ
from mediocrity so widely as their mid-parents,
and still fewer would differ as widely as the more
exceptional of the two parents. The more bounti-
fully a parent is gifted by nature, the more rare
will be his good fortune if he begets a son who is as
richly endowed as himself, and still more so if he
has a son who is endowed yet more largely. But
the law is even-handed; it levies an equal succes-
sion-tax on the transmission of badness as of
goodness. If it discourages the extravagant hopes
of a gifted parent that his children will inherit all
his powers, it no less discountenances extravagant
fears that they will inherit all his weakness and
disease ” (p. 106).

“Tt must be clearly understood that there is
nothing in these statements to invalidate the
general doctrine that the children of a gifted pair
are much more likely to be gifted than the children
of a mediocre pair. They merely express the fact
that the ablest of all the children of a few gifted
pairs is not likely to be as gifted as the ablest of all
the children of a very great many mediocre pairs ”
(p. 106).

Nor must the fact of regression be supposed
to affect the general value of a good stock or the
general disadvantage of a bad one. Two gifted
members of a poor stock may be personally equiva-

1 The mid-parent is a statistical fiction, with a stature half that
of the two parents when allowance is made for the average difference
of stature in the two sexes.

FACTS OF INHERITANCE 143

lent to two ordinary members of a good stock,
but “the children of the former will tend to re-
gress ; those of the latter will not” (p. 198).

Let us give a concrete illustration from Prof. Karl
Pearson’s “Grammar of Science” (1900, p. 454):
“ Fathers of a given height have not sons all of a
given height, but an array of sons of a mean height
different from that of the father and nearer to the
mean height of sons in general. Thus, take fathers
of stature 72 inches, the mean height of their sons
is 70°8 in., or we have a regression towards the mean
of the general population. On the other hand,
fathers with a mean height of 66 in. give a
group of sons of mean height 68°3 in., or they have
progressed towards the mean of the general popula-
tion of sons. The father with a great excess of the
character contributes sons with an excess, but a
less excess of it; the father with a great defect
of the character contributes sons with a defect,
but less defect of it. The general result is a sensible
stability of type and variation from generation to
generation.” :

There seems no reason to doubt the general
occurrence of regression towards mediocrity, though
the law requires modification in regard to charac-
ters which are subject to keen selection, either
natural or sexual, and though it does not apply to
sharply defined “unit characters” which do not
blend.

Gatton’s Law or ANCESTRAL INHERITANCE.—
It is necessary, however, to ask what this statis-
tically established fact of filial regression really
means biologically.

In all ordinary cases of reproduction the off-
spring has a strictly dual or bi-parental inheritance.

144. DARWINISM AND HUMAN LIFE

Whatever the inheritance may be in its expression—
whether it show a blend or takes after one side of the
house—it is made up, to begin with, of equal con-
tributions from the two parents. Obviously, how-
ever, if the concept of the continuity of the germ-
plasm be correct, the contribution from the father
is made up of contributions from his two parents,
and the contribution from the mother is made up
of contributions from her two parents. And so
on backwards. Thus we reach the idea, to be
corrected in cases where Mendelian inheritance has
been proved for particular characters, that an
individual inheritance is a mosaic of ancestral
contributions. Incidental corroborations of this
fruitful idea are familiar to all—e.g. in the re-
expression of peculiarities which were characteristic
of, say, a grandfather or a great-grandmother.
But we owe to Galton’s careful statistical work,
as to stature and other qualities in man, and as
to coat-colour in Basset hounds, a generalisation
which formulates the share which the various
ancestors have, on an average, in the inheritance
of any individual organism. This Law of Ancestral
Inheritance is as follows: “The two parents
between them contribute, on the average, one-half
of each inherited faculty, each of them contributing
one-quarter of it. The four grandparents con-
tribute between them one-quarter, or each of them
one-sixteenth ; and so on, the sum of the series
g+tt+set ig +..., being equal to 1, as
it should be. It is a property of this infinite
series that each term is equal to the sum of all
those that follow: thus} =}4+4+4+ ,4+...,
4=%+ i+ --., and so on. The prepo-
tencies or subpotencies of particular ancestors, in

FACTS OF INHERITANCE 145

any given pedigree, are eliminated by a law that
deals only with average contributions, and the
varying prepotencies of sex in respect to different
qualities are also presumably eliminated.” Thus
an inheritance is not merely dual, but through the
parents it is multiple, and the average contribu-
tions made by grand-parents, great-grandparents,
etc., are definite, and diminish in a precise ratio
according to the remoteness of the ancestors.

EXPERIMENTAL Stupy.—Perhaps we may most
profitably illustrate the experimental study of
heredity by asking what the possible results are
of pairing two hypothetical organisms. Although
prediction as to the result of any individual pairing
is apt to be falsified (except in clear cases of
Mendelian inheritance), there are some well-
known alternatives of expectation.

(1) Patring of Similar Pure-bred Porms.—Let
us begin with the offspring of similar pure-bred
organisms. When similar forms are bred together
for several generations a certain uniformity of type
is likely to result. If by selection the most similar
are mated together, while the least similar are
persistently removed from the stock, and if there
is also some measure of inbreeding, then there is
likely to be more or less constant uniformity of
type. These “ pure-bred” organisms produce
others like themselves, and we suppose this to mean
that the hereditary items in the ovum have not
only their counterpart, but their equivalent, among
the hereditary items in the spermatozoon. This,
then,is one of the modes of inheritance—that the off-
spring closely resemble the parents and one another.
The variability is restricted within a small range.

(2) Blending.—Passing from the mating of

10

146 DARWINISM AND HUMAN LIFE

similar pure-bred organisms to other cases, we note,
as a frequent occurrence, that the offspring is a
combination of the paternal and maternal charac-
teristics in such a thoroughgoing way that the
result may be described as an intimate blend. Ina
cross between the long-eared lop-rabbit and a short-
eared breed, Castle found that forms with ears of
intermediate length are produced, and that these
intermediates breed true. The colour of the skin
in mankind seems to blend when white and black
races are crossed. Many plant hybrids are precisely
intermediate between the two parents.

(3) Particulate Inheritance.—The offspring often
show what may be called a coarse-grained or
non-blended combination of the paternal and
maternal characteristics, the former appearing in
one part of the body, the latter in another part, as
when a light-coloured horse and a dark-coloured
mare have a piebald foal, or when a sheep-dog has
an eye like its father on one side and an eye like its
mother on the other side. This is often described
as particulate inheritance.

(4) Exclusive Inheritance.—It often happens
that the offspring takes wholly after one of its
parents, or wholly as regards particular organs, —
and extreme forms of this are spoken of as exclusive
inheritance. The inheritance of eye-colour in
mankind belongs to this type. Although the
inheritance is dual, it seems as if only one set of
the heritable characters found expression—at least
as regards particular organs. The more pure-bred
parent is the more likely to be prepotent in the
inheritance. This exclusive inheritance may be
the first step in a clear Mendelian case, which we
shall consider later.

FACTS OF INHERITANCE 147

(5) Reversion.—Another mode of inheritance
—known as Reversion—is seen when the offspring
exhibits features which were not expressed in its
immediate ancestry, but were characteristic of
more remote ancestry, as when crossing different
races of pigeons, which have been breeding true,
results in the production of the ancestral rock-
dove type. Professor Cossart Ewart crossed an
“Owl” with an “ Archangel” and obtained a
hybrid more like the former than the latter. He
crossed this with a prepotent white fantail and
obtained two pigeons closely resembling the wild
rock-dove type. Darwin laid stress on such
reversionary Blue Rocks which occur when widely
differmg breeds are crossed and the hybrids are
bred together, but some recent experiments, e.g.
those of Staples-Browne, suggest that there may
be a Mendelian interpretation even of Darwin’s
classic cases of reversion. The case of rabbits is
very suggestive. When rabbits of different colours
are turned loose and breed together, their descend-
ants tend to be eventually all grey. Darwin
regarded this as a reversion, and it may still be
described as reversionary; but it is not due to
the reassertion of long latent grey colouring. The
return to grey is due, as the Mendelian experiments
show, to the recombination of at least eight
colour-ingredients that go to the make-up of
wild greyness. Man has sifted out all the various
colours from the complex coloration of the wild
stock, and when the long-separated items are
brought together again by unrestricted inter-
breeding there is, naturally enough, a reconstruction
of the original grey colour.

(6) New Departures—Just as we began by

148. DARWINISM AND HUMAN LIFE

noting that the offspring of carefully pure-bred
types might be almost replicas of the parents,
so we must notite the opposite extreme, where
the offspring represent something quite new—a
novel position of organic cara “ freak,”
or “sport,” or “ mutation,” “* discontinuous
variation.” That these new cap hie have some-
times formed the beginning of a new domesticated
breed or cultivated variety is well known; and
it is possible that species in nature may sometimes
have arisen in a similar way.

(7) Mendelian Inheritance—In typical cases
of Mendelian inheritance we have to do with the
pairing of two pure-bred types which differ from
one another in respect of one or more unit char-
acters, which may be obvious qualities, such as
colour and markings, or more subtle qualities,
such as the loaf-producing “ strength ” of wheat,
its susceptibility or immunity in respect to rust,
the broodiness or non-broodiness of poultry,
the horned or hornless state of the head in
cattle.

The result of the crossing is that the “ hybrid ”
progeny all resemble one parent in respect of
the contrasted characters. There are no inter-
mediates, for Mendelian characters do not blend.
The offspring of grey and white mice are all grey;
the ofispring of giant and dwarf peas are all tall ;
and so on. It is usual to speak of the character
that persists and is expressed as the dominant
character, while that which remains unexpressed
or latent is called recessive.

But when the “hybrids” are inbred, the next
generation shows a reappearance of the original
parental types both dominant and recessive—

STREvTh ey

FACTS OF INHERITANCE 149

both breeding true—and a number of forms,
usually eke pure dominants, which, when inbred,
again produce “pure dominants,” “pure
recessives,’ and “impure dominants ” like them-
selves. In typical cases, where attention is paid
to one pair of contrasted characters, the proportions
of the “hybrids” always approximate to the
formula—l pure dominant: 2 impure dominants :
1 pure recessive.
This may be expressed in a simple schema :

D & R «#8 %waws Parents
| | |
- D(R) is aie Hybrids. F}
. x
. DR)

|
| | |
IDD + 2D(R) + IRR = _ 2nd Generation F?

Extracted Impure Extracted
Pure Dominants Pure
Dominants xx Recessives

| | |
DD IDD+2D(R)+RR RR 3rd Generation F?

Mendel explained his results by the ingeniously
simple hypothesis of segregation. He supposed
that the germ-cells of the hybrids segregated into
two contingents, one half bearing the dominant
character and one half bearing the recessive
character. If fertilisations follow the laws of
chance the second generation should theoretically
show the proportions which actually occur. When
there are two pairs of contrasted characters—
for instance, when a tall yellow-seeded (Dd) pea
is crossed with a dwarf green-seeded one (Rr)—
the offspring are tall yellows (Dd), combining the

150 DARWINISM AND HUMAN LIFE

two dominant features; and when these are self-
fertilised (which is equivalent to inbreeding),
out of 16 offspring there are 9 tall yellows (Dd),
3 tall greens (Dr), 3 dwarf yellows (Rd), and one
dwarf green (Rr). When a rabbit of the wild
grey colour is crossed with an albino, the offspring
are all grey, and these, if bred together, give in
certain cases 9 greys, 3 blacks, and 4 albinos,
which is a slight modification of the ordinary
9:3:3, 1 ratio due to the impossibility of dis-
tinguishing, by external appearance, between two
different kinds of albino.

Unit CHaracters.—We do not at sical know
with certainty how many qualities and parts can
be called “unit characters” in the Mendelian
sense. The only criterion is the experimental one:
can the character be lost, as a whole, in cross-
breeding? Prof. W. E. Castle! gives an illustra-
tion: “If we cross a black guinea-pig with one
which lacks black—say a brown one—we obtain
only black offspring ; but these bred inéer se produce
black offspring and brown ones, in the proportion
three black to one brown. We thus learn that
black is a unit character. It was contributed by -
one parent to the cross, but not by the other, and
transmitted by the cross-bred individual to half
its offspring, but not to the other half. This is
Mendel’s explanation of the 3:1 ratio, now
familiar to every biologist.

“ But if we cross the same black parent in the
foregoing case, not with a brown individual, but
with a white one or with a yellow one, we may
obtain, not black offspring, but wild-coloured

1 «The Behaviour of Unit Characters in Heredity,” in “ Fifty
Years of Darwinism ’’ (1909), p. 148.

FACTS OF INHERITANCE 151

‘agouti’ ones, which bred inter se will produce
agouti, black, white (or else yellow) young, with
perhaps those of other new classes in addition.
Such a result as this puzzled Darwin, and would
naturally puzzle any one; but in the light of
Mendel’s law becomes capable of ready explanation.
The production of black pigment is a process in
which more than one unit character is concerned,
the production of a grey coat involves more
units still. ... What was unknown to Mendel
has been made clear since 1900: that in many
cases two or more independent unit characters
must be present to produce a single visible
effect.”

Tue Case or ANDALUSIAN Fowis.—The pheno-
mena of Mendelian inheritance are well illustrated
in the case of the Blue Andalusian fowl. We quote
Mr. Punnett’s account: “The Andalusian has long
been known to possess an inconvenient peculiarity :
it will not breed true. It always throws‘ wasters ”
of two sorts: blacks, and whites marked with some
black splashes. There are, therefore, three kinds
of Andalusians, and consequently six possible
types of mating among these three varieties. With
regard to the results of these types of mating,
careful experiment has brought out the following
facts :

Blue x Blue gives Blacks, Blues, and Whites, in the ratiol :2:1.
Blue x Black ,, Blacks and Blues in equal numbers.

Blue x White,, Blues and Whites in equal numbers.
Black x Black ,, Blacks only.

White x White ,, Whites only.

Black x White,, Blues only.

1 “Mendelism in Relation to Disease,” ‘Proc. Roy. Soc.
Medicine’? (March 1908),

152 DARWINISM AND HUMAN LIFE

“ We are dealing here with a case in which every
possible form of mating has been carried out, and
some of the results, at first sight, seem paradoxical.
Thus, for instance, the blacks always breed true,
whatever their ancestry may have been; and the
same holds good for the whites. The white that
is produced by two blues, themselves the product
of mating blue with blue over many generations,
breeds as true to whiteness as the white of pure
white ancestry. A black is pure for blackness and
a white is pure for whiteness, whatever the ancestry
of the bird may have been. Again, it seems at first
sight incongruous that the mating of black with
white should give just twice as many blues as two
blues mated together.

“We are dealing with an alternative pair of
characters, blackness and whiteness. Every germ-
cell, or gamete, whether ovum or spermatozoon,
bears a representative of this pair. But it can
bear only one representative, viz. evther blackness
or whiteness. Hence for this pair of characters
there are two, and only two, types of gamete:
‘black’ gametes and ‘white’ gametes. When
a black gamete meets a black the result is a black
bird; when a white meets a white the result is a
white bird; but when a white meets a black the
resulting zygote’ contains the representatives or
factors for both blackness and whiteness, and
develops into a blue bird. Now we must suppose
that the gametic representative of a character,
the factor, is an unsplittable entity so far as
inheritance is concerned. The zygote, being

1 Gamete is the technical term for a germ-cell, either egg-cell

or sperm-cell; zygote is the technical term for the egg-cell after it
has been fertilised by the sperm-cell,

FACTS OF INHERITANCE 153

formed by two gametes, must contain two factors.
It is a double structure, and, when it comes to
form gametes, these single structures are produced
by the separation of the two factors present in
any zygotic cell. The factors representing the
characters are said to segregate from one another in
the process. In a zygote produced by the union
of similar gametes, the segregation is between like
factors, and all the gametes produced are alike.
But a zygote which has been formed by two
dissimilar gametes, each bearing one of the factors
corresponding to a pair of characters, must, on
forming gametes, give rise to gametes of two sorts,
and must give rise to them in equal numbers.
On this simple hypothesis is afforded a ready
explanation of the various experimental facts
given above.

“A blue hen is producing equal numbers of
‘black’ and ‘white’ eggs—let us say 2n of
each. To fertilise these eggs are brought large
numbers of spermatozoa of the two sorts, black and
white, in equal numbers. Every black egg, then,
has an equal chance of being fertilised by a black
or a white spermatozoon. In the former case it
will form a black, and in the latter a blue, bird.
From our 2n black eggs we shall obtain n black,
and 7” blue birds; that is to say, the mating of
blue with blue must, on the assumption of the
purity of the gametes, give black, blue, and white
in the ratio 1: 2: 1.”

Wattzine Micz.—Let us take another illustra-
tion relating to the quaint Japanese waltzing
mice, which waltz round and round in circles and
have only one semicircular canal of the ear well
developed. When waltzing mice are crossed with

154 DARWINISM AND HUMAN LIFE

normal mice all the progeny are normal. The
waltzing habit is recessive, the normal is dominant.
When the hybrids are inbred the resulting genera-
tion consists of normal mice and waltzing mice in
the proportion of three dominants to one recessive.
The .recessives of this generation, when inbred,
yield only recessives, for as many generations as
one likes to breed them. The dominants are
found to be of two kinds: one-third of them—
called pure dominants—when inbred yield only
dominants; the other two-thirds—called impure
dominants—yield dominants and recessives in the
old proportions of 3: 1.

It is supposed that the hybrids have germ-cells
of two kinds, one half bearing the waltzing charac-
ter, the other the normal character. Hach germ-cell
is “ pure” as regards this character. There are
twice as many chances of the unlike combination
occurring—that is, of normal and waltzing—as of
the like combination occurring—that is, of normal
meeting normal, or waltzing waltzing. In other
words, the percentage of individuals in the three
groups will be what it is: 25 pure normal, 50
impure normal, and 25 pure waltzing.

OccURRENCE OF MENDELIAN INHERITANCE.—
Mendelian phenomena are known in rats, mice,
rabbits, guinea-pigs, poultry, canaries, snails, silk-
worms, and some other animals; in peas, beans,
stocks, wheat, barley, maize, and some other
plants. The characters which illustrate it are
such as size, colour, markings, crests, horns, hairi-
ness, peculiar features such as the waltzing habit
in mice, and elusive properties, such as broodiness
in hens, time of ripening and immunity in wheat.

It is doubtful how far Mendelian phenomena

FACTS OF INHERITANCE 155

occur in man. Human eyes may be arranged in
two groups: (a) those with brown pigment on the
outer as well as on the inner surface of the iris
(usually browns and greens) ; and (b) those without
such brown pigment on the outer side, but with
some pigment on the inner side (blues and greys).
It appears, from the researches of Hurst and of
Prof. and Mrs. Davenport, that the first type is
dominant and the second recessive. Hurst also
gives some evidence that “ fiery red ’’ hair behaves
as a recessive to brown, and that the musical sense
is recessive to the non-musical. The clearest case,
as yet, is that peculiar condition of the hands and
feet known as brachydactyly, which Farabee and
Drinkwater have found to be dominant to the
normal condition. Of great interest also is Mr.
Nettleship’s account of the descendants of one
Jean Nougaret (born 1637) who was afflicted with
night blindness—a condition apparently due to loss
of the visual purple. There are records of over
2,000 individuals; and the night blindness is
dominant over the normal. During two and a half
centuries no normal member of the family who
has married another normal, whether related or
not, has ever transmitted the disease.
PracticaAL IMpoRTANCE OF MENDELISM.—The
work of the Mendelian school of experimenters
since 1900 is full of achievement and promise, and
no naturalist can help envying those who have been
able to share in it, all the more that their dis-
coveries are full of practical as well as theoretical
import. Prof. Bateson writes: “If we want to
raise mangels that will not run to seed, or to breed
a cow that will give more milk in less time, or milk
with more butter and less water, we can turn to

156 DARWINISM AND HUMAN LIFE

genetics with every hope that something can be
done in these laudable directions. But here I
would plead what I cannot but regard as a higher
usefulness in our work. Genetic inquiry aims at
providing knowledge that may bring, and I think
will bring, certainty into a region of human affairs
and concepts which might have been supposed re-
served for ages to be the domain of the visionary.”
He alludes to liability to particular disease, addic-
tion to a particular vice, and so on, and says: “ As
regards the more tangible of these physical and
mental characteristics there can be little doubt
that, before many years have passed, the laws of
their transmission will be expressible in simple
formule.” *

Mucnu Procress, BUT GREAT UNCERTAINTY.—
Especially through the work of the Mendelians
great strides have been made in the last ten years
in our knowledge of the laws of inheritance. By
breeding two pairs of rabbits which, to the ordinary
eye, seem identical, an experimenter like Mr. Hurst
acquires a knowledge of their inherent germinal
qualities (or gametic constitution), and he can
successfully predict the difference between the
results of mating the two pairs. The statisticians
can predict average results in 1,000 offspring; the
Mendelian breeder can predict the distribution of
certain characters in a litter. In spite of this
progress, and partly because of it, we are confronted
with an array of unanswered questions concerning
this most fascinating of problems. In what cases
are the facts of inheritance clearly Mendelian,
and how do these cases differ from others that
seem as clearly non-Mendelian? Is it the case

1 W. Bateson, ‘‘ The Methods and Scope of Genetics ” (1908).

FACTS OF INHERITANCE 157

that particular ancestral qualities may be latent
for more than two generations, and then re-assert
themselves as reversions? What adjustment of
statement, if any, will bring Galton’s Law (a
statistical conclusion) and Mendel’s Law (an
experimental conclusion) into harmony ? What is
the nature of the character which we call “ male-
ness’ or “femaleness,” and is there any law
which will formulate its distribution in the progeny
ofa pair? These are some of the urgent questions
towards the answering of which facts are accumu-
lating every month.

THE TRANSMISSION OF ACQUIRED CHARACTERS.—
Let us turn, however, for a little to the long-drawn-
out controversy as to the possible transmission of
“acquired characters,” or somatic modifications.
It may be said that the disputants are now agreed
as to the precise point at issue, and perhaps it
may also be said that neither the yeas nor the nays
ring out so confidently as they did ten years ago.
Let us state the case. Members of the same species
often differ from one another, and these differences
can be measured and registered under the title of
** observed differences,” which commits one to no
theory. Many of these differences depend on age
and sex, and these can be readily recognised and
allowed for. Others depend on peculiarities of
“nurture,” in the wide sense; that is, they are
the direct results of peculiarities in surrounding
influences or in function. Such changes in plant
or animal are impressed from without, they are
“exogenous” in origin, they are acquired not
inborn, and they are technically called “ somatic
modifications,” or “ acquired characters.” They
may be defined as structural changes in the body of

158 DARWINISM AND HUMAN LIFE

an individual directly induced by changes in function
or in environment, which transcend the limit of
organic elasticity and thus persist after the inducing
conditions have ceased to operate. Thus fattening
and sunburning are modifications, though the
predisposition to them may be inborn ; the forma-
tion of a callosity as the result of pressure and
the reduction of a muscle by prolonged disuse are
modifications, though it does not, of course, follow
that callosities and reduced muscles may not come
aboutin a quite different way, namely, by a germinal
variation. Now, when we subtract from the total
of observed differences between members of the
same species all that can be described as modifica-
tions, we find a large remainder which we must
define off as inborn or germinal variations. We
cannot causally relate them to any peculiarities
in the organism’s habits or surroundings, they are
often distinct at birth or hinted at before birth,
they are rarely alike even among forms whose
conditions of life seem absolutely uniform. They
are endogenous, not exogenous in origin; they are
results of changes in the germinal material; they
are born, not made ; and they are more or less trans-
missible, though they are not by any means always
transmitted.! They form—at least some of them
form—the raw material of organic evolution,
whereas modifications, as defined, are probably not
of direct importance in evolution, since we have no
secure evidence that they are ever transmitted as
such, or in any representative degree.

1 Darwin assumed that little fluctuations are more certainly
transmissible than marked idiosyncrasies, but all that we are quite
certain of is that a number of variations, both large and small, are
definitely transmissible.

FACTS OF INHERITANCE 159

There is no doubt that modifications are very
common, that they are of much individual import-
ance, that they may have an indirect influence
through the body on the offspring (especially in
the case of mammalian mothers), that they may
have an indirect importance in evolution in several
ways, but the precise point at issue is this: Does
a structural change in a part of the body, induced by
use or disuse, or by change in surroundings and
nurture generally, ever influence the germ-plasm in
the reproductive organs in such a specific or re-
presentative way that the offspring will thereby
exhibit the same modification that the parent ac-
quired, or even a tendency towards it? We do not
know of any clear case which would at present
warrant the assertion that a somatic modification
is ever transmitted from parent to offspring.

In regard to this important question, let us try to
clear the ground by noting a few of the common
misunderstandings.*

I. How can there be progressive evolution if
acquired characters are not entailed? By the
accumulation of germinal variations, such as those
which have separated the higher from the lower
races of mankind. Yet Herbert Spencer actually
said, ‘‘ Hither there has been inheritance of acquired
characters, or there has been no evolution.” In
1796 the speed of the English trotter was a mile
in 2 mins. 37 secs. ; it is now a mile in 2 mins.
10 secs., or less; but that is the result of the
selection of inborn variations, not of the trans- -
mission of acquired characters.

II. Many facts in nature are readily interpretable

1 See “Heredity,” by J. Arthur Thomson, (Murray. London
1908.)

160 DARWINISM AND HUMAN LIFE

on the theory that the results of use and disuse and
of environmental change are, as such, transmissible.
The black skin may be interpreted as due to the
sun. The callosities on the knees of the wart-hog
may be interpreted as due to pressure on the ground.
The twelve hours’ sleeping and waking of many
acacias may be interpreted as a functional adap-
tation which has become hereditary. But the
interpretations may be erroneous.

III. Many beg the question by starting with a
character, like short-sightedness or gout, which
has not been proved to be a modification. First
catch your modification. The little toe is said to
be dwindling in consequence of wearing tight boots ;
but we are not sure that there is dwindling, and if
there is, we have no experimental reason for blaming
the boots.

IV. The reappearance of a modification in suc-
cessive generations is often mistaken for trans-
mission. It may be hammered on to each suc-
cessive generation. Nigeli put Alpine plants in
rich garden soil and they became very different,
and their progeny likewise; but transference to
poor soil brought back the Alpine characters, which
showed that the new characters had not taken
any hereditary grip.

V. Infection of the offspring by the parent before
birth has nothing to do with inheritance in the
true sense.

VI. Transmission in unicellular organisms is not
to the point, for, as they have no “ body,” the
concept of somatic modifications does not apply to
them.

VII. Changes in the germ-cells along with
changes in the body, where there are deeply

FACTS OF INHERITANCE 161

saturating influences such as poisons, are not
cogent.

VIII. Modifications may have secondary effects
on the germ-cells and the offspring, e.g. in the way
of bad nutrition, but unless the offspring show
peculiarities in the same direction as the original
modifications, we have no data bearing precisely
on the question at issue.

A belief in the inheritance of modifications was
perhaps expressed in the old proverb, “ The fathers
have eaten sour grapes, and the children’s teeth
are set on edge ”—a proverb which Ezekiel, with
such solemnity, said was not any more to be used
in Israel. Now if “setting on edge” was a
structural modification, and if the children’s teeth
were “set on edge” as their fathers’ had been
before them, there would be a presumption in
favour of the transmission of this acquired char-
acter, though it would be still necessary to inquire
carefully whether the children had not been in the
vineyard too. If, as Romanes said, the children
were born with wry necks, we should have to deal
with the inheritance of an indirect result of the
parents’ vagaries of appetite, and not with any
direct representation in inheritance of the particu-
lar modification produced in the paternal dentition.

IX. Finally, there is no use appealing to data
from fewer than three generations. Sheep trans-
ported to a cold country get longer fleece, their
offspring have still longer fleece; but this is not
to the point, since the offspring were subjected to
the modifying influences from birth. We wish
to know whether the third generation is more
markedly modified than the second.

Disease.—As a particular case we may take

11

162 DARWINISM AND HUMAN LIFE

the important question of the transmissibility of
acquired disease. When the question is carefully
considered, it seems possible to distinguish be-
tween (1) abnormal or deranged processes which
have their roots in germinal peculiarities or de-
fects (variations), and (2) abnormal or deranged
processes which have been directly induced
in the body by acquired modifications, t.e. as
the results of unnatural surroundings or habits,
including the intrusion of parasites. There is
very little evidence to suggest that this second
kind of disease is heritable as such, though the
indirect effects may influence the offspring. When
we go further and come to understand that pre-
natal infection is not inheritance, that inheritance
of a predisposition to a disease is not inheritance
of the disease, that the general weakening of the
offspring through disease in the parent is a very
different matter from the transmission of a specific
disease, we are almost irresistibly led to the con-
clusion that in the sense in which the word “ in-
herited ’” is used in biology, there are no inherited
diseases. What does seem to be inherited, how-
ever, is a defectiveness or degeneracy of the germ-
plasm which finds one expression in the parent and
another in the offspring.

Facts anp Possipitities.—The evidence in
support of the transmission of acquired characters
is either very anecdotal or very uncritical, and,
until some cogent cases are forthcoming, the
thoroughgoing scepticism which Weismann ex-
pressed many years ago remains justified.

Besides the unsatisfactory nature of the evidence,
we have to admit the difficulty of imagining any
means whereby a modification of a particular

FACTS OF INHERITANCE 163

organ of the body can react upon the germ-cells in
a manner so specific that these can, when they
develop, reproduce the particular parental modifi-
cation or any approach to it. Darwin and Spencer
both faced this difficulty, and tried to meet it; but
no one now accepts their provisional hypotheses.
It is true that a mechanism may exist though it
remains unknown ; it is true that important in-
fluences, mysterious in their nexus, pass from
reproductive organs to body; but we should not
have recourse to difficult hypotheses before we
are sure that there is any need for them. There
is no doubt that the germ-plasm may be influ-
enced by the blood, but this is different from
admitting the transmission of a particular acquired
character.

In a well-known case, where the evidence points,
according to some, to the heritability of an arti-
ficially induced epileptic condition, it has been
suggested that the epilepsy produces a toxin which
passes to the germ-cells so that the offspring are
epileptically affected. Now if we dared to suppose
that a deeply saturating modification produces a
representative chemical substance analogous to a
toxin, and that this passes to the germ-cells, the
hereditary reappearance of a modification would
be more conceivable.

There are many who think that, sooner or later,
there must be a return to Darwin’s idea of pan-
genesis—of specific substances passing from body
to germ-cells. The study of hormones is a line of
investigation that is of much interest in this con-
nection. “ Hormones” are specific substances
produced by cells, and passed into the blood-
stream to play an important part in stimulating

164 DARWINISM AND HUMAN LIFE

or controlling developmental and metabolic pro-
cesses. Injection of extracts of thyroid has usually
a beneficial effect in reducing goitre. Injection of
extracts of foctus has an effect on the mammary
glands. Injection of testicular extract causes the
temporary development of a cock’s comb on a hen.
There are enough of facts of this kind to make us
chary of dogmatism in regard to the possibility of
an influence passing from a modification of the
body to the germ-cells thereof. As Prof. E. B.
Wilson says: “ Let us admit freely that such an
interaction as Darwin assumed may be a real and
potent factor in heredity, though it gives us no
hint of its existence in the visible apparatus of
the cell. In the present defective state of our
knowledge we may well grant that there may
be many a thing between germ-cell and body
that is not yet dreamed of in our biological
philosophy.” ?

A Srrixine Casz.—Kammerer’s experiments on
salamanders afford the most remarkable piece of
evidence as yet adduced in support of the thesis
that acquired characters may be transmitted.

(a) The common yellow and_black-spotted
salamander (Salamandra maculosa) is either vivi-
parous, producing a large number of larve
25-30 mm. in length with four limbs and short
gills, or ovo-viviparous, laying large eggs which
hatch out into similar larvee 23-25 mm. in length.
After a few months of larval life in the water,
they undergo metamorphosis into land-salamanders
45-56 mm. in length.

(6) The black Alpine Salamander (Salamandra

1 «The Cell in Relation to Heredity and Evolution,” in “ Fifty
Years of Darwinism ” (1909), p. 113.

FACTS OF INHERITANCE 165

atra) produces at birth two fully formed terrestrial
young 38-40 mm. in length.

(c) Kammerer kept S. maculosa in the cold,
and got it, after a few pregnancies, to produce only
two young ones, as in S. atra.

(2) He kept S. atra in a warm place with plenty
of water, and got it to produce 3-9 aquatic larva,
thus approaching the condition in S. maculosa.

(e) The offspring of the Salamanders thus
treated (c and d), became sexually mature when
three and a half years old in conditions normal
to S. maculosa. The offspring of (c) gave birth
(1) to very advanced larve, 45 mm. long with
much-reduced gills, metamorphosing several days
after, or moderately advanced aquatic larve
40 mm. long, with large gills; or (2) to small
larvee, 20 mm. long, with rudimentary gills, laid
on land, and metamorphosing after four weeks
into salamanders 29 mm. long. Thus there was
a partial persistence of a modified mode of re-
production in the absence of the modifying
conditions.

(f) The offspring of (d) bore in the water 3-5
larve, 33-40 mm. or 21-23 mm. in length, light
in colour, and possessing gills. Thus there was
an augmentation of the parental modification
(d) in conditions which resembled those of the
original experiment.

The difficulties in regard to this very interesting
set of experiments are: (1) they do not deal
with a structural modification ; (2) it is possible
that the experimental conditions acted directly
on the germ-cells in (c) and (d); (3) there was
some measure of artificiality in the conditions
under which the second generation developed,

166 DARWINISM AND HUMAN LIFE

which may have disturbed the normal routine of
reproduction.

LogicaL Position oF THE QuESTION.—Let us
notice the logical position of the question. There
are two possible lines of argument: (a) by experi-
ment, and (6) by interpretation. (a) As to ez-
periment, it is plain that hundreds of failures
to prove the transmission do not demonstrate
its impossibility. They only show that it is
not usual. One good case experimentally proved
would show that the transmission is possible.
The best case we know is Kammerer’s, and it
does not seem cogent. Perhaps better cases will
become known. The Lamarckian does not, of
course, say that every change of conditions will
produce appreciable hereditary effects in a few
generations, or that any particular change of
conditions chosen more or less arbitrarily for
experimental purposes will produce recognisable
results in the following generation. But do we
know of any clear case of even a faint trace of a
well-defined structural modification being trans-
mitted ? (b) As to the second method, that of
the interpretation of facts, it cannot be conclusive
either, since each side has to prove a negative in
order to establish its case. The Neo-Lamarckians
have to show that the phenomena they adduce
as illustrations of modification-inheritance cannot
be interpreted as the results of selection operating
on germinal variations. In order to do this to
the satisfaction of the other side, the Neo-Lamarck-
ians must prove that the characters in question
are outside the scope of natural selection, that
they are non-utilitarian and not correlated with
any useful characters—a manifestly difficult task,

FACTS OF INHERITANCE 167

The Neo-Darwinians, on the other hand, have to
prove that the phenomena in question cannot
be the results of modification-inheritance. And
this is, in most cases, impossible. Thus we seem
to reach a logical dead-lock. What we need are
more facts.

CaSES WHERE THE THEORY OF MOopDIFICATION-
INHERITANCE IS INAPPLICABLE.—It is true, how-
ever, that there are certain characters of particular
organisms in regard to which it may be said with
some security that they could not have arisen by
the inheritance of acquired modifications. Thus
many insects, and the like, have adaptive characters
in their cuticular structures—knobs for crushing,
saws suited for cutting, gimlets suited for boring,
and so on. But these cuticular structures are
non-cellular, non-living parts of the external
investment of the body; they are made and
remade (after moulting) by the underlying, living
skin. How, then, can they be interpreted in
terms of modification-inheritance ? The matter
becomes even more difficult when we consider
cases in which the adaptiveness is in the colour
or markings of these inert cuticular parts. Weis-
mann has argued that, since there are some adaptive
characters which cannot be interpreted in terms
of modification-inheritance, this hypothetical factor
need not be assumed in attempting to interpret
the origin of other adaptations, similar to the
former, except that the factor in question is not
by the nature of the case apparently excluded
from having any connection with them.

But it cannot be said that this application of
the “law of parsimony ” is altogether successful.
Tt may recoil on those who use it, It might be

168 DARWINISM AND HUMAN LIFE

argued that there are some adaptive characters
which cannot be readily interpreted in terms
of natural selection (as is implied in the appeal
of some Neo-Darwinians to “ intra-selection,”
** germinal selection,” and so on), and that therefore
natural selection cannot be regarded as a generally
acting factor. Moreover, the Neo-Lamarckian is
at liberty to reply that he does not regard the
modification-inheritance theory as applicable to
all possible cases.

IMPORTANCE OF ENVIRONMENT AND FUNCTION
Remains.—Although bodily changes due _ to
changes in environment or in function may not
be transmissible, the importance of these influences
remains. (1) An inheritance cannot be realised
without an environment, any more than a man
whose legacy was a cheque could make much of
it without a bank. (2) Changes in environment
and funotion, saturating through the body, may
stimulate the variability of the germ-plasm. This
may be the cause of mutation. (3) Living creatures
are in many cases very plastic, and their modifica-
tions are often of great individual importance,
and may even preserve the life. (4) The secondary
efiects of modifications may reach and influence
the germ-cells. (5) Every one admits that the
state of the maternal constitution is very important
in all cases where there is an intimate connection
between the mother and the unborn young.

SELECTION AND StimuLus.—In two other ways
changes in the conditions of life are of great im-
portance: they form part of the mechanism of
selection, whereby the relatively less fit variants
are quickly or slowly, roughly or gently, eliminated,
and they act as a stimulus to the intrinsic self-

FACTS OF INHERITANCE 169

assertiveness and “endeavour after well-being ”
which characterise living creatures. We must
advance beyond the conventional view that the
environment is like a net closing in upon passive
victims, which can only escape if they have been
fitted by germinal variation (or acquired modifica-
tion) to pass through some of the meshes; we
must recognise, as a fact of life, what Lamarck
and many others have discerned, that organisms
actively assert themselves against this closing
net, and by active endeavour (also, of course, a
variational character when traced back) may
win their way through. At certain levels every
one is actively on the outlook for “a niche of
organic opportunity.” In his “ Luck or Cunning ? ”
Mr. Samuel Butler asked, “ Do animals and plants
grow into conformity with their surroundings
because they and their fathers take pains, or
because their uncles and aunts go away?” The
accurate answer is that the question is wrongly
put, for even those who most believe in the
negative importance of uncles and aunts going
away will be willing to admit, likewise, the positive
importance of “taking pains.” A rehabilitation
of the Lamarckian position perhaps depends on
making clear what the “effort” of the creature
amounts to, and what it really means.

Inprrect Importance or MopIFicaTIons.—
But there is another important consideration,
which has been stated independently by Profs.
Mark Baldwin, Lloyd Morgan, and H. F. Osborn,
namely, that adaptive modifications may act as
the fostering nurses of germinal variations in the
same direction. We have referred to this else-
where, but it may give greater completeness to

170 DARWINISM AND HUMAN LIFE

our survey if we quote a brief statement of the
idea as expounded by Lloyd Morgan (“ Habit
and Instinct” (1896), p. 319):

“ Persistent modification through many genera-
tions, though not transmitted to the germ, neverthe-
less affords the opportunity for germinal variation
of like nature.

“ Suppose that a group of plastic organisms is
placed under new conditions. Those whose innate
plasticity is equal to the occasion are modified
and survive. Those whose plasticity is not equal
to the occasion are eliminated. . . . Such modifica-
tion takes place generation after generation, but,
as such, is not inherited. . . . But any congenital
variations similar in direction to these modifications
will tend to support them and to favour the
organism in which they occur. Thus will arise
a congenital predisposition to the modifications
in question.

“The plasticity still continuing, the modifica-
tions become yet further adaptive. Thus plastic
modification leads, and germinal variation follows ;
the one paves the way for the other.

“The modification, as such, is not inherited,
but is the condition under which congenital
variations are favoured and given time to get a
hold on the organism, and are thus enabled by
degrees to reach the fully adaptive level.”

PRaAcTicaL IMpoRT OF THE QUESTION AS TO THE
TRANSMISSIBILITY OF ACQUIRED CHARACTERS.—
It is scarcely necessary to point out that the long-
drawn-out discussion is one of great importance,
affecting our whole theory of evolution, and even
our everyday conduct. Herbert Spencer went
the length of saying that “a right answer to the

FACTS OF INHERITANCE 171

question, whether acquired characters are or are
not transmitted, underlies right beliefs, not only
in biology and psychology, but also in education,
ethics, and politics.”

A modification is a definite change in the
individual body, due to some change in “ nurture.”
There is no secure evidence that any such individual
gain or loss can be transmitted as such, or in any
representative degree. How does this affect our
estimate of the value of “nurture”? How should
the sceptical or negative answer, which we believe
to be the scientific one, affect our practice in regard
to education, physical culture, amelioration of
function, improvement of environment, and so on 2

(a) Every inheritance requires an appropriate
nurture if it is to realise itself in development.
Nurture supplies the liberating stimuli necessary
for the full expression of the inheritance. A
man’s character as well as his physique is a function
of “nature” and of “nurture.” In the language
of the old Parable of the Talents, what is given
must be traded with. A boy may be truly enough
a chip of the old block, but how far he shows him-
self such depends on “nurture.” The conditions
of nurture determine whether the expression of
the inheritance is to be full or partial. It need
hardly be said that the strength of an (inherited)
individuality may be such that it expresses itself
almost in the face of inappropriate nurture. History
abounds in instances. As Goethe said, man is
always achieving the impossible. Semon relates
a pretty experiment with young acacias (Albizzia
lophantha). They had never been exposed to the
normal alternation of day and night, to which
their race responds by expanding and closing the

172. DARWINISM AND HUMAN LIFE

leaves. Semon exposed them to artificial days and
nights of six hours’ or twenty-four hours’ duration ;
but the plants exhibited the twelve-hours’ cycle
quite unmistakably—just a little altered. After
this experiment Semon exposed the plants to
continuous darkness or continuous illumination.
The twelve-hours’ cycle still manifested itself for
a time, but gradually became indistinct. Here
we see the inherited nature struggling, as it were,
against inappropriate nurture.

(b) Although modifications do not seem to be
transmitted as such, or in any representative degree,
there is no doubt that they or their secondary
results may in some cases affect the offspring.
This is especially the case in typical mammals,
where there is before birth a prolonged (placental)
connection between the mother and the unborn
young. In such cases the offspring is for a time
almost part of the maternal body, and liable to be
affected by modifications thereof—eg. by good
or bad nutritive conditions. In other cases, also,
it may be that deeply saturating parental modifica-
tions, such as the results of alcoholic and other
poisoning, affect the germ-cells, and thus the -
offspring. A disease may saturate the body with
toxins and waste-products, and these may provoke
prejudicial germinal variations.

(c) Though modifications due to changed
“nurture ” do not seem to be transmissible, they
may be reimpressed on each generation, Thus

“nurture ”’ becomes not less, but more, important
in our eyes. “Is my grandfather’s environment
not my heredity?” asks an American author
quaintly and pathetically. Well, if not, let us
secure for ourselves and for our children those

FACTS OF INHERITANCE 173

factors in the “ grandfather’s environment ” that
made for progressive evolution, and eschew those
that tended elsewhere.

Are modifications due to changed nurture not
entailed on offspring ? Perhaps it is just as well,
for we are novices at nurturing even yet. More-
over, the non-transmissibility cuts both ways: if
individual modificational gains are not handed on,
neither are the losses.

Is the “ nature ”—the germinal constitution, to
wit, all that passes from generation to generation—
the capital sum without the results of individual
usury ? Then we are freed, at least, from undue
pessimism, because of the many harmful functions
and environments that disfigure our civilisation.
Many detrimental acquired characters are to be
seen all around us, but if they are not transmissible,
they need not last.

(d) The plasticity of the organism admits of
definite modifications being reimpressed on succes-
sive generations of individuals, and this is the more
important when we consider what has been said
in the section on “ The Indirect Importance of
Modifications.” They may serve as modificational
screens until coincident variations in the same
direction can emerge and establish themselves.
This also cuts both ways in human societies, where
natural selection is interfered with, and where
naturally prejudicial deviations from the norm are
not necessarily punished by elimination.

(e) Of particular importance is the fact that
man, in contrast to other creatures, has developed
around him an external heritage, a social framework
of customs and traditions, of laws and institutions,
of literature and art, by which results almost

174 DARWINISM AND HUMAN LIFE

equivalent to the organic transmission of certain
kinds of modifications may be brought about.

(f) Is there not some result of the almost tire-
some controversy on “ the inheritance of acquired
characters,” if we are thereby freed from indulging
in false hopes, but are forced to the conviction
that “nurture” is more important than ever ?
Although what is “acquired” may not be in-
herited, what is not inherited may be acquired.
Thus we are led to direct our energies even more
strenuously to the business of reimpressing desir-
able modifications, and therefore to developing
our functions and environments in the direction
of progress.

It may be, however, that our methods must
change with the change in our expectations. For
though we can, by modification, directly influence
the individual, and in some measure even control
the expression of his inheritance, it is not through
modifications that we can hope directly to influence
posterity. Man is a slowly reproducing, slowly
varying organism. What is above all precious is
the conservation of good stock. No number of
veneering modifications—superficial screens of or-
ganic defects—can atone for allowing a deteriora-
tion of the germinal inheritance to diffuse itself
or to accumulate. For progress which is really
organic—for progress, that is, in our natural
inheritance—we must wait, or rather work,
patiently.

Even when it is impossible to do much, there is
practical importance in accuracy—which is greatly
needed in connection with human heredity. How
slow of dying is, for instance, the fallacy that ancient
and powerful families are necessarily degenerate.

FACTS OF INHERITANCE 175

In spite of what Galton and other careful workers
have said, it is persistently asserted that noble
and illustrious families usually end in sterility—
a mistake largely due to ignoring the female lines
of descent.

INHERITANCE OF Moran CHaracter.—In the
development of “ character” much depends upon
early nurture, education, and surrounding in-
fluences generally, but how the individual reacts to
these must largely depend on his inheritance.
Truly the individual himself makes his own
character, but what does that mean but the
habitual adjustment of an hereditarily determined
constitution to surrounding influence? Nurture
supplies the stimulus for the expression of the
moral inheritance, and how far the inheritance
can express itself depends on the nurture-stimuli
available just as surely as the result of nurture is
conditioned by the hereditarily determined nature
on which it operates. It may be urged that
character, being a product of habitual modes of
feeling, thinking, and acting, cannot be spoken of
as inherited, but bodily character is similarly a
product dependent upon vital experience. Some
children are “born good” or “born bad,” just
as some children are born strong and others weak,
some energetic and others “ tired” or “ old.”

It is entirely useless to boggle over the difficulty
that we are unable to conceive how dispositions for
good or ill lie implicit within the protoplasmic unit
in which the individual life begins. The fact is
undoubted that the initiatives of moral character
are in some degree transmissible, though, from the
nature of the case, the influences of education,
example, environment, and the like, are here more

176 DARWINISM AND HUMAN LIFE

potent than in regard to structural features. We
cannot make a silk purse out of a sow’s ear, though
the plasticity of character under nurture is a fact
which gives us all hope. Explain it we cannot,
but the transmission of the raw material of
character is a fact, and we must still say, with Sir
Thomas Browne: “Bless not thyself that thou
wert born in Athens; but, among thy multiplied
acknowledgments, lift up one hand to heaven
that thou wert born of honest parents, that
modesty, humility, and veracity lay in the same
egg, and came into the world with thee.”

THREE GENERAL ConcLusions.—(1) The study
of inheritance is apt to leave a fatalistic impression
in the mind, and to some extent this is justified.
We cannot get away from our inheritance. As
the poet Heine said, half laughingly half bitterly :
“* A man should be very careful in the selection of
his parents.” On the other hand, looking forward,
we may change the word “ parent ” into “ partner,”
recognising that a good inheritance is the most
precious of all possessions, and that it should be
guarded from mixture with bad stock.

(2) But, again, the conclusion is strongly borne
in on us that a good nurture is the necessary comple-
ment of a good nature and the individual corrective
of a poor nature.

(3) If there is little or no scientific warrant for
our being other than extremely sceptical at present
as to the inheritance of acquired characters—or
better, the transmission of modifications—this
scepticism lends greater importance than ever, on
the one hand, to a good “ nature,” to secure which
is the business of careful mating ; and, on the other
hand, to a good “ nurture,” to secure which for our

FACTS OF INHERITANCE 177

children is one of the most obvious and binding
duties : the hopefulness of the task resting especi-
ally upon the fact that, unlike the beasts that
perish, man has a lasting external heritage of
ideas and ideals, embodied in prose and verse, in
statue and painting, in cathedral and university,
in tradition and convention, and above all in
society itself.

CHAPTER VI
SELECTION: ORGANIC AND SOCIAL

179

CHAPTER VI
SELECTION: ORGANIC AND SOCIAL

Influence of Malthus—Darwin’s Position—The Theory stated—The
Theory of Natural Selection to be tested as an Interpretative
Formula—lIllustrations of Natural Selection—Objections and
Criticisms — Adaptations—Changes since Darwin’s Day—
Evidences of Natural Selection—Lessening the Burden of the
Theory—Sexual Selection—Isolation—Gradual Diminution of
Natural Selection in Mankind—Contrast between the Human
Race and the Animal World—Some Natural Selection
remains—The Dilemma of Civilisation—The extreme laissez-
fatre Position—Social Surgery—How far is Social Selection
compensating for Diminished Natural Selection ?—Reversed
Selection in Human Society—Summary of the Argument—
Constructive Suggestions—Selection of Eutopias—Selection of
Healthful Occupations—Eugenic Selection.

Darwin is often called the Newton of biology,
though some say he was rather its Copernicus.
In any case, he discerned in nature the working of
a great process, which has helped us to understand
how things have come to be as they are. Among
his services there is none greater than this, that he
discovered the efficacy of Natural Selection, which
means Nature’s sifting. The raw materials are
inborn variations; the internal condition is the
heritability of the favourable variations; the
external condition is the struggle for existence ;
the process of sifting is discriminate elimination ;
the result is the survival of the fittest to the given
conditions.

INFLUENCE OF Mattuus.—Adumbrations of the

181

182 DARWINISM AND HUMAN LIFE

general idea of selection are to be found in various
pre-Darwinian documents,' but it was to Malthus
only that Darwin, who was very generous in dealing
with anticipations, owned any debt. He speaks
of this in a well-known passage in his ‘ Autobio-
graphy”: “In October, 1838, fifteen months after
I had begun my systematic inquiry, I happened
to read for amusement ‘ Malthus on Population,’
and, being well prepared to appreciate the struggle
for existence which everywhere goes on from
long-continued observations of the habits of animals
and plants, it at once struck me that, under these
circumstances, favourable variations would tend
to be preserved and unfavourable ones to be
destroyed. The result of this would be the forma-
tion of new species. Here, then, I had at last got a
theory by which to work.”

Twenty years after—Darwin having published no
theory meanwhile—history repeated itself. Alfred
Russel Wallace was collecting insects at Ternate
and suffering badly from fever. As he was resting
one day between fits, he happened to recall Malthus’
“Principles of Population” which he had read
about twelve years before—the first book that he
had come across approaching philosophical biology.
He thought of what Malthus had said regarding
the way disease, famine, and war keep down the
population of savage races to a much lower average
than that of civilised peoples; he thought of the
similar elimination that goes on in the animal
world, and it occurred to him to ask the question,
‘Why do some die and some live?” ‘“ And the
answer was, clearly, that on the whole the best
fitted live. From the effects of disease the most

1 Hg. by Charles Wells, Patrick Matthew, James Cowles Prichard,

SELECTION: ORGANIC AND SOCIAL 183

healthy escaped; from enemies, the strongest,
the swiftest, or the most cunning; from famine,
the best hunters or those with the best digestion ;
and so on. Then it suddenly flashed upon me
that this self-acting process would necessarily
improve the race, because in every generation the
inferior would inevitably be killed off and the
superior—that is, the fittes-—would survive. Then
at once I seemed to see the whole effect of this. .. .”
His words in the 1858 paper were: “ If any species
should produce a variety having slightly increased
powers of preserving existence, that variety must
inevitably in time acquire a superiority in numbers.”
Thus, for the second time, from the domain of
human society the idea of natural selection was
suggested.

Perhaps the suggestion was made a third time,
for it is an interesting fact that in 1852—six years
before the theory of natural selection was launched
by Darwin and Wallace, when Herbert Spencer
wrote his famous evolutionist article on “ The
Development Hypothesis,” he published another
important essay entitled, ‘A Theory of Popula-
tion,” toward the close of which he came within an
ace of recognising that the struggle for existence
was a factor in organic evolution. Spencer was
not guilty of reading much, but it would be striking
if he too had been stimulated by Malthus. In any
case we have the fact that, at a time when pressure
of population was practically interesting men’s
minds, Darwin, Wallace, and Spencer were in-
dependently led towards a theory of organic
evolution. There could be no better illustration
of the Comtian thesis that science is a social
phenomenon. Prof. Patrick Geddes suggests that

184 DARWINISM AND HUMAN LIFE

the severity of industrial competition, which had
increased bitterly between Malthus’s time and
Darwin’s, was at least subconsciously in the mind
of both Darwin and Wallace, and gave spring to
the theory which they projected upon nature.’
Darwin’s Posrrion.—Let us try to understand
Darwin’s problem. His studies as a naturalist
had made him acquainted with a large number of
animals and plants, and two facts had especially
impressed him: first, that the various kinds are
suited to the niches which they fill—suited often
as hand to glove; and second, that in many cases
the various kinds are closely linked together by
resemblances which evidently mean blood-relation-
ship. What Darwin wished to get at was a theory
of the origin of one species from another, and a
theory of the origin of the adaptations with which
the world of life is full. He found the answer to
both his questions in discovering a process actually
at work—Nature’s sifting of the changes that crop
up. He defined it as “the preservation, during
the battle for life, of varieties which possess any
advantage in structure, constitution, or instinct.”

1 Following Bacon, we may draw a useful distinction between
a scientific theory in the stage of suggestion—an anticipation of
nature, and a scientific theory in the stage of verification—an inter-
pretation of nature. In the stage of suggestion the theory of
natural selection was in greater part sociomorphic; but it passed,
by Darwin’s careful workmanship, into the stage of verification,
and it should be remembered that the validity of a scientific theory
is not affected by what suggested it. A theory is to be estimated
by its power of formulating a definite order of facta.

At the same time those who insist on using the formula of natural
selection in the interpretation of human affairs, and who call it
a biological formula, must remember the history—that it was from
the human domain that the suggestion of the theory came. Per-

haps there is some supplementary suggestion from human s ociety,
equally valuable, which no Darwin has yet arisen to appreciate.

SELECTION: ORGANIC AND SOCIAL 185

His general line of thought was something like
this. The gardener and the breeder watch for
changes or variations ; they select for propagation
those variants that please them, keeping all others
away; gradually they establish new varieties that
breed true. So it is in nature, Darwin said, where
variations are continually cropping up. But what
takes the place of the breeder? Nature’s sifting
in the struggle for existence. Man has done much
in a short time; what may Nature not have
done in a long time? As has often been pointed
out, there are some differences in detail between
artificial and natural selection, but the essential
features are the same.

“The theory of natural selection,” Mr. Wallace
writes,! “commonly called Darwinism, is one of
the most simple and easy of comprehension in the
whole range of science; yet, after fifty years of
continuous exposition and study, there is perhaps
none that is so widely and persistently misunder-
stood.” Let us therefore linger over it.

When one visits that scientific Aladdin’s cave
called the British Museum (Natural History), one
is impressed, on entering, by the statue of Darwin,
and from it the eye falls to a tree full of pigeons
with the wild rock-dove (Columba livia) as a centre,
and on the branches round about Pouters and
Carriers, Tumblers and Trumpeters, Jacobins and
Fantails, and other breeds. That case of pigeons
is a Darwinian diagram, for Darwin chose these
birds for special study—and they led him to a
goal as famous as Ararat. There are over two
hundred very well-marked breeds of domestic
pigeons, and there are at least ten that would be

1 Fortnightly Review (March 1909), p. 411.

186 DARWINISM AND HUMAN LIFE

ranked as distinct genera if they occurred wild.
Yet there is strong evidence that all are scions
of the blue rock-pigeon (Columba livia). Darwin
pointed out that the social, non-arboreal habits,
the mode of cooing, and other characters of
domestic pigeons, point to Columba livia; that
this bird has a wide range of distribution; that
it is very variable in plumage, easily tamed, and
actually domesticated ; that all races of domestic
pigeons are fertile when crossed, and their off-
spring are usually fertile—two facts which point
to one origin for all; that all domestic pigeons
tend to revert to the blue rock-pigeon; and
so on.

In the same way, as is well known, Darwin
brought forward evidence that all the breeds of
poultry—Hamburghs and Dorkings, Bantams and
Silk-fowl, and all the rest of them—are descended
from the jungle-fowl, Gallus bankiva, which is
still found wild in some parts of India and the
Malay Islands. There seems to be evidence that
the jungle-fowl—which our gamecock most nearly
resombles—was domesticated in the East before
1400 B.c., and was introduced into Europe about
600 B.c. The clear cases of pigeon and fowl were
backed up by more difficult cases, such as those
of horse and dog, where it seems almost certain
that the domesticated breeds have arisen from
several distinct wild species.

At all events, Darwin proved, up to the hilt, that
the breeder is a transformist. Circe changed men
into pigs; the prehistoric breeders made a wolfish
creature into a trustworthy guardian of their
flocks. What is the method? The breeder can-
not create ; he waits for what turns up, and then he

SELECTION: ORGANIC AND SOCIAL 187

directs. He directs by bringing similars together
and by eliminating undesirables from the flock
or herd. So Nature directs—but automatically
—by singling and sifting in the struggle for
existence.

Tue Turory Statep.—(1) Darwin started with
the fountain of change within the living creature,
whence variations are always welling forth. Off-
spring are not quite like their parents, or like one
another. It is a fact that there are individual
variations, for better and for worse, between living
creatures of the same kind. In some cases it is
definitely known that these variations may be
transmitted.

(2) Life is very prolific, and in every kind of
living creature—except man—the majority die
young. There is not usually any increase in
numbers from generation to generation. There
is a ceaseless struggle for existence—a phrase to
be taken in a wide and metaphorical sense as a
description of what goes on in nature because of
the limits of space and the self-assertiveness of the
individual, because of the prolific multiplication
of the eaters and the insufficiently rapid supply of
the eatable, because of the changeful and merciless
physical environment, and all the subtle interrela-
tions of things in the web of life, whose warp and
woof are love and hunger.

It is very important to realise the web of life
in this connection, for, as an acute critic points out,
it alone warrants us in believing that “slight
differences may give one creature an advantage
over its neighbour in a nicely balanced struggle for
life. In other words, it introduces the conception
of a correlation between even minute variations and

188 DARWINISM AND HUMAN LIFE

991

the survival or non-survival of their possessors.
As Darwin says, in a notable passage: “ Battle
within battle must be continually recurring, with
varying success; and yet, in the long run, the
forces are so nicely balanced that the merest trifle
would give the victory to one organic being over
another.”

(3) The theory continues, that, if variations occur
in the direction of increased fitness, and if the
variations are heritable, and if there is discriminate
elimination with reference to these variations,
then the possessors of the fitter variations must be
favoured with longer life and larger families—with
survival, in short. And if this is kept up con-
sistently, then new adaptations, and, with the help
of isolation, new species, will arise. Those mem-
bers of a species that are handicapped will become
a minority and eventually their type will be
eliminated. Those that have varied so as to be in
any appreciable way favoured will become the
majority, and eventually the type, of the species.

A little reflection will show that there are two
main modes of natural selection. It may produce
its effects by the discriminate elimination of the .
less fit, or by the increased and more effective
reproductivity incident on the success of the more
fit. These two modes are sometimes distinguished
as Lethal and Reproductive Selection respectively.
In both cases the fitter members of a generation
contribute more than the less fit to the next genera-
tion. If we regard sexual selection as a special
case of natural selection, which seems the clearest
view, we have to include extreme cases like that

1 “ Evidence of Natural Selection,” by E. S. Russell, in Rivista
di Sctenza (1908), vol. iii.

SELECTION: ORGANIC AND SOCIAL 189

of the single drone that overtakes the queen-bee
in her nuptial flight—all the others being left to
die non-reproductive.

Darwin summed up the theory in a couple of
sentences: “As many more individuals of each
species are born than can possibly survive, and
as, consequently, there is frequently recurring
struggle for existence, it follows that any being,
if it vary however slightly in any manner profitable
to itself, under the complex and sometimes varying
conditions of life, will have a better chance of
surviving, and thus be naturally selected. From
the strong principle of inheritance any selected
variety will tend to propagate its new and modified
form.”

Toe THrory oF Naturat SELECTION TO BE
TESTED AS AN INTERPRETATIVE FormuLA.—For
what has occurred in the past the theory of natural
selection can never be proved; we can only show
that it offers a reasonable interpretation, that it is
a formula that fits. In the case of many of the
most remarkable adaptations, such as those of
mimicry and protective resemblance, it is the only
interpretation in the field that has any approach to
feasibility.

In regard to what is going on at present, several
attempts have been made (as we shall see later)
to catch natural selection at work, to prove the
occurrence of discriminate elimination with refer-
ence to a particular character, to show that what
determines that one organism should be taken
and another left is that the first lacked something —
which the survivor has. This is extremely im-
portant, for it is “ as easy as winking ” to imagine
possible utilities for a particular character, whereas

199 DARWINISM AND HUMAN LIFE

it is our business to prove that the survivors survive
because they have the character in question.

InLusTRATIONS oF NatuRAL SELECTION.—In the
1858 essay Darwin gave the following imaginary
illustration. Some dog-like animal lives on rabbits,
and on hares, when it can get them; the rabbits
become scarcer, and the hares more plentiful, so
the carnivore turns its attention to hares; those
carnivores that varied in the direction of swiftness
and sharp-sightedness would get on best, would be
more successful as regards numbers and vigour of
offspring; in a thousand generations there would
be a marked effect—as surely, he said, as grey-
hounds can be improved by selection and careful
breeding.

Many insects in Madeira have reduced and
useless wings, or none, while their allies in Europe
have them well developed. The Darwinian inter-
pretation is, that as Madeira, like similar islands,
is exposed to sudden gales, the flying insects have
been blown out to sea, while those that varied in
the direction of flightlessness have survived. It
is easy to make fun of this, as Samuel Butler did
when he said it was like explaining our own
presence by the fact that our cousins, uncles, and
aunts had gone away. A little reflection, however,
will show that the theory fits the facts, and our
confidence in the interpretation grows when we
find that other exposed and wind-swept islands
agree with Madeira in having flightless insects.
Thus, in the stormy and shelterless Kerguelen all
the insects (including a moth, several flies, and
many beetles) are flightless and most are wingless.

Many Arctic mammals and birds—such as fox
and falcon—have a beautiful white colour: what

SELECTION: ORGANIC AND SOCIAL 191

is the selectionist interpretation of this charac-
teristic ? The first step is to recognise that animals
are very variable as regards colouring, and thus
there is raw material to workon. Furthermore, a
variation in the direction of whiteness is common—
white blackbirds and swallows, white rats and
moles, being well known. It seems likely that a
ferment essential to the manufacture of the pig-
ment drops out of the inheritance of these
albinos. The change is of germinal origin, and
it is hereditary. Now there is a keen struggle
for existence in Arctic regions, and any character
that gives its possessor a pull is likely to have
selective value. But there are various advan-
tages in a white dress in snowy regions—it is
the least conspicuous and the most comfortable.
Those who turn white will get on best, other things
being equal. Therefore we have white races in
Arctic regions, and we may corroborate the
argument by referring to a simple experiment.
Prof. Davenport had 300 chickens in a field, 80
per cent. white or black and conspicuous, 20 per
cent. spotted and inconspicuous. In a short time
twenty-four were killed by crows, but only one
of the killed was spotted.

In a heavy snowstorm at Johannesburg in
August 1909, many hundreds of trees were destroyed
by the weight of snow on the branches. It was
interesting, after the storm, to notice that the
elimination was in a marked degree discriminate.
The trees that suffered most were the imported
Australian trees, such as Blue Gums and Black
Wattles, quickly growing, with soft wood, and
with abundant foliage that caught the snow. On
the other hand, the deodars from the Himalaya

192 DARWINISM AND HUMAN LIFE

Mountains, constitutionally adapted to let the
snow slide from their pendulous branches and
acicular leaves, had hardly a twig broken. If
similar storms occurred several times a year, instead
of once in twenty years, there would soon be no
Blue Gums or Wattles.

OBJECTIONS AND ORITICISMs.—Darwin’s sugges-
tion was that new adaptations, new varieties, new
species have arisen by the elimination of the
relatively unfit variants and by the selection of
the relatively fit. In other words, natural selection
is the main directive factor in evolution. That is
to say, given variations, the secret of success is
sifting. Against this theory all manner of objec-
tions have been urged—fair and unfair, competent
and incompetent, wise and foolish. The army of
objections is so huge that one feels there must be
strong virtue in a theory that is so vigorous after
fifty years. It should always be remembered
that the best and the severest critic of the theory
of natural selection was Charles Darwin himself.
We do not propose to defend the theory or to
slay the thrice slain, but the following statements
may serve to remove some common misunder-
standings.

(1) It must be clearly understood that the
“ fittest ’ which survive are not necessarily best
or highest on any absolute standard, but simply
fittest for the given conditions. The liver-fluke is
“ fit,” as well as the sheep.

(2) Until we know more about the origin of
the variations which form the raw material of

1 An admirable statement of the objections to the theory of
natural selection, and an answer to them, will be found in Prof.
Plate’s ‘‘ Handbook to Darwinism.” (Leipsig, 1908.)

SELECTION: ORGANIC AND SOCIAL 193

progress we are open to the reproach of giving
a theory of the survival, but not of the arrival
of the fittest. Yet there are often two misunder-
standings in the minds of those who play with
this reproach, which Darwin met long ago. (a) It
is, of course, clear that natural selection is Siva,
the Destroyer,’ and that L’Hvolution créatrice is
the secret of the organism. Natural selection
prunes a growing and changeful tree. Natural
selection is a directive, not an originative, factor.
The problem of origins is the problem of variation.
(b) It must also be noted that, if the fittest have
arisen by very gradual steps, by the accumulation
of variations small in amount, then the reproach
of explaining, not the arrival, but only the survival,
loses much of its force.

(3) With unwearying reiteration the objection
is raised that the initial stages of new adaptations
will be too minute to have survival value. This
difficulty has been often dealt with, and it may
suffice here to point out (a) that no one can
decide, in ana priort way, how small a change may
be of critical moment ; (b) that in the fine texture
of the web of life a trivial difference, as Darwin
said, may determine survival ; (c) that elimination
may be effective though it is not accomplished in
a generation; and (d) that an incipient change

1 Most biologists admit, what Darwin himself clearly recognised,
that in strictness the real process is natural elimination. As an
American biologist says: ‘The fit are not selected—it is the unfit
who fail to survive, and the fit are merely the survivors. The
process is negative throughout. A railway train selects its pas-
sengers in the same sense—those who come in time get aboard,
those who do not, get left.” At the same time it must be under-
stood that, although the process is negative, the results are in part
positive.

13

194 DARWINISM AND HUMAN LIFE

may be carried through its initial stages by being
correlated with another more important change.
(4) The eliminative processes that most Dar-
winians believe in, because they see them going
on, may be slow as well as quick, gentle as well
as severe, environmental as well as competitive.
The selected are not necessarily those saved from
the jaws of violent death; they may be simply
those who, in virtue of a heritable peculiarity, have
a rather longer and more successful life and a
rather larger and more successful family. The
only eliminative processes that can be believed
in as counting for much in evolution are those
which are discriminate and consistent. Thinning
turnips may serve as our diagram of indiscriminate
elimination (only very indirectly does it improve
the turnip race); Luther Burbank carefully
burning some of his most interesting creations
because they are not quite right for his purpose
may serve as our diagram of discriminate elimina-
tion. But while the modes of natural selection
are many and various, the logic of the process
is always the same—when a heritable peculiarity
is of critical moment in favouring survival it will
tend to persist, provided (a) that its occurrence
is sufficiently frequent, and (b) that the dis-
criminate selection fostering it is kept up con-
sistently for a long enough period.
ApapTaTions.—No one can rightly appreciate
the theory of natural selection who does not
realise in some measure the universal occurrence
of those detailed fitnesses of structure and function
which are called adaptations.1 The general idea

1 We use the word adaptation to express a result achieved ; it is
sometimes used to express the process of reaching that result.

SELECTION: ORGANIC AND SOCIAL 195

of fitness is familiar; we are irresistibly pleased
in our own affairs with arrangements like safety-
valves and regulators which bring about important
results in an effective way ; we pour contempt on
tools that will not work, on machines that will not
go. But we have not to travel beyond our own
bodies to find illustrations of safety-valves and
regulators that put to scorn all machinery, and
one of the perennial delights of natural history,
in the wide sense, is its continual discovery of
fresh instances of hand-and-glove adaptations.
There is wonderful fitness even in one of the
lowest forms of life—it is always changing and yet
it remains the same, it answers back effectively
to external stimuli, it grows and passes from one
phase to another, it reproduces itself, and it is
said that some of the simplest never die. We
cannot, at present, get behind this primary
adaptiveness of living creatures—it is implied in
what we mean by living. Itis convenient, however,
to keep the word “adaptation” for something
super-added to what we must take for granted,
and yet it is difficult to draw the line. The power
of growth is a primary attribute; the capacity of
regrowing a readily broken limb depends on
this; and yet it is difficult to understand why,
for instance, a chameleon should not be able to
regrow its tail, as almost all other lizards can do,
unless we regard the distribution of the regenerative
capacity as adaptive, adjusted in the course of
ages to frequently recurrent needs. We say that
the immunity which certain organisms have to
certain poisons is an adaptation, it has been
wrought out and added on; but is it not, perhaps,
a special case of the immunity which even simple

196 DARWINISM AND HUMAN LIFE

organisms have to considerable accumulations of
their own self-made poisons or waste-products ?
To illustrate adaptations Weismann takes, for
instance, the whale-type among mammals, and
refers to “the fish-like form of the body, the
hairlessness of the skin, the transformation of
the fore-limbs to flippers, the disappearance of
the hind-limbs and the development of tail-flukes,
the layer of blubber under the skin, which affords
the protection from cold necessary to a warm-
blooded animal,” and so on through a long list.
The whale is a great bundle of adaptations to
a mode of life which is peculiar for a mammal.
Whether we take actively functional parts,
such as our own hand, or passively functional
structures, such as a feather; whether we take
obvious features, such as the typical spindle-like
shape of fishes, or more recondite features, such as
the structure of a bone; whether we take mimicry
or migration, ‘ wherever we tap organic nature,”
as Romanes said, “it seems to flow with purpose.”
Natural selection is the theory of the indirect
coming about of this wide-spread purposefulness—

the possibility of variations in the direction of

fitness being granted. Lamarckism, which assumes
the hereditary accumulation of functional and
environmental modifications, is a theory of direct
adaptation—on the whole simpler than the selection
theory, but suffering from the serious disadvantage
that its fundamental assumption is still without
cogent evidence in its favour.

Birds’ eggs are of diverse shapes, and we know
in some detail the actual factors which determine
these. We also know that individual variations
in the shape are not uncommon. We can under-

SELECTION: ORGANIC AND SOCIAL 197

stand, then, that if a certain shape were particularly
well suited for special conditions, that shape would
be selected, 1.e. the birds that were constitutionally
unable to lay eggs of the fit shape would be
eliminated. Now Darwin points out that, in
sea-birds like guillemots and razor-bills, which
lay their eggs on the narrow ledges of precipitous
cliffs, the shape of egg is very markedly top-like.
The adaptiveness of the shape is that, if the egg
be jostled by the parent or some other bird, or
be caught in a swirl of wind, it rotates on its
short axis without rolling from its original position.

Let us take another instance. The A’sop prawn
(Hippolyte varians) may be red, yellow, blue,
orange, olive, violet, brown, green, and other
colours. It is born without a bias and it takes
on the colour of its surroundings, both when
young and when adult. Put some in a glass
aquarium, and line the sides and floor with paper
of almost any colour; the prawn follows, and
from one colour it may be changed to any other.

As bright yellow, blue, and violet are not
common colours among the seaweed, it has been
argued that the power of colour-change cannot be
the outcome of selection. But that is an absurd
conclusion; it is by no means certain that the
bright colours are absent among seaweed, and,
besides, adaptiveness is rarely perfect.

Many colour-adaptations are very striking. Thus
Prof. Poulton has shown that certain caterpillars
will, within certain limits, take on the colour
of their surroundings, and Engelmann has shown
that the peculiar alge known as Oscillatoria
become green in red light, red in green light—
physiologically the best possible colours.

198 DARWINISM AND HUMAN LIFE

We may speak of an organism as a bundle of
adaptations, but we are not justified in saying that
every structure is an adaptation. There are some
structures whose use is unknown, and there are
others which seem to be of no value, such as well-
concealed decorativeness. It may be, however,
that some of the details whose significance is
unknown are the architectural correlates of im-
portant characters.

CHANGES SINCE Darwin’s Day.—Darwin did not
doubt the legitimacy of supposing that some of
the direct effects of use and disuse and of the
influence of surroundings may be transmitted as
such or in a representative degree. He was,
therefore, to a limited extent a Lamarckian, and
there are some competent authorities who occupy
a similar position. We are far from dogmatically
declaring that the Lamarckian position is quite
untenable, but we have hinted at some of the
difficulties which have led us to abandon it until
further evidence is forthcoming.

Leaving this as a drawn battle, we wish to
refer briefly to two marked changes since Darwin’s
day. In the first place, there has been a useful
attempt to give some experimental demonstration
of the working of natural selection. In the
second place, there is a growing feeling among
different bodies of workers that it is not necessary
to burden the shoulders of the natural selection
theory so heavily as heretofore.

Evipences oF Natursi SELEcTION.—One of
the most interesting—though, from the nature of
the case, least impressive—steps of progress since
Darwin’s day is the attempt to secure definite
evidence of the operation of natural selection.

SELECTION: ORGANIC AND SOCIAL 199

It must be admitted that Darwin left the theory
in this form: Variations occur abundantly ; there
is a complex, subtle struggle for existence; there is
a constant process of sifting and winnowing; if fit
variations occur among the rest, and if there is
discriminate elimination so intense that survival
depends on the presence or absence of the variation
in question, then new adaptations must result.
Those who have something of a naturalist’s ex-
perience and have some appreciation of the enor-
mous scale upon which Nature works—as to time,
as to numbers, as to chances—have usually been
content to accept this theory of natural selection
as a good working hypothesis.

But what we wish is actual proof of discriminate
elimination, that survivors do survive in virtue of
particular qualities. A few illustrations in the
present may legitimise our belief that similar
processes occurred in the past. Let us summarise
the best of these illustrations.

With silk threads Cesnola? tethered forty-five
green praying mantises to green herbage, and sixty-
five of the brown variety to withered plants. He
watched them for seventeen days, and all survived
unnoticed by birds. But when he put twenty-five
green ones among brown herbage all were killed
by birds in eleven days, while of forty-five brown
ones on green grass, only ten survived at the end
of seventeen days. Here we have definite proof of
a selective death-rate, definite proof of the selective
value of the protective coloration.

Poulton and Saunders? fastened 600 pupze of the

1 See “‘ Biometrika,” vol. iii. p. 58.
2 «Report of the British Association, Bristol Meeting” (1899),
pp. 906-909.

200 DARWINISM AND HUMAN LIFE

tortoise-shell butterfly (Vanessa urtice) to nettles,
tree-trunks, fences, walls, and so on. At Oxford
there was a mortality of 93 per cent., pointing to
an extremely high elimination-rate, and the only
pupz that survived were on nettles, where they
were least conspicuous. At St. Helens, in the Isle
of Wight, the elimination was 92 per cent. on fences
where the pups were conspicuous, as against
57 per cent. among nettles where they were incon-
spicuous. Here, again, there is definite evidence of
discriminate elimination.

Another illustration is to be found in the late
Prof. Weldon’s! well-known experiments on crabs.
He placed 248 male shore-crabs (Carcinus menas)
in a vessel of sea-water containing in suspension
a quantity of china-clay; and 94 survived. It was
found that the mean of the frontal breadths of
the survivors was distinctly smaller than that of
the eliminated. ‘A difference in the mean value
of a character between survivors and eliminated,
when both have been exposed to identical environ-
mental conditions, is proof that the character is
being acted upon by natural selection. . . .”? That
is, by the ordinary “ secular selection,” for there
is another mode—“ periodic selection,” in which
the mean value of the character is not changed,
but extreme deviations from the mean are lopped
off. “Periodic selection’ can be detected by the
decrease in the range of variability.

Measuring small specimens (10-15 mm.) of
shore-crab taken from Plymouth Sound, in the

1 « Proc. Royal Soc.” (1895), vol. lvii. pp. 360-79. Also Nature
(1898), vol. lviii. pp. 499-506 and 595-6.

2 See “ The Evidence of Natural Selection,” by E. S. Russell,
in Rivista di Scienza (1908), vol. iii.

SELECTION: ORGANIC AND SOCIAL 201

years 1893, 1895, and 1898, Prof. Weldon found
that, during the time between the first measure-
ment and the last, the frontal breadth of the crabs,
taken relatively to their length, had distinctly
decreased. As the amount of suspended clay and
sewage in Plymouth Sound had increased during
the same period, Prof. Weldon concluded that
those with broad fronts were being persistently -
eliminated. As the experiment referred to above
shows, those with narrow fronts withstand the
muddy water better. The inference was that the
elimination was definitely discriminate.

Prof. Bumpus’ relates an interesting observa-
tion on the house-sparrow in North America.
After a storm 136 were picked up and brought
into the laboratory, where 72 revived and 64 suc-
cumbed. Survivors and eliminated were measured
as to length, size of wing, weight, length of head,
length of humerus, of femur, of tibio-tarsus, width
of head, and length of sternum. For all but the
last of these characters the range of variation
was considerably greater in those that succumbed,
the extreme variants (e.g. those with longest as well
as shortest wing-span) were eliminated (periodic
selection). Moreover, the survivors were a little
shorter, lighter, longer in the leg, the humerus, and
the breast-bone. General stability of structure, Prof.
Bumpus says, was the essential characteristic of
the survivors.

A fine proof of the efficacy of natural selection

1 For criticism see J. T. Cunningham, in Nature (1898), vol. viii.
pp. 593-4.

2 « The Elimination of the Unfit as Illustrated by the Introduced
Sparrow,” by Hermon C. Bumpus, Biol. Lect. Woods Holl, Boston
(1898), pp. 209-26,

202 DARWINISM AND HUMAN LIFE

is given by Prof. H. E. Crampton ' for the Saturnid
moth, Philosamia cynthia. A large number of pupz
were collected from a small area, and kept till they
hatched. But only 16°6 per cent. of the total
number collected gave perfect moths. Many of
the pupe were dead within the cocoon (“ pupal
elimination ”), 129 out of 310 died in the period
between the formation of the imago and its
emergence (“ pupal imaginal elimination ’’). Mr.
Crampton compared 134 male pupz that survived
pupation with 130 that died immediately after
pupation, as regards length, width, and depth of
the bust of each, and as regards length and breadth
of antenne. Those that survived were longer,
narrower in the bust, and had longer, stouter
antenne. Similarly, he compared 176 surviving
female pupe with 180 that died, and selection. in
type was found to be certain for all dimension’.
and to be in the same direction as in the male
pupe. The survivors were also less variable.
We need not discuss the pupal-imaginal elimina-
tion, where the results were somewhat different.
It is interesting to notice, as Mr. Crampton points
out, that the selected characters are not such as
seem to be directly or indirectly “useful” to
their possessors, yet they are demonstrated to have
the high utility of determining survival—which
is indeed, for the evolutionist, the final criterion
of utility.’

We cannot do more than allude to the careful
statistical methods by which Prof. Karl Pearson
and others have proved that there is selective

1 « Biometrika ” (1904), vol. iii. pp. 113-30.
2 See ‘The Evidence of Natural Selection.” by E. S. Russell,
in Rivista dt Scienza (1909), vol. iii.

SELECTION: ORGANIC AND SOCIAL 203

death-rate in man. A certain number of people
are killed every year in Britain by lightning;
their death is purely fortuitous. But this cannot
be said of phthisis, where the elimination is in part
quite definitely discriminate. Even from the fact
that longevity is truly heritable it is evident that
there must be a selective death-rate in mankind.

LESSENING THE BURDEN OF THE THEORY.—
another change which seems now coming about as
the result of discussion and investigation is ex-
pressed in a growing tendency to lessen the burden
that has been hitherto laid—faute de mieux—on
the shoulders of Natural Selection. We cannot
do more than illustrate” how different bodies of
workers are arriving at tne same general conclusion.

(a) If we find increasing warrant for postulating
the occurrence of mutations of considerable magni-
tude and for believing that they are not readily
lost “zhen they once emerge, then it is not necessary
# — }pose that every character has arisen by the

‘gccUfnuiation of minute steps. It goes without
saying that mutations must pass through the
selection sieve.

(6) Whether we postulate mutations or fluctua-
tions, we cannot but sympathise with the heresy
which is often whispered, that it is very difficult
to give a concrete selectionist interpretation of
what may be called the “ big lifts’”’' in evolution.

1 The difficulty in regard to “big lifts” is bound up with the
question whether there are any qualitative steps in evolution, or
whether change apparently qualitative may not be due to the
accumulation of minute quantitative changes. It is said th
there are no transitions between a sledge and a wheeled cart, and
that a new unity cannot arise piecemeal. It is difficult, however,
to feel confidence in these arguments from analogy. Conscience, or
the habit of judging our actions by a standard, is a very a

204 DARWINISM AND HUMAN LIFE

Given heritable fluctuations and selection, we can
perhaps interpret the perfecting of an adaptive
structure, such as an elephant’s trunk. Given
mutations and selection and isolation, we can
perhaps interpret the origin of a new species.
But when we face the “ big lifts ” the difficulty is
very great. Gymnosperms have probably evolved
from fern-like plants. But “* the seed and all that
goes with it is a new character, and how selection
could have originated it is a question at whose
answer even scientific imagination balks. It is
evident that the ovules of Gymnosperms are related
by descent to the sporangia of ferns in some way,
but so extensive a change does not seem to come
within the possibilities of natural selection.” ?

It may be noted that some paleobotanists,
notably Grand’Eury and Zeiller, maintain that the
rock-record is distinctly suggestive of the su¢den
appearance of new forms differing by mprked
characters from those that gave them birth. , -»,

(c) Another view which finds adherents is\ *¢¢z
many minor characters are the physiologica\ or
developmental concomitants of major characters
which have undeniable selection-value. They
follow in the wake of the more primary qualities.
Thorns used to be interpreted by the eager Darwin-
ians as a protection against grazing animals, and
human character, and yet it is conceivable that it has evolved from
pre-human habits by a series of very slight changes, some of the
links being found in self-subordinating behaviour among animals,
in parental care, in the law of the pack. As Norman Wilde puts it,
“Because darkness passes through twilight into day by imper-
aeptible degrees, we do not deny the difference in quality between
darkness and light.”

“The Theory of Natural Selection from the Standpoint of
Botany,” by Prof. John M, Coulter, in “ Fifty Years of Darwinism”

(1909 AP 60.

SELECTION: ORGANIC AND SOCIAL 205

they seem sometimes to have this value. But
this cannot be the whole truth. Apart from the
just objections that thorns are often prevalent in
countries where there are few grazing animals and
that they do not appear in the early stages when
they are most needed, experiment has shown that
many thorns arise in response to poor nutrition.’
Thorns are the natural outcrops of a kind of con-
stitution suited to dry countries.

This idea was familiar enough to Darwin, as we
see from the emphasis which he laid on instances
of “correlated variability.” .In this connection,
Sir Ray Lankester observed, at the Cambridge
Centemary Celebrations: “In my opinion he has
thus furnished the key to the explanation of what
are called useless specific characters and of in-
cipient organs. That key consists in the fact that
a general physiological property, or character of
utility, is often selected and perpetuated which
carries with it distinct, even remote, correlated
growths and peculiarities obvious to our eyes, yet

1 See Coulter, op. cit. (1909), and Geddes, ‘Proc. Brit. Assoc.”’
(1889.) Prof. Coulter points to significant facts like the following :
the nettle can get on quite well without its stinging hairs; many
seeds, especially in arid regions, develop a testa so hard that it inter-
feres with the breaking through of the embryo—which looks like
“ over-adaptation ” ; further investigation has played havoc with
the pretty story of the extra-floral nectaries attracting a body-guard
of harmless ants. It is probable that in these and a hundred other
cases our task is rather that of discovering the physiological and
embryological significance of the structures in question, than that
of searching diligently for a utilitarian justification which does
not exist. A familiar example may be found in our finger-printa,
which illustrate discontinuity in evolution—the apparently abrupt
origin of new patterns; but, as we have no warrant for supposing
that natural selection operates in any way in this case, we must
suppose that these patterns are the expressions of internal growth-
conditions.

206 DARWINISM AND HUMAN LIFE

having no functional value. At a later stage in
the history of such a form these correlated growths
may acquire value and become the subject of
selection.” *

(d) Among paleontologists, too, there are some,
like Prof. H. F. Osborn, who make out a strong
case for the origin of new characters by definite
progressive variation, and “not by the selection
of the fit from the fortuitous.” In other words,
many paleontologists claim that indefinite varia-
tions off the main line are absent, so far as the
rock-record tells.

“The law of gradual appearance or origin of
many new characters in definite or determinate
directions from the very beginning I regard as
the grandest contribution which paleontology has
made to evolution.”? We must attach great
importance to this expression of opinion, for it is
shared by many who, like Prof. Osborn, have
given their life to studying the actual history ; but
it must be borne in mind that highly specialised
types, like Ammonites and mammals, may be like
well-pruned trees—they may have been selected
through long periods into lines of determinate
variation. The power of divergent idiosyncrasy
may have been pruned out of them.

After referring to the work of Waagen on
Ammonites and his own work on mammals (e.g.
their teeth), Prof. H. F. Osborn says: “ The law
of gradual change in certain determinate, definite,
and, at least in some cases, adaptive directions,
through very long periods of time, and the absence

1 Nature (July 1, 1909), p. 10.
2 “Darwin and Paleontology,” by H. F. Osborn, in “ Fifty
Years of Darwinism ” (1909).

SELECTION: ORGANIC AND SOCIAL 207

of chance and non-direction in the origin of a large
number of adaptive and other new characters, is
the common working principle both in Vertebrate
and Invertebrate paleontology.” ’

(e) Another change of view—rank heresy to those
of the straiter sect of Darwinians—is seen in the
writings of not a few naturalists who do not feel
themselves bound to find a use for everything.
There are many apparently trivial characters, for
which careful investigation has discovered very
definite and unexpected utility—Weismann gives,
as an example, the beautiful microscopic anchors
and discs of lime found in the skin of the burrow-
ing, worm-like Holothurians known as Synaptids ;
but, on the other hand, the tyranny of an ex-
treme zoological utilitarianism may become absurd.
When the wind blows the long, sharp-pointed leaf
of the sand-binding bent-grass it often makes a
perfect circle on the sand, but there is no signifi-
cance in this. Nor is there in the beautiful ripple-
marks on the sand or in the frost-flowers in the
window. It seems likely that there are many
such things in living creatures—registrations of
orderly rhythms of the body, but not useful. The
barring on a feather may be of life-saving value,
it may also mean nothing more than diurnal
variations in blood-pressure when the feather was
a-making.

SexuaL SeExection.—As a corollary to his
theory of natural selection, Darwin expounded a
theory of sexual selection, in which he interpreted
some of the secondary peculiarities of the sexes
as the outcome of selective processes involved in
the combats of rival suitors and in the choice

1 Op. cit. (1909).

208 DARWINISM AND HUMAN LIFE

exercised by the coy females. All sorts of mascu-
line weapons, such as antlers; all sort of decora-
tions, such as brilliant plumage; all sorts of
excitants, such as love-calls and fragrance, may
be interpreted in terms of the sexual selection
which seems to occur in many cases, especially
where there are more males than females, or where
polygamy occurs. The whole matter is difficult,
perhaps more difficult than Darwin thought, and
there is great difference of opinion in regard to it.
Wallace does not see his way to believing at all
in the action of female choice ; Weismann is whole-
heartedly with Darwin. It must suffice to state
a few conclusions based on some of the post-
Darwinian contributions to this fascinating subject.
(a) The combats of rival males are often very
fierce. The younger or weaker candidates may be
killed, or expelled, or left unmated. In such
cases there seems little reason to doubt the dis-
criminateness of the elimination. In some curious
cases, as in spiders, the tournaments are prolonged,
but the combatants do not seem to hurt one
another; and it is possible that the significance
of the jousting is to excite the females, who some-
times stand by, as it were interested spectators.
In some other cases, eg. among Lamellicorn
beetles and Bearded Monkeys, there seems to be
more bluffing than fighting, for precedence is given
to the candidate of most imposing appearance.
(b) In regard to those masculine characters which
indubitably attract the female and probably serve
to excite her and to overcome her coyness, there
seems, as Wallace has consistently maintained,
very little evidence that the female chooses a
partner out of a number of suitors. At the same

SELECTION: ORGANIC AND SOCIAL 209

time, there is evidence, in some cases, that certain
males are left out in the cold unmated, and that
these are inferior in attractiveness or in stimulating
power.

(c) While the cases of preferential mating which
Darwin relied on, for instance among birds and
butterflies, require further study in the light of
criticism, there is no doubt that in many cases the
males exert themselves to display their special
qualities. Thus Prof. and Mrs. Peckham have
described, in spiders of the family Attide, the extra-
ordinary dances of the males before the females.
That the female literally chooses the handsomest
dancer remains unproved, yet it is well known
that she often punishes a suitor who does not
adequately please her by killing him there and
then.

(d) In many cases, e.g. the antlers of stags,
there is a very intimate correlation between the
reproductive organs and the development of the
secondary sex characters. It seems that an internal
secretion from the reproductive organs is neces-
sary to start the development of certain secondary
sex characters. There is also evidence that the
secondary differences between males and females
hang together physiologically, being manifold out-
crops of the deep constitutional difference which
makes of one animal an egg-producer and of another
a sperm-producer. But this kind of inquiry, still
very incipient, is at a level deeper than that of
sexual selection, which does not touch the question
of origins.

(e) It is now generally believed that what the
female chooses is not so much slight improvements
in chirping or song, slight excellences in colour

14

210 DARWINISM AND HUMAN LIFE

or scent, but rather the tout-ensemble of that male
who most excites her sexual interest. As Weis-
mann says: ‘“‘ Even though we certainly cannot
assume that the females exercise a conscious choice
of the ‘handsomest’ male, and deliberate, like
judges in a court of justice, over the perfections
of their wooers, we have no reason to doubt that
distinctive forms (decorative feathers and colours)
have a particularly exciting effect upon the female,
just as certain odours have among animals of so
many different groups, including the butterflies.” *

Though Darwin sometimes seems to credit the
female with no small degree of esthetic fastidious-
ness, he also states that “it is not probable that
she consciously deliberates; but she is most
excited or attracted by the most beautiful, or
melodious, or gallant males.” As Lloyd Morgan
says: “ The most vigorous, defiant, and mettle-
some male is preferred, just because he alone affords
a contributory stimulation adequate to evoke the
pairing impulse, with its attendant emotional
tone.”” From the human point of view, perhaps
the most important point is that, in the course
of evolution, sexual behaviour has come to be
associated with psychological values which hitch
it to the skies.

IsoLaTion.—Besides selection in its varied forms
there is another directive factor in evolution—
which Darwin to some extent recognised—and
that is Isolation. This term is used to include
all the means which restrict the range of inter-
crossing within a species: geographical barriers,
such as arise when a peninsula becomes an island ;
temporal barriers, such as arise when the members

1 “ Darwin and Modern Science ”’ (1909), p. 47.

SELECTION: ORGANIC AND SOCIAL 211

of a species reach sexual maturity at different
times of year; habitudinal barriers, when a species
splits into two or more castes with different habits
of life ; physiological barriers, such as arise by some
variation in the reproductive organs; and psycho-
logical barriers, which rest on profound antipathies.
The subject has been worked at a good deal since
Darwin’s day, by Wagner, Gulick, Romanes,
Jordan, and others—and Romanes went the length
of saying that Isolation was a sine qua non in the
origin of new species. The great difficulty is to
get a sufficient body of reliable facts.

From many passages in Darwin’s works it is
evident that he recognised that isolation, or segrega-
tion, is important in natural selection, just as it is
in artificial selection. “I do not doubt,” he says,
“that isolation is of considerable importance in
the formation of new species.” But he did not
analyse the idea as some post-Darwinian workers
have done. .

When a species spreads, several contingents may
become isolated from one another, and, if different
variations spring up in the several contingents,
then the isolation will favour the origin of distinct
species. It works in two ways: (1) by preventing
intercrossing and its possibly levelling effects, and
(2) by involving close inbreeding, which develops
prepotency or stability of type. There is one
bird peculiar to Britain, namely, the red grouse,
but it is closely allied to the Scandinavian willow
grouse, and it seems impossible to doubt that
the literal isolation of Britain has allowed the
red grouse to diverge as a new species from the
willow grouse stock.

There are said to be eighty species of the land-

212 DARWINISM AND HUMAN LIFE

snail Cerion on the Bahama Islands, and Gulick
reports 200-300 species of the land-snail Achate-
nella in the various valleys of the Sandwich Island
Oahu.

President Jordan has devoted some attention
to the occurrence of cognate or “ geminate ”
species on opposite sides of some barrier. “In
a general way, such species agree with each other
in all the respects which usually distinguish species
within the genus. Their differences appear in minor
regards, characters of degree, or proportion—
traits which we may safely suppose to be of more
recent origin than the ordinary characters marking
off species within the group.” As examples of
what are probably in some measure the results
of isolation, he takes the following: ‘ Hach
well-separated island in the West Indies has its
own form of golden warbler. Each island in the
East Indies has its own forms of reptiles, monkeys,
snails, and fresh-water fishes. Each island in
Hawaii has its own species of each genus of
Drepanine birds; each forest its own type of
land-snails. Hach of the three groups of rookeries
in Bering Sea has its own species of fur-seal.
Each section of the Isthmus of Panama has its”
geminate species of fishes, representing nearly
every genus or sub-genus of the shore-water off
Mexico.” *

There is considerable evidence to show that
isolation, with its attendant inbreeding, has played
an important rdle in human evolution, fixing and
intensifying and giving hereditary grip to types
which began their career in small communities.

1 “Tsolation as a Factor in Organic Evolution,” in “ Fifty
Years of Darwinism ” (1909), p. 81.

bbb

be

SELECTION: ORGANIC AND SOCIAL 213

SELECTION IN HUMAN SOCIETY

GrapuaL Diminution or NaturaL SELECTION
IN Manxrnp.—In early days man had probably
a precarious foothold on the earth, contending
with wild beasts and with physical conditions of
which he had little mastery. The serpent bit
his heel, the thorns cut his naked skin, the floods
rose and drowned him in his cave. There was
probably much squabbling around the platter of
subsistence, a keen and literal struggle, and it
may be that we owe much to the natural selection
of those ancient days. But as age succeeded
age, and man’s brain developed, he cared less
and less for what serpent or thorn or flood could
do; his struggle for existence changed in tone
and colour. And nowadays, except in the out-
skirts of civilisation, there are few wild beasts
that worry man much, the serpent that bites
his heel is usually more or less microscopic,
every year increases his mastery over physical
forces, and he is extending his kingdom to the
heavens.

All through the ages there has been a winnowing
by disease and famine, still very marked in certain
peoples, and to this also, as regards some of our
qualities, we have probably owed much. Of the
primeval crudity of the struggle for existence,
to which sections of mankind are sometimes
forced back, we get occasional appalling glimpses ;
for instance, when a panic unmans men altogether.
But every one knows that. we do all that in us
lies to put a stop to elimination by disease and
famine. Partly through genuine sympathy, partly

214 DARWINISM AND HUMAN LIFE

from a desire to avoid unpleasantness, we insist
on keeping the unfit alive.

As the struggle with physical forces and with
wild beasts became easier, with more frequent
breathing-times and with more encouragement to
self-assertiveness, there came to be more com-
petition between fellows, and it may be that we
owe much to the deadly inter-tribal wars of ancient
times, which would tend to favour not only strength
but solidarity. The conflict of races still continues
among civilised peoples, in trade as much as in
war; and, if there must be this conflict, it is to
be desired that, as the result of it, there may be
“mastery for the foreseeing nation, for the nation
with the cleaner bill of health, the more united
purpose of all classes, and the sounder intellectual
equipment of its units.”! It is impossible to
ignore, however, that the whole aspect has changed
in modern times, and that the issues are less
clear. We cannot trust to the selective process
with equanimity. It is obvious, for instance,
that the issue of the conflict often depends very
largely on length of purse and up-to-date-ness of
equipment, and only to a slight extent on the.
organic qualities of the race or people.

CONTRAST BETWEEN THE Human RAcE AND THE
AntmAL Wor.ip.—It is not necessary to spend
time in showing at length that the venue changes
greatly when we pass from the animal world to
the human race. Apart from the social feelings
which make the cruder forms of natural selection
intolerable, there are many complicating factors.

(1) Animals have very little power outside their

1“ The Scope and Importance to the State of the Science of
Nationa] Eugenics,” by Karl Pearson. London, 1909.

SELECTION: ORGANIC AND SOCIAL 215

own constitution of strengthening their position
in the struggle for existence, but man has much.
He gets to himself appliances and instruments,
engines and machines, and the dwarf bends the
Titan to his will.

(2) If a number of unsociable men were ship-
wrecked on a Robinson Crusoe island and lived
each for himself, a more or less natural selection
maght occur. In human societary forms, however,
there is so much division of labour that, all social
sentiment apart, many get a chance whom Nature
would not tolerate. As a simple illustration, we
may note that the extremely short-sighted are
by no means excluded from having a successful
career. Even short-sighted dogs and horses sur-
vive in domestication. But in wild nature a
short-sighted vulture must perish; it cannot get
spectacles.

(3) Most animals have to get their own food
directly ; we cite as great rarities cases like that
of the slave-keeping ants, who not only have
their food collected but have literally to be fed
by their minions. But in mankind the majority
get their bread and butter in exchange for some-
thing else. Thus types that could not survive
in open nature flourish bravely. —

(4) Most animals have no inheritance outside
of themselves, but in' mankind there are many
kinds of external legacies. It is only in a very
literal sense that the millionaire’s son can say,
“Naked came I forth,’ and an inherited title
may save a man in the social struggle for existence
when neither his body nor his brains could avail.

Some Natura SeLection Remains.—While
much of the selection that takes place in human

216 DARWINISM AND HUMAN LIFE

society is very different from natural selection,
and while we systematically thwart the process
of natural selection, some still persists in present
operation. Let us get a hold of Prof. Karl
Pearson’s argument. If Darwinism applies to
man, “we must have evidence (1) that man
varies, (2) that these variations, favourable or
unfavourable, are inherited, and (3) that they
are selected.” (1) “ The extent of variation in
both man and woman has been measured by the
Biometric School in nearly two hundred cases.”
(2) “There appears no doubt that good and
bad physique, the liability to and the immunity
from disease, the moral characters and the mental
temperament, are inherited in man and with
much the same intensity.” (3) Careful work has
shown that the death-rate in man is partly selective
—a function of his constitution. But while there
is still some natural selection left at work, it
has diminished out of all proportion to the need
for it. “‘Consciously or unconsciously, we have
suspended the racial purgation maintained in less
developed communities by natural selection.”

Sir Ray Lankester has pointed out that the
ceaseless increase of man is absolutely peculiar
to him of all living species, animal or vegetable,
and this is, as Saleeby says, “the source of the
major facts of history and the besetting condition
of every social problem that can be named at
this hour.” Man’s persistent increase is the more
remarkable since he is well known to be a slowly
reproducing animal—slowest perhaps, except a
few extreme cases like the elephant. The point
is this, that whereas most animals have a much
higher birth-rate than man, there is none with

SELECTION: ORGANIC AND SOCIAL 217

such a low death-rate. The meaning of this is
that man has thrown off the natural selection
bondage, and insists on saying, and saying success-
fully, “I will live,’ when every natural chance
is against him.

Tue Ditemma or Civizisation.—The whole
trend of evolution since civilisation began has
been to throw off the yoke of natural selection,
and we are thus brought face to face with a for-
midable dilemma. It is impossible to return to a
natural selection regime, and yet we have not
been able to put an equally effective social selection
into operation. No one has stated the dilemma
more clearly than Herbert Spencer: “ The law)
that each creature shall take the benefits and
the evils of its own nature has been the law under
which life has evolved thus far. Any arrangements
which, in a considerable degree, prevent superiority
from profiting by the rewards of superiority, or
shield inferiority from the evils it entails—any
arrangements which tend to make it as well to be
inferior as to be superior, are arrangements dia
metrically opposed to the progress of organisation,
and the reaching of a higher life.”
Tue Extreme “ LAIssez-FAIRE” Position.—In
face of this dilemma various suggestions have been
made. The first is that we should try to restrict
our kindness—a kindness which the future may
call cruelty. Plato, in his “ Laws,” recognised the
value of the “ purgation of the State” which was
effected automatically by a stern struggle for
existence; and to an interference with natural
selection, it is said, much of our sea of troubles is

oS

1 See “ The Kingdom of Man,” by Sir E. Ray Lankester. (London,
1906.)

218 DARWINISM AND HUMAN LIFE

due. Can we not return, then, in some measure
to the old regime? Should we not be more
guarded in our interference with natural elimination,
e.g. in preventing the elimination of weaklings and
wasters whose survival and propagation cannot but
be a drag on the race ?

This suggestion is open to many objections. In
the first place, there is the general answer that, as
civilisation has involved continuous interference
with natural selection, there is danger in the
proposal to pursue directly opposite tactics. In
the second place, the theoretical suggestion to
return to the old natural selection regime is not
practicable, partly because of the complexity of
our social organisation, which offers so many
niches of opportunity to weaklings and wasters,
and partly because, without a great change in social
sentiment, it is in civilised communities quite
impossible not to try to save those to whom
Nature would show no mercy. It is likely that
we are often cruel in our charity, but we cannot
altogether help it.

Besides these general objections to the extreme
laissez-faire position, there are many particular
objections. Let us take, for instance, the sugges-
tion that we should cease supporting hospitals and
the like.

(1) Our attempt to lessen an artificially ex-
aggerated infantile mortality cannot be accurately
described as an interference with the order of
nature !

(2) Much weakness which we try to strengthen
is only superficially, not organically weak; and
while we keep alive some who are rotten we save
many who only require temporary shelter. One

SELECTION: ORGANIC AND SOCIAL 219

enthusiast over bacterial selection says: ‘ The
higher the infantile mortality which medicine so
energetically combats, the surer is the next
generation of being purged of all weak and sickly
organisms.” But he forgets that the infantile
maladies also affect the intrinsically strong and
“capable, and often weaken them, one might say,
quite gratuitously.

(3) Many of the microbes which thin our ranks
are very indiscriminate: they remove the wrong
people. Prof. Berry Haycraft, im his “Darwinism
and Race Progress,” points out that the hygienists,
in warring against microbes, are eliminating the
eliminators who have made our race what it is.
This is a very doubtful thesis; but, even if it
were true, it is open to us, as the author of
course recognises, to put other modes of selection
into operation. Can man not select better than
bacteria ?

Socrat SurcERy.—A second suggestion, which
goes a step further than the first, is that we should
take more thought for the morrow by deliberately
pruning our stock of its diseased buds, especially
of those who, if they survive, will be miserable
themselves and a cause of misery to others.

Nietsche had the courage to say what many feel,
that it would be a kindness to suppress a good many
of us. There is no doubt about that, but would
it be a permissible kindness? ‘Who is sufficient
for these things? It is one thing to discourage
in every feasible way—compatible with rational
social sentiment—the breeding of weaklings by
weaklings; it is another thing to look a fellow
creature in the eyes and say, “ You must die.”
Remove weaklings, forsooth! read over the roll of

220 DARWINISM AND HUMAN LIFE

them first; might they not say, “ Yet we are
the movers and shakers of the world for ever, it
seems 7’ ?

Perhaps the time may come when the noblest
social sentiment and a maturer science will agree
that this bud and that should not be allowed to
open; but the time is not yet. The biologist dis-
trusts social surgery because of his ignorance ;
the sociologist rejects it because the thought of it
makes the foundations of society tremble, and
because the social ideal of good citizens is wider
than the ideal of good physique ; and the practical
man will not hear of it because he knows that it
is not in us to practise it. Even if the way
were clear, it would be like destroying fruits and
leaving roots, and securing a fictitious comfort by
an entirely artificial method of disowning our
social liabilities.

Is SociaL SELECTION COMPENSATING FOR THE
Diminution oF NaturaL SELection ?—A third
suggestion leads us nearer practicable tactics, for
it raises an inquiry into the modes of selection
which are at present in operation in human societies.
How do these compare with natural selection, and
how far can they be trusted to effect the purgation
of the State ?

Whatever form natural selection may take—
and it has a thousand—this is always true about
it, that the eliminated are eliminated because of
some defect in or pertaining to them, “the unlit
lamp and the ungirt loin ” in some form, and that
the survivors survive because of some relatively
advantageous quality in or pertaining to them.
But there are many selective processes in human
society which depend on something else than the

lee, cee ee

SELECTION: ORGANIC AND SOCIAL 221

inherent bodily or mental quality of those selected.
Let us consider some illustrations of these.

A German Professor, writing of the enormous
mortality of children in large towns, says that all
those young lives must pass out because there is
no place laid for them at Nature’s great table:
“Natural selection, don’t you know.” But the
hideous mortality in question has almost nothing
to do with Nature’s great table or with natural
selection. Howcan one tell? The statistics show,
to some extent, what the children die of, and it is,
to a large extent, of their parents! For some
large towns the deaths of infants have been care-
fully classified, not only as to the cause of death,
but in reference to what the parents do or do not
do; the mortality is double in some classes what it
is in others; and this seems certain, that in many
cases the selection is not related to the physique
of those eliminated. The selection depends, in
great part, on the parental standard of comfort and
standard of character.

But, it may be said, if there is a differential death-
rate, a larger infant-mortality in the less thrifty
families, will that not work out right in the long
run, since their elimination implies a sifting out of
the hereditarily thriftless types? The answer is
that, along with the greater mortality, there is
associated a greater fecundity, so that the sifting
is partially counteracted ; moreover, it is not to
be supposed that the less thrifty families with high
infant mortality are to be thought of as necessarily
undesirables; much of the thriftlessness is as
artificial as much of the mortality is unnecessary.

Take another instance, which may serve to bring
out the difference in method and results between

222 DARWINISM AND HUMAN LIFE

social selection and natural selection. In some
countries there are posts as foresters and police
which are filled by picked men, often by very
desirable types physically, mentally, and morally.
Here, then, is the setting up of a standard and a
rejection of the unfit ; and, of course, it works in the
right direction. But it is easy to see that it differs
from what goes on in nature, and that the issues are
complicated. For instance, as a German writer
points out, the ineligible were also ineligible for
military service. There are no disadvantageous
consequences of this; the rejected are spared time
and money, they can marry earlier, and so on.

The stress of competition exercises a certain
selective influence, but how differently it works
from natural selection! It does not necessarily
make for the elimination of the unsuccessful; it
shifts him. It may compel him into an occupation
where his chances of death are lessened. If he is
driven out of regular employment altogether, he
passes into ranks with a high death-rate, but even
then natural selection does not work, for he usually
has a large family in the meantime. Thus we see
that many processes of differential elimination in
human societies turn out, on close inspection, to ~
be very different from natural selection, and this
is our whole point at present—that these processes
of social selection cannot be trusted, and that
nothing is more absurd than to murmur “ Survival
of the fittest ’—since that is precisely what is not
happening either in the Darwinian sense or in any
other.

REVERSED SELECTION IN Human Society.—
Those who are unfamiliar with the biological point
of view seem to find it difficult to bear in mind

SELECTION: ORGANIC AND SOCIAL 223

that organisms may evolve “ downwards ” as well
as “upwards” in becoming fitter to given con-
ditions. By “ upwards ” is meant in the direction
of a more differentiated and integrated organisa-
tion—a more complex and controlled constitution—
and we have a habit of regarding ourselves as being
very much “up.” Now, while it is true that the
general trend of evolution throughout the ages has
been “upwards,” we must not forget that the
tapeworm has been evolved as truly as the golden
eagle, the one in a dark bypath, the other on the
mountain-tops, both well adapted to their con-
ditions of life.

The term “reversed selection” has been applied
to cases where, under altered conditions, organisms
seem to have gone “‘ downwards,” but the term is
unfortunate. If by selection a race is becoming
better adapted to the conditions of its life, it is
to the cold-blooded scientific onlooker immaterial
whether the direction of the race-movement is
up or down. It is evolution all the same. Con-
sidering the movement in relation to a standard,
however, we may say that some selective pro-
cesses make for progress along the lines which
have marked the general trend of evolution—
greater complexity, greater control, a fuller, freer
life—and that other selective processes make for
change in the opposite direction.

Our question now is, are there in human society
selective processes at work which make for de-
generacy ? We all know the difficulty of answering
this question, because social processes are so com-
plex and many-sided. Even when. the social
selection is in part wrong we cannot always stop
it. Civilisation is a long-drawn-out compromise.

224 DARWINISM AND HUMAN LIFE

In illustration, let us briefly consider the bio-
logical aspect of prolonged wars. In his “ Human
Harvest ” President Jordan tells of a man more
strenuous than wise, who possessed a stud of
horses, which he would make more strong and fleet.
“So he rode them swiftly with all his might,
day and night, always on the course, always
pushed to the utmost, leaving only the dull and
sluggish to remain in the stalls. For it was his
dream to fill these horses with the spirit of action,
with the glory of swift motion, that this glory
might be carried on and on to the last generation
of horses. There were some who could not keep
the pace, and to these, and these alone, he assigned
the burden of bearing colts. And the feeble and
broken, the dull of wit, the coarse of limb, became
each year the mothers of the colts.... For a
time whip and spur made good the lack of native
movement ...; but the current of life ran steadily
downward. Each generation yielded weaker colts,
rougher, duller, clumsier colts, and no amount of
training or lash or spur made any permanent
difference for the better. The horse-harvest was
bad. Thoroughbred and race-horse gave place
to common beasts, for in the removal of the noble
the ignoble always finds its opportunity. It is
always the horse that remains which determines
the future of the stud. In like fashion, from the
man who is left flows the current of human history.”

Let us observe how Jordan works out his thesis
in relation to man. “In the conquests of Rome,
Vir, the real man, went forth to battle and to the
work of foreign invasion ; Homo, the human being,
remained in the farm and the workshop and begat
the new generation.” Prof. Seeck, one of the

SELECTION: ORGANIC AND SOCIAL 225

historians of the downfall of the ancient world,
says that it was due mainly to “ the rooting out of
the best.” “Only cowards remained, and from
their brood came forward the new generations.”
“Wars are not paid for in war times,” Franklin
said; “the bill comes later.” “The Roman
Empire,” says Seeley, “ perished for want of men.”
There were plenty of people—“ people with too
much guano in their composition,” as Emerson
said ; but even Julius Caesar noted that men were
becoming terribly scarce. Prof. Bury writes: ‘‘ The
effect of the wars was that the ranks of the small
farmers were decimated, while the number of
slaves who did not serve in the army multiplied.”
The German historian goes on: “ Out of every
hundred thousand strong men, eighty thousand
were slain. Out of every hundred thousand
weaklings, ninety to ninety-five thousand were
left to survive.”

But all that was long ago. So we take up
Jordan’s “ Human Harvest” again, and turn to
France—to France, ever young and splendid in
spirit. But the birth-rate continues steadily to
fall; the average stature is lower by two inches
than it was a century ago; and, as with ourselves,
there are other disquieting symptoms. These are
doubtless due to a variety of co-operating causes,
but can we exclude what one of themselves has
said, that “it will take long periods of peace and
plenty before France can recover the tall statures
mowed down in the wars of the republic and the
first empire ”’ ?

Year after year Napoleon seized the youth of
good stature, and left their bones in great heaps
throughout Europe. “ You can always fill the

15

226 DARWINISM AND HUMAN LIFE

places of soldiers,” he said; but he had eventually
to be content with boys. “The mighty swirl of
the Moscow campaign sucked in 150,000 lads of
under twenty years of age into the devouring
vortex”; out of 600,000 who crossed the Niemen
to conquer Russia, 20,000 famished, frost-bitten
spectres staggered back. It was the rapid suc-
cession of skimmings that told. “In less than
half a year after the loss of half a million men a
new army, nearly as numerous, was forthcoming
and the grim roll-call of wasted men, many of
them wasted heroes—about half of whom were
French—amounted, according to some, to three
millions.” It is true that glorious France survived
all this bleeding, but how impoverished, qualita-
tively as well as quantitatively! and even a great
life-saver like Pasteur could not restore the cubit
of stature which the great life-destroyer had
lopped off.

We admit that wars have been necessary and
righteous—especially necessary—and that they
may be so still, but this opinion does not affect the
fact that prolonged war in which a nation takes
part is bound to impoverish the breed, since the.
character of the breed always depends on the men
who are left. How else can we understand what
has happened so often, that an older civilisation

1 While I plead guilty to disbelief in the biological value of
modern war, I do not think this is inconsistent with an appreciation
of the soldier’s qualities. Who does not admire what Mr. Sandeman
describes in his “Uncle Gregory”? (1909) . . . “That quite un-
mistakable note that you get in a very few people who, in one way
or another, have actually accepted death, and are only, so to speak,
alive in the meantime. It belongs to the flawless perfection of the
military spirit, with its entire detachment from life itself, from self-
will, from fear, and from ease, and from all pretences.”

SELECTION: ORGANIC AND SOCIAL 227

is overthrown by another less evolved ? The only
thing a nation dies of is lack of men: and is
there not disquieting evidence of the increase of
incapables ? It is said that we cannot relax one
spine of our national belligerence, since we must,
at all costs, uphold our national supremacy, having
all these teeming millions to feed. But is this not,
in part at least, a vicious circle? The question
arises whether it is not in great part preoccupation
with militarism that is responsible for keeping up
our national misery. With a little money saved
off belligerence, what might not be done towards
social improvement !

An end, then, to the courage and the daring and
the chivalry which war has ever kept alive! But
can any one seriously believe this? The story of
the exploration and conquest of earth and sea is
full of heroes, whose work was constructive, not
destructive. The man who has grit enough to
bring about the afforestation er the irrigation of
a country is not less worthy of honour than its
conqueror.

SumMaRY oF THE ARGUMENT.—In early days
there was a keen struggle for existence with the
forces of nature, with wild beasts, and between
fellow-men. There was much natural selection.
Gradually the venue changed, there has been a
persistent emancipation from the yoke of natural
selection, and among civilised peoples it has now
but little sway. This exposes our race to the
gravest risks of retrogression. To obviate this,
some suggest that we should return in part to the
old regime; other advise the practice of some
social surgery ; but neither of these suggestions is
feasible—for general tactics at least. It is also

228 DARWINISM AND HUMAN LIFE

suggested that there are many forms of social
selection in operation which take the place of
natural selection ; but inquiry—here very super-
ficial—shows that these forms of social selection
do not work out as natural selection does, and
that some of them have results which are, from
the biological point of view, retrogressive.

Constructive Sucaustions.—As we are here
mainly concerned with getting the biology of the
problem clear, we cannot do more than hint at
the general policy of betterment. In general,
it cannot be other than this—to adhere to and
increase those forms of selection which make for
the survival of beautiful and healthful surround-
ings, educative and wholesome occupations, sane
and progressive men and women. The first ideal
has been called that of Kutopias, the second that
of Eutechnics, the third that of Eugenics.1 They
obviously correspond to the three fundamental
categories of biology: Environment, Function,
and Organism.

SELEcTION or HKurorias.—Possessed by certain
enthusiasms or illusions, a man may gladly live—
and perhaps more gladly die—on a cinder-heap ;
and there is a local patriotism which throws a
halo round any home. But deep down in every
healthy human being, rooted perhaps in a once
closer contact._with nature, there is a love of
the fresh air, the clean earth, the running brook,
the waving trees, the singing birds—a beautiful
place, in short, such as even a garden city might
afford.

The biological importance of living in beautiful

1 The first two by Prof. Patrick Geddes, the third by Sir Francis
Galton,

SELECTION: ORGANIC AND SOCIAL 229

surroundings is inestimable. It makes for health
of body and brain ; it awakens long-dormant buds ;
it fills up the life with wholesome delights; it pro-
duces pleasant modifications on the individual; and
who can tell how its potent messages may travel
by “the wireless telegraphy of ante-natal life” ?

All this is familiar, yet are we not slow to adopt
a resolute policy of securing one of the really good
things in life—a EHutopia? Every one knows that
this is no Utopia, if we can only make up our
minds to live more in the present and less in the
future.

SeLection or HeattHruy Occupations.—With-
in the hands of all men of good-will there is
a powerful instrument of progress, technically
known as “the criticism of consumption.” It is
one of the most effective factors in amelioration,
especially as regards the selection of healthful
occupations. Perhaps more might be made of it
if the strategy involved was more generally recog-
nised. When we discover that certain articles
are socially injurious, bad for the maker, bad for
the buyer, we should not buy them, but get instead
something which it was good for a man to make,
and good for us to have. Now, if we do this
consistently and keep at it unwaveringly, and
get others to do the same, we will, if we keep
the selection a-going long enough, often enough,
stringently enough, put an end to an ugly article
and an injurious occupation. The process is never
quick enough to be unjust or cruel, as the swings
of fashion often are. Apply this consistent selec-
tion to favouring wholesome people, not wasters,
constructive occupations, not destructive ones,
beautiful places, not ugly ones—and we have

230 DARWINISM AND HUMAN LIFE

returned to Nature’s method on a higher turn of
the spiral. Even natural selection would favour
the survival of qualities like healthfulness; it is
for a rational social selection to continue the
endless task.

EKucenic SELEcTIon.—The third aspect of the
biological ideal towards which it is necessary to
select is the improvement of the human breed—
the ideal of eugenics. There is perhaps no nobler
enthusiasm, and while some of the enthusiasts are
occasionally carried away by their zeal, we must
not reject the quiet wisdom of a veteran general
like Sir Francis Galton, because of the extravagant
utterances of subalterns. But, apart from subal-
terns, it is not easy for even expert students pos-
sessed by a worthy enthusiasm to keep the complex
issues in perspective. Illustrations may be found,
for instance, in the excellent exposition of the
eugenist argument which Dr. Saleeby has given us
in his “ Parenthood and Race-Culture ” (1909).
“ The idea of selection for parenthood as determining
the nature, fate, and worth of living races is Darwin’s
chief contribution to thought, and finds in eugenics
its supreme application.”

“The question is not whether a given proposal
is socialistic, individualistic, or anything else, but
whether it is eugenic. If it is eugenic, that is final.
To this all parties will come, and by this all parties
will be judged. . . . I claim for eugenics that it is
the final and only judge of all proposals, and
principles, however labelled, new or old, orthodox
or heterodox.” This is forcibly put, but it illus-
trates the difficulty of appreciating the complexity
of the human situation. The -eugenic ideal is
the breeder’s ideal—vigorous organisms, and the

SELECTION: ORGANIC AND SOCIAL 231

eugenist’s method is the breeder’s method—
selection for parenthood; but the difficulty is that
we have to deal with larger ends than men, we
cannot ignore the social framework and a whole
hierarchy of social integrates. Even if we ignore
them in theory, they will be too strong for us in
practice. The eugenic programme must submit
to social criticism, which will not be merely
theoretical.

Let us recall some of the facts which bring the
importance of the eugenic ideal home to us. One
quarter of the married people of this country,
one-sixth to one-eighth of the total adult popula-
tion, Prof. Karl Pearson tells us, produce 50 per
cent. of the next generation. “ How essential it
is for the maintenance of a physically and mentally
fit race that this one-sixth to one-eighth of our
population should be drawn from the best, not the
worst stocks!” “We cannot recruit the nation
from its inferior stocks without deteriorating our
national character.” This is the argument which
Pearson so powerfully develops.

Of course the statistics of diminishing birth-rate
require careful treatment by experts. The average
annual birth-rate per 1,000 has fallen from 35°35
in 1876-80 to 28°10 in 1901-1905, but against this
we must notice that the death-rate has also fallen
from 20°79 to 16. The ominous fact is that it
was by a gradual but persistent diminution of
natality that France reached her present state of
a death-rate in excess of the birth-rate.

Yet Prof. Pearson’s point is not so much the
general diminution, but the differential diminution.
In Britain the diminution seems greatest where
it is least wanted, namely, among the workers of

232 DARWINISM AND HUMAN LIFE

the community and among the more far-seeing
and provident classes. French statistics show
that the birth-rate is less in proportion to the
standard of comfort. At present the birth-rate in
France is said to be below the death-rate in all
sections except manufacturing centres. Among
academically educated Americans the average
number of offspring is less than two.

There seems no doubt as to the ominously rapid
multiplication of the relatively unfit. ‘‘ Degener-
ate stocks under present social conditions are not
short-lived ; they live to have more than the normal
size of family.”” They have at present a better
chance to survive and multiply than ever before.
Especially in Britain do the weeds spread quicker
than the flowers. The feeble-minded are prolific ;
certain kinds of degenerates are prolific; the
thriftless are prolific. From a study of 150 de-
generate families, Dr. Tredgold found that the
average number of children in a family was 7°3,
not including those still-born, instead of the normal
average of four.

Let us be as generous as we can. An unpro-
mising bud may burst into a fine flower: John
Bunyan’s father was a tinker. But every one is
agreed that there should be no breeding from
epileptics, lunatics, paralytics; should not this
list be added to?: Is it not a pity, for instance,

1 In his Robert Boyle Lecture on “‘ The Scope and Importance
to the State of the Science of National Eugenics” (2nd ed., 1909)
Prof. Karl Pearson says: “If we realise the antinomy which
Eugenics brings to our notice between high civilisation and racial
purgation, we ask: How can the dominant fertility of the fitter
social stocks be maintained when natural selection has been sus-
pended ? I do not think any wise man would be prepared with a
full answer to this question to-day. There is no sovereign remedy

a a

SELECTION: ORGANIC AND SOCIAL 233

that we should look with favour on the marriage
of deaf-mutes? Let us admit that many of the
unfit may be only modificationally unfit—ill-
nourished plants in the crowded garden—requiring
only new soil. Many criminals are simply ana-
chronisms—people out of time and out of place—
who need, not incarceration, but transplantation.
Cure the poacher by making him a collector. But
this will not cover all. .

Let us admit, too, that very bad stock—such
as the uncontrolled alcoholic type—tends to work
itself out. Taints may be swamped, just as ex-
cellences often are.

Prof. Biffen has bred into a good stock of
corn the quality of immunity to rust which a
poor stock had, and perhaps—perhaps—the
future has in store for us analogous ways of
getting a clean thing out of an unclean in human
kind.

Meanwhile, what is to be done? Many gentle
measures are possible—fostering pride of race,
encouraging the marriage of desirables, developing
for degeneracy. Every method is curative which tends to decrease
the fertility of the unfit and to emphasise that of the fit. We may
find it difficult to define the socially fit, although physique and
ability will carry us far ; but when we turn to the habitual criminal,
the professional tramp, the tuberculous, the insane, the mentally
defective, the alcoholic, the diseased from birth or from excess,
there can be little doubt of their social unfitness. Here every
remedy which tends to separate them from the community, every
segregation which reduces their chances of parentage, is worthy of
consideration. . . . Is not something more to be insisted upon with
regard to the increase of good stock? . . . A clean body, a sound
if slow mind, a vigorous and healthy stock, a numerous progeny—
these factors were largely representative of the typical Englishman
of the past ; and we see to-day that one and all these characteristics
can be defended on scientific grounds ; they are the essentials of an

imperial race,”

234 DARWINISM AND HUMAN LIFE

prejudice against the marriage of undesirables,
fuller recognition of woman’s rights, both as to
mating and maternity. For another step we shall
soon be ready—a form of rational social selection
—the institution of a sort of marriage test and some
attempt to prevent the multiplication of those who,
by their own inefficiency, have fallen back on the
community for support.

Social sentiment will not permit social surgery,
which is probably just as well; but we cannot be
proud of our tender-heartedness when we reflect
on what we do permit in the way of slow murder
in the present and in the way of keeping up misery
for the future.

In this connection Mr. Whetham writes:
“When we have built and endowed schools and
hospitals, pulled down insanitary dwellings and
thrown open green spaces, brought in fresh water
and uncontaminated milk, vaccinated babies and
destroyed tuberculous cows, when we have estab-
lished a cult of fresh air, a whole science of nature-
study, and the paraphernalia of the simple life—
we are brought up sharp against a stone wall. We
are informed that our unemployed are chiefly
unemployable, that the provision of more lunatic
asylums is of greater urgency than the provision
of increased school accommodation, that a whole
class of feeble-minded individuals has grown up
and is totally unprovided for, that ability is more
difficult to find and mediocrity shows no tendency
to rise, that general physical deterioration may
be knocking at our doors—in short, in spite of all
our efforts, matters are conceivably worse than
when we started, and an uncomfortable feeling
comes that “in spite of ” might possibly be more

SELECTION: ORGANIC AND SOCIAL 235

ce

correctly written “on account of.”* Unless we
are prepared to do nothing, saying with Sir Boyle
Roche, “ What has posterity done for us?” then we
must try “ to replace Nature’s selective death-rate
by a selective birth-rate.”*? In any case, we can
share in forming public opinion.

Whymper, in his “Scrambles among the Alps,”
says some forcible things about the marriage—the
Church marriage—of cretins who swarm in the
valley of Aosta and elsewhere. For many genera-
tions the strongest and healthiest peasants had to
go to the wars; the idiotic and goitrous were left.
The disease may not be in itself hereditary, but
susceptibility to it is; and in one village it was
said that all had a goitre except the young priest.
In any case the cretins of Aosta thrive and multiply,
and the consummation of the tragedy is that the
Church solemnises their union. At one end we
have the celibacy of the clergy—often remarkably
fine peasant thinkers and dreamers—and the
celibacy of the most gentle and spiritual women—
a segregation from the race of some of its finest
types—at the other end the blessing of the goitrous
pair. Which things are a parable.

Some sneer at eugenics as obtruding into the
sanctity of human relationships the counsels of
the farm-yard; but reflection will show that the
sanctity is heightened, not lessened, when the
solemn issues are realised.

It is likewise quite certain that, whether we

1 “Tnheritance and Sociology,” by W. C. D. Whetham, in The
Nineteenth Century and After (No. 363, Jan. 1909), pp. 74-90.

2 Saleeby, “‘ Parenthood and Race Culture” (1909).

3 Of course one hopes it has been changed in the last few years.

It was true quite lately.

236 DARWINISM AND HUMAN LIFE

have celibate fellowships at the colleges, or adver-
tise for a gardener “ without encumbrances,” or
dismiss women teachers on marriage, or refrain
from marrying till we have ten times the income
our father had when he begat us—the list can be
continued ad nauseam—we are ignoring the funda-
mental laws of good breeding or eugenics, just as
we are when we refrain from condemning the
marriage of the feeble-minded or from protesting
against certain charitable devices which create
more misery than they relieve.

By way of illustration, let us think for a moment
of China—a country of extraordinary interest
to the biologist. It has kept up a continuity of
state organisation and culture for four thousand
years ; the people have big brains and marvellous
physique; they are very fertile, the aristocracy
not less than the unlearned; they have genuine
old families, gomg back to Confucius, and not
decadent; they are in many ways very moral;
and so on.

Now there are many reasons for all this, but
two strike the biologist: (1) To an extent quite
impossible for us, the Chinese allow natural selec-
tion in famine and disease, etc., to go on with-
out hindrance. Here we cannot imitate them.
(2) For thousands of years, on the other hand,
the Chinese have paid great attention to breeding,
to family histories, to family life, to family feeling,
and honour of ancestry. Ages ago they used to
send a policeman to eligible bachelors with a notice
to marry. In their positive eugenic practices the
Chinese are worthy of our imitation.

And what is the conclusion of all this talk 2
Nothing new. More and more our human societies

SELECTION: ORGANIC AND SOCIAL 237

free themselves from natural selection, and it
behoves us to make sure that some rational
winnowing takes the place of the automatic
process of nature. There are many processes of
social selection going on, some for evil and some
for good. They require to be sternly criticised,
especially as those that are for good do not seem
to be getting any grip of the organic qualities of
the breed.

We must take more thought of the improve-
ment of our breed, not only for its own sake—
for healthfulness is as fundamental as virtue is
supreme—but also lest we become involved in
some terrible inter-societary struggle and find—
like Samson—when we arise and go out and
shake ourselves, as at other times before, that
our strength has gone from us in our sleep.

REPRESENTATIVE BOOKS ON
DARWINISM

239

' REPRESENTATIVE BOOKS ON DARWINISM

CHAPTER I

ALLEN, Grant: “Charles Darwin.” 3rd Edition. London, 1886.

Bzrtany, G. T.: “Charles Darwin.” London, 1886.

Boutier, Samuren: “Evolution: Old and New.” 2nd Edition.
London, 1882.

Darwin, Caries: “ His Life told in an Autobiographical Chapter,
and in a Selected Series of his Published Letters.” Edited
by his son, Francis Darwin. London, 1902.

—— “Life and Letters.” Edited by his son, Francis Darwin
3 vols. London, 1887.

—— “More Letters of Charles Darwin.” Edited by Francis
Darwin and A. C. Seward. 2 vols. London, 1903.

“The Darwin-Wallace Celebration.” Linnean Society of London,
1908.

Drizscu, Hans: “Science and Philosophy of the Organism.”
2 vols. London, 1908.

France, R. H.. “Der heutige Stand der Darwinschen Fragen.”
Leipzig, 1907.

Haxcxet, Ernst: “Generelle Morphologie.” 2 vols. Berlin,
1866.

— “Natural History of Creation.” London, 1879. 9th German
Edition. Berlin, 1898.

Harrmany, E. von: “ Wahrheit und Irrthum im Darwinismus.”

' Jena, 1892.

Hover, C. F.: “Charles Darwin: His Life and Work.” New
York, 1891.

Kettoae, V. L.: “ Darwinism To-day.” Holt: New York, 1907.

Looy, W. A.: “ Biology and its Makers.” New York, 1908.

Lotsy, J. P.: “ Vorlesungen iiber Descendenz-theorien.” 2 vols.
Fischer: Jena, 1906.

MarsHaut, A. Miznzs: “Lectures on the Darwinian Theory.”
Nutt: London, 1894.

Ossorn, H. F.: “From the Greeks to Darwin.” Macmillan Co, :
New York, 1895.

241 16

242 REPRESENTATIVE BOOKS ON DARWINISM

Pauty, A.: ‘“ Wahres und Falsches an Darwin’s Lehre.” Rein-
hardt: Miinchen, 1902.

Romanszs, G. J.: ‘ Darwin and After Darwin.” 3 vols. London,
1892-7.

Scunemerr, K. C.: “Einfiihrung in die Descendenz-theorie.”
Fischer: Jena, 1906.

Srrpirrz, G.: “Die Darwinsche Theorie.” 2nd Edition. Leipzig,
1875.

Srwarp, A. C. (Editor): “Darwin and Modern Science.” Cam-
bridge, 1909.

Watwacz, ALFRED RussEL: “ Darwinism.” Macmillan: London,
1889. /

Wicanp, A.: “Der Darwinismus und die Naturforschung Newtons
und Cuviers.”” 3 vols. Braunschweig, 1874-7.

Zincter, H. E.: “ Ueber den derzeitigen Stand der Descendenzlehre
in der Zoologie.” Fischer: Jena, 1902.

CHAPTER I

Batus, H. W.: “'The Naturalist on the Amazons.” 5th Edition.
London, 1884.

Darwin, Cuartes: “ The Formation of Vegetable Mould through
the Action of Worms.” “‘Insectivorous Plants.” ‘“‘ Na-
turalist’s Voyage.” “Origin of Species.”

Ferritze, Eun: “Le Darwinisme.” Alcan, Paris.

Gaye, Sztmva: “The Great World’s Farm.”’ Seeley: London, 1893.

GrpprEs, Parriok: ‘Chapters in Modern Botany.” Murray:
London, 1893.

Jorpan, D. 8., and Kenioae, V. L.: “Evolution and Animal
Life.” New York, 1907.

Kerver: “Natural History of Plants.” Vol. i.

Mitizr, Hermann: “ Fertilisation of Flowers.” London, 1883.

Srzrne, Canus: “ Werden und Vergehen.” 3rd Edition. Berlin,
1886.

Tyomson, J. ArntHuR: “The Study of Animal Life.” Murray:
London, 1890

Watiace, A. R.: “Island Life.” London, 1880.

Warts, Ginpert: “ Natural History of Selborne.” 1788,

CHAPTER III

Battey, L. H.: “The Survival of the Unlike.” London, 1896.
Coz, C. C.: “Nature versus Natural Selection.” London, 1898.
Corz, E. D.; ‘* The Origin of the Fittest.” London, 1887,

REPRESENTATIVE BOOKS ON DARWINISM 243

Darwin, Cuartes: “Origin of Species.” “ Climbing Plants.”
** Power of Movement in Plants.”

Espinas, A.: “ Des Sociétés Animales.” Paris, 1877.

Grrop, P.: ‘Les Sociétés chez les Animaux.” Paris, 1890.

Groos, R.: ‘‘ The Play of Animals.” London, 1900.

Heaptey, F. W.: “ Life and Evolution.”

—— “Problems of Evolution.” Duckworth: London, 1900.

Huxiey, T. H.: “The Struggle for Existence.” Collected Essays.

Kropotriy, P.: “Mutual Aid a Factor of Evolution.” Heine-
mann: London, 1902.

Watacg, A. R.: “ Darwinism.” London, 1889,

CHAPTER IV
VARIATIONS, MUTATIONS, ETC.

Bary, L. H.: “Plant-breeding.” 3rd Edition. New York,
1904.

“Batzson, W.: “Materials for the Study of Variation.” Mac-
millan: London, 1894.

Bercson, H.: “ L’Evolution Créatrice.” Paris, 1907.

Corz, E. D.: “The Primary Factors of Organic Evolution.”
Chicago, 1896.

Darwin, CHartEs: “Variation of Animals and Plants under
Domestication.” Murray: London, 1868.

Ermer, G. H. Th.: ‘ Organic Evolution.” Trans., London, 1890.

Grppss, P., and THomson, J. ArTHUR: “The Evolution of Sex.”
“Contemp. Sci. Ser.” Scott: London, 1889.

Loox, R. H.: “ Recent Progress in the Study of Variation, Heredity,
and Evolution.” Murray: London, 1908.

Morean, T. H.: “Experimental Zoology.” Macmillan Co.:
New York, 1907.

Naeeur, C. von: “ Mechanisch-physiologische Theorie der Abstam-
mungslehre.” Miinchen, 1884.

Semprr, K.: “The Natural Conditions of Existeece as they
affect Animal Life.” Kegan Paul: London, 1881.

Varniany, H. pu: “Experimental Evolution.” Macmillan:
London, 1892.

Vernon, H. M.: “ Variation in Animals and Plants.” ‘Internat.
Sci. Ser.” Kegan Paul: London, 1903.

Vzizs, H. pe: “Die Mutations-theorie.” 2 vols. Veit: Leipzig,
1901, 1903.

—— “Species and Varieties, their Origin by Mutation.” Chicago‘
1905. :

ZizGcLER, H. E.: “ Ueber den derzeitigen Stand der Descendenzlehre
in der Zoologie.” Fischer: Jena, 1902.

16*

244 REPRESENTATIVE BOOKS ON DARWINISM

CHAPTER V
HEREDITY
Batrson, W.: ‘“Mendel’s Principles of Heredity.” Cambridge,
1909.
—— ‘“ The Methods and Scope of Genetics.” Cambridge, 1908.
Brooks, W. K.: ‘“‘ The Foundations of Zoology.” Macmillan Co.:
New York, 1898.
Corr, E. D.: “The Primary Factors of Organic Evolution.”
Chicago, 1896. '
Correns, C.: ‘‘ Ueber Vererbungsgesetze.” Borntriger: Berlin,
1905.
Darwin, Cuartes: “Variation of Animals and Plants under
Domestication.” Murray: London, 1868.
Deruace, Yves: “ L’hérédité.” 2nd Edition. Paris, 1903.
Ewart, J. C.: “The Penycuik Experiments.” Edinburgh, 1899.
Gatton, Francis: ‘ Natural Inheritance.” Macmillan: London,

1889.

Giarp, A.: ‘“‘Controverses Transformistes.” Naud: Paris,
1904.

Hutton, F. W.: “Darwinism and Lamarckism.” London,
1899. :

Morean, C. Luoyp: ‘‘ Habit and Instinct.”’ Arnold: London,
1896.

Pauty, A.: ‘“Darwinismus und Lamarckismus.” Reinhardt:

Miinchen, 1905.

Punnett, R. C.: “Mendelism.” Cambridge. 2nd Edition,
1905.

Rew, G. AncHDaLL: “ Principles of Heredity.” Chapman & Hall:
London, 1905.

Rienano, E.: “ Ueber die Vererbung erworbener Higenschaften.”
Engelmann: Leipzig, 1907

Semon, R.: “ Die Mneme als erhaltendes Princip im Wechse des
Organischen Geschehens.” Engelmann: Leipzig, 1904.

Spencer, Hersert: “Principles of Biology.’ Williams & Nor-
gate: London, 1866-8. 2 vols. Revised Edition, 1898.

Tuomson, J. Antuur: “ Heredity.” Murray: London, 1908.

Weismann, Aucust: “The Germ-plasm.” ‘Contemp. Sci. Ser.”
Scott: London, 1893.

—— ‘‘Essays on Heredity and Kindred Subjects.” Oxford,
1891-2.

Witson, E. B.: “The Cell in Development and in Inheritance.’
2nd Edition. Macmillan: London, 1900.

ZizGier, H. E.: “ Die Vererbungslehre in der Biologie.”” Fischer :
Jena, 1905.

REPRESENTATIVE BOOKS ON DARWINISM 245

CHAPTER VI
SELECTION, ORGANIC AND SOCIAL

Ammon, O.: ‘ Die natiirliche Auslese beim Menschen.” Fischer:
Jena, 1893.

—— “Der Abanderungsspielraum.” Diimmler: Berlin, 1896.

Batpwin, J. Marx: “ Development and Evolution.” New York.
1902.

Coz, C. C.: “Nature versus Natural Selection.” London, 1895.

Darwin, CHARLES: “ Origin of Species.” Murray: London, 1859.

—— “Descent of Man.” Murray: London, 1871.

Gutick, J. T.: “ Evolution, Racial and Habitudinal.” Washing-
ton, 1905.

Heaptey, F. W.: ‘Life and Evolution.” ‘ Problems of Evolu-
tion.”” London, 1900.

Jorpan, D. 8.: “Footnotes to Evolution.” New York, 1898.

—— “The Human Harvest.” Boston, 1907.

LanxesteR, E. Ray: “ The Kingdom of Man.” London, 1907.

McDovaatt, W.: “An Introduction to Social Psychology.”
London, 1908.

Moraan, T. H.: “Evolution and Adaptation.” Macmillan Co.:
New York, 1903.

Prarson, Karu: ‘The Chances of Death.” 2 vols. Amold:
London, 1897. ‘‘ The Grammar of Science.” 2nd Edition.
Black: London, 1900. ‘‘ National Life from the Stand-
point of Science”’: London, 1901.

Pirate, L.: ‘“Selektionsprinzip und Probleme der Artbildung.
Ein Handbuch des Darwinismus.” 3rd Edition. Engel-
mann: Leipzig, 1908.

Povutron, E B.: ‘Charles Darwin and the Theory of Natural
Selection.” London, 1896. “Essays on Evolution.”
London, 1908.

Sauezsy, C. W.: “Parenthood and Race Culture.” London, 1909.

Spmncer, Herpert: “The Inadequacy of Natural Selection.”
London, 1893.

Watuiace, ALFRED Russet: “Contributions to the Theory of
Natural Selection.”” Macmillan: London, 1890.
Weismann, Avaust: “The Evolution Theory.” 2 vols. Arnold:

London, 1904.

Wo rr, E.: “ Beitrige zur Kritik der Darwinschen Lehre.” Leip-

zig, 1898.

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