CHAPTER XV.

THE ORIGIN OF SPECIES (1859).

[Sidenote: THE ORIGIN OF SPECIES.]

It is very interesting to separate the two arguments which occur

interwoven in the “Origin”--the argument for evolution and the

argument for natural selection. The paramount importance of Darwin’s

contributions to the evidences of organic evolution are often forgotten

in the brilliant theory which he believed to supply the motive cause

of descent with modification. Organic evolution had been held to be

true by certain thinkers during many centuries; but not only were

its adherents entirely without a sufficient motive cause, but their

evidences of the process itself were erroneous or extremely scanty.

It was Darwin who first brought together a great body of scientific

evidence which placed the process of evolution beyond dispute, whatever

the causes of evolution may have been. And accordingly we find that,

even at first, natural selection was attacked far more generally than

the doctrine of descent with modification.

In Chapter I., Variation under Domestication and man’s power of

selection in forming breeds of animals and plants are discussed; in

Chapter II., Variation under Nature; in Chapter III., the Struggle for

Existence; in Chapter IV., which Darwin, in writing to his publisher,

called “the Keystone of my Arch,” the three preceding chapters are

carried to their conclusion, and the operation of natural selection

is explained and discussed. Hence, these four chapters deal almost

exclusively with this process.

Chapter V. has for its subject the Laws of Variation, and explains

causes of modification (external conditions, use and disuse,

correlation, reversion, etc.) other than natural selection and the

relation of the latter to the former.

In Chapter VI. difficulties are considered--partly those in the way

of a belief in evolution and partly those which, at first sight, seem

to be incapable of explanation on the theory of natural selection.

Chapter VII. deals with a special difficulty of the latter kind, viz.

Instinct, and shows how it can be accounted for by natural selection

acting upon variation, although allowing some weight to the inheritance

of habit. Chapter VIII. deals with Hybridism, the sterility of first

crosses and of hybrids being considered as an objection to the doctrine

of Descent with Modification. Chapter IX. treats of the Imperfection

of the Geological Record as the explanation of the apparently

insufficient evidence of evolution during past ages. Chapter X., on the

Geological succession of Organic Beings, shows that, allowing for this

Imperfection of Record, the facts brought to light by Geology support a

belief in evolution and in some cases even in natural selection. Hence

these five chapters deal partly with difficulties in the way of an

acceptance of organic evolution and partly with those encountered by

natural selection.

Of the three remaining chapters before the XIVth, and last, which

contains the Recapitulation and Conclusion, two--XI. and XII.--are

concerned with Geographical distribution, while the XIIIth deals with

Classification, Morphology, Embryology and Rudimentary Organs. These

three chapters are almost entirely devoted to the proof that the facts

of Nature with which they deal are not inconsistent with, but rather

support, and often strongly support, a belief in Organic Evolution.

Hence we see that this, incomparably the greatest work which the

biological sciences have seen, begins with an explanation and defence

and definition of the sphere of natural selection--then passes to

consider difficulties which are partly those of natural selection, and

partly of organic evolution--while it finally treats of the evidences

of the latter process and the difficulties which a belief in it

encounters.

This arrangement was a very wise one for a book which was intended to

convince a large circle of readers; for the human mind so craves after

an explanation, that it was of more importance for the success of the

work to show first that an intelligible cause of evolution had been

proposed, than to follow the more logical order of first setting forth

the evidences of evolution.

The second edition (fifth thousand) was issued in January, 1860, the

third (seventh thousand) in 1861, the fourth (eighth thousand) in 1866,

the fifth (tenth thousand) in 1869, the sixth in 1872: in 1887 the

twenty-fourth thousand was reached.

A note to the last edition states that the second “was little more

than a reprint of the first. The third edition was largely corrected

and added to, and the fourth and fifth still more largely.” The sixth

edition also contains “numerous small corrections,” and is about

one-fourth larger than the first edition, although this material is,

owing to the smaller print and more crowded lines, compressed into a

smaller number of pages. The sixth edition also differs from the first

in containing a glossary, an historical sketch, and a note and list of

the chief corrections.

The titles of Chapters I., II., and III. remain the same in the first

and last editions. Herbert Spencer’s phrase is added to Darwin’s

term, as the heading of Chapter IV., which accordingly becomes in the

last edition “Natural Selection; or the Survival of the Fittest.”

This change was certainly introduced in order to help readers to

grasp the meaning of Darwin’s title, which had been very generally

misunderstood. The heading of Chapter V. remains the same, while in

Chapter VI.--“Difficulties on Theory”--“on” is replaced by “of the.”

This chapter is, in the last edition, succeeded by a new one dealing

with many of the difficulties which had been raised or had occurred

to Darwin in the interval between the two editions; it is headed

“Miscellaneous Objections to the Theory of Natural Selection.” The

titles of the remaining eight chapters are unchanged.

The first part of the title of the first edition--“On the Origin of

Species”--becomes “The Origin of Species” in the last edition, and is

still further shortened to “Origin of Species” on the outside of the

volume.

The form of the earlier editions was admirably suited for the purpose

of attracting, and--so far as was possible with so difficult a

subject--convincing, a large number of readers. When the subject

was new and strange, the more numerous details of the last edition,

and the smaller print which became necessary, would have acted as a

hindrance to the complete success of the work. Authors and publishers

are sometimes apt to forget that the form of a book has a great deal to

do with the absorption of the ideas contained in it, especially when

the argument is from the nature of the case difficult to follow, and

the subject a new one. Francis Darwin in the “Life and Letters” justly

condemns the unattractive form of the sixth edition of the work.

CHAPTER XVI.

THE INFLUENCE OF DARWIN UPON LYELL (1859–64).

In considering the reception of the “Origin of Species,” it will

be well first to show its effect upon Darwin’s intimate scientific

friends, most of whom had been familiar with his work for many years,

and then to deal with its effects upon biologists generally, especially

those of Darwin’s own country.

The gradual strengthening of Darwin’s influence over his old teacher

Lyell, is one of the most interesting episodes in the personal history

of the scientific men of this century.

[Sidenote: LYELL’S SLOW CONVERSION.]

Lyell, after reading the proof-sheets of the “Origin,” wrote on

October 3rd, 1859, praising the work very warmly, and suggesting a few

improvements, some of which were adopted. Lyell hesitated to accept

the theory, because he saw clearly that it would be impossible to stop

short at the human species, while a common origin of men and beasts was

distasteful to him. Thus, he said:--

“I have long seen most clearly that if any concession is made,

all that you claim in your concluding pages will follow. It is

this which has made me so long hesitate, always feeling that

the case of man and his races, and of other animals, and that

of plants is one and the same, and that if a ‘vera causa’ be

admitted for one, instead of a purely unknown and imaginary one,

such as the word ‘Creation,’ all the consequences must follow.”

To this letter Darwin replied (October 11th) at great length, in a most

instructive letter, arguing in considerable detail on all the points

alluded to by Lyell. He evidently thought that Lyell’s opinion was of

the utmost importance for the success of Natural Selection. “If ever

you are [perverted],” he wrote at the end of the letter, “I shall know

that the theory of Natural Selection is, in the main, safe.”

About this time Darwin seems to have heard that Lyell had made up his

mind to admit the doctrine of evolution into a new edition of the

“Manual,” and he wrote (November 23rd):--

“I honour you most sincerely. To have maintained in the position

of a master, one side of a question for thirty years, and then

deliberately give it up, is a fact to which I much doubt whether

the records of science offer a parallel.”

Lyell’s public confession of faith was, however, not to be made for

some years, and Darwin’s letter was a little premature.

Space will not permit me to quote from the long correspondence

with Lyell in the years following the appearance of the “Origin,”

although these letters are of the deepest interest, and deal in the

most luminous manner with the difficulties of natural selection and

evolution, as they appeared to one of the acutest intellects of that

time. The letters soon began to produce an effect, and Darwin wrote

(September 26th, 1860) to Asa Gray:--

“I can perceive in my immense correspondence with Lyell, who

objected to much at first, that he has, perhaps unconsciously to

himself, converted himself very much during the last six months,

and I think this is the case even with Hooker. This fact gives me

far more confidence than any other fact.”

Later on Darwin evidently became a little annoyed that Lyell still

delayed to declare his belief one way or the other. Thus he wrote to

Asa Gray (May 11th, 1863):--

“You speak of Lyell as a judge; now what I complain of is that

he declines to be a judge.... I have sometimes almost wished

that Lyell had pronounced against me. When I say ‘me,’ I only

mean _change of species by descent_. That seems to me the

turning-point. Personally, of course, I care much about Natural

Selection; but that seems to me utterly unimportant, compared to

the question of Creation _or_ Modification.”

Shortly before this date, on February 24th, he wrote to Hooker in

much the same style. These communications were called forth by the

appearance of “The Antiquity of Man,” and it is clear that Darwin’s

disappointment at Lyell’s suspended judgment was due to their

correspondence, which had encouraged him to expect some definite

opinion on the question. “From all my communications with him, I must

ever think that he has really entirely lost faith in the immortality

of species,” he wrote in his letter to Hooker. On March 6th he wrote

to Lyell himself, expressing his disappointment, and again a few days

later, rather complaining that his work was treated as a modification

of Lamarck’s:--

“This way of putting the case ... closely connects Wallace’s and

my views with what I consider, after two deliberate readings, as

a wretched book, and one from which (I well remember my surprise)

I gained nothing.”

When the second edition of “The Antiquity of Man” appeared in a few

months, there was a significant change in one sentence:--

“Yet we ought by no means to undervalue the importance of the

step which will have been made, should it hereafter become

the generally received opinion of men of science (as I fully

expect it will) that the past changes of the organic world have

been brought about by the subordinate agency of such causes as

Variation and Natural Selection.”

The words in parentheses had been added, and constituted Lyell’s first

public expression of an opinion in favour of Darwin’s views.

About this time an article appeared in the _Athenæum_ (March 28th,

1863), attacking the opinions in favour of evolution contained in

Dr. Carpenter’s work on Foraminifera, and supporting spontaneous

generation. This was one of the rare occasions on which Darwin entered

into controversy, and he wrote attacking spontaneous generation, and

pointing out the numerous classes of facts which are connected by

an intelligible thread of reasoning by means of his theory. In this

letter he quoted the altered sentence from the second edition of the

“Antiquity.” Darwin’s letter was answered in an article (May 2nd) in

which it was argued that _any_ theory of descent would connect the

various classes of facts equally well. To this Darwin replied in a

characteristic letter. It was evident that he was most reluctant to

continue the controversy, but thought it fair to admit publicly the

force of his opponent’s arguments.

[Sidenote: ACCESSION OF LYELL.]

In 1864 the Copley Medal of the Royal Society was given to Darwin. At

the anniversary dinner of the Society, after the meeting at which the

medals are presented by the President, Sir Charles Lyell in his speech

made a “confession of faith” as to the “Origin.” Darwin was prevented

by illness from receiving the medal in person and from being present at

the dinner.

The tenth edition of the “Principles” was published in 1867 and 1868,

and in it Lyell clearly stated his belief in evolution. Sir Joseph

Hooker, in his presidential address to the British Association at

Norwich in 1868, eloquently spoke of the “new foundation” with which

Lyell had under-pinned the edifice he had raised, and had thus rendered

it “not only more secure, but more harmonious in its proportion than

it was before.” Wallace, too, in an article in the _Quarterly Review_

(April, 1869), spoke with equal eloquence and force of the significance

of Lyell’s change of opinion.

Lyell’s death took place in 1875, eleven years after his definite

acceptance of Darwin’s views. Darwin, in writing to Miss Arabella

Buckley (now Mrs. Fisher, formerly secretary to Sir Charles Lyell),

fully acknowledged the deep debt which he owed to Lyell’s teachings:

“I never forget that almost everything which I have done in science

I owe to the study of his great works.” Huxley says in his obituary

of Charles Darwin (reprinted in “Darwiniana,” 1893, p. 268): “It is

hardly too much to say that Darwin’s greatest work is the outcome of

the unflinching application to Biology of the leading idea and the

method applied in the ‘Principles’ to Geology.” Every biologist who

realises--as who can help realising?--the boundless opportunities which

Darwin’s work has opened for him, will feel that he too owes a deep

personal debt to Darwin’s great teacher.

CHAPTER XVII.

INFLUENCE OF DARWIN UPON HOOKER AND ASA GRAY--NATURAL SELECTION AND

DESIGN IN NATURE (1860–68).

Hooker wrote on November 21st, speaking of the “glorious book” in the

warmest terms. Later on in the year he wrote again in the same spirit,

but speaking of the difficulty he found in assimilating the immense

mass of details: “It is the very hardest book to read, to full profits,

that I ever tried--it is so cram-full of matter and reasoning.” Hooker

must, however, have been familiar with the arguments and proofs,

and for this reason did not attempt any detailed discussion. It is

unnecessary to say more of Hooker’s reception of the “Origin.” During

their long friendship Darwin had discussed the difficulties and the

evidences of his theory more fully with him than with any other man;

and, as “a man sharpeneth the countenance of his friend,” the influence

of Hooker was one of the most potent forces under which Darwin produced

the greatest work of his life.

Many years later, when Hooker was awarded, in 1887, the Copley Medal

of the Royal Society, reviewing his past experiences and work in his

speech at the anniversary dinner, he concluded by telling us that his

long and intimate friendship with Charles Darwin was the great event of

his scientific career.

[Sidenote: ASA GRAY.]

In sending a copy to Asa Gray, he wrote (November 11th):--

“I fully admit that there are very many difficulties not

satisfactorily explained by my theory of descent with

modification, but I cannot possibly believe that a false theory

would explain so many classes of facts as I think it certainly

does explain. On these grounds I drop my anchor, and believe that

the difficulties will slowly disappear.”

Asa Gray’s reply was contained in a letter to Hooker, written January

5th, 1860, four days after reading the “Origin.” He asks that Darwin

may be told of what he had written. He says that the book “is done in

a _masterly manner_. It might well have taken twenty years to produce

it.” He expressed the intention of reviewing the book, and seeing that

Darwin and Hooker had fair play in America. A little later (January

23rd) he wrote to Darwin about the American reprint, etc., and spoke of

the work itself in somewhat greater detail:--

“The _best part_, I think, is the _whole_, _i.e._ its _plan_

and _treatment_, the vast amount of facts and acute inferences

handled as if you had a perfect mastery of them.... Then your

candour is worth everything to your cause. It is refreshing to

find a person with a new theory who frankly confesses that he

finds difficulties.... The moment I understood your premisses,

I felt sure you had a real foundation to hold on.... I am free

to say that I never learnt so much from one book as I have from

yours.”

He considered that the attempt to account for the formation of organs

such as eyes by natural selection, was the weakest point in the book.

This view is to be explained by his strong teleological convictions.

Although Asa Gray was the great exponent of the “Origin” in America,

he could not agree with Darwin on one important point--viz. on the

exclusion of the ordinary conceptions of design in nature by the

principle of natural selection. He believed that the two conceptions

could be reconciled, and that design in some way worked in and through

natural selection. By design is here meant what Huxley called “the

commoner and coarser form of teleology,” and which he believed to be

now refuted--“the teleology which supposes that the eye, such as we see

it in man or one of the higher vertebrata, was made with the precise

structure it exhibits for the purpose of enabling the animal which

possesses it to see, has undoubtedly received its death-blow.” Huxley

goes on to point out that there is a “wider teleology, which ... is

actually based upon the fundamental proposition of evolution ... that

the whole world ... is the result of the mutual interaction, according

to definite laws, of the forces possessed by the molecules of which

the primitive nebulosity of the universe was composed.” Therefore,

“a sufficient intelligence could, from a knowledge of the properties

of the molecules of that vapour, have predicted, say, the state of

the fauna of Britain in 1869, with as much certainty as one can say

what will happen to the vapour of the breath on a cold winter’s day.”

(“Genealogy of Animals,” _The Academy_, 1869, reprinted in “Critiques

and Addresses,” and quoted in his chapter “On the Reception of the

‘Origin of Species’” in the “Life and Letters,” Vol. II.)

But at the time of the appearance of the “Origin,” many who sympathised

with the general drift of the argument were not yet prepared for

the “wider teleology.” Of these Asa Gray may be taken as the

representative; and it will be of interest to follow the controversy

between him and Darwin as regards design and natural selection. The

recently published “Letters of Asa Gray to Charles Darwin” (Macmillan)

enable us to follow the correspondence from the side of the great

American evolutionist.

Writing November 26th, 1860, Darwin refers to one of Asa Gray’s

articles on the “Origin”:--

“I grieve to say that I cannot honestly go as far as you do

about Design. I am conscious that I am in an utterly hopeless

muddle. I cannot think that the world, as we see it, is the

result of chance; and yet I cannot look at each separate thing

as the result of Design. To take a crucial example, you lead me

to infer--that you believe ‘that variation has been led along

certain beneficial lines.’ I cannot believe this; and I think

you would have to believe, that the tail of the Fantail was led

to vary in the number and direction of its feathers in order to

gratify the caprice of a few men. Yet if the Fantail had been a

wild bird, and had used its abnormal tail for some special end,

as to sail before the wind, unlike other birds, everyone would

have said, ‘What a beautiful and designed adaptation.’ Again, I

say I am, and shall ever remain, in a hopeless muddle.”

Elsewhere Darwin suggested that the pouter pigeon, if it occurred

wild, and used its inflated crop as a float, would be considered as a

striking example of design.

This controversy between them continued for many years. We find Asa

Gray referring to the argument of the pigeons three years later. Thus

he wrote (September 1st, 1863):--

“I will consider about fantastic variation of pigeons. I see afar

trouble enough ahead quoad design in nature, but have managed to

keep off the chilliness by giving the knotty questions a rather

wide berth. If I rather avoid, I cannot ignore the difficulties

ahead. But if I adopt your view boldly, can you promise me any

less difficulties?”

Writing the concluding paragraphs of the “Variations of Animals

and Plants under Domestication,” Darwin evidently bore in mind his

controversies on the subject with Asa Gray and Lyell, and the attacks

of the Duke of Argyll and others. Sending advanced sheets to Asa Gray,

he wrote on October 16th, 1867:--

“I finish my book with a semi-theological paragraph, in which I

quote and differ from you; what you will think of it, I know not.”

In relation to this interesting controversy, I think it well to quote,

almost in full, the metaphor by which Darwin enforced his argument that

the origin of species by natural selection precluded a belief in design

in nature as it was ordinarily conceived at the time.

This metaphor forms an important part of the conclusion of the work in

question (“Variation of Animals and Plants,” etc.):

“The long-continued accumulation of beneficial variations will

infallibly have led to structures as diversified, as beautifully

adapted for various purposes and as excellently co-ordinated, as

we see in the animals and plants around us. Hence I have spoken

of selection as the paramount power, whether applied by man to

the formation of domestic breeds, or by nature to the production

of species. I may recur to the metaphor given in a former

chapter: if an architect were to rear a noble and commodious

edifice, without the use of cut stone, by selecting from the

fragments at the base of a precipice wedged-formed stones for his

arches, elongated stones for his lintels, and flat stones for his

roof, we should admire his skill and regard him as the paramount

power. Now, the fragments of stone, though indispensable to the

architect, bear to the edifice built by him the same relation

which the fluctuating variations of organic beings bear to the

varied and admirable structures ultimately acquired by their

modified descendants.

“Some authors have declared that natural selection explains

nothing, unless the precise cause of each slight individual

difference be made clear. If it were explained to a savage

utterly ignorant of the art of building, how the edifice had been

raised stone upon stone, and why wedge-formed fragments were used

for the arches, flat stones for the roof, &c.; and if the use of

each part and of the whole building were pointed out, it would

be unreasonable if he declared that nothing had been made clear

to him, because the precise cause of the shape of each fragment

could not be told. But this is a nearly parallel case with the

objection that selection explains nothing, because we know not

the cause of each individual difference in the structure of each

being.”

* * * * *

“The shape of the fragments of stone at the base of our precipice

may be called accidental, but this is not strictly correct; for

the shape of each depends on a long sequence of events, all

obeying natural laws.... But in regard to the use to which the

fragments may be put, their shape may be strictly said to be

accidental....”

In his article in the _Nation_ (March 19th, 1868), Asa Gray criticised

the metaphor as follows:--

“But in Mr. Darwin’s parallel, to meet the case of nature

according to his own view of it, not only the fragments of rock

(answering to variation) should fall, but the edifice (answering

to natural selection) should rise, irrespective of will or

choice!”

This passage is quoted in the “Life and Letters” (Vol. III., p. 84),

and Francis Darwin makes the convincing reply:--

“But my father’s parallel demands that natural selection shall be

the architect, not the edifice--the question of design only comes

in with regard to the form of the building materials.”

Darwin’s reply was contained in his letter to Asa Gray dated May 8th,

1868:--

“You give a good slap at my concluding metaphor: undoubtedly I

ought to have brought in and contrasted natural and artificial

selection; but it seemed so obvious to me that natural selection

depended on contingencies even more complex than those which

must have determined the shape of each fragment at the base

of my precipice. What I wanted to show was that, in reference

to pre-ordainment, whatever holds good in the formation of an

English pouter-pigeon holds good in the formation of a natural

species of pigeon. I cannot see that this is false. If the right

variations occurred, and no others, natural selection would be

superfluous.”

To this, Asa Gray replied in his letter of May 25th:--

“As to close of my article, to match close of your book,--you

see plainly I was put on the defence by your reference to an

old hazardous remark of mine. I found your stone-house argument

unanswerable in substance (for the notion of design must after

all rest mostly on faith, and on accumulation of adaptations,

&c.); so all I could do was to find a vulnerable spot in the

shaping of it, fire my little shot, and run away in the smoke.

“Of course I understand your argument perfectly, and feel the

might of it.”

From this last letter I think we may conclude that Asa Gray’s

feelings on this subject rested, as he says, “on faith,” and that,

intellectually, he saw no way of meeting Darwin’s arguments.

CHAPTER XVIII.

INFLUENCE OF DARWIN UPON HUXLEY.

[Sidenote: HUXLEY AND NATURAL SELECTION.]

It is of the utmost interest to trace the influence of Darwin upon

Huxley, his great General in the numerous controversial battles which

had to be fought before the new views were to secure a fair hearing

and, at length, complete success. Now that we are quietly enjoying the

fruit of his many victories, we are apt to forget how much we owe to

Huxley, not only for evolution, but for that perfect freedom in the

expression of thought and opinion which we enjoy. For Huxley fought

on wider issues than those raised by evolution, wide as these are;

and with a success so great that it is inconceivable that any new and

equally illuminating thought which the future may hold in store for

us, will meet with a reception like that accorded to the “Origin of

Species.”

At first sight it seems a simple matter to describe the effect of the

“Origin” upon Huxley, considering that he, more than any other man,

expounded it, and defended it from the most weighty of the attacks made

upon it. Hence, it is only natural to believe, as many have done, that

he was in entire agreement with the conclusions of the book as regards

natural selection as well as evolution. On the other hand, the opinion

has often been expressed that Huxley, although agreeing with the

“Origin” for some years after its first appearance, changed his mind in

later years, and no longer supported Darwin’s views.

I shall give reasons for rejecting both these opinions about Huxley,

although the first is far nearer the truth than the second. The

latter is clearly untenable, and was probably merely an inference

from the fact that after a time Huxley ceased to enter into Darwinian

controversies. But this was because he had done his work with entire

success, and therefore turned his attention in other directions.

Whenever he was called on to write or speak about Darwinism, as he was

on two occasions within a few months of his death, his writings and

speeches left no doubt about his thoughts on the subject. Furthermore,

in the Preface to “Darwiniana,” written in 1893, he expressly denied

that he had recanted or changed his opinions about Darwin’s views.

In order to appreciate the influence of Darwin upon Huxley, we must

find out the beliefs of the latter upon the “species question” before

the appearance of the “Origin.” In his chapter “On the Reception of

the ‘Origin of Species’” (“Life and Letters,” Vol. II.) Huxley says

that, before 1858, he took up an agnostic position as regards evolution

“... upon two grounds: firstly, that up to that time, the evidence in

favour of transmutation was wholly insufficient; and, secondly, that no

suggestion respecting the causes of the transmutation assumed, which

had been made, was in any way adequate to explain the phenomena.” It

is obvious that these two grounds are entirely distinct, and that the

logical foundation of the first is far more secure than that of the

second.

The effect of the “Origin” was completely to convince Huxley on the

first ground: from that time he never doubted the truth of evolution,

however it may have been brought about. With regard to the second

ground, it is quite clear that Huxley had a very high opinion of

natural selection: he thought it incomparably the best suggestion upon

the subject that had ever been made, and he firmly believed that it

accounted for something--that it may even have taken a dominant part

in bringing about evolution. On the other hand, he never felt quite

confident about the entire sufficiency of the evidence in its favour.

It is probable that he was far more interested in the establishment

of evolution as a fact than in natural selection as an explanation of

it. He saw the vast amount of research in all kinds of new or almost

neglected lines, which would be directly inspired by evolution. And his

own investigations in some of these lines soon afforded some of the

most weighty evidence in favour of the doctrine. Natural selection had

not the same personal interest for him; no one has expounded it better

or defended it more vigorously and successfully, but Huxley’s own

researches never lay in directions which would have made them available

as a test of the theory. Of natural selection he might have used the

words of Mercutio--it may not be “so deep as a well, nor so wide as a

church door,” to contain the whole explanation of evolution, “but ’tis

enough ’twill serve”; it will, at any rate, prevent him from feeling

the second ground on which he had maintained an agnostic position.

I believe that he maintained these views with inflexible consistency

throughout his life, the only indications of change being in the last

year, when the contrast between his certainty of evolution and his

uncertainty of natural selection, as expressed in the two speeches

quoted on pp. 140, 141, was, perhaps, more sharply marked than at any

other period.

It is now proposed to support this conclusion by many extracts from

Huxley’s writings, as well as from his speeches, which have been

alluded to above. The deep interest of the subject, and the wide

differences of opinion with regard to it, justify, and indeed demand,

copious quotations selected from works and speeches, written and spoken

at many different times during the years between 1858 and 1894.

It may not be out of place to emphasise the fact that the sole

responsibility for the conclusions here drawn rests with the author of

this volume, and that the evidence on which the conclusions rest is

supplied in full.

About a month before the “Origin” was published, Darwin wrote to

Professor Huxley asking for the names of foreigners to whom to send his

book. This communication is of great interest as being the earliest

letter, accessible to the public, which he wrote to Huxley. In it he

says: “I shall be _intensely_ curious to hear what effect the book

produces on you”; but he evidently thought that Huxley would disagree

with much in it, and must have been surprised as well as gratified at

the way in which it was received. In his chapter “On the Reception of

the ‘Origin of Species’” (“Life and Letters,” Vol. II.), Huxley writes:

“My reflection, when I first made myself master of the central idea of

the ‘Origin,’ was, ‘How extremely stupid not to have thought of that.’”

Huxley replied on November 23rd, 1859--the day before the publication

of the “Origin”--saying that he had finished the book on the previous

day. His letter was a complete acceptance of evolution as apart from

any theory which may account for it; and a thorough agreement with

natural selection as a “true cause for the production of species.”

At no time in his life did he state how far he considered natural

selection to be a sufficient cause. He was only “prepared to go to the

stake, if requisite, in support of” the chapters which marshal the

evidence for evolution (ix., and most parts of x., xi., and xii.).

With regard to the earlier chapters, which propound the theory of

natural selection, his exact words are:--

“As to the first four chapters, I agree thoroughly and fully

with all the principles laid down in them. I think you have

demonstrated a true cause for the production of species, and have

thrown the _onus probandi_, that species did not arise in the way

you suppose, on your adversaries.”

Darwin replied with much warmth, and expressed himself as “Now

contented and able to sing my _Nunc Dimittis_.”

In the _Times_ of December 26th, 1859, appeared a masterly article upon

the “Origin,” and, after a time, it became known that Huxley was its

author. Volume II. of the “Life and Letters” explains the circumstances

under which the review was written. The article is reprinted as the

first essay (“The Darwinian Hypothesis,” I.) in “Darwiniana” (Vol.

II. of the “Collected Essays of Professor Huxley,” London, 1893). The

following quotation (pp. 19, 20) shows the attitude he took up with

regard to natural selection:--

“That this most ingenious hypothesis enables us to give a reason

for many apparent anomalies in the distribution of living

beings in time and space, and that it is not contradicted by

the main phenomena of life and organisation appear to us to be

unquestionable; and, so far, it must be admitted to have an

immense advantage over any of its predecessors. But it is quite

another matter to affirm absolutely either the truth or falsehood

of Mr. Darwin’s views at the present stage of the enquiry. Goethe

has an excellent aphorism defining that state of mind which he

calls “Thätige Skepsis”--active doubt. It is doubt which so loves

truth that it neither dares rest in doubting, nor extinguish

itself by unjustified belief; and we commend this state of mind

to students of species, with respect to Mr. Darwin’s or any other

hypothesis as to their origin. The combined investigations of

another twenty years may, perhaps, enable naturalists to say

whether the modifying causes and the selective power, which Mr.

Darwin has satisfactorily shewn to exist in Nature, are competent

to produce all the effects he ascribes to them; or whether,

on the other hand, he has been led to over-estimate the value

of the principle of natural selection, as greatly as Lamarck

over-estimated his _vera causa_ of modification by exercise.”

Of all the statements about natural selection made by Huxley, this one

seems to me the nearest to the spirit of the two speeches he made in

1894, in which it became evident that the intervening thirty-five years

had not brought the increased confidence he had hoped for. Furthermore,

in the Preface to “Darwiniana” (1893) he expressly stated that he had

not changed his mind as regards this article and the next which will be

considered (see p. 137, where the passage is quoted).

In 1860 Huxley wrote the article on “The Origin of Species” which

appeared in the _Westminster Review_ for April, and is reprinted in

“Darwiniana.” He here states the reasons for his doubts about natural

selection in considerable detail. At the beginning of the essay

(“Darwiniana,” p. 23) he asserts that--

“... all competent naturalists and physiologists, whatever their

opinions as to the ultimate fate of the doctrines put forth,

acknowledge that the work in which they are embodied is a solid

contribution to knowledge and inaugurates a new epoch in natural

history.”

Towards the end of the essay, after vindicating the logical method

followed by Darwin, he continues (pp. 73–75):--

“There is no fault to be found with Mr. Darwin’s method, then;

but it is another question whether he has fulfilled all the

conditions imposed by that method. Is it satisfactorily proved,

in fact, that species may be originated by selection? that

there is such a thing as natural selection? that none of the

phœnomena exhibited by species are inconsistent with the origin

of species in this way? If these questions can be answered

in the affirmative, Mr. Darwin’s view steps out of the ranks

of hypotheses into those of proved theories; but, so long as

the evidence at present adduced falls short of enforcing that

affirmation, so long, to our minds, must the new doctrine be

content to remain among the former--an extremely valuable, and

in the highest degree probable, doctrine, indeed the only extant

hypothesis which is worth anything in a scientific point of view;

but still a hypothesis, and not yet the theory of species.

“After much consideration, and with assuredly no bias against Mr.

Darwin’s views, it is our clear conviction that, as the evidence

stands, it is not absolutely proven that a group of animals,

having all the characters exhibited by species in Nature, has

ever been originated by selection, whether artificial or natural.

Groups having the morphological character of species, distinct

and permanent races in fact, have been so produced over and

over again; but there is no positive evidence, at present, that

any group of animals has, by variation and selective breeding,

given rise to another group which was even in the least degree

infertile with the first. Mr. Darwin is perfectly aware of this

weak point, and brings forward a multitude of ingenious and

important arguments to diminish the force of the objection. We

admit the value of these arguments to their fullest extent; nay,

we will go so far as to express our belief that experiments,

conducted by a skilful physiologist, would very probably obtain

the desired production of mutually more or less infertile breeds

from a common stock, in a comparatively few years; but still, as

the case stands at present, this ‘little rift within the lute’ is

not to be disguised nor overlooked.”

He concludes with a summary of the results of his argument. The

sentences which bear on the present question are as follows (pp. 77,

78):--

“Our object has been attained if we have given an intelligible,

however brief, account of the established facts connected with

species, and of the relation of the explanation of those facts

offered by Mr. Darwin to the theoretical views held by his

predecessors and his contemporaries, and, above all, to the

requirements of scientific logic. We have ventured to point

out that it does not, as yet, satisfy all those requirements;

but we do not hesitate to assert that it was superior to

any preceding or contemporary hypothesis, in the extent of

observational and experimental basis on which it rests, in its

rigorously scientific method, and in its power of explaining

biological phenomena, as was the hypothesis of Copernicus to the

speculations of Ptolemy. But the planetary orbits turned out to

be not quite circular after all, and, grand as was the service

Copernicus rendered to science, Kepler and Newton had to come

after him. What if the orbit of Darwinism should be a little

too circular? what if species should offer residual phenomena,

here and there, not explicable by natural selection? Twenty

years hence naturalists may be in a position to say whether this

is, or is not, the case; but in either event they will owe the

author of ‘The Origin of Species’ an immense debt of gratitude.

We should leave a very wrong impression on the reader’s mind if

we permitted him to suppose that the value of that work depends

wholly on the ultimate justification of the theoretical views

which it contains. On the contrary, if they were disproved

to-morrow, the book would still be the best of its kind--the

most compendious statements of well-sifted facts bearing on the

doctrine of species that has ever appeared.”

It is clear that two very distinct points are urged in this criticism

of natural selection--(1) the difficulty that selective methods

applied by man have not as yet produced all the characteristics of

true species; (2) supposing the latter difficulty to be surmounted or

sufficiently explained, the uncertainty as to how much or how little of

the process of evolution has been due to natural selection.

Later in the same year Darwin seems to have been a little disappointed

that Huxley’s confidence did not increase. Thus, he wrote on December

2nd, 1860:--

“I entirely agree with you that the difficulties on my notions

are terrific; yet having seen what all the _Reviews_ have said

against me, I have far more confidence in the _general_ truth

of the doctrine than I formerly had. Another thing gives me

confidence--viz. that some who went half an inch with me now go

further, and some who were bitterly opposed are now less bitterly

opposed. And this makes me feel a little disappointed that you

are not inclined to think the general view in some slight degree

more probable than you did at first. This I consider rather

ominous. Otherwise I should be more contented with your degree

of belief. I can pretty plainly see that if my view is ever to

be generally adopted, it will be by young men growing up and

replacing the old workers, and then young ones finding that they

can group facts and search out new lines of investigation better

on the notion of descent than on that of creation.”

In 1863 Huxley delivered a course of lectures to working men on “The

Causes of the Phenomena of Organic Nature”; here, too, he expressed

his opinions about natural selection with great clearness and force.

These lectures are reprinted as the concluding part of “Darwiniana,”

and the references are to the pages of that volume of his collected

essays.

On page 464 we read--

“Here are the phenomena of Hybridism staring you in the face, and

you cannot say, ‘I can, by selective modification, produce these

same results.’ Now, it is admitted on all hands, at present, so

far as experiments have gone, it has not been found possible

to produce this complete physiological divergence by selective

breeding.... If we were shewn that this must be the necessary and

inevitable results of all experiments, I hold that Mr. Darwin’s

hypothesis would be utterly shattered.”

He then goes on to show that this is very far from proved, and

concludes (page 466)--

“that though Mr. Darwin’s hypothesis does not completely

extricate us from this difficulty at present, we have not the

least right to say it will not do so.”

A passage on page 467 shows that Huxley placed natural selection

infinitely higher than any other attempt to account for evolution, and

indeed that he regarded all other attempts with scorn.

“I really believe that the alternative is either Darwinism or

nothing, for I do not know of any rational conception or theory

of the Organic universe which has any scientific position at all

beside Mr. Darwin’s.... Whatever may be the objections to his

views, certainly all other theories are absolutely out of court.”

On page 468 he continues--

“But you must recollect that when I say I think it is either Mr.

Darwin’s hypothesis or nothing; that either we must take his

view, or look upon the whole of organic nature as an enigma, the

meaning of which is wholly hidden from us; you must understand

that I mean that I accept it provisionally, in exactly the same

way as I accept any other hypothesis.”

He concludes the lectures and the volume in which they are now

reproduced by the following eloquent testimony to the unique value of

the “Origin of Species”:--

“I believe that if you strip it of its theoretical part it still

remains one of the greatest encyclopædias of biological doctrine

that any one man ever brought forth, and I believe that, if you

take it as the embodiment of an hypothesis, it is destined to be

the guide of biological and psychological speculation for the

next three or four generations.”

The next essay from which I quote was written in 1871. At the beginning

of “Mr. Darwin’s Critics” (“Darwiniana,” p. 120) he uses words which,

if they stood alone, might be interpreted as an indication of a

stronger conviction.

“Whatever may be thought or said about Mr. Darwin’s doctrines, or

the manner in which he has propounded them, this much is certain,

that, in a dozen years, the ‘Origin of Species’ has worked as

complete a revolution in biological science as the ‘Principia’

did in astronomy--and it has done so, because, in the words of

Helmholtz, it contains an ‘essentially new creative thought.’”

This last quotation, and the following one, from “Evolution in

Biology,” written in 1878, are, I think, among the strongest

utterances in favour of natural selection to be found in the Collected

Essays. At the conclusion of the above-named essay (_l. c._, p. 223) he

states that it was clearly seen that--

“if the explanation would apply to species, it would not

only solve the problem of their evolution, but that it would

account for the facts of teleology, as well as for those of

morphology;...”

“How far ‘natural selection’ suffices for the production of

species remains to be seen. Few can doubt that, if not the whole

cause, it is a very important factor in that operation; and that

it must play a great part in the sorting out of varieties into

those which are transitory and those which are permanent.”

The seventh essay, “The Coming of Age of ‘The Origin of Species,’” was

written in 1880. His complete confidence in evolution, as shown in this

essay, may be contrasted with his cautious statements about natural

selection. He boldly affirms evolution to be the fundamental doctrine

of the “Origin of Species,” while natural selection is, I believe,

neither mentioned nor even alluded to. On this great occasion he thus

emphasised the immense debt we owe to Darwin in that he was the first

to produce adequate evidence in favour of the ancient doctrine of

evolution, a benefit quite distinct from that which he conferred in the

theory of natural selection (see pp. 100–102).

The following are among the most confident statements about evolution

to be found in this essay. Speaking of the “Origin,” he says (p.

229):--

“... the general doctrine of evolution, to one side of which it

gives expression, obtains, in the phenomena of biology, a firm

base of operations whence it may conduct its conquest of the

whole realm of nature.”

And again, on page 332:--

“The fundamental doctrine of the ‘Origin of Species,’ as of all

forms of the theory of evolution applied to biology, is ‘that

the innumerable species, genera, and families of organic beings

with which the world is peopled have all descended, each within

its own class or group, from common parents, and have all been

modified in the course of descent.’”

Furthermore, on page 242 we read:--

“I venture to repeat what I have said before, that so far as the

animal world is concerned, evolution is no longer a speculation,

but a statement of historical fact. It takes its place alongside

of those accepted truths which must be reckoned with by

philosophers of all schools.”

And on the same page he quotes with approval the statement by M.

Filhol of the results to which he had been led by his palæontological

investigations:--

“Under the influence of natural conditions of which we have no

exact knowledge, though traces of them are discoverable, species

have been modified in a thousand ways: species have arisen which,

becoming fixed, have thus produced a corresponding number of

secondary species.”

Similarly, in the Obituary notice in _Nature_ (1882), Huxley speaks

of the secure position in which Darwin had placed the doctrine of

evolution as his great achievement. The following eloquent passage

occurs on page 247 of “Darwiniana”:--

“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, irrefragibly established

in science,...”

In the impressive speech in which Huxley handed over the statue of

Darwin to the Prince of Wales, as representative of the Trustees of

the British Museum, on June 9th, 1885 (“Darwiniana,” p. 248), the

references to Darwin are most consistent with the view that the support

to evolution was held by the speaker to be the great work of his life.

Natural selection is not mentioned.

The next publication on this subject by Huxley is the celebrated

chapter “On the Reception of the ‘Origin of Species,’” in the second

volume of the great “Life and Letters.” In this chapter he speaks

rather more confidently about natural selection than in some of the

earlier essays and in the later speeches:--

“The reality and the importance of the natural processes on which

Darwin founds his deductions are no more doubted than those

of growth and multiplication; and, whether the full potency

attributed to them is admitted or not, no one doubts their vast

and far-reaching significance.”

But of evolution he speaks far more strongly:--

“To any one who studies the signs of the times, the emergence

of the philosophy of Evolution, [“bound hand and foot and

cast into utter darkness during the millennium of theological

scholasticism”] in the attitude of claimant to the throne of the

world of thought, from the limbo of hated and, as many hoped,

forgotten things, is the most portentous event of the nineteenth

century.”

And for this he gives Darwin the credit.

Later on he indicates the sense in which his keen appreciation of

natural selection is to be understood. Thus, such strong statements as--

“... the publication of the Darwin and Wallace papers in 1858,

and still more that of the ‘Origin’ in 1859, had the effect ...

of the flash of light, which to a man who has lost himself in a

dark night, suddenly reveals a road which, whether it takes him

straight home or not, certainly goes his way”;

and--

“The facts of variability, of the struggle for existence, of

adaptation to conditions, were notorious enough; but none of

us had suspected that the road to the heart of the species

problem lay through them, until Darwin and Wallace dispelled

the darkness, and the beacon-fire of the ‘Origin’ guided the

benighted,”

if they stood alone, might naturally be interpreted as an unqualified

testimony to the permanent truth of natural selection. But this

interpretation is expressly excluded:--

“Whether the particular shape which the doctrine of evolution, as

applied to the organic world, took in Darwin’s hands, would prove

to be final or not, was, to me, a matter of indifference. In my

earliest criticisms of the ‘Origin’ I ventured to point that its

logical foundation was insecure ...; and that insecurity remains.”

Its value for Huxley was that it was “incomparably more probable than

the creation hypothesis”; that it was “a hypothesis respecting the

origin of known organic forms, which assumed the operation of no causes

but such as could be proved to be actually at work”; that it provided

“clear and definite conceptions which could be brought face to face

with facts and have their validity tested”; that it freed us “for ever

from the dilemma--refuse to accept the creation hypothesis, and what

have you to propose that can be accepted by any cautious reasoner?”

Indeed, the hypothesis did away with this dilemma, even if it were

itself to disappear; for “if we had none of us been able to discern

the paramount significance of some of the most patent and notorious of

natural facts, until they were, so to speak, thrust under our noses,

what force remained in the dilemma--creation or nothing? It was obvious

that, hereafter, the probability would be immensely greater, that

the links of natural causation were hidden from our purblind eyes,

than that natural causation should be incompetent to produce all the

phenomena of nature.”

Therefore, “the only rational course for those who had no other object

than the attainment of truth, was to accept ‘Darwinism’ as a working

hypothesis, and see what could be made of it.” Furthermore, “Whatever

may be the ultimate fate of the particular theory put forth by Darwin,

... all the ingenuity and all the learning of hostile critics has not

enabled them to adduce a solitary fact, of which it can be said, this

is irreconcilable with the Darwinian theory.”

Taking this argument as a whole, it seems to me to amount to the words

of Mercutio quoted at the beginning of this chapter.

In the following year (1888) Huxley wrote the Obituary Notice of

Darwin for the Proceedings of the Royal Society: it is reprinted in

“Darwiniana” (pp. 253 _et seq._). In this admirable essay the author

recognises that Darwin evidently accepted evolution before he could

offer any explanation of the motive cause by which that process

took place. The theory of descent with modification had often been

thought of before, “but in the eyes of the naturalist of the ‘Beagle’

(and, probably, in those of most sober thinkers), the advocates of

transmutation had done the doctrine they expounded more harm than

good.” Huxley speaks of the “Origin” as “one of the hardest books to

master,” in this agreeing with Hooker (see p. 111).

In this essay Huxley gives a clear and excellent statement of natural

selection, prefaced by these words (p. 287):--

“Although, then, the present occasion is not suitable for any

detailed criticism of the theory, or of the objections which have

been brought against it, it may not be out of place to endeavour

to separate the substance of the theory from its accidents; and

to shew that a variety not only of hostile comments, but of

friendly would-be improvements, lose their _raison d’être_ to the

careful student.”

Then follows a brief but epigrammatic description, such as only Huxley

could have written, of the theory, and some of the chief arguments

which have revolved round it. Occasionally he speaks as if he were

stating his own opinion as well as Darwin’s, but throughout it seems

to me that his object is not to give his own views but to write a fair

and clear account of Darwin’s theory, and to defend it from a number

of criticisms and modifications which have been, from time to time,

brought forward.

“Darwiniana” was published in 1893, and this is the date of the

Preface, in which Huxley speaks of--

“... the ancient doctrine of Evolution, rehabilitated and placed

upon a sound scientific foundation, since, and in consequence of,

the publication of the ‘Origin of Species....’”

He thinks that readers will admit that in the first two essays (see

pages 124–128 of the present volume)--

“... my zeal to secure fair play for Mr. Darwin, did not drive

me into the position of a mere advocate; and that, while doing

justice to the greatness of the argument, I did not fail to

indicate its weak points. I have never seen any reason for

departing from the position which I took up in these two essays;

and the assertion which I sometimes meet with nowadays, that I

have ‘recanted’ or changed my opinions about Mr. Darwin’s views,

is quite unintelligible to me.”

“As I have said in the seventh essay, [see pages 131, 132 of the

present volume] the fact of evolution is to my mind sufficiently

evidenced by palæontology; and I remain of the opinion expressed

in the second, that until selective breeding is definitely proved

to give rise to varieties infertile with one another, the logical

foundation of the theory of natural selection is incomplete.”

It is therefore clear, as I have before stated, that Huxley, in 1893,

re-stated his criticisms and qualifications of thirty years before,

and expressed his conviction anew of the validity of the objections

which he then raised against a full and complete acceptance of natural

selection.

We now come to the last and most significant of all Huxley’s utterances

on evolution and natural selection, made on two great occasions in the

last year of his life. Lord Salisbury, in his eloquent and interesting

Presidential Address to the British Association at Oxford (August 8th,

1894), had said of Darwin:--

“He has, as a matter of fact, disposed of the doctrine of the

immutability of species.... Few now are found to doubt that

animals separated by differences far exceeding those that

distinguish what we know as species have yet descended from

common ancestors.”

While thus completely admitting evolution in the organic world, Lord

Salisbury attacked natural selection on two grounds--first, on the

insufficiency of the time allowed by physicists for a process which

is, of necessity, extremely slow in its operation; secondly, on the

ground that “we cannot demonstrate the process of natural selection in

detail; we cannot even, with more or less ease, imagine it.” And his

main objection under this head was the supposed difficulty in securing

the union of successful variations. The actual words have been already

quoted on page 83, where it was shown that the criticism does not apply

to natural selection, but to a theory mistaken by the speaker for that

of Darwin. Curiously enough, the first objection of the insufficiency

of time was the indirect cause of a subsequent trenchant criticism by

Professor Perry of the line of mathematical reasoning on which the

limit had been fixed.

Huxley was called on to second the vote of thanks, and his speech had

evidently been considered with the greatest care. I quote the passages

which bear on evolution and natural selection from the _Times_ of

August 9th, 1894, in which a _verbatim_ report is furnished:--

“... As one of those persons who for many years past had made

a pretty free use of the comfortable word ‘evolution,’ let him

remind them that 34 years ago a considerable discussion, to which

the President had referred, took place in one of their sectional

meetings upon what people frequently called the ‘Darwinism

question,’ but which on that occasion was not the Darwinism

question, but the very much deeper question which lay beneath

the Darwinism question--he meant the question of evolution....

The two doctrines, the two main points, for which these men

[Sir John Lubbock, Sir J. Hooker, and the speaker] fought were

that species were mutable, and that the great variety of animal

forms had proceeded from gradual and natural modification of the

comparatively few primitive forms....”

After alluding to the revolution in thought which had taken place in

thirty-four years, he said:--

“As he noted in the presidential address to which they had just

listened with such well-deserved interest, he found it stated on

that which was then and at this time the highest authority for

them, that as a matter of fact the doctrine of the immutability

of species was disposed of and gone. He found that few were

now found to doubt that animals separated by differences far

exceeding those which they knew as species were yet descended

from a common ancestry. Those were their propositions; those

were the fundamental principles of the doctrine of evolution.

Darwinism was not evolution, nor Spencerism, nor Hæckelism, nor

Weismannism, but all these were built on the fundamental doctrine

which was evolution, which they maintained so many years, and

which was that upon which their President had put the seal of his

authority that evening....”

Huxley thus hailed the statements of the President in favour of

evolution, while the attacks on natural selection he merely met by

saying that the address would have made a good subject for discussion

in one of the sections, and by insisting with impressive solemnity that

evolution was a very different thing from natural selection, thereby

implying that the former would be unaffected by the fate of the latter.

The second occasion was between three and four months later, when

Huxley spoke at the Anniversary Dinner of the Royal Society, November

30th, 1894, after having been awarded the Darwin Medal at the afternoon

meeting. I quote his words from the _verbatim_ report of the _Times_

for December 1st:--

“... I am as much convinced now as I was 34 years ago that

the theory propounded by Mr. Darwin, I mean that which he

propounded--not that which has been reported to be his by too

many ill-instructed, both friends and foes--has never yet been

shewn to be inconsistent with any positive observations, and if

I may use a phrase which I know has been objected to and which

I use in a totally different sense from that in which it was

first proposed by its first propounder, I do believe that on

all grounds of pure science it ‘holds the field,’ as the only

hypothesis at present before us which has a sound scientific

foundation.... I am sincerely of opinion that the views which

were propounded by Mr. Darwin 34 years ago may be understood

hereafter as constituting an epoch in the intellectual history of

the human race. They will modify the whole system of our thought

and opinion, our most intimate convictions. But I do not know, I

do not think anybody knows, whether the particular views which he

held will be hereafter fortified by the experience of the ages

which come after us; ... whether the particular form in which

he has put them before us (the Darwinian doctrines) may be such

as is finally destined to survive or not is more, I venture to

think, than anybody is capable at this present moment of saying.”

It is unnecessary to say anything about this passage, which fitly sums

up and sets the seal on the long series of quotations I have felt

obliged to make.

It may not be out of place, however, to state in a few words why

many naturalists, including the present writer, are not inclined to

accept the extremely cautious and guarded language of one upon whom,

with regard to so many other subjects, they have ever looked as their

teacher and guide. Concerning the verification of a hypothesis, Huxley

said in his lectures to working men (“Darwiniana,” pages 367, 368)--

“... that the more extensive verifications are,--that the more

frequently experiments have been made, and results of the same

kind arrived at,--that the more varied the conditions under which

the same results are attained, the more certain is the ultimate

conclusion....”

And again--

“In scientific enquiry it becomes a matter of duty to expose a

supposed law to every possible kind of verification, and to take

care, moreover, that this is done intentionally, and not left to

a mere accident....”

It may well be that the length of time required before an

artificially-selected race will exhibit, when interbred with the parent

species, phenomena of hybridism similar to those which are witnessed

when distinct natural species are interbred--will be fatal to the

production of this important line of evidence. But there is nothing to

hinder us from holding the reasonable belief that such evidence might

be obtained if we had command of the necessary conditions; and in the

meantime other evidence of the most satisfactory kind is accumulating,

and on a vast scale. Whenever a naturalist approaches a problem in the

light of the theory of natural selection, and is able, by its aid,

to predict a conclusion which subsequent investigation proves to be

correct, he is helping in the production of evidence in favour of the

theory. When a naturalist has found the formula “if natural selection

be true so-and-so ought to happen” the safest of all guides into

the unknown, when it has brought him success many times and in very

different directions, when he knows that many other workers in other

fields of biological inquiry have had a similarly happy experience, he

gradually comes to feel a profound confidence in the permanent truth

and the far-reaching importance of the great theory which has served

him so well.

CHAPTER XIX.

THE DIFFICULTY WITH WHICH THE “ORIGIN” WAS UNDERSTOOD.

Even earlier than Huxley, H. C. Watson wrote warmly accepting natural

selection. In his letter, which is dated November 21st, 1859, he said:--

“Your leading idea will surely become recognised as an

established truth in science--_i.e._ ‘Natural Selection.’ It has

the characteristics of all great natural truths, clarifying what

was obscure, simplifying what was intricate, adding greatly to

previous knowledge. You are the greatest revolutionist in natural

history of this century, if not of all centuries.”

[Sidenote: MISUNDERSTANDING OF THE THEORY.]

For some years to come, however, such views as these were the

exception, as will soon be shown.

The Duke of Argyll has argued (_Nineteenth Century_, December,

1887) that the success of “Natural Selection” has followed from the

convincing character of the words used, scientific men (“the populace

of science” he calls them) being so easily led by the power of loose

analogies that they have been convinced of the truth of the principle

because they are familiar with Nature on the one hand, and selection as

a process on the other!

As I am not aware that this preposterous suggestion has ever been

publicly disproved, and since therefore some readers of the journal in

question may have been misled by it, I have collected much evidence,

which proves that the principle of natural selection was only absorbed

with the very greatest difficulty, and that the words used in

describing it for a long time entirely failed to inform even eminent

scientific men of the essential characteristics of the theory itself,

and certainly failed most signally to convince them. Conviction came

very gradually as the theory was slowly understood and was seen to

offer an intelligible explanation of an immense and ever-increasing

number of facts.

I will now bring together quotations from Darwin’s letters in 1859 and

1860, showing how soon he came to realise the difficulty with which

natural selection was understood, and to feel that he might have been

more successful with some other title.

In 1859 he wrote to Dr. W. B. Carpenter--“I have found the most

extraordinary difficulty in making even able men understand at what

I was driving.” The remaining quotations are all taken from letters

written in 1860. By the middle of this year, when he was feeling

oppressed by hostile reviews and unfair and ignorant criticisms (“I

am getting wearied at the storm of hostile reviews, and hardly any

useful”), he often alludes to the failure of opponents to understand

his theory. Thus, in a letter to Hooker (June 5th), he says:--

“This review, however, and Harvey’s letter have convinced me that

I must be a very bad explainer. Neither really understand what

I mean by Natural Selection.... I hope to God you will be more

successful than I have been in making people understand your

meaning.”

He says almost the same thing in a letter to Lyell (June 6th):--

“... I am beginning to despair of ever making the majority

understand my notions.... I must be a very bad explainer. I

hope to Heaven that you will succeed better. Several reviews

and several letters have shown me too clearly how little I am

understood. I suppose ‘Natural Selection’ was a bad term; ...

I can only hope by reiterated explanations finally to make the

matter clearer.”

Writing to Asa Gray, he says:--

“... I have had a letter of fourteen folio pages from Harvey

against my book, with some ingenious and new remarks; but it is

an extraordinary fact that he does not understand at all what I

mean by Natural Selection.”

Later on, he again wrote to Lyell:--

“Talking of ‘natural selection’; if I had to commence _de novo_,

I would have used ‘natural preservation.’ For I find men like

Harvey of Dublin cannot understand me, though he has read the

book twice. Dr. Gray of the British Museum remarked to me that,

‘_selection_ was obviously impossible with plants! No one could

tell him how it could be possible!’ And he may now add that the

author did not attempt it to him!”

And still later he wrote asking Lyell’s advice as to additions to a

new edition of the “Origin,” saying:--“I would also put a note to

‘Natural Selection,’ and show how variously it has been misunderstood.”

This note is to be found on page 63 of the sixth edition. In it he

tells us that some writers have “even imagined that natural selection

induces variability,” instead of merely preserving it; others that

natural selection “implies conscious choice in the animals which become

modified”; others that it is set up “as an active power or Deity.”

In writing (December) to Murray about a new edition of the “Origin,”

he alludes to the “many corrections, or rather additions, which I

have made in hopes of making my many rather stupid reviewers at least

understand what is meant.”

He seems to have retained a very vivid recollection of the difficulty

with which his theory was understood at first; thus he tells us in his

“Autobiography”:--

“I tried once or twice to explain to able men what I meant by

Natural Selection, but signally failed.”

Why the term “natural selection” was chosen by Darwin is very clearly

shown in the three following quotations from letters to distinguished

scientific men, which were probably written in answer to attacks or

criticisms on this very point.

He writes to Lyell in 1859, “Why I like the term is that it is

constantly used in all works on breeding.”

Writing to H. G. Bronn in 1860, he explains his motives with great

clearness and force:--

“Several scientific men have thought the term ‘Natural Selection’

good, because its meaning is _not_ obvious, and each man could

not put on it his own interpretation, and because it at once

connects variation under domestication and nature.... Man has

altered, and thus improved the English race-horse by _selecting_

successive fleeter individuals; and I believe, owing to the

struggle for existence, that similar _slight_ variations in a

wild horse, _if advantageous to it_, would be _selected_ or

_preserved_ by nature; hence Natural Selection.”

In 1866 he wrote to Wallace, comparing the term with that which we owe

to Herbert Spencer:--

“I fully agree with all that you say on the advantages of H.

Spencer’s excellent expression of ‘the survival of the fittest.’

This however had not occurred to me till reading your letter. It

is, however, a great objection to this term that it cannot be

used as a substantive governing a verb; and that it is a real

objection I infer from H. Spencer continually using the words,

natural selection. I formerly thought, probably in an exaggerated

degree, that it was a great advantage to bring into connection

natural and artificial selection; this indeed led me to use a

term in common, and I still think it some advantage.... The term

Natural Selection has now been so largely used abroad and at

home, that I doubt whether it could be given up, and with all its

faults I should be sorry to see the attempt made. Whether it will

be rejected must now depend ‘on the survival of the fittest.’ As

in time the term must grow intelligible the objections to its use

will grow weaker and weaker. I doubt whether the use of any term

would have made the subject intelligible to some minds, clear

as it is to others; for do we not see even to the present day

Malthus on Population absurdly misunderstood? This reflection

about Malthus has often comforted me when I have been vexed at

the mis-statement of my own views.”

A large number of critics not only failed to understand natural

selection, but they asserted that it was precisely the same theory as

that advanced by Lamarck or one of the other writers on evolution

before Darwin. This seems almost incredible to us at the present

day, when the biological world is divided into two sections on the

very subject, and when it is generally recognised that Lamarck’s

theory would be, if it were proved to be sound, a formidable rival to

natural selection as a motive cause of evolution. But the following

quotations--a few among many--leave no doubt whatever upon the subject.

Evidence on this point reached Darwin almost immediately after the

appearance of the “Origin.” Thus he writes to Hooker on December 14th,

1859:--

“Old J. E. Gray, at the British Museum, attacked me in fine

style: ‘You have just reproduced Lamarck’s doctrine, and nothing

else, and here Lyell and others have been attacking him for

twenty years, and because _you_ ... say the very same thing, they

are all coming round; it is the most ridiculous inconsistency,’

&c. &c.”

In the following year, Wilberforce, Bishop of Oxford, writing in the

_Quarterly Review_ for July, 1860, appeals to Lyell,

“in order that with his help this flimsy speculation may be as

completely put down as was what in spite of all denials we must

venture to call its twin though less-instructed brother, the

‘Vestiges of Creation.’”

Again, Dr. Bree, in “Species not Transmutable,” says:

“The only real difference between Mr. Darwin and his two

predecessors, [Lamarck and the “Vestiges”] is this:--that while

the latter have each given a mode by which they conceive the

great changes they believe in have been brought about, Mr. Darwin

does no such thing.”

One of the most interesting of the countless examples of

misunderstanding is contained in a recently published letter from W. S.

Macleay to Robert Lowe.[H] This letter was written from Elizabeth Bay,

and is dated May, 1860, evidently just after the first edition of the

“Origin,” a copy of which had been sent by Robert Lowe, had been read

by Macleay.

“Again if this primordial cell had a Creator, as Darwin seems

to admit, I do not see what we gain by denying the Creator, as

Darwin does, all management of it after its creation. Lamarck

was more logical in supposing it to have existed of itself from

all eternity--indeed this is the principal difference that I

see between this theory of Darwin’s and that of Lamarck, who

propounded everything essential in the former theory, in a work

now rather rare--his ‘Philosophie Zoologique.’ But you may see

an abridgment of it in so common a book as his ‘Histoire Nat.

des Animaux Vertébrés,’ vol. i., pp. 188, _et seq._--Edit. 1818,

where the examples given of natural selection are the gasteropod

molluscs.... Natural selection (sometimes called ‘struggles’ by

Darwin) is identical with the ‘Besoins des Choses’ of Lamarck,

who, by means of his hypothesis, for instance, assigns the

constant stretching of the neck to reach the acacia leaves as

the cause of the extreme length of it in the giraffe; much in

the same way the black bear, according to Darwin, became a

whale, which I believe as little as his other assertion that our

progenitors anciently had gills--only they had dropped off by

want of use in the course of myriads of generations.”

I had long been anxious to possess a copy of the first edition of the

“Origin,” and was fortunate enough to come across one about the time

when Macleay’s letter was pointed out to me by my wife. I opened the

title-page, and found upon it the signature “W. S. Macleay”; it must

have been the very volume given him by Robert Lowe, which Macleay had

read and believed he had been fairly criticising. Out of Macleay’s

volume, therefore, I quote the sentences he referred to in his letter.

Darwin’s real statement about the black bear which “became a whale” is

to be found on page 184:--

“In North America the black bear was seen by Hearne swimming

for hours with widely open mouth, thus catching, like a whale,

insects in the water. Even in so extreme a case as this, if

the supply of insects were constant, and if better adapted

competitors did not already exist in the country, I can see

no difficulty in a race of bears being rendered, by natural

selection, more and more aquatic in their structure and habits,

with larger and larger mouths, till a creature was produced as

monstrous as a whale.”

The statement about the gills which “dropped off by want of use”

becomes in the original (p. 191):--

“In the higher vertebrata the branchiæ have wholly

disappeared--the slits on the sides of the neck and the loop-like

course of the arteries still marking in the embryo their former

position.”

Although the hypothetical case of the black bear--carefully guarded as

it is--does not now appear to us at all extravagant (indeed, in the

cleft cheeks of the goat-sucker we have a precisely analogous case),

Darwin seems to have thought it unsuitable, probably because it became

an easy butt for ignorant ridicule. We find accordingly that in the

second and all subsequent editions everything after the word “water”

is omitted, while “almost” is inserted before “like a whale.” He was

alluding to this passage when he wrote to Lyell (December 22nd, 1859):

“Thanks about ‘Bears,’ a word of ill-omen to me.” Furthermore, Andrew

Murray[I] says, concerning the sentences as they stand in the first

edition:--

“In quoting this, I do not at all mean to give it as a fair

illustration of Mr. Darwin’s views. I only refer to it as

indicating the extent to which he is prepared to go. The example

here given I look upon (as I have reason to know that Mr. Darwin

himself does) merely as an extreme and somewhat extravagant

illustration, imagined expressly to show in a forcible way how

‘natural selection’ would operate in making a mouth bigger and

bigger, because more advantageous.”

CHAPTER XX.

THE DIFFICULTY WITH WHICH THE “ORIGIN” WAS UNDERSTOOD

(_continued_)--VIEWS ON SPONTANEOUS GENERATION.

The history of opinion on evolution and natural selection, in the years

which followed the publication of the “Origin,” can be traced in the

titles of the papers and subjects of discussion at successive meetings

of the British Association. In the Presidential Address delivered by

Professor Newton to the Biological Section of the Manchester meeting in

1887, there is a most interesting account of the struggles which took

place:--

“The ever-memorable meeting ... at Oxford in the summer of 1860

saw the first open conflict between the professors of the new

faith and the adherents of the old one. Far be it from me to

blame those among the latter who honestly stuck to the creed in

which they had educated themselves; but my admiration is for the

few dauntless men who, without flinching from the unpopularity

of their cause, flung themselves in the way of obloquy, and

impetuously assaulted the ancient citadel in which the sanctity

of ‘species’ was enshrined and worshipped as a palladium. However

strongly I myself sympathised with them, I cannot fairly state

that the conflict on this occasion was otherwise than a drawn

battle; and thus matters stood when in the following year the

Association met in this city [Manchester]. That, as I have

already said, was a time of ‘slack water.’ But though the ancient

beliefs were not much troubled, it was for the last time that

they could be said to prevail; and thus I look upon our meeting

in Manchester 1861 as a crisis in the history of biology. All

the same, the ancient beliefs were not allowed to pass wholly

unchallenged; and one thing is especially to be marked--they

were challenged by one who was no naturalist at all, by one who

was a severe thinker no less than an active worker; one who was

generally right in his logic, and never wrong in his instinct;

one who, though a politician, was invariably an honest man--I

mean the late Professor Fawcett. On this occasion he brought the

clearness of his mental vision to bear upon Mr. Darwin’s theory,

with the result that Mr. Darwin’s method of investigation was

shewn to be strictly in accordance with the rules of deductive

philosophy, and to throw light where all was dark before.”

Professor Newton specially alluded to this interesting case of

Professor Fawcett as illustrating his conviction that the theory of

natural selection--

“did not, except in one small point, require a naturalist to

think it out and establish its truth.... But in order to see the

effect of this principle upon organic life the knowledge--the

peculiar knowledge--of the naturalist was required. This was

the knowledge of those slight variations which are found in

all groups of animals and plants.... Herein lay the triumph

of Mr. Darwin and Mr. Wallace. That triumph, however, was not

celebrated at Manchester. The question was of such magnitude as

to need another year’s incubation, and the crucial struggle came

a twelvemonth later when the Association met at Cambridge. The

victory of the new doctrine was then declared in a way that none

could doubt. I have no inclination to join in the pursuit of the

fugitives.”

There is reason to believe that Professor Newton’s impressions of the

result of the celebrated meeting of the British Association at Oxford

in 1860 are more accurate than those of the eyewitness quoted in the

“Life and Letters.” The latter has pictured a brilliant triumph for

Huxley in the renowned duel with the Bishop of Oxford. But I have

been told by more than one of the audience that Huxley was really too

angry to speak effectively, nor is this to be wondered at, considering

the extreme provocation. Mr. William Sidgwick, who was present and

sympathised warmly with Huxley, has told me that this was his opinion.

I have heard the same from the Rev. W. Tuckwell, who also quoted a

remark of the late Professor Rolleston tending in the same direction.

Mr. Tuckwell said that it was clear that the audience as a whole

was not carried away by Huxley’s speech, but, on the contrary, was

obviously shocked at it; and he contrasted that occasion with another

at which he was also present, in the North, several years later,

when Huxley replied to an opponent who, like the bishop, appealed to

the theological prejudices of his hearers. But by that time the new

teachings had been absorbed, and Huxley gained a signal triumph.

[Sidenote: OPPOSITION.]

It must not be supposed that Darwin was by any means indifferent to the

attacks on his views. On the contrary, his sensitive nature was greatly

depressed by the violent and often most unfair criticisms to which he

was subjected, although beneath this evident disturbance lay the firm

conviction that he had seen the truth, and that the truth would in the

end be seen by others.

After the great fight with the bishop at the British Association at

Oxford, he wrote to Hooker (July 2nd, 1860):--

“I have read lately so many hostile views, that I was beginning

to think that perhaps I was wholly in the wrong, and that ----

was right when he said the whole subject would be forgotten in

ten years; but now that I hear that you and Huxley will fight

publicly (which I am sure I never could do), I fully believe that

our cause will, in the long-run, prevail.”

Looking at the history of opinion on this subject, the slowness with

which the new ideas were absorbed appears remarkable. Even so able a

man as the late Professor Rolleston wrote in 1870 (“Forms of Animal

Life,” Introduction, p. xxv., First Edition) the following carefully

guarded sentences, which, it is to be noted, deal with evolution rather

than natural selection. Speaking of “the theory of evolution with which

Mr. Darwin’s name is connected,” Rolleston says:--

“Many of the peculiarities which attach to biological

classifications would thus receive a reasonable explanation; but

where verification is, _ex hypothesi_, impossible, such a theory

cannot be held to be advanced out of the region of probability.

The acceptance or rejection of the general theory will depend, as

does the acceptance or rejection of other views supported merely

by probable evidence, upon the particular constitution of each

individual mind to which it is presented!”

It was too much to expect that many of the older scientific men would

retain sufficient intellectual flexibility to be able to recognise, as

Lyell had, that the facts of nature were explained and predicted better

by the new views than by those in which they had grown up. Darwin

thoroughly understood this, and, writing to his friends, maintained

that the fate of his views was in the hands of the younger men.

A grand yet simple conception like that of natural selection,

explaining and connecting together innumerable facts which people had

previously explained differently, or had become accustomed to regard as

inexplicable, must always remain as a stumbling-block to the majority

of those who have reached or passed middle life before its first

appearance.

Hardly anything is more characteristic of Darwin than the tone with

which he wrote to acknowledged opponents. Thus his letters to L.

Agassiz (1868), Quatrefages (1869 or 1870), and Fabre (1880), are

models of the way in which a correspondence which would present

peculiar difficulties to most people may be conducted. In these letters

there is not the least attempt to slur over or minimise the points of

wide difference; on the contrary, they are most candidly stated, but

with so much respect and sympathy, and with such marked appreciation

of the knowledge he had gained from his correspondent, that the reader

must have regretted the divergence of opinion as greatly as the writer.

Tyndall has given a very interesting and pathetic account of the

evident distress with which Professor L. Agassiz, chief of the

opponents of Darwin in America, recognised the success of the

teachings he could not accept.

“Sprung from a race of theologians, this celebrated man combated

to the last the theory of natural selection. One of the many

times I had the pleasure of meeting him in the United States

was at Mr. Winthrop’s beautiful residence at Brookline, near

Boston. Rising from luncheon, we all halted, as if by a common

impulse in front of a window, and continued there a discussion

which had been started at table. The maple was in its autumn

glory; and the exquisite beauty of the scene outside seemed, in

my case, to interpenetrate without disturbance the intellectual

action. Earnestly, almost sadly, Agassiz turned and said to the

gentlemen standing round, ‘I confess that I was not prepared to

see this theory received as it has been by the best intellects

of our time. Its success is greater than I could have thought

possible.’”[J]

The history of science can hardly supply anything more sad than the

blight which may fall on a man’s career because he is unable, from

conscientious motives, to use some great means of advance. Such a

weapon for the progress of science was provided by the Darwinian

theory, and men were to be henceforth divided according to their use

or neglect of the new opportunities. Men who up to that time had been

equals were to be for ever separated, some to press forward in the

front rank of scientific discovery, others to remain as interesting

relics of a byegone age.

It is hardly necessary to say that this does not apply to men, like

Agassiz, who had already left their mark deep upon the science of their

day, but it has a very real application to those men whose position

was to be estimated by work done after the year 1858.

In the midst of those years of struggle and anxiety which followed the

appearance of the “Origin,” we meet with another instance of the same

extraordinary foresight which appeared in his contention in favour of

the persistence of the great oceans and continental areas. I refer to

his views on spontaneous generation--a very ancient belief, and one

which from time to time has been the will-o’-the-wisp of biological

speculation, leading it into all kinds of fruitless and dangerous

regions.[K]

Dr. Carpenter’s “Introduction to the Study of Foraminifera” had been

reviewed in the _Athenæum_ (March 28th, 1863), the writer attacking

evolution and favouring spontaneous generation, or, as it was then

called, heterogeny. Darwin wrote to Hooker, who had lent him a copy of

the paper, “Who would have ever thought of the old stupid _Athenæum_

taking to Oken-like transcendental philosophy written in Owenian

style!... It will be some time before we see ‘slime, protoplasm, etc.,’

generating a new animal.... It is mere rubbish, thinking at present of

the origin of life; one might as well think of the origin of matter.”

In 1871 he wrote:--

“It is often said that all the conditions for the first

production of a living organism are now present, which could

ever have been present. But if (and oh! what a big if!) we could

conceive in some warm little pond, with all sorts of ammonia

and phosphoric salts, light, heat, electricity, etc., present,

that a proteine compound was chemically formed ready to undergo

still more complex changes, at the present day such matter would

be instantly devoured or absorbed, which would not have been the

case before living creatures were formed.”

About 1870 Dr. H. C. Bastian began working on the subject, and brought

forward in his “Origin of Lowest Organisms” (1871), and “The Beginnings

of Life” (1872), what he believed to be conclusive evidence of the

truth of spontaneous generation, for which he proposed the term

Archebiosis. His enthusiasm and strong convictions were contagious, and

for a time the belief spread rather widely, although it soon collapsed

before the researches and arguments of Pasteur, Tyndall, and Huxley.

Darwin read “The Beginnings of Life,” and wrote about it to Wallace

(August 28th, 1872) as follows:--

“His [Bastian’s] general argument in favour of Archebiosis is

wonderfully strong, though I cannot think much of some few of

his arguments. The result is that I am bewildered and astonished

by his statements, but am not convinced, though, on the whole,

it seems to me probable that Archebiosis is true. I am not

convinced, partly I think owing to the deductive cast of much of

his reasoning; and I know not why, but I never feel convinced

by deduction, even in the case of H. Spencer’s writings.... I

must have more evidence that germs, or the minutest fragments of

the lowest forms, are always killed by 212° of Fahr.... As for

Rotifers and Tardigrades being spontaneously generated, my mind

can no more digest such statements, whether true or false, than

my stomach can digest a lump of lead.”

CHAPTER XXI.

VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION: PANGENESIS (1868).

We now come to consider the succession of invaluable works produced by

Darwin after the appearance of the “Origin,” the last of which--that on

Earthworms--was published about six months before his death.

Darwin’s method of bringing these results before the world was

somewhat different from that most generally adopted by scientific men

in this country, although of common occurrence in Germany. The great

majority of scientific facts are here published by the proceedings

or transactions of scientific societies, or in special journals; and

although a scientific man frequently brings together his general

results into a volume for the public, the original communications

remain as the detailed exposition of his researches.

Darwin, too, wrote a very large number of memoirs for the scientific

societies, as may be seen from the list in Appendix III. of the “Life

and Letters,” but the volumes which he subsequently published included

_all_ the previous details, with the addition of much new matter, and

it is these volumes rather than the original communications which form

the authoritative statement of his investigations. Such a method was

possible and desirable with the subjects upon which he worked, all

of which were of great interest to the thinking part of the general

public, as well as to the experts; but in less attractive subjects it

is not probable that the plan could be carried out in this country with

any prospect of success.

It has already been stated that Darwin looked on the “Origin of

Species” as a short abstract of a greater work he intended to publish.

It is likely that he at first contemplated a comprehensive work like

the “Origin” itself, but soon found that his notes on domesticated

animals and plants, the general results of which had been condensed

into the first three chapters of the “Origin,” would form a work

more than twice the size of the latter. He began arranging these

notes on January 9th, 1860 (January 1st is the date given in the

“Autobiography”), as soon as the second edition of the “Origin” was off

his hands, but his “enormous correspondence,” as he calls it in the

“Autobiography,” with friends about the “Origin,” and the reviews and

discussions upon it, must have occupied a large part of his time; and

then there was the third edition to bring out (published April, 1861).

This edition must have cost much labour, as many parts were modified

and enlarged to meet the objections or misunderstanding of reviewers.

Francis Darwin tells us that the third chapter of “Animals and Plants,

&c.,” was still on hand at the beginning of 1861. His work on this book

was furthermore interrupted by illnesses and by other researches.

Thus, during 1860 he worked at Drosera, and during the latter part

of 1861 and beginning of 1862 at the fertilisation of orchids. In

his diary for 1866 we meet with the entry, “_Nov. 21st_--Finished

‘Pangenesis,’” and later on, “_Dec. 22nd_--Began concluding chapter

of book.” In this year, too, he brought out the fourth edition of the

“Origin.” When the time for publication approached Darwin was much

disappointed at the dimensions of the work. It was not published till

January 30th, 1868, when it was proved that his fears were groundless,

for a second edition of 1,250 copies were required in the following

month, the 1,500 of the first edition having been all absorbed.

This work is considered by some writers to be the greatest produced by

Darwin; but I think we shall be right in accepting his own opinion that

such words should be applied to the “Origin.” It is probable, however,

that this book stands second in importance in the splendid list of

works which have done so much to increase our knowledge of nature and

to inspire others to continue the good work.

[Sidenote: ON VARIATION.]

“The Variation of Animals and Plants under Domestication” opens with

a very clearly written account of natural selection; it proceeds to

treat of the domestic quadrupeds and birds, describing the differences

between the various breeds of each species, and making out as far as

possible the history of their development from each other and from the

wild stock. Cultivated plants are then treated in the same manner.

The first volume concludes with two most important chapters on

bud-variation and anomalous modes of reproduction, and on inheritance.

The second volume deals with inheritance, crossing, effect of

conditions of life, sterility, hybridism, selection by man, causes

and laws of variability. Finally, all the main lines are brought to

a common centre in the wonderful chapter in which he discloses his

“provisional hypothesis of pangenesis.” This is of such interest,

and is so characteristic of its author’s power of viewing the most

divergent facts from a common standpoint, that it is desirable to give

a tolerably full account of it.

The following is a brief statement of the various classes of facts

which Darwin attempted to connect by his hypothesis.

_Reproduction_ is sexual and asexual, and the latter is of various

kinds, although their differences are more apparent than real. It may

be concluded that gemmation or budding, fission or division, the repair

of injuries, the maintenance of each part, and the growth of the embryo

“are all essentially the results of one and the same great power.”

In parthenogenesis the ovum can develop without fertilisation, and

hence the union of germs from different individuals cannot serve as

an essential characteristic of sexual, as compared with asexual,

generation. Although sexually-produced individuals tend to vary far

more than those which are produced asexually, this is not always the

case, and the variability, when it occurs, is subject to the same

laws. Sexually-produced individuals very generally pass in development

from a lower to a higher grade; but this can hardly be said to occur in

certain forms, such as Aphis, etc.

The differences between the two forms of reproduction being thus much

less than at first sight appears, we are led to inquire for the reason

why the more complex and difficult process is so universal. Sexual

reproduction appears to confer two benefits on organisms--(1) “When

species are rendered highly variable by changed conditions of life,

the free intercrossing of the varying individuals will tend to keep

each form fitted for its proper place in nature, and crossing can be

effected only by sexual generation”; (2) Many experiments tend to show

that free and wide intercrossing induces vigour in the offspring.

Darwin concludes that the reason why the germ-cell perishes if it does

not unite with another from the opposite sex is simply because it

includes “too little formative matter for independent existence and

development.” He was led to this conclusion by the fact that the male

and female germ-cells “do not in ordinary cases differ in their power

of giving character to the embryo,” and also from experiments which

seemed to show that a certain number of pollen grains or of spermatozoa

may be required to fertilise a single seed or ovum. “The belief that

it is the function of the spermatozoa to communicate life to the ovule

seems a strange one, seeing that the unimpregnated ovule is already

alive, and continues for a considerable time alive.”

It is very remarkable to note how largely Professor Weismann’s

conclusions on this subject were anticipated by this part of Darwin’s

work.

_Graft hybrids._--The probability that a graft may alter the character

of the stock to which it is united, so that hybrid buds might be formed

by budding or grafting the tissues of distinct varieties or species,

would, if it became a certainty, prove the essential identity of

sexual and asexual reproduction; “for the power of combining in the

offspring the characters of both parents is the most striking of all

the functions of sexual generation.”

_Direct action of the male element on the female._--Pollen from another

species is known to affect the mother-plant in certain cases. Thus

pollen from the lemon has caused stripes of lemon-peel in the fruit of

the orange; the peel is, of course, formed by the mother-plant, and

is quite different from the part which the male element is adapted to

affect--viz. the ovule. Similar cases are known among animals, as in

the celebrated example of Lord Morton’s mare.

_Development._--The changes by which the embryo reaches maturity

differ immensely, even within the limits of the same compact group.

Forms which closely resemble each other in the mature state, and

are intimately related to each other, such as the various species

of lobster and crayfish, etc., pass through a totally different

developmental history. Hence we are led to believe in the complete

independence of “each structure from that which precedes and follows it

in the course of development.”

_The functional independence of the elements or units of the body.

Variability and inheritance._--Variability generally results “from

changed conditions acting during successive generations.” The influence

is exerted on the sexual system, and if extreme, impotence tends to be

produced. Bud-variation proves that “variability is not necessarily

connected with the sexual system.” The inherited effects of use and

disuse of parts imply that the changes in the cells of a distant part

of the body affect the reproductive cells, so that the being produced

from one of these cells inherits the changes. “Nothing in the whole

circuit of physiology is more wonderful.”

“Inheritance is the rule and non-inheritance the anomaly.” Inheritance

follows laws, such as the tendency for a character to appear at

corresponding ages in parent and offspring. Reversion “proves to us

that the transmission of a character and its development ... are

distinct powers.” Crossing strongly induces reversion. “Every character

which occasionally reappears is present in a latent form in each

generation.”

* * * * *

[Sidenote: PANGENESIS.]

The hypothesis of pangenesis attempts to explain and connect together

all the facts and conclusions which have been summarised in the

preceding pages. This hypothesis assumes that each one of the

countless cells of which the body of a higher animal is composed throws

off a minute gemmule which, with those derived from other cells, exists

in the body, and when supplied with nutriment multiplies by division.

Each gemmule is capable of ultimate development into a cell similar

to the one from which it, either directly or indirectly, arose. Each

cell of the body dispatches its representative, as it were, to each

single germ-cell, and this explains how it is that the latter possess

the power of reproducing the likeness of the parent body. But the

germ-cells also receive dormant gemmules which may remain undeveloped

until some generation in the remote future. The development of the

gemmules into cells depends on their union with the developing cells

which precede them in the order of growth. Gemmules are thrown off

during each stage of growth and during maturity.

This hypothesis of pangenesis is so called because the whole body is

supposed to produce the elements from which new individuals arise, the

germ-cells being only the union of these elements into clusters.

The fact that hybrids may be produced by grafting, that the pollen can

act on the tissues of the female plant, and the male germ-cells on the

future offspring of the female, implies that the reproductive material

can exist and the reproductive processes take place in the tissues, and

that they are not confined to the germ-cells.

The retention of dormant gemmules, and their passage from generation

to generation until their development, may seem improbable; but is it

more so than the _fact_ which their presence would explain--viz. the

transmission of latent structures and their ultimate reappearance?

The development of the whole plant from a Begonia leaf implies that

these gemmules are very widely distributed through the tissues.

The elective affinity of the gemmules for the cells which precede them

in growth may be paralleled by the affinity of the male and female

germ-cells, as we see in the preference of a plant for the pollen

grains of its own over those of closely-allied species, or by the

attraction of the minute germs of disease to certain tissues of the

body.

It is possible that the numerous gemmules thrown off by the cells of

a complex structure, such as a feather, “may be aggregated into a

compound gemmule.” In the case of a petal, however, where parts as well

as the whole are apt to develop, as is seen in the case of “stripes of

the calyx assuming the colour and texture of the corolla,” it is more

probable that the gemmules are separate and free. The cell itself is a

complex structure, and we do not know whether its separate parts are

not developed from the separate gemmules of an aggregate.

Such an hypothesis explains the fundamental similarity which has

already been shown to exist between all modes of reproduction. The

gemmules collected in bud or germ-cell are essentially similar;

and were it not for the special advantages of sexual reproduction

(increased vigour and more marked variation of offspring), we can well

believe that it would have been much less general. The formation of

graft-hybrids, and the action of the male element on the mother and on

future offspring, become intelligible. The antagonism between growth

and sexual reproduction in animals, and between increase by buds, etc.,

and seeds in plants, can be understood by the use of gemmules in one

direction preventing their simultaneous use in another.

The regrowth of an amputated part, as in the salamander or snail,

is explained by the presence and development of gemmules previously

thrown off from the part. The difficulty that a limb is produced of the

same age as that which was lost, and not a larval limb, and that the

cells with which the gemmules must unite at first are not those which

precede them in the course of growth, but mature cells, is met by the

consideration that this power is a special one adapted to meet special

dangers to certain parts of certain animals, and that it is therefore

probable that appropriate provision has been made by natural selection:

it may be in the form of “a stock of nascent cells or of partially

developed gemmules.” The existence of these latter in buds, and their

absence from sexual cells, may account for bud development being the

more direct and brief of the two. The much greater tendency to repair

lost parts in lower and younger forms may be due to the same cause.

The occasional tendency of hybrids to resemble one parent in one part

and the other in another may be due to superabundance of gemmules in

the fertilised germ, those from one parent having “some advantage in

number, affinity, or vigour over those derived from the other parent.”

The general preponderance of one parent over the other may be similarly

explained. The cases in which “the colour or other characters of either

parent tend to appear in stripes or blotches” are to be understood by

the gemmules having an affinity for others of the same kind.

_The sterility of hybrids_ is entirely due to the reproductive organs

being affected; in the case of plants they continue to propagate freely

by buds. The hybrid cells throw off hybrid gemmules which collect in

the buds but cannot do so in the reproductive organs.

_Development and metamorphosis._--The remarkable facts of development

and metamorphosis are well explained by the hypothesis. Allied forms

may pass to a similar end through very dissimilar stages or conversely.

Parts may appear to develop within previously existing corresponding

parts, or they may appear within parts which are quite distinct. These

divergent facts are explained by the hypothesis, each part during each

stage being formed independently from the gemmules of the same part

in previous generations, and not, although it may appear to do so,

from the corresponding parts of earlier stages. In the process of time

certain parts during certain stages may be affected by use or disuse or

surroundings, and the parts of subsequent generations will be similarly

affected, because formed from correspondingly altered gemmules; but

this need not affect the other stages of the same parts.

_Transposition and multiplication of parts._--The cases of abnormal

transposition or multiplication of organs--for instance, the

development of teeth in the palate or of pollen in the edge of a

petal--are to be explained by supposing that the gemmules unite with

wrong cells instead of, or as well as, the right ones; “and this would

follow from a slight change in their elective affinities.” Such slight

changes are known to occur; for instance, certain plants “absolutely

refuse to be fertilised by their own pollen, though abundantly fertile

with that of any other individual of the same species.” Inasmuch as the

cells of adjoining parts will often have nearly the same structure, we

can understand that some slight change in elective affinity may affect

a large area. Hence we can account for a crowd of horns on the head of

a sheep, or many spurs on the leg of a fowl, etc. Frequently repeated

parts are extremely liable to vary in number; in this case we have a

large number of closely allied gemmules and of points for their union,

and slight changes in elective affinity would be specially apt to

occur.

VARIABILITY.--Changed conditions may lead to irregularity in the number

of gemmules derived from various parts of the body; deficiency in

number might cause variation in any part by leaving some of the cells

free to unite with allied gemmules.

The direct action of surroundings, or the effect of use or disuse

on a part, may cause corresponding modifications of the gemmules,

and through these of the part in the succeeding generation. “A more

perplexing problem can hardly be proposed,” and yet it receives an

explanation on this hypothesis. Such causes must, as a rule, act during

many generations before the modification reappears in the offspring.

This may be due to the unaltered gemmules derived from earlier

generations, and their gradual replacement by the increasing number of

altered gemmules.

Variation in plants is much more frequent in sexually produced than it

is in asexually produced individuals. This may be due to the absence

in the latter of that great cause of variability, changes in the

reproductive organs under altered conditions. Furthermore, the former

alone pass through the earlier phases of development, when structure is

most plastic and yields most readily to the causes inducing variability.

The stability of hybrids and of many varieties when propagated by buds,

as compared with their reversion to the parent form when propagated by

seed, remains inexplicable.

Hence variability is explained as due (1) to the irregularity in

number of gemmules, to their transpositions, and redevelopment

when dormant; and (2) to their actual modification and the gradual

replacement by them of unaltered gemmules.

INHERITANCE.--The non-transmission by heredity of mutilations, even

when repeated for many generations, as in docking the tails of

certain domesticated breeds, may be explained by the persistence of

gemmules from still earlier generations. The cases of inheritance when

mutilations are followed by disease, as in Brown-Séquard’s experiments

on guinea-pigs, may be due to the gemmules being attracted to the

diseased part and there destroyed.

The disappearance of a rudimentary part, together with its occasional

reappearance by reversion, is to be understood by the existence of

ancestral gemmules, for which the corresponding cells have, except in

the cases of reversion, lost their affinity. When the disappearance is

final and complete, the gemmules have probably perished altogether.