No More Learning

She often used exaggerated language, and when I quizzed
her by exaggerating what she had said, how clearly can I now
see the little toss of the head, and exclamation of "Oh, papa,
what a shame of you! " In the last short illness, her conduct in
simple truth was angelic. She never once complained; never
became fretful; was ever considerate of others, and was thankful
in the most gentle, pathetic manner for everything done for her.
When so exhausted that she could hardly speak, she praised
everything that was given her, and said some tea "was beauti-
fully good. " When I gave her some water she said, "I quite
thank you;" and these I believe were the last precious words ever
addressed by her dear lips to me.
We have lost the joy of the household and the solace of our
old age.
She must have known how we loved her. Oh that she
could now know how deeply, how tenderly, we do still and shall
ever love her dear joyous face! Blessings on her!
April 30th, 1851.


## p. 4404 (#174) ###########################################

CHARLES ROBERT DARWIN
4404
.
RELIGIOUS VIEWS
From Life and Letters'
I
AM much engaged, an old man, and out of health, and I can-
not spare time to answer your questions fully,-nor indeed
can they be answered. Science has nothing to do with
Christ, except in so far as the habit of scientific research makes
a man cautious in admitting evidence. For myself, I do not
believe that there ever has been any revelation. As for a future
life, every man must judge for himself between conflicting vague
probabilities.
During these two years [October 1836 to January 1839] I was
led to think much about religion.
Whilst on board the Beagle I was quite orthodox, and I
remember being heartily laughed at by several of the officers
(though themselves orthodox) for quoting the Bible as an un-
answerable authority on some point of morality. I suppose it
was the novelty of the argument that amused them. But I had
gradually come by this time-i. e. , 1836 to 1839-to see that the
Old Testament was no more to be trusted than the sacred books
of the Hindoos. The question then continually rose before my
mind and would not be banished,—is it credible that if God
were now to make a revelation to the Hindoos, he would permit
it to be connected with the belief in Vishnu, Siva, etc. , as
Christianity is connected with the Old Testament? This appeared
to me utterly incredible.
By further reflecting that the clearest evidence would be
requisite to make any sane man believe in the miracles by which
Christianity is supported,-and that the more we know of the
fixed laws of nature the more incredible do miracles become,
that the men at that time were ignorant and credulous to a
degree almost incomprehensible by us,—that the Gospels cannot
be proved to have been written simultaneously with the events,
-that they differ in many important details, far too important,
as it seemed to me, to be admitted as the usual inaccuracies of
eye-witnesses; - by such reflections as these, which I give not as
having the least novelty or value, but as they influenced me,— I
gradually came to disbelieve in Christianity as a divine revela-
tion. The fact that many false religions have spread over large
portions of the earth like wild-fire had some weight with me.


## p. 4405 (#175) ###########################################

CHARLES ROBERT DARWIN
4405
But I was very unwilling to give up my belief; I feel sure
of this, for I can well remember often and often inventing day-
dreams of old letters between distinguished Romans, and manu-
scripts being discovered at Pompeii or elsewhere, which confirmed.
in the most striking manner all that was written in the Gospels.
But I found it more and more difficult, with free scope given to
my imagination, to invent evidence which would suffice to con-
vince me. Thus disbelief crept over me at a very slow rate,
but was at last complete. The rate was so slow that I felt no
distress.
Although I did not think much about the existence of a
personal God until a considerably later period of my life, I will
here give the vague conclusions to which I have been driven.
The old argument from design in Nature, as given by Paley,
which formerly seemed to me so conclusive, fails, now that
the law of natural selection has been discovered. We can no
longer argue that for instance the beautiful hinge of a bivalve
shell must have been made by an intelligent being, like the
hinge of a door by man. There seems to be no more design in
the variability of organic beings, and in the action of natural
selection, than in the course which the wind blows. But I have
discussed this subject at the end of my book on the 'Variations
of Domesticated Animals and Plants'; and the argument there
given has never, as far as I can see, been answered.
But passing over the endless beautiful adaptations which
we everywhere meet with, it may be asked, How can the gener-
ally beneficent arrangement of the world be accounted for?
Some writers indeed are so much impressed with the amount of
suffering in the world, that they doubt, if we look to all sen-
tient beings, whether there is more of misery or of happiness;
whether the world as a whole is a good or bad one. According
to my judgment happiness decidedly prevails, though this would
be very difficult to prove. If the truth of this conclusion be
granted, it harmonizes well with the effects which we might
expect from natural selection. If all the individuals of any
species were habitually to suffer to an extreme degree, they
would neglect to propagate their kind; but we have no reason to
believe that this has ever, or at least often, occurred. Some
other considerations moreover lead to the belief that all sen-
tient beings have been formed so as to enjoy, as a general rule,
happiness.


## p. 4406 (#176) ###########################################

4406
CHARLES ROBERT DARWIN
Every one who believes as I do, that all the corporeal and
mental organs (excepting those which are neither advantageous
nor disadvantageous to the possessor) of all beings have been
developed through natural selection, or the survival of the fittest,
together with use or habit, will admit that these organs have
been formed so that their possessors may compete successfully
with other beings, and thus increase in number. Now an animal
may be led to pursue that course of action which is most bene-
ficial to the species by suffering, such as pain, hunger, thirst,
and fear; or by pleasure, as in eating and drinking, and in the
propagation of the species, etc. ; or by both means combined, as
in the search for food. But pain or suffering of any kind, if
long continued, causes depression and lessens the power of action,
yet is well adapted to make a creature guard itself against any
great or sudden evil. Pleasurable sensations, on the other hand,
may be long continued without any depressing effect; on the
contrary, they stimulate the whole system to increased action.
Hence it has come to pass that most or all sentient beings
have been developed in such a manner, through natural selec-
tion, that pleasurable sensations serve as their habitual guides.
We see this in the pleasure from exertion, even occasionally from
great exertion of the body or mind,-in the pleasure of our
daily meals, and especially in the pleasure derived from sociabil-
ity, and from loving our families. The sum of such pleasures
as these, which are habitual or frequently recurrent, give, as I
can hardly doubt, to most sentient beings an excess of happi-
ness over misery, although many occasionally suffer much. Such
suffering is quite compatible with the belief in natural selec-
tion, which is not perfect in its action, but tends only to ren-
der each species as successful as possible in the battle for life.
with other species, in wonderfully complex and changing circum-
stances.
That there is much suffering in the world, no one disputes.
Some have attempted to explain this with reference to man by
imagining that it serves for his moral improvement. But the
number of men in the world is as nothing compared with that
of all other sentient beings, and they often suffer greatly with-
out any moral improvement. This very old argument from the
existence of suffering against the existence of an intelligent First
Cause seems to me a strong one; whereas, as just remarked,
the presence of much suffering agrees well with the view that


## p. 4407 (#177) ###########################################

CHARLES ROBERT DARWIN
4407
all organic beings have been developed through variation and
natural selection.
At the present day, the most usual argument for the exist-
ence of an intelligent God is drawn from the deep inward con-
viction and feelings which are experienced by most persons.
Formerly I was led by feelings such as those just referred to
(although I do not think that the religious sentiment was ever
strongly developed in me), to the firm conviction of the existence.
of God and of the immortality of the soul. In my Journal I
wrote that whilst standing in the midst of the grandeur of a
Brazilian forest, "it is not possible to give an adequate idea of
the higher feelings of wonder, admiration, and devotion, which
fill and elevate the mind. " I well remember my conviction that
there is more in man than the mere breath of his body. But
now the grandest scenes would not cause any such convictions
and feelings to rise in my mind. It may be truly said that I am
like a man who has become color-blind, and the universal belief
by men of the existence of redness makes my present loss of
perception of not the least value as evidence. This argument
would be a valid one if all men of all races had the same inward
conviction of the existence of one God; but we know that this
is very far from being the case. Therefore I cannot see that
such inward convictions and feelings are of any weight as evi-
dence of what really exists. The state of mind which grand
scenes formerly excited in me, and which was intimately con-
nected with a belief in God, did not essentially differ from that
which is often called the sense of sublimity; and however diffi-
cult it may be to explain the genesis of this sense, it can hardly
be advanced as an argument for the existence of God, any more
than the powerful though vague and similar feelings excited by
music.
With respect to immortality, nothing shows me [so clearly]
how strong and almost instinctive a belief it is, as the consid-
eration of the view now held by most physicists, namely, that
the sun with all the planets will in time grow too cold for life,
unless indeed some great body dashes into the sun, and thus
gives it fresh life. Believing as I do that man in the distant
future will be a far more perfect creature than he now is, it is
an intolerable thought that he and all other sentient beings
are doomed to complete annihilation after such long-continued
slow progress.
To those who fully admit the immortality of


## p. 4408 (#178) ###########################################

4408
CHARLES ROBERT DARWIN
the human soul, the destruction of our world will not appear so
dreadful.
Another source of conviction in the existence of God, con-
nected with the reason, and not with the feelings, impresses me
as having much more weight. This follows from the extreme
difficulty or rather impossibility of conceiving this immense and
wonderful universe, including man, with his capacity of looking
far backward and far into futurity, as the result of blind chance
or necessity. When thus reflecting I feel compelled to look to a
First Cause, having an intelligent mind in some degree anal-
ogous to that of man; and I deserve to be called a Theist.
This conclusion was strong in my mind about the time, as far
as I can remember, when I wrote the 'Origin of Species'; and
it is since that time that it has very gradually, with many
fluctuations, become weaker. But then arises the doubt: Can the
mind of man, which has, as I fully believe, been developed
from a mind as low as that possessed by the lowest animals, be
trusted when it draws such grand conclusions ?
I cannot pretend to throw the least light on such abstruse
problems. The mystery of the beginning of all things is insoluble
by us; and I for one must be content to remain an Agnostic.
C. DARWIN TO MISS JULIA WEDGWOOD: ON DESIGN
From Life and Letters >
JULY 11th [1861].
SOME
COME one has sent us 'Macmillan,' and I must tell you how
much I admire your article; though at the same time I
must confess that I could not clearly follow you in some
parts, which probably is in main part due to my not being at all
accustomed to metaphysical trains of thought. I think that you
understand my book perfectly, and that I find a very rare event
with my critics. The ideas in the last page have several times
vaguely crossed my mind. Owing to several correspondents I
have been led lately to think, or rather to try to think, over
some of the chief points discussed by you. But the result has
been with me a maze-something like thinking on the origin of
evil, to which you allude. The mind refuses to look at this
universe, being what it is, without having been designed; yet


## p. 4409 (#179) ###########################################

CHARLES ROBERT DARWIN
4409
where one would most expect design,- viz. , in the structure of
a sentient being,- the more I think on the subject, the less I
can see proof of design. Asa Gray and some others look at each
variation, or at least at each beneficial variation (which A. Gray
would compare with the rain-drops which do not fall on the sea,
but on to the land to fertilize it), as having been providentially
designed. Yet when I asked him whether he looks at each
variation in the rock-pigeon, by which man has made by accumu-
lation a pouter or fantail pigeon, as providentially designed for
man's amusement, he does not know what to answer; and if he
or any one admits [that] these variations are accidental, as far
as purpose is concerned (of course not accidental as to their
cause or origin), then I can see no reason why he should rank
the accumulated variations by which the beautifully adapted
woodpecker has been formed, as providentially designed. For it
would be easy to imagine the enlarged crop of the pouter, or
tail of the fantail, as of some use to birds in a state of nature,
having peculiar habits of life. These are the considerations
which perplex me about design; but whether you will care
hear them, I know not.
[On the subject of design, he wrote (July 1860) to Dr.
Gray: -]
One word more on "designed laws" and "undesigned results. "
I see a bird which I want for food, take my gun and kill it; I
do this designedly. An innocent and good man stands under a
tree and is killed by a flash of lightning. Do you believe (and
I really should like to hear) that God designedly killed this man?
Many or most persons do believe this; I can't and don't.
If you
believe so, do you believe that when a swallow snaps up a gnat,
that God designed that that particular swallow should snap up
that particular gnat at that particular instant? I believe that
the man and the gnat are in the same predicament. If the
death of neither man nor gnat is designed, I see no good
reason to believe that their first birth or production should be
necessarily designed.
·


## p. 4410 (#180) ###########################################

4410
CHARLES ROBERT DARWIN
CORRESPONDENCE
From The Life and Letters'
.
C. DARWIN TO J. D. HOOKER
My Dear Hooker:
I
AM astonished at your note. I have not seen the Athenæum,
but I have sent for it, and may get it to-morrow; and will
then say what I think.
Down, February 24th [1863].
I have read Lyell's book [The Antiquity of Man']. The
whole certainly struck me as a compilation, but of the highest
class; for when possible the facts have been verified on the spot,
making it almost an original work. The Glacial chapters seem
to me best, and in parts magnificent. I could hardly judge about
Man, as all the gloss of novelty was completely worn off. But
certainly the aggregation of the evidence produced a very strik-
ing effect on my mind. The chapter comparing language and
changes of species seems most ingenious and interesting. He has
shown great skill in picking out salient points in the argument
for change of species; but I am deeply disappointed (I do not
mean personally) to find that his timidity prevents him giving
any judgment.
From all my communications with him,
I must ever think that he has really entirely lost faith in the
immutability of species; and yet one of his strongest sentences is
nearly as follows: "If it should ever be rendered highly probable
that species change by variation and natural selection," etc. , etc.
I had hoped he would have guided the public as far as his own
belief went.
One thing does please me on this subject,
that he seems to appreciate your work. No doubt the public or
a part may be induced to think that as he gives to us a larger
space than to Lamarck, he must think there is something in our
views. When reading the brain chapter, it struck me forcibly
that if he had said openly that he believed in change of species,
and as a consequence that man was derived from some quadru-
manous animal, it would have been very proper to have discussed
by compilation the differences in the most important organ, viz. ,
the brain. As it is, the chapter seems to me to come in rather
by the head and shoulders. I do not think (but then I am as
prejudiced as Falconer and Huxley, or more so) that it is too
•


## p. 4411 (#181) ###########################################

CHARLES ROBERT DARWIN
4411
It might per-
severe. It struck me as given with judicial force.
haps be said with truth that he had no business to judge on a
subject on which he knows nothing; but compilers must do this
to a certain extent. (You know I value and rank high com-
pilers, being one myself. ) I have taken you at your word, and
scribbled at great length. If I get the Athenæum to-morrow, I
will add my impression of Owen's letter.
The Lyells are coming here on Sunday evening to stay till
Wednesday. I dread it, but I must say how much disappointed
I am that he has not spoken out on species, still less on man.
And the best of the joke is that he thinks he has acted with the
courage of a martyr of old. I hope I may have taken an exag-
gerated view of his timidity, and shall particularly be glad of
your opinion on this head. When I got his book I turned over
the pages, and saw he had discussed the subject of species, and
said that I thought he would do more to convert the public than
all of us; and now (which makes the case worse for me) I must,
in common honesty, retract. wish to Heaven he had said not
a word on the subject.
WEDNESDAY MORNING. I have read the Athenæum. I do
not think Lyell will be nearly so much annoyed as you expect.
The concluding sentence is no doubt very stinging.
No one
but a good anatomist could unravel Owen's letter; at least it is
quite beyond me.
Lyell's memory plays him false when he says all anatomists
were astonished at Owen's paper: it was often quoted with
approbation. I well remember Lyell's admiration at this new
classification! (Do not repeat this. ) I remember it because,
though I knew nothing whatever about the brain, I felt a con-
viction that a classification thus founded on a single character
would break down, and it seemed to me a great error not to
separate more completely the Marsupialia.
What an accursed evil it is that there should be all this quar-
reling, within what ought to be the peaceful realms of science.
I will go to my own present subject of inheritance and forget
it all for a time. Farewell, my dear old friend.
C. DARWIN.
•


## p. 4412 (#182) ###########################################

4412
CHARLES ROBERT DARWIN
C. DARWIN TO T. H. HUXLEY
OCTOBER 3d, 1864.
My Dear Huxley:
IF I do not pour out my admiration of your article on Köl-
liker, I shall explode. I never read anything better done. I
had much wished his article answered, and indeed thought of
doing so myself, so that I considered several points. You have
hit on all, and on some in addition, and oh, by Jove, how well
you have done it! As I read on and came to point after point
on which I had thought, I could not help jeering and scoffing at
myself, to see how infinitely better you had done it than I could.
have done. Well, if any one who does not understand Natural
Selection will read this, he will be a blockhead if it is not as
clear as daylight. Old Flourens was hardly worth the powder
and shot; but how capitally you bring in about the Academi-
cian, and your metaphor of the sea-sand is inimitable.
It is a marvel to me how you can resist becoming a regular
reviewer. Well, I have exploded now, and it has done me a
deal of good.
C. DARWIN TO E. RAY LANKESTER
Down, March 15th [1870].
My Dear Sir:
I Do not know whether you will consider me a very trouble-
some man, but I have just finished your book, and cannot
resist telling you how the whole has much interested me. No
doubt, as you say, there must be much speculation on such a
subject, and certain results cannot be reached; but all your
views are highly suggestive, and to my mind that is high
praise. I have been all the more interested, as I am now
writing on closely allied though not quite identical points. I
was pleased to see you refer to my much despised child,
'Pangenesis,' who I think will some day, under some better
nurse, turn out a fine stripling. It has also pleased me to
see how thoroughly you appreciate (and I do not think that
this is general with the men of science) H. Spencer; I sus-
pect that hereafter he will be looked at as by far the greatest
living philosopher in England; perhaps equal to any that have


## p. 4413 (#183) ###########################################

CHARLES ROBERT DARWIN
4413
lived. But I have no business to trouble you with my notions.
With sincere thanks for the interest which your work has
given me,
I remain, yours very faithfully,
CH. DARWIN.
FROM A LETTER TO J. D. HOOKER
CLIFF COTTAGE, BOURNEMOUTH, September 26th, 1862.
My Dear Hooker:
Do NOT read this till you have leisure. If that blessed
moment ever comes, I should be very glad to have your
opinion on the subject of this letter. I am led to the opin--
ion that Drosera must have diffused matter in organic con-
nection, closely analogous to the nervous matter of animals.
When the glans of one of the papillæ or tentacles in its natural
position is supplied with nitrogenized fluid and certain other
stimulants, or when loaded with an extremely slight weight, or
when struck several times with a needle, the pedicel bends near
its base in under one minute. These varied stimulants are con-
veyed down the pedicel by some means; it cannot be vibration,
for drops of fluid put on quite quietly cause the movement; it
cannot be absorption of the fluid from cell to cell, for I can see
the rate of absorption, which, though quick, is far slower, and in
Dionæa the transmission is instantaneous; analogy from animals
would point to transmission through nervous matter. Reflecting
on the rapid power of absorption in the glans, the extreme
sensibility of the whole organ, and the conspicuous movement
caused by varied stimulants, I have tried a number of substances
which are not caustic or corrosive,
but most of which
are known to have a remarkable action on the nervous matter
of animals. You will see the results in the inclosed paper. As
the nervous matter of different animals is differently acted on
by the same poisons, one would not expect the same action on
plants and animals; only, if plants have diffused nervous matter,
some degree of analogous action. And this is partially the case.
Considering these experiments, together with the previously
made remarks on the functions of the parts, I cannot avoid the
conclusion that Drosera possesses matter at least in some degree
analogous in constitution and function to nervous matter. Now
do tell me what you think, as far as you can judge from my
abstract. Of course many more experiments would have to be
•


## p. 4414 (#184) ###########################################

CHARLES ROBERT DARWIN
4414
tried; but in former years I tried on the whole leaf, instead of
on separate glands, a number of innocuous substances, such as
sugar, gum, starch, etc. , and they produced no effect.
Your
opinion will aid me in deciding some future year in going on
with this subject. I should not have thought it worth attempt-
ing, but I had nothing on earth to do.
My dear Hooker, yours very sincerely,
CH. DARWIN.
P. S. — We return home on Monday 28th. Thank Heaven!
-
THE STRUGGLE FOR EXISTENCE
From the Origin of Species >
BE
EFORE entering on the subject of this chapter, I must make a
few preliminary remarks, to show how the struggle for
existence bears on Natural Selection. It has been seen in
the last chapter that amongst organic beings in a state of nature
there is some individual variability; indeed, I am not aware that
this has ever been disputed. It is immaterial for us whether
a multitude of doubtful forms be called species, or sub-species,
or varieties; what rank, for instance, the two or three hundred
doubtful forms of British plants are entitled to hold, if the exist-
ence of any well-marked varieties be admitted. But the mere
existence of individual variability and of some few well-marked
varieties, though necessary as the foundation for the work, helps
us but little in understanding how species arise in nature. How
have all those exquisite adaptations of one part of the organiza-
tion to another part, and to the conditions of life, and of one
organic being to another being, been perfected? We see these
beautiful co-adaptations most plainly in the woodpecker and the
mistletoe; and only a little less plainly in the humblest parasite
which clings to the hairs of a quadruped or feathers of a bird;
in the structure of the beetle which dives through the water; in
the plumed seed which is wafted by the gentlest breeze: in
short, we see beautiful adaptations everywhere and in every part
of the organic world.
Again, it may be asked, how is it that varieties, which I have
called incipient species, become ultimately converted into good
and distinct species, which in most cases obviously differ from
each other far more than do the varieties of the same species?


## p. 4415 (#185) ###########################################

CHARLES ROBERT DARWIN
4415
How do those groups of species, which constitute what are
called distinct genera, and which differ from each other more
than do the species of the same genus, arise? All these results,
as we shall more fully see in the next chapter, follow from the
struggle for life. Owing to this struggle, variations, however
slight and from whatever cause proceeding, if they be in any
degree profitable to the individuals of a species, in their infi-
nitely complex relations to other organic beings and to their
physical conditions of life, will tend to the preservation of such
individuals, and will generally be inherited by the offspring.
The offspring also will thus have a better chance of surviving;
for of the many individuals of any species which are periodically
born, but a small number can survive. I have called this prin-
ciple, by which each slight variation, if useful, is preserved, by
the term Natural Selection, in order to mark its relation to
man's power of selection. But the expression often used by Mr.
Herbert Spencer, of the Survival of the Fittest, is more accurate
and is sometimes equally convenient. We have seen that man
by selection can certainly produce great results, and can adapt
organic beings to his own uses, through the accumulation of
slight but useful variations given to him by the hand of Nature.
But Natural Selection, as we shall hereafter see, is a power
incessantly ready for action, and is as immeasurably superior
to man's feeble efforts as the works of Nature are to those
of Art.
We will now discuss in a little more detail the struggle for
existence. In my future work this subject will be treated, as it
well deserves, at greater length. The elder De Candolle and
Lyell have largely and philosophically shown that all organic
beings are exposed to severe competition. In regard to plants,
no one has treated this subject with more spirit and ability than
W. Herbert, Dean of Manchester, evidently the result of his
great horticultural knowledge. Nothing is easier 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 ingrained
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. We behold the face of
nature bright with gladness, we often see superabundance of
food; we do not see, or we forget, that the birds which are idly


## p. 4416 (#186) ###########################################

4416
CHARLES ROBERT DARWIN
singing round us mostly live on insects or seeds, and are thus
constantly destroying life; or we forget how largely these song-
sters, or their eggs, or their nestlings, are destroyed by birds
and beasts of prey; we do not always bear in mind that though
food may be now superabundant, it is not so at all seasons of
each recurring year.
I should premise that I use this term in a large and meta-
phorical 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. Two canine ani-
mals, in a time of dearth, may be truly said to struggle with
each other which shall get food and live. But a plant on the
edge of a desert is said to struggle for life against the drought,
though more properly it should be said to be dependent on the
moisture. A plant which annually produces a thousand seeds, of
which only one on an average comes to maturity, may be more
truly said to struggle with the plants of the same and other
kinds which already clothe the ground. The mistletoe is depend-
ent on the apple and a few other trees, but can only in a far-
fetched sense be said to struggle with these trees, for if too
many of these parasites grow on the same tree, it languishes
and dies. But several seedling mistletoes, growing close to-
gether on the same branch, may more truly be said to struggle
with each other. As the mistletoe is disseminated by birds, its
existence depends on them; and it may metaphorically be said
to struggle with other fruit-bearing plants, in tempting the
birds to devour and thus disseminate its seeds. In these several
senses, which pass into each other, I use for convenience's sake
the general term of Struggle for Existence.
THE GEOMETRICAL RATIO OF INCREASE
From Origin of Species>
A
STRUGGLE for existence inevitably follows from the high rate
at which all organic beings tend to increase. Every being
which during its natural lifetime produces several eggs or
seeds must suffer destruction during some period of its life, and
during some season or occasional year; otherwise, on the princi-
ple of geometrical increase, its numbers would quickly become


## p. 4417 (#187) ###########################################

CHARLES ROBERT DARWIN
4417
so inordinately great that no country could support the product.
Hence, as more individuals are produced than can possibly sur-
vive, there must in every case be a struggle for existence, either
one individual with another of the same species, or with the
individuals of distinct species, or with the physical conditions of
life. It is the doctrine of Malthus applied with manifold force
to the whole animal and vegetable kingdoms; for in this case
there can be no artificial increase of food, and no prudential
restraint from marriage. Although some species may be now
increasing, more or less rapidly, in numbers, all cannot do so,
for the world would not hold them.
There is no exception to the rule that every organic being
naturally increases at so high a rate that if not destroyed, the
earth would soon be covered by the progeny of a single pair.
Even slow-breeding man has doubled in twenty-five years; and
at this rate, in less than a thousand years there would literally
not be standing-room for his progeny. Linnæus has calculated
that if an annual plant produced only two seeds-and there is
no plant so unproductive as this-and their seedlings next year
produced two, and so on, then in twenty years there would be a
million plants. The elephant is reckoned the slowest breeder of
all known animals, and I have taken some pains to estimate its
probable minimum rate of natural increase; it will be safest to
assume that it begins breeding when thirty years old: and goes
on breeding till ninety years old, bringing forth six young in
the interval, and surviving till one hundred years old: if this be
so, after a period of from 740 to 750 years there would be
nearly nineteen million elephants alive, descended from the first
pair.
But we have better evidence on this subject than mere theo-
retical calculations, namely, the numerous recorded cases of the
astonishingly rapid increase of various animals in a state of
nature, when circumstances have been favorable to them during
two or three following seasons. Still more striking is the evi-
dence from our domestic animals of many kinds which have run
wild in several parts of the world; if the statements of the rate of
increase of slow-breeding cattle and horses in South America, and
latterly in Australia, had not been well authenticated, they would
have been incredible. So it is with plants; cases could be given
of introduced plants which have become common throughout
whole islands in a period of less than ten years. Several of
VIII-277


## p. 4418 (#188) ###########################################

4418
CHARLES ROBERT DARWIN
the plants, such as the cardoon and a tall thistle, which are
now the commonest over the wide plains of La Plata, clothing
square leagues of surface almost to the exclusion of every other
plant, have been introduced from Europe; and there are plants
which now range in India, as I hear from Falconer, from Cape
Comorin to the Himalaya, which have been imported from
America since its discovery. In such cases—and endless others
could be given-no one supposes that the fertility of the animals
or plants has been suddenly and temporarily increased in any
sensible degree. The obvious explanation is that the conditions.
of life have been highly favorable, and that there has conse-
quently been less destruction of the old and young, and that
nearly all the young have been enabled to breed.
Their geo-
metrical ratio of increase, the result of which never fails to be
surprising, simply explains their extraordinarily rapid increase
and wide diffusion in their new homes.
In a state of nature almost every full-grown plant annually
produces seed, and amongst animals there are very few which do
not annually pair. Hence we may confidently assert that all
plants and animals are tending to increase at a geometrical
ratio, that all would rapidly stock every station in which they
could anyhow exist,- and that this geometrical tendency to in-
crease must be checked by destruction at some period of life.
Our familiarity with the larger domestic animals tends, I think,
to mislead us: we see no great destruction falling on them, but
we do not keep in mind that thousands are annually slaughtered
for food, and that in a state of nature an equal number would
have somehow to be disposed of.
The only difference between organisms which annually pro-
duce eggs or seeds by the thousand, and those which produce
extremely few, is that the slow breeders would require a few
more years to people, under favorable conditions, a whole dis-
trict, let it be ever so large. The condor lays a couple of eggs
and the ostrich a score, and yet in the same country the condor
may be the more numerous of the two; the Fulmar petrel lays
but one egg, yet it is believed to be the most numerous bird in
the world. One fly deposits hundreds of eggs, and another, like
the hippobosca, a single one; but this difference does not deter-
mine how many individuals of the two species can be supported
in a district. A large number of eggs is of some importance to
those species which depend on a fluctuating amount of food, for
――――


## p. 4419 (#189) ###########################################

CHARLES ROBERT DARWIN
4419
it allows them rapidly to increase in number. But the real
importance of a large number of eggs or seeds is to make up for
much destruction at some period of life; and this period in the
great majority of cases is an early one. If an animal can in any
way protect its own eggs or young, a small number may be
produced, and yet the average stock be fully kept up; but if
many eggs or young are destroyed, many must be produced, or
the species will become extinct. It would suffice to keep up the
full number of a tree which lived on an average for a thousand
years, if a single seed were produced once in a thousand years,
supposing that this seed were never destroyed, and could be
insured to germinate in a fitting place. So that, in all cases, the
average number of any animal or plant depends only indirectly
on the number of its eggs or seeds.
In looking at nature, it is most necessary to keep the fore-
going considerations always in mind-never to forget that every
single organic being may be said to be striving to the utmost to
increase in numbers; that each lives by a struggle at some period
of its life; that heavy destruction inevitably falls either on the
young or old, during each generation or at recurrent intervals.
Lighten any check, mitigate the destruction ever so little, and
the number of the species will almost instantaneously increase to
any amount.
OF THE NATURE OF THE CHECKS TO INCREASE
From The Origin of Species >
THE
HE causes which check the natural tendency of each species.
to increase are most obscure. Look at the most vigorous
species: by as much as it swarms in numbers, by so much
will it tend to increase still further. We know not exactly
what the checks are, even in a single instance. Nor will this
surprise any one who reflects how ignorant we are on this
head, even in regard to mankind, although so incomparably bet-
ter known than any other animal. This subject of the checks to
increase has been ably treated by several authors, and I hope in
a future work to discuss it at considerable length, more especially
in regard to the feral animals of South America. Here I will
make only a few remarks, just to recall to the reader's mind some


## p. 4420 (#190) ###########################################

4420
CHARLES ROBERT DARWIN
of the chief points. Eggs or very young animals seem generally
to suffer most, but this is not invariably the case.
With plants
there is a vast destruction of seeds; but from some observations
which I have made, it appears that the seedlings suffer most,
from germinating in ground already thickly stocked with other
plants. Seedlings also are destroyed in vast numbers by various
enemies: for instance, on a piece of ground three feet long and
two wide, dug and cleared, and where there could be no choking
from other plants, I marked all the seedlings of our native weeds
as they came up, and out of 357 no less than 295 were destroyed,
chiefly by slugs and insects. If turf which has long been mown
-and the case would be the same with turf closely browsed by
quadrupeds-be let to grow, the more vigorous plants gradually
kill the less vigorous though fully grown plants; thus out of
twenty species growing on a little plot of mown turf (three feet
by four) nine species perished, from the other species being
allowed to grow up freely.
The amount of food for each species of course gives the ex-
treme limit to which each can increase; but very frequently it is
not the obtaining food, but the serving as prey to other animals,
which determines the average numbers of a species. Thus there
seems to be little doubt that the stock of partridges, grouse, and
hares in any large estate depends chiefly on the destruction of
vermin. If not one head of game were shot during the next
twenty years in England, and at the same time if no vermin
were destroyed, there would in all probability be less game than
at present, although hundreds of thousands of game animals are
now annually shot. On the other hand, in some cases, as with
the elephant, none are destroyed by beasts of prey; for even the
tiger in India most rarely dares to attack a young elephant pro-
tected by its dam.
Climate plays an important part in determining the average
numbers of a species, and periodical seasons of extreme cold or
drought seem to be the most effective of all checks. I estimated
(chiefly from the greatly reduced numbers of nests in the spring)
that the winter of 1854-5 destroyed four-fifths of the birds in my
own grounds; and this is a tremendous destruction, when we
remember that ten per cent. is an extraordinarily severe mor-
tality from epidemics with man. The action of climate seems at
first sight to be quite independent of the struggle for existence;
but in so far as climate chiefly acts in reducing food, it brings


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CHARLES ROBERT DARWIN
4421
on the most severe struggle between the individuals, whether of
the same or of distinct species, which subsist on the same kind
of food. Even when climate,- for instance, extreme cold,- acts
directly, it will be the least vigorous individuals, or those which
have got least food through the advancing winter, which will
suffer most.
When we travel from south to north, or from a damp region
to a dry, we invariably see some species gradually getting rarer
and rarer, and finally disappearing; and the change of climate
being conspicuous, we are tempted to attribute the whole effect
to its direct action. But this is a false view; we forget that
each species, even where it most abounds, is constantly suffering
enormous destruction at some period of its life, from enemies
or from competitors for the same place and food; and if these
enemies or competitors be in the least degree favored by any
slight change of climate, they will increase in numbers; and as
each area is already fully stocked with inhabitants, the other spe-
cies must decrease. When we travel southward and see a species
decreasing in numbers, we may feel sure that the cause lies quite
as much in other species being favored as in this one being hurt.
So it is when we travel northward; but in a somewhat lesser
degree, for the number of species of all kinds, and therefore of
competitors, decreases northward; hence in going northward, or
in ascending a mountain, we far oftener meet with stunted
forms, due to the directly injurious action of climate, than we
do in proceeding southward or in descending a mountain. When
we reach the arctic regions, or snow-capped summits, or abso-
lute deserts, the struggle for life is almost exclusively with the
elements.
That climate acts in main part indirectly by favoring other
species, we clearly see in the prodigious number of plants which
in our gardens can perfectly well endure our climate, but which
never become naturalized, for they cannot compete with our
native plants nor resist destruction by our native animals.
When a species, owing to highly favorable circumstances,
increases inordinately in numbers in a small tract, epidemics-
at least, this seems generally to occur with our game animals—
often ensue; and here we have a limiting check independent of
the struggle for life. But even some of these so-called epidemics
appear to be due to parasitic worms, which have from some
cause, possibly in part through facility of diffusion amongst the


## p. 4422 (#192) ###########################################

4422
CHARLES ROBERT DARWIN
crowded animals, been disproportionally favored: and here comes
in a sort of struggle between the parasite and its prey.
On the other hand, in many cases, a large stock of individ-
uals of the same species, relatively to the numbers of its ene-
mies, is absolutely necessary for its preservation. Thus we can
easily raise plenty of corn and rape-seed, etc. , in our fields,
because the seeds are in great excess compared with the number
of birds which feed on them; nor can the birds, though having
a superabundance of food at this one season, increase in number
proportionally to the supply of seed, as their numbers are checked.
during winter; but any one who has tried, knows how trouble-
some it is to get seed from a few wheat or other such plants in
a garden: I have in this case lost every single seed. This view
of the necessity of a large stock of the same species for its
preservation, explains I believe some singular facts in nature,
such as that of very rare plants being sometimes extremely
abundant in the few spots where they do exist; and that of
some social plants being social, that is, abounding in individuals,
even on the extreme verge of their range.
For in such cases,
we may believe that a plant could exist only where the condi-
tions of its life were so favorable that many could exist together
and thus save the species from utter destruction. I should add
that the good effects of inter-crossing, and the ill effects of close
inter-breeding, no doubt come into play in many of these cases;
but I will not here enlarge on this subject.
THE COMPLEX RELATIONS OF ALL ANIMALS AND PLANTS
TO EACH OTHER IN THE STRUGGLE FOR EXISTENCE
From the Origin of Species >
M
ANY cases are on record, showing how complex and unex-
pected are the checks and relations between organic beings
which have to struggle together in the same country.
I will give only a single instance, which though a simple one
interested me. In Staffordshire, on the estate of a relation
where I had ample means of investigation, there was a large
and extremely barren heath which had never been touched by
the hand of man; but several hundred acres of exactly the
same nature had been inclosed twenty-five years previously


## p. 4423 (#193) ###########################################

CHARLES ROBERT DARWIN
4423
and planted with Scotch fir. The change in the native vege-
tation of the planted part of the heath was most remarkable,
more than is generally seen in passing from one quite differ-
ent soil to another: not only the proportional numbers of the
heath-plants were wholly changed, but twelve species of plants
(not counting grasses and carices) flourished in the plantations,
which could not be found on the heath. The effect on the
insects must have been still greater, for six insectivorous birds
were very common in the plantations which were not to be
seen on the heath; and the heath was frequented by two or
three distinct insectivorous birds. Here we see how potent has
been the effect of the introduction of a single tree, nothing
whatever else having been done, with the exception of the land
having been inclosed so that cattle could not enter.
But how important an element inclosure is, I plainly saw near
Farnham in Surrey. Here there are extensive heaths with a
few clumps of old Scotch firs on the distant hill-tops: within the
last ten years large spaces have been inclosed, and self-sown
firs are now springing up in multitudes, so close together that
all cannot live. When I ascertained that these young trees had
not been sown or planted, I was so much surprised at their
numbers that I went to several points of view, whence I could
examine hundreds of acres of the uninclosed heath, and literally
I could not see a single Scotch fir except the old planted clumps.
But on looking closely between the stems of the heath, I found
a multitude of seedlings and little trees which had been perpetu-
ally browsed down by the cattle. In one square yard, at a
point some hundred yards distant from one of the old clumps,
I counted thirty-two little trees; and one of them, with twenty-
six rings of growth, had during many years tried to raise its
head above the stems of the heath, and had failed. No wonder
that as soon as the land was inclosed it became thickly clothed
with vigorously growing young firs. Yet the heath was SO
extremely barren and so extensive that no one would ever
have imagined that cattle would have so closely and effectually
searched it for food.
Here we see that cattle absolutely determine the existence of
the Scotch fir; but in several parts of the world insects deter-
mine the existence of cattle. Perhaps Paraguay offers the most
curious instance of this; for here neither cattle nor horses nor
dogs have ever run wild, though they swarm southward and


## p. 4424 (#194) ###########################################

CHARLES ROBERT DARWIN
4424
northward in a feral state; and Azara and Rengger have shown
that this is caused by the greater number in Paraguay of a cer-
tain fly, which lays its eggs in the navels of these animals when
first born. The increase of these flies, numerous as they are,
must be habitually checked by some means, probably by other
parasitic insects. Hence if certain insectivorous birds were to de-
crease in Paraguay, the parasitic insects would probably increase;
and this would lessen the number of the 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. Not that under nature the relations will ever be as
simple as this. Battle within battle must be continually recur-
ring with varying success; and yet in the long run the forces
are so nicely balanced that the face of nature remains for long
periods of time uniform, though assuredly the merest trifle would
give the victory to one organic being over another. Neverthe-
less, so profound is our ignorance and so high our presumption,
that we marvel when we hear of the extinction of an organic
being; and as we do not see the cause, we invoke cataclysms to
desolate the world, or invent laws on the duration of the forms
of life!
OF NATURAL SELECTION; OR THE SURVIVAL OF THE FITTEST
From the Origin of Species'
SEVE
EVERAL writers have misapprehended or objected to the term
Natural Selection. Some have even imagined that Natural
Selection induces variability, whereas it implies only the
preservation of such variations as arise and are beneficial to the
being under its conditions of life. No one objects to agricultur-
ists speaking of the potent effects of man's selection; and in this
case the individual differences given by nature, which man for
some object selects, must of necessity first occur. Others have
objected that the term selection implies conscious choice in the
animals which become modified; and it has even been urged that
as plants have no volition, Natural Selection is not applicable to
L
t


## p. 4425 (#195) ###########################################

CHARLES ROBERT DARWIN
4425
them! In the literal sense of the word, no doubt, Natural Selec-
tion is a false term; but who ever objected to chemists speaking
of the elective affinities of the various elements? -and yet an
acid cannot strictly be said to elect the base with which it in
preference combines. It has been said that I speak of Natural
Selection as an active power or Deity; but who objects to an
author speaking of the attraction of gravity as ruling the move-
ments of the planets? Every one knows what is meant and is
implied by such metaphorical expressions; and they are almost
necessary for brevity. So again it is difficult to avoid personify-
ing the word Nature; but I mean by nature only the aggregate
action and product of many natural laws, and by laws the
sequence of events as ascertained by us. With a little famil-
iarity such superficial objections will be forgotten.
We shall best understand the probable course of Natural
Selection by taking the case of a country undergoing some slight
physical change; for instance, of climate. The proportional num-
bers of its inhabitants will almost immediately undergo a change,
and some species will probably become extinct. We may con-
clude, from what we have seen of the intimate and complex
manner in which the inhabitants of each country are bound
together, that any change in the numerical proportions of the
inhabitants, independently of the change of climate itself, would
seriously affect the others. If the country were open on its bor-
ders, new forms would certainly immigrate, and this would
likewise seriously disturb the relations of some of the former
inhabitants. Let it be remembered how powerful the influence
of a single introduced tree or mammal has been shown to be.
But in the case of an island, or of a country partly surrounded
by barriers, into which new and better adapted forms could not
freely enter, we should then have places in the economy of
nature which would assuredly be better filled up if some of the
original inhabitants were in some manner modified; for had the
area been open to immigration, these same places would have
been seized on by intruders. In such cases, slight modifications
which in any way favored the individuals of any species by bet-
ter adapting them to their altered conditions, would tend to be
preserved; and Natural Selection would have free scope for the
work of improvement.
We have good reason to believe, as shown in the first chap-
ter, that changes in the conditions of life give a tendency to


## p. 4426 (#196) ###########################################

4426
CHARLES ROBERT DARWIN
increased variability; and in the foregoing cases the conditions
have changed, and this would manifestly be favorable to Natural
Selection by affording a better chance of the occurrence of prof-
itable variations. Unless such occur, Natural Selection can do
nothing. Under the term of "variations," it must never be for-
gotten that mere individual differences are included. As man
can produce a great result with his domestic animals and plants
by adding up in any given direction individual differences, so
could Natural Selection, but far more easily from having incom-
parably longer time for action. Nor do I believe that any great
physical change, as of climate, or any unusual degree of isola-
tion to check immigration, is necessary in order that new and
unoccupied places should be left, for Natural Selection to fill up
by improving some of the varying inhabitants. For as all the
inhabitants of each country are struggling together with nicely
balanced forces, extremely slight modifications in the structure or
habits of one species would often give it an advantage over
others; and still further modifications of the same kind would
often still further increase the advantage, as long as the species
continued under the same conditions of life and profited by sim-
ilar means of subsistence and defense. No country can be
named, in which all the native inhabitants are now so perfectly
adapted to each other and to the physical conditions under which
they live, that none of them could be still better adapted or im-
proved; for in all countries the natives have been so far con-
quered by naturalized productions that they have allowed some
foreigners to take firm possession of the land. And as foreign-
ers have thus in every country beaten some of the natives, we
may safely conclude that the natives might have been modified
with advantage, so as to have better resisted the intruders.
As man can produce, and certainly has produced, a great
result by his methodical and unconscious means of selection, what
may not Natural Selection effect? Man can act only on external
and visible characters; Nature, if I may be allowed to personify
the natural preservation or survival of the fittest, cares nothing
for appearances, except in so far as they are useful to any being.
She can act on every internal organ, on every shade of constitu-
tional difference, on the whole machinery of life. Man selects
only for his own good; Nature only for that of the being which
she tends. Every selected character is fully exercised by her, as
is implied by the fact of their selection. Man keeps the natives


## p. 4427 (#197) ###########################################

CHARLES ROBERT DARWIN
4427
of many climates in the same country: he seldom exercises each
selected character in some peculiar and fitting manner; he feeds
a long and a short-beaked pigeon on the same food; he does not
exercise a long-backed or long-legged quadruped in any peculiar
manner; he exposes sheep with long and short wool to the same
climate. He does not allow the most vigorous males to struggle
for the females. He does not rigidly destroy all inferior animals,
but protects during each varying season, as far as lies in his
power, all his productions. He often begins his selection by some
half-monstrous form; or at least by some modification prominent
enough to catch the eye or to be plainly useful to him. Under
Nature, the slightest differences of structure or constitution may
well turn the nicely balanced scale in the struggle for life, and
so be preserved. How fleeting are the wishes and efforts of
man! How short his time, and consequently how poor will be
his results, compared with those accumulated by Nature during
whole geological periods! Can we wonder then that Nature's
productions should be far "truer" in character than man's pro-
ductions; that they should be infinitely better adapted to the most
complex conditions of life, and should plainly bear the stamp of
far higher workmanship?
It may metaphorically be said that Natural Selection is daily
and hourly scrutinizing, throughout the world, the slightest varia-
tions; rejecting those that are bad, preserving and adding up all
that are good; silently and insensibly working, whenever and
wherever opportunity offers, at the improvement of each organic
being in relation to its organic and inorganic conditions of life.
We see nothing of these slow changes in progress until the hand
of time has marked the lapse of ages, and then so imperfect is
our view into long-past geological ages, that we see only that the
forms of life are now different from what they formerly were.
In order that any great amount of modification should be
effected in a species, a variety when once formed must again,
perhaps after a long interval of time, vary or present individual
differences of the same favorable nature as before; and these
must be again preserved, and so onward step by step. Seeing
that individual differences of the same kind perpetually recur,
this can hardly be considered as an unwarrantable assumption.
But whether it is true, we can judge only by seeing how far the
hypothesis accords with and explains the general phenomena of
nature. On the other hand, the ordinary belief that the amount


## p. 4428 (#198) ###########################################

4428
CHARLES ROBERT DARWIN
of possible variation is a strictly limited quantity, is likewise a
simple assumption.
Although Natural Selection can act only through and for the
good of each being, yet characters and structures, which we are
apt to consider as of very trifling importance, may thus be acted
on. When we see leaf-eating insects green, and bark-feeders
mottled gray; the Alpine ptarmigan white in winter, the red
grouse the color of heather,- we must believe that these tints
are of service to these birds and insects in preserving them from
danger. Grouse, if not destroyed at some period of their lives,
would increase in countless numbers; they are known to suffer
largely from birds of prey; and hawks are guided by eyesight to
their prey - so much so, that on parts of the Continent persons
are warned not to keep white pigeons, as being the most liable
to destruction. Hence Natural Selection might be effective in
giving the proper color to each kind of grouse, and in keeping
that color, when once acquired, true and constant.
Nor ought
we to think that the occasional destruction of an animal of any
particular color would produce little effect: we should remember
how essential it is in a flock of white sheep to destroy a lamb
with the faintest trace of black. We have seen how the color
of hogs which feed on the "paint-root" in Virginia, determines
whether they shall live or die. In plants, the down on the
fruit and the color of the flesh are considered by botanists as
characters of the most trifling importance; yet we hear from
an excellent horticulturist, Downing, that in the United States
smooth-skinned fruits suffer far more from a beetle, a curculio,
than those with down; that purple plums suffer far more from a
certain disease than yellow plums; whereas another disease attacks
yellow-fleshed peaches far more than those with other colored
flesh. If with all the aids of art, these slight differences make a
great difference in cultivating the several varieties, assuredly, in
a state of nature, where the trees would have to struggle with
other trees and with a host of enemies, such differences would
effectually settle which variety, whether a smooth or downy, a
yellow or a purple-fleshed fruit, should succeed.
In looking at many small points of difference between species,
which, as far as our ignorance permits us to judge, seem quite
unimportant, we must not forget that climate, food, etc. , have no
doubt produced some direct effect. It is also necessary to bear
in mind that owing to the law of correlation, when one part
----


## p. 4429 (#199) ###########################################

CHARLES ROBERT DARWIN
4429
varies, and the variations are accumulated through Natural
Selection, other modifications, often of the most unexpected
nature, will ensue.
As we see that those variations which under domestication
appear at any particular period of life, tend to reappear in the
offspring at the same period; -for instance, in the shape, size,
and flavor of the seeds of the many varieties of our culinary and
agricultural plants; in the caterpillar and cocoon stages of the
varieties of the silkworm; in the eggs of poultry, and in the
color of the down of their chickens; in the horns of our sheep and
cattle when nearly adult; so in a state of nature Natural
Selection will be enabled to act on and modify organic beings at
any age, by the accumulation of variations profitable at that age,
and by their inheritance at a corresponding age.
If it profit a
plant to have its seeds more and more widely disseminated by
the wind, I can see no greater difficulty in this being effected
through Natural Selection, than in the cotton-planter increasing
and improving by selection the down in the pods on his cotton-
trees. Natural Selection may modify and adapt the larva of an
insect to a score of contingencies wholly different from those
which concern the mature insect; and these modifications may
effect, through correlation, the structure of the adult. So, con-
versely, modifications in the adult may affect the structure of the
larva; but in all cases Natural Selection will insure that they
shall not be injurious: for if they were so, the species would
become extinct.
Natural Selection will modify the structure of the young in
relation to the parent, and of the parent in relation to the
young. In social animals it will adapt the structure of each
individual for the benefit of the whole community, if the com-
munity profits by the selected change.