CHAPTER 1.V.--EVOLUTION, 1870-1882.

LETTER 235. TO J. JENNER WEIR. Down, March 17th [1870].

It is my decided opinion that you ought to send an account to some

scientific society, and I think to the Royal Society. (235/1. Mr. Jenner

Weir's case is given in "Animals and Plants," Edition II., Volume I.,

page 435, and does not appear to have been published elsewhere.

The facts are briefly that a horse, the offspring of a mare of Lord

Mostyn's, which had previously borne a foal by a quagga, showed a

number of quagga-like characters, such as stripes, low-growing mane,

and elongated hoofs. The passage in "Animals and Plants," to which he

directs Mr. Weir's attention in reference to Carpenter's objection, is

in Edition I., Volume I., page 405: "It is a most improbable hypothesis

that the mere blood of one individual should affect the reproductive

organs of another individual in such a manner as to modify the

subsequent offspring. The analogy from the direct action of foreign

pollen on the ovarium and seed-coats of the mother plant strongly

supports the belief that the male element acts directly on the

reproductive organs of the female, wonderful as is this action, and not

through the intervention of the crossed embryo." For references to Mr.

Galton's experiments on transfusion of blood, see Letter 273.) I would

communicate it if you so decide. You might give as a preliminary reason

the publication in the "Transactions" of the celebrated Morton case

and the pig case by Mr. Giles. You might also allude to the evident

physiological importance of such facts as bearing on the theory of

generation. Whether it would be prudent to allude to despised pangenesis

I cannot say, but I fully believe pangenesis will have its successful

day. Pray ascertain carefully the colour of the dam and sire. See

about duns in my book ["Animals and Plants"], Volume I., page 55. The

extension of the mane and form of hoofs are grand new facts. Is the

hair of your horse at all curly? for [an] observed case [is] given by me

(Volume II., page 325) from Azara of correlation of forms of hoof with

curly hairs. See also in my book (Volume I., page 55; Volume II., page

41) how exceedingly rare stripes are on the faces of horses in England.

Give the age of your horse.

You are aware that Dr. Carpenter and others have tried to account for

the effects of a first impregnation from the influence of the blood

of the crossed embryo; but with physiologists who believe that the

reproductive elements are actually formed by the reproductive glands,

this view is inconsistent. Pray look at what I have said in "Domestic

Animals" (Volume I., pages 402-5) against this doctrine. It seems to

me more probable that the gemmules affect the ovaria alone. I remember

formerly speculating, like you, on the assertion that wives grow like

their husbands; but how impossible to eliminate effects of imitation and

same habits of life, etc. Your letter has interested me profoundly.

P.S.--Since publishing I have heard of additional cases--a very good

one in regard to Westphalian pigs crossed by English boar, and all

subsequent offspring affected, given in "Illust. Landwirth-Zeitung,"

1868, page 143.

I have shown that mules are often striped, though neither parent may be

striped,--due to ancient reversion. Now, Fritz Muller writes to me from

S. Brazil: "I have been assured, by persons who certainly never had

heard of Lord Morton's mare, that mares which have borne hybrids to an

ass are particularly liable to produce afterwards striped ass-colts." So

a previous fertilisation apparently gives to the subsequent offspring a

tendency to certain characters, as well as characters actually possessed

by the first male.

In the reprint (not called a second edition) of my "Domestic Animals" I

give a good additional case of subsequent progeny of hairless dog being

hairy from effects of first impregnation.

P.S. 2nd. The suggestion, no doubt, is superfluous, but you ought, I

think, to measure extension of mane beyond a line joining front or back

of ears, and compare with horse. Also the measure (and give comparison

with horse), length, breadth, and depth of hoofs.

LETTER 236. TO J.D. HOOKER. Down, July 12th [1870].

Your conclusion that all speculation about preordination is idle waste

of time is the only wise one; but how difficult it is not to speculate!

My theology is a simple muddle; I cannot look at the universe as the

result of blind chance, yet I can see no evidence of beneficent design

or indeed of design of any kind, in the details. As for each variation

that has ever occurred having been preordained for a special end, I

can no more believe in it than that the spot on which each drop of rain

falls has been specially ordained.

Spontaneous generation seems almost as great a puzzle as preordination.

I cannot persuade myself that such a multiplicity of organisms can have

been produced, like crystals, in Bastian's (236/1. On September 2nd,

1872, Mr. Darwin wrote to Mr. Wallace, in reference to the latter's

review of "The Beginnings of Life," by H.C. Bastian (1872), in "Nature,"

1872, pages 284-99: "At present I should prefer any mad hypothesis, such

as that every disintegrated molecule of the lowest forms can reproduce

the parent-form; and that these molecules are universally distributed,

and that they do not lose their vital power until heated to such a

temperature that they decompose like dead organic particles.") solutions

of the same kind. I am astonished that, as yet, I have met with no

allusion to Wyman's positive statement (236/2. "Observations and

Experiments on Living Organisms in Heated Water," by Jeffries Wyman,

Prof. of Anatomy, Harvard Coll. ("Amer. Journ. Sci." XLIV., 1867, page

152.) Solutions of organic matter in hermetically sealed flasks were

immersed in boiling water for various periods. "No infusoria of any kind

appeared if the boiling was prolonged beyond a period of five hours.")

that if the solutions are boiled for five hours no organisms appear;

yet, if my memory serves me, the solutions when opened to air

immediately became stocked. Against all evidence, I cannot avoid

suspecting that organic particles (my "gemmules" from the separate cells

of the lower creatures!) will keep alive and afterwards multiply under

proper conditions.

What an interesting problem it is.

LETTER 237. TO W.B. TEGETMEIER. Down, July 15th [1870].

It is very long since I have heard from you, and I am much obliged

for your letter. It is good news that you are going to bring out a new

edition of your Poultry book (237/1. "The Poultry Book," 1872.), and

you are quite at liberty to use all my materials. Thanks for the curious

case of the wild duck variation: I have heard of other instances of a

tendency to vary in one out of a large litter or family. I have too many

things in hand at present to profit by your offer of the loan of the

American Poultry book.

Pray keep firm to your idea of working out the subject of analogous

variations (237/2. "By this term I mean that similar characters

occasionally make their appearance in the several varieties or races

descended from the same species, and more rarely in the offspring of

widely distinct species" ("Animals and Plants," II., Edition II., page

340).) with pigeons; I really think you might thus make a novel and

valuable contribution to science. I can, however, quite understand how

much your time must be occupied with the never-ending, always-beginning

editorial cares.

I keep much as usual, and crawl on with my work.

LETTER 238. TO J.D. HOOKER. Down, September 27th [1870].

Yours was a splendid letter, and I was very curious to hear something

about the Liverpool meeting (238/1. Mr. Huxley was President of the

British Association at Liverpool in 1870. His Presidential Address

on "Biogenesis and Abiogenesis" is reprinted in his collected Essays,

VIII., page 229. Some account of the meeting is given in Huxley's "Life

and Letters," Volume I., pages 332, 336.), which I much wished to be

successful for Huxley's sake. I am surprised that you think his address

would not have been clear to the public; it seemed to me as clear as

water. The general line of his argument might have been answered by the

case of spontaneous combustion: tens of thousands of cases of things

having been seen to be set on fire would be no true argument against any

one who maintained that flames sometimes spontaneously burst forth. I am

delighted at the apotheosis of Sir Roderick; I can fancy what neat and

appropriate speeches he would make to each nobleman as he entered the

gates of heaven. You ask what I think about Tyndall's lecture (238/2.

Tyndall's lecture was "On the Scientific Uses of the Imagination."):

it seemed to me grand and very interesting, though I could not from

ignorance quite follow some parts, and I longed to tell him how

immensely it would have been improved if all the first part had been

made very much less egotistical. George independently arrived at the

same conclusion, and liked all the latter part extremely. He thought the

first part not only egotistical, but rather clap-trap.

How well Tyndall puts the "as if" manner of philosophising, and shows

that it is justifiable. Some of those confounded Frenchmen have lately

been pitching into me for using this form of proof or argument.

I have just read Rolleston's address in "Nature" (238/3. Presidential

Address to the Biological Section, British Association, 1870. "Nature,"

September 22nd, 1870, page 423. Rolleston referred to the vitality of

seeds in soil, a subject on which Darwin made occasional observations.

See "Life and Letters," II., page 65.): his style is quite unparalleled!

I see he quotes you about seed, so yesterday I went and observed more

carefully the case given in the enclosed paper, which perhaps you might

like to read and burn.

How true and good what you say about Lyell. He is always the same; Dohrn

was here yesterday, and was remarking that no one stood higher in the

public estimation of Germany than Lyell.

I am truly and profoundly glad that you are thinking of some general

work on Geographical Distribution, or so forth; I hope to God that your

incessant occupations may not interrupt this intention. As for my book,

I shall not have done the accursed proofs till the end of November

(238/4. The proofs of the "Descent of Man" were finished on January

15th, 1871.): good Lord, what a muddled head I have got on my wretched

old shoulders.

LETTER 239. TO H. SETTEGAST. Down, September 29th, 1870.

I am very much obliged for your kind letter and present of your

beautiful volume. (239/1. "Die Thierzucht," 1868.) Your work is not new

to me, for I heard it so highly spoken of that I procured a copy of the

first edition. It was a great gratification to me to find a man who had

long studied with a philosophical spirit our domesticated animals, and

who was highly competent to judge, agreeing to a large extent with my

views. I regretted much that I had not known your work when I published

my last volumes.

I am surprised and pleased to hear that science is not quite forgotten

under the present exciting state of affairs. Every one whom I know in

England is an enthusiastic wisher for the full and complete success of

Germany.

P.S. I will give one of my two copies of your work to some public

scientific library in London.

LETTER 240. TO THE EDITOR OF THE "PALL MALL GAZETTE." Down, March 24th

[1871].

Mr. Darwin presents his compliments to the Editor, and would be greatly

obliged if he would address and post the enclosed letter to the author

of the two admirable reviews of the "Descent of Man." (240/1. The

notices of the "Descent of Man," published in the "Pall Mall Gazette" of

March 20th and 21st, 1871, were by Mr. John Morley. We are indebted to

the Editor of the "Pall Mall Gazette" for kindly allowing us to consult

his file of the journal.)

LETTER 241. TO JOHN MORLEY. Down, March 24th, 1871.

From the spirit of your review in the "Pall Mall Gazette" of my last

book, which has given me great pleasure, I have thought that you would

perhaps inform me on one point, withholding, if you please, your name.

You say that my phraseology on beauty is "loose scientifically, and

philosophically most misleading." (241/1. "Mr. Darwin's work is one of

those rare and capital achievements of intellect which effect a grave

modification throughout all the highest departments of the realm of

opinion...There is throughout the description and examination of Sexual

Selection a way of speaking of beauty, which seems to us to be highly

unphilosophical, because it assumes a certain theory of beauty, which

the most competent modern thinkers are too far from accepting, to allow

its assumption to be quite judicious...Why should we only find the

aesthetic quality in birds wonderful, when it happens to coincide with

our own? In other words, why attribute to them conscious aesthetic

qualities at all? There is no more positive reason for attributing

aesthetic consciousness to the Argus pheasant than there is for

attributing to bees geometric consciousness of the hexagonal prisms and

rhombic plates of the hive which they so marvellously construct. Hence

the phraseology which Mr. Darwin employs in this part of the subject,

though not affecting the degree of probability which may belong to this

theory, seems to us to be very loose scientifically, and philosophically

most misleading."--"Pall Mall Gazette.") This is not at all improbable,

as it is almost a lifetime since I attended to the philosophy of

aesthetics, and did not then think that I should ever make use of my

conclusions. Can you refer me to any one or two books (for my power of

reading is not great) which would illumine me? or can you explain in one

or two sentences how I err? Perhaps it would be best for me to explain

what I mean by the sense of beauty in its lowest stage of development,

and which can only apply to animals. When an intense colour, or two

tints in harmony, or a recurrent and symmetrical figure please the eye,

or a single sweet note pleases the ear, I call this a sense of

beauty; and with this meaning I have spoken (though I now see in not a

sufficiently guarded manner) of a taste for the beautiful being the same

in mankind (for all savages admire bits of bright cloth, beads, plumes,

etc.) and in the lower animals. If the blue and yellow plumage of a

macaw (241/2. "What man deems the horrible contrasts of yellow and blue

attract the macaw, while ball-and-socket-plumage attracts the Argus

pheasant"--"Pall Mall Gazette," March 21st, 1871, page 1075.) pleases

the eye of this bird, I should say that it had a sense of beauty,

although its taste was bad according to our standard. Now, will you have

the kindness to tell me how I can learn to see the error of my ways? Of

course I recognise, as indeed I have remarked in my book, that the

sense of beauty in the case of scenery, pictures, etc., is something

infinitely complex, depending on varied associations and culture of the

mind. From a very interesting review in the "Spectator," and from your

and Wallace's review, I perceive that I have made a great oversight in

not having said what little I could on the acquisition of the sense

for the beautiful by man and the lower animals. It would indeed be an

immense advantage to an author if he could read such criticisms as yours

before publishing. At page 11 of your review you accidentally misquote

my words placed by you within inverted commas, from my Volume II., page

354: I say that "man cannot endure any great change," and the omitted

words "any great" make all the difference in the discussion. (241/3.

"Mr. Darwin tells us, and gives us excellent reasons for thinking, that

'the men of each race prefer what they are accustomed to behold; they

cannot endure change.' Yet is there not an inconsistency between this

fact and the other that one race differs from another exactly

because novelties presented themselves, and were eagerly seized and

propagated?")

Permit me to add a few other remarks. I believe your criticism is quite

just about my deficient historic spirit, for I am aware of my ignorance

in this line. (241/4. "In the historic spirit, however, Mr. Darwin must

fairly be pronounced deficient. When, for instance, he speaks of the

'great sin of slavery' having been general among primitive nations, he

forgets that, though to hold a slave would be a sinful degradation to a

European to-day, the practice of turning prisoners of war into slaves,

instead of butchering them, was not a sin at all, but marked a decided

improvement in human manners.") On the other hand, if you should ever be

led to read again Chapter III., and especially Chapter V., I think you

will find that I am not amenable to all your strictures; though I felt

that I was walking on a path unknown to me and full of pitfalls; but I

had the advantage of previous discussions by able men. I tried to say

most emphatically that a great philosopher, law-giver, etc., did far

more for the progress of mankind by his writings or his example than

by leaving a numerous offspring. I have endeavoured to show how the

struggle for existence between tribe and tribe depends on an advance in

the moral and intellectual qualities of the members, and not merely on

their capacity of obtaining food. When I speak of the necessity of a

struggle for existence in order that mankind should advance still higher

in the scale, I do not refer to the MOST, but "to the MORE highly

gifted men" being successful in the battle for life; I referred to

my supposition of the men in any country being divided into two equal

bodies--viz., the more and the less highly gifted, and to the former on

an average succeeding best.

But I have much cause to apologise for the length of this ill-expressed

letter. My sole excuse is the extraordinary interest which I have felt

in your review, and the pleasure which I have experienced in observing

the points which have attracted your attention. I must say one word

more. Having kept the subject of sexual selection in my mind for very

many years, and having become more and more satisfied with it, I feel

great confidence that as soon as the notion is rendered familiar to

others, it will be accepted, at least to a much greater extent than at

present. With sincere respect and thanks...

LETTER 242. TO JOHN MORLEY. Down, April 14th [1871].

As this note requires no answer, I do not scruple to write a few lines

to say how faithful and full a resume you have given of my notions on

the moral sense in the "Pall Mall," and to make a few extenuating or

explanatory remarks. (242/1. "What is called the question of the moral

sense is really two: how the moral faculty is acquired, and how it is

regulated. Why do we obey conscience or feel pain in disobeying it? And

why does conscience prescribe one kind of action and condemn another

kind? To put it more technically, there is the question of the

subjective existence of conscience, and there is the question of its

objective prescriptions. First, why do I think it obligatory to do my

duty? Second, why do I think it my duty to do this and not do

that? Although, however, the second question ought to be treated

independently, for reasons which we shall presently suggest, the

historical answer to it, or the various grounds on which men have

identified certain sorts of conduct with duty, rather than conduct of

the opposite sorts, throws light on the other question of the conditions

of growth of the idea of duty as a sovereign and imperial director.

Mr. Darwin seems to us not to have perfectly recognised the logical

separation between the two sides of the moral sense question. For

example, he says (i. 97) that 'philosophers of the derivative school of

morals formerly assumed that the foundation of morality lay in a form of

Selfishness; but more recently in the Greatest Happiness principle.'

But Mr. Mill, to whom Mr. Darwin refers, has expressly shown that the

Greatest Happiness principle is a STANDARD, and not a FOUNDATION, and

that its validity as a standard of right and wrong action is just as

tenable by one who believes the moral sense to be innate, as by one who

holds that it is acquired. He says distinctly that the social feelings

of mankind form 'the natural basis of sentiment for utilitarian

morality.' So far from holding the Greatest Happiness principle to

be the foundation of morality, he would describe it as the forming

principle of the superstructure of which the social feelings of

mankind are the foundation. Between Mr. Darwin and utilitarians, as

utilitarians, there is no such quarrel as he would appear to suppose.

The narrowest utilitarian could say little more than Mr. Darwin says

(ii. 393): 'As all men desire their own happiness, praise or blame is

bestowed on actions and motives according as they tend to this end;

and, as happiness is an essential part of the general good, the Greatest

Happiness principle INDIRECTLY serves as a NEARLY safe standard of right

and wrong.' It is perhaps not impertinent to suspect that the faltering

adverbs which we have printed in italics indicate no more than the

reluctance of a half-conscious convert to pure utilitarianism. In

another place (i. 98) he admits that 'as all wish for happiness, the

Greatest Happiness principle will have become a most important secondary

guide and object, the social instincts, including sympathy, always

serving as the primary impulse and guide.' This is just what Mr. Mill

says, only instead of calling the principle a secondary guide, he would

call it a standard, to distinguish it from the social impulse, in which,

as much as Mr. Darwin, he recognises the base and foundation."--"Pall

Mall Gazette," April 12th, 1871.) How the mistake which I have made in

speaking of greatest happiness as the foundation of morals arose, is

utterly unintelligible to me: any time during the last several years

I should have laughed such an idea to scorn. Mr. Lecky never made a

greater blunder, and your kindness has made you let me off too easily.

(242/2. In the first edition of the "Descent of Man," I., page 97, Mr.

Lecky is quoted as one of those who assumed that the "foundation

of morality lay in a form of selfishness; but more recently in the

'greatest happiness' principle." Mr. Lecky's name is omitted in this

connection in the second edition, page 120. In this edition Mr. Darwin

makes it clearer that he attaches most importance to the social instinct

as the "primary impulse and guide.") With respect to Mr. Mill, nothing

would have pleased me more than to have relied on his great authority

with respect to the social instincts, but the sentence which I quote at

[Volume I.] page 71 ("if, as is my own belief, the moral feelings are

not innate, but acquired, they are not for that reason less natural")

seems to me somewhat contradictory with the other words which I quote,

so that I did not know what to think; more especially as he says so very

little about the social instincts. When I speak of intellectual activity

as the secondary basis of conscience, I meant in my own mind secondary

in period of development; but no one could be expected to understand so

great an ellipse. With reference to your last sentence, do you not think

that man might have retrograded in his parental, marriage, and other

instincts without having retrograded in his social instincts? and I

do not think that there is any evidence that man ever existed as a

non-social animal. I must add that I have been very glad to read your

remarks on the supposed case of the hive-bee: it affords an amusing

contrast with what Miss Cobbe has written in the "Theological Review."

(242/3. Mr. Darwin says ("Descent of Man" Edition I., Volume I., page

73; Edition II., page 99), "that if men lived like bees our unmarried

females would think it a sacred duty to kill their brothers." Miss Cobbe

remarks on this "that the principles of social duty would be reversed"

("Theological Review," April 1872). Mr. Morley, on the other hand, says

of Darwin's assertion, that it is "as reassuring as the most absolute

of moralists could desire. For it is tantamount to saying that the

foundations of morality, the distinctions of right and wrong, are deeply

laid in the very conditions of social existence; that there is in face

of these conditions a positive and definite difference between the moral

and the immoral, the virtuous and the vicious, the right and the wrong,

in the actions of individuals partaking of that social existence.")

Undoubtedly the great principle of acting for the good of all the

members of the same community, and therefore the good of the species,

would still have held sovereign sway.

LETTER 243. TO J.D. HOOKER.

(243/1. Sir Joseph Hooker wrote (August 5th, 1871) to Darwin about Lord

Kelvin's Presidential Address at the Edinburgh meeting of the British

Association: "It seems to me to be very able indeed; and what a good

notion it gives of the gigantic achievement of mathematicians and

physicists!--it really made one giddy to read of them. I do not think

Huxley will thank him for his reference to him as a positive unbeliever

in spontaneous generation--these mathematicians do not seem to me to

distinguish between un-belief and a-belief. I know no other name for the

state of mind that is produced under the term scepticism. I had no idea

before that pure Mathematics had achieved such wonders in practical

science. The total absence of any allusion to Tyndall's labours, even

when comets are his theme, seems strange to me.")

Haredene, Albury, Guildford, August 6th [1871].

I have read with greatest interest Thomson's address; but you say so

EXACTLY AND FULLY all that I think, that you have taken all the words

from my mouth; even about Tyndall. It is a gain that so wonderful a man,

though no naturalist, should become a convert to evolution; Huxley, it

seems, remarked in his speech to this effect. I should like to know what

he means about design,--I cannot in the least understand, for I presume

he does not believe in special interpositions. (243/2. See "British

Association Report," page cv. Lord Kelvin speaks very doubtfully of

evolution. After quoting the concluding passage of the "Origin," he goes

on, "I have omitted two sentences...describing briefly the hypothesis of

'the origin of species by Natural Selection,' because I have always felt

that this hypothesis does not contain the true theory of evolution,

IF EVOLUTION THERE HAS BEEN in biology" (the italics are not in

the original). Lord Kelvin then describes as a "most valuable and

instructive criticism," Sir John Herschel's remark that the doctrine of

Natural Selection is "too like the Laputan method of making books, and

that it did not sufficiently take into account a continually guiding and

controlling intelligence." But it should be remembered that it was

in this address of Lord Kelvin's that he suggested the possibility of

"seed-bearing meteoric stones moving about through space" inoculating

the earth with living organisms; and if he assumes that the whole

population of the globe is to be traced back to these "moss-grown

fragments from the ruins of another world," it is obvious that he

believes in a form of evolution, and one in which a controlling

intelligence is not very obvious, at all events not in the initial and

all-important stage.) Herschel's was a good sneer. It made me put in the

simile about Raphael's Madonna, when describing in the "Descent of Man"

the manner of formation of the wondrous ball-and-socket ornaments, and I

will swear to the truth of this case. (243/3. See "Descent of Man,"

II., page 141. Darwin says that no one will attribute the shading of the

"eyes" on the wings of the Argus pheasant to the "fortuitous concourse

of atoms of colouring-matter." He goes on to say that the development of

the ball-and-socket effect by means of Natural Selection seems at first

as incredible as that "one of Raphael's Madonnas should have been formed

by the selection of chance daubs of paint." The remark of Herschel's,

quoted in "Life and Letters," II., page 241, that the "Origin"

illustrates the "law of higgledy-piggledy," is probably a conversational

variant of the Laputan comparison which gave rise to the passage in the

"Descent of Man" (see Letter 130).)

You know the oak-leaved variety of the common honeysuckle; I could not

persuade a lady that this was not the result of the honeysuckle climbing

up a young oak tree! Is this not like the Viola case?

LETTER 244. TO JOHN LUBBOCK (LORD AVEBURY). Haredene, Albury, Guildford,

August 12th [1871].

I hope the proof-sheets having been sent here will not inconvenience

you. I have read them with infinite satisfaction, and the whole

discussion strikes me as admirable. I have no books here, and wish much

I could see a plate of Campodea. (244/1. "On the Origin of Insects." By

Sir John Lubbock, Bart. "Journ. Linn. Soc. (Zoology)," Volume XI., 1873,

pages 422-6. (Read November 2nd, 1871.) In the concluding paragraph the

author writes, "If these views are correct the genus Campodea [a beetle]

must be regarded as a form of remarkable interest, since it is the

living representative of a primaeval type from which not only the

Collembola and Thysanura, but the other great orders of insects, have

all derived their origin." (See also "Brit. Assoc. Report," 1872, page

125--Address by Sir John Lubbock; and for a figure of Campodea see

"Nature," Volume VII., 1873, page 447.) I never reflected much on the

difficulty which you indicate, and on which you throw so much light.

(244/2. The difficulty alluded to is explained by the first sentence of

Lord Avebury's paper. "The Metamorphoses of this group (Insects) have

always seemed to me one of the greatest difficulties of the Darwinian

theory...I feel great difficulty in conceiving by what natural process

an insect with a suctorial mouth, like that of a gnat or butterfly,

could be developed from a powerfully mandibulate type like the

orthoptera, or even from the neuroptera...A clue to the difficulty

may, I think, be found in the distinction between the developmental and

adaptive changes to which I called the attention of the Society in a

previous memoir."

The distinction between developmental and adaptive changes is mentioned,

but not discussed, in the paper "On the Origin of Insects" (loc. cit.,

page 422); in a former paper, "On the Development of Chloeon (Ephemera)

dimidiatum ("Trans. Linn. Soc." XXV. page 477, 1866), this question is

dealt with at length.) I have only a few trifling remarks to make. At

page 44 I wish you had enlarged a little on what you have said of the

distinction between developmental and adaptive changes; for I cannot

quite remember the point, and others will perhaps be in the same

predicament. I think I always saw that the larva and the adult might be

separately modified to any extent. Bearing in mind what strange changes

of function parts undergo, with the intermediate state of use (244/3.

This slightly obscure phrase may be paraphrased, "the gradational stages

being of service to the organism."), it seems to me that you speak

rather too boldly on the impossibility of a mandibulate insect being

converted into a sucking insect (244/4. "There are, however, peculiar

difficulties in those cases in which, as among the lepidoptera, the same

species is mandibulate as a larva and suctorial as an embryo" (Lubbock,

"Origin of Insects," page 423).); not that I in the least doubt the

value of your explanation.

Cirripedes passing through what I have called a pupal state (244/5.

"Hence, the larva in this, its last stage, cannot eat; it may be called

a "locomotive Pupa;" its whole organisation is apparently adapted for

the one great end of finding a proper site for its attachment and final

metamorphosis." ("A Monograph on the Sub-Class Cirripedia." By Charles

Darwin. London, Ray Soc., 1851.)) so far as their mouths are concerned,

rather supports what you say at page 52.

At page 40 your remarks on the Argus pheasant (244/6. There is no

mention of the Argus pheasant in the published paper.) (though I have

not the least objection to them) do not seem to me very appropriate

as being related to the mental faculties. If you can spare me these

proof-sheets when done with, I shall be obliged, as I shall be

correcting a new edition of the "Origin" when I return home, though this

subject is too large for me to enter on. I thank you sincerely for the

great interest which your discussion has given me.

LETTER 245. TO J.D. HOOKER.

(245/1. The following letter refers to Mivart's "Genesis of Species.")

Down, September 16th [1871].

I am preparing a new and cheap edition of the "Origin," and shall

introduce a new chapter on gradation, and on the uses of initial

commencements of useful structures; for this, I observe, has produced

the greatest effect on most persons. Every one of his [Mivart's] cases,

as it seems to me, can be answered in a fairly satisfactory manner. He

is very unfair, and never says what he must have known could be said on

my side. He ignores the effect of use, and what I have said in all my

later books and editions on the direct effects of the conditions of

life and so-called spontaneous variation. I send you by this post a very

clever, but ill-written review from N. America by a friend of Asa Gray,

which I have republished. (245/2. Chauncey Wright in the "North American

Review," Volume CXIII., reprinted by Darwin and published as a pamphlet

(see "Life and Letters," III., page 145).)

I am glad to hear about Huxley. You never read such strong letters

Mivart wrote to me about respect towards me, begging that I would

call on him, etc., etc.; yet in the "Q. Review" (245/3. See "Quarterly

Review," July 1871; also "Life and Letters," III., page 147.) he

shows the greatest scorn and animosity towards me, and with uncommon

cleverness says all that is most disagreeable. He makes me the most

arrogant, odious beast that ever lived. I cannot understand him; I

suppose that accursed religious bigotry is at the root of it. Of course

he is quite at liberty to scorn and hate me, but why take such trouble

to express something more than friendship? It has mortified me a good

deal.

LETTER 246. TO J.D. HOOKER. Down, October 4th [1871].

I am quite delighted that you think so highly of Huxley's article.

(246/1. A review of Wallace's "Natural Selection," of Mivart's "Genesis

of Species," and of the "Quarterly Review" article on the "Descent of

Man" (July, 1871), published in the "Contemporary Review" (1871), and in

Huxley's "Collected Essays," II., page 120.) I was afraid of saying all

I thought about it, as nothing is so likely as to make anything appear

flat. I thought of, and quite agreed with, your former saying that

Huxley makes one feel quite infantile in intellect. He always thus acts

on me. I exactly agree with what you say on the several points in the

article, and I piled climax on climax of admiration in my letter to him.

I am not so good a Christian as you think me, for I did enjoy my

revenge on Mivart. He (i.e. Mivart) has just written to me as cool as a

cucumber, hoping my health is better, etc. My head, by the way, plagues

me terribly, and I have it light and rocking half the day. Farewell,

dear old friend--my best of friends.

LETTER 247. TO JOHN FISKE.

(247/1. Mr. Fiske, who is perhaps best known in England as the author of

"Outlines of Cosmic Philosophy," had sent to Mr. Darwin some reports of

the lectures given at Harvard University. The point referred to in the

postscript in Mr. Darwin's letter is explained by the following extract

from Mr. Fiske's work: "I have endeavoured to show that the transition

from animality (or bestiality, stripping the word of its bad

connotations) to humanity must have been mainly determined by the

prolongation of infancy or immaturity which is consequent upon a high

development of intelligence, and which must have necessitated the

gradual grouping together of pithecoid men into more or less definite

families." (See "Descent," I., page 13, on the prolonged infancy of the

anthropoid apes.))

Down, November 9th, 1871.

I am greatly obliged to you for having sent me, through my son, your

lectures, and for the very honourable manner in which you allude to my

works. The lectures seem to me to be written with much force, clearness,

and originality. You show also a truly extraordinary amount of knowledge

of all that has been published on the subject. The type in many parts

is so small that, except to young eyes, it is very difficult to read.

Therefore I wish that you would reflect on their separate publication,

though so much has been published on the subject that the public may

possibly have had enough. I hope that this may be your intention, for I

do not think I have ever seen the general argument more forcibly put so

as to convert unbelievers.

It has surprised and pleased me to see that you and others have detected

the falseness of much of Mr. Mivart's reasoning. I wish I had read your

lectures a month or two ago, as I have been preparing a new edition of

the "Origin," in which I answer some special points, and I believe

I should have found your lectures useful; but my MS. is now in the

printer's hands, and I have not strength or time to make any more

additions.

P.S.--By an odd coincidence, since the above was written I have received

your very obliging letter of October 23rd. I did notice the point to

which you refer, and will hereafter reflect more over it. I was indeed

on the point of putting in a sentence to somewhat of the same effect in

the new edition of the "Origin," in relation to the query--Why have not

apes advanced in intellect as much as man? but I omitted it on account

of the asserted prolonged infancy of the orang. I am also a little

doubtful about the distinction between gregariousness and sociability.

...When you come to England I shall have much pleasure in making your

acquaintance; but my health is habitually so weak that I have very small

power of conversing with my friends as much as I wish. Let me again

thank you for your letter. To believe that I have at all influenced

the minds of able men is the greatest satisfaction I am capable of

receiving.

LETTER 248. TO E. HACKEL. Down, December 27th, 1871.

I thank you for your very interesting letter, which it has given me much

pleasure to receive. I never heard of anything so odd as the Prior in

the Holy Catholic Church believing in our ape-like progenitors. I much

hope that the Jesuits will not dislodge him.

What a wonderfully active man you are! and I rejoice that you have been

so successful in your work on sponges. (248/1. "Die Kalkschwamme: eine

Monographie; 3 volumes: Berlin, 1872. H.J. Clark published a paper "On

the Spongiae Ciliatae as Infusoria flagellata" in the "Mem. Boston Nat.

Hist. Soc." Volume I., Part iii., 1866. See Hackel, op. cit., Volume I.,

page 24.) Your book with sixty plates will be magnificent. I shall be

glad to learn what you think of Clark's view of sponges being flagellate

infusorians; some observers in this country believe in him. I am glad

you are going fully to consider inheritance, which is an all-important

subject for us. I do not know whether you have ever read my chapter

on pangenesis. My ideas have been almost universally despised, and I

suppose that I was foolish to publish them; yet I must still think that

there is some truth in them. Anyhow, they have aided me much in making

me clearly understand the facts of inheritance.

I have had bad health this last summer, and during two months was able

to do nothing; but I have now almost finished a next edition of the

"Origin," which Victor Carus is translating. (248/2. See "Life and

Letters," III., page 49.) There is not much new in it, except one

chapter in which I have answered, I hope satisfactorily, Mr. Mivart's

supposed difficulty on the incipient development of useful structures.

I have also given my reasons for quite disbelieving in great and sudden

modifications. I am preparing an essay on expression in man and the

lower animals. It has little importance, but has interested me. I

doubt whether my strength will last for much more serious work. I

hope, however, to publish next summer the results of my long-continued

experiments on the wonderful advantages derived from crossing. I shall

continue to work as long as I can, but it does not much signify when

I stop, as there are so many good men fully as capable, perhaps more

capable, than myself of carrying on our work; and of these you rank as

the first.

With cordial good wishes for your success in all your work and for your

happiness.

LETTER 249. TO E. RAY LANKESTER. Down, April 15th [1872].

Very many thanks for your kind consideration. The correspondence was in

the "Athenaeum." I got some mathematician to make the calculation, and

he blundered and caused me much shame. I send scrap of proofs from last

edition of the "Origin," with the calculation corrected. What grand work

you did at Naples! I can clearly see that you will some day become our

first star in Natural History.

(249/1. Here follows the extract from the "Origin," sixth edition, page

51: "The elephant is reckoned the slowest breeder of all known animals,

and I have taken some pains to estimate its probable minimum rate of

natural increase. It will be safest to assume that it begins breeding

when thirty years old, and goes on breeding till ninety years old,

bringing forth six young in the interval, and surviving till one hundred

years old; if this be so, after a period of from 740 to 750 years, there

would be nearly nineteen million elephants alive, descended from the

first pair." In the fifth edition, page 75, the passage runs: "If this

be so, at the end of the fifth century, there would be alive fifteen

million elephants, descended from the first pair" (see "Athenaeum," June

5, July 3, 17, 24, 1869).)

LETTER 250. TO C. LYELL. Down, May 10th [1872].

I received yesterday morning your present of that work to which I, for

one, as well as so many others, owe a debt of gratitude never to be

forgotten. I have read with the greatest interest all the special

additions; and I wish with all my heart that I had the strength and

time to read again every word of the whole book. (250/1. "Principles of

Geology," Edition XII., 1875.) I do not agree with all your criticisms

on Natural Selection, nor do I suppose that you would expect me to do

so. We must be content to differ on several points. I differ must about

your difficulty (page 496) (250/2. In Chapter XLIII. Lyell treats

of "Man considered with reference to his Origin and Geographical

Distribution." He criticizes the view that Natural Selection is capable

of bringing about any amount of change provided a series of minute

transitional steps can be pointed out. "But in reality," he writes, "it

cannot be said that we obtain any insight into the nature of the forces

by which a higher grade of organisation or instinct is evolved out of a

lower one by becoming acquainted with a series of gradational forms or

states, each having a very close affinity with the other."..."It is when

there is a change from an inferior being to one of superior grade, from

a humbler organism to one endowed with new and more exalted attributes,

that we are made to feel that, to explain the difficulty, we must obtain

some knowledge of those laws of variation of which Mr. Darwin grants

that we are at present profoundly ignorant" (op. cit., pages 496-97).)

on a higher grade of organisation being evolved out of lower ones. Is

not a very clever man a grade above a very dull one? and would not the

accumulation of a large number of slight differences of this kind lead

to a great difference in the grade of organisation? And I suppose that

you will admit that the difference in the brain of a clever and dull man

is not much more wonderful than the difference in the length of the nose

of any two men. Of course, there remains the impossibility of explaining

at present why one man has a longer nose than another. But it is foolish

of me to trouble you with these remarks, which have probably often

passed through your mind. The end of this chapter (XLIII.) strikes me as

admirably and grandly written. I wish you joy at having completed your

gigantic undertaking, and remain, my dear Lyell,

Your ever faithful and now very old pupil, CHARLES DARWIN.

LETTER 251. TO J. TRAHERNE MOGGRIDGE. Sevenoaks, October 9th [1872].

I have just received your note, forwarded to me from my home. I thank

you very truly for your intended present, and I am sure that your book

will interest me greatly. I am delighted that you have taken up the

very difficult and most interesting subject of the habits of insects, on

which Englishmen have done so little. How incomparably more valuable

are such researches than the mere description of a thousand species! I

daresay you have thought of experimenting on the mental powers of

the spiders by fixing their trap-doors open in different ways and at

different angles, and observing what they will do.

We have been here some days, and intend staying some weeks; for I was

quite worn out with work, and cannot be idle at home.

I sincerely hope that your health is not worse.

LETTER 252. TO A. HYATT.

(252/1. The correspondence with Professor Hyatt, of Boston, U.S.,

originated in the reference to his and Professor Cope's theories of

acceleration and retardation, inserted in the sixth edition of the

"Origin," page 149.

Mr. Darwin, on receiving from Mr. Hyatt a copy of his "Fossil

Cephalopods of the Museum of Comparative Zoology. Embryology," from the

"Bull. Mus. Comp. Zool." Harvard, Volume III., 1872, wrote as follows

(252/2. Part of this letter was published in "Life and Letters," III.,

page 154.):--)

October 10th, 1872.

I am very much obliged to you for your kindness in having sent me your

valuable memoir on the embryology of the extinct cephalopods. The work

must have been one of immense labour, and the results are extremely

interesting. Permit me to take this opportunity to express my sincere

regret at having committed two grave errors in the last edition of my

"Origin of Species," in my allusion to yours and Professor Cope's views

on acceleration and retardation of development. I had thought that

Professor Cope had preceded you; but I now well remember having formerly

read with lively interest, and marked, a paper by you somewhere in my

library, on fossil cephalopods, with remarks on the subject. (252/3. The

paper seems to be "On the Parallelism between the Different Stages of

Life in the Individual and those in the Entire Group of the Molluscous

Order Tetrabranchiata," from the "Boston. Soc. Nat. Hist. Mem." I.,

1866-69, page 193. On the back of the paper is written, "I cannot

avoid thinking this paper fanciful.") It seems also that I have quite

misrepresented your joint view; this has vexed me much. I confess that I

have never been able to grasp fully what you wish to show, and I presume

that this must be owing to some dulness on my part...As the case stands,

the law of acceleration and retardation seems to me to be a simple [?]

statement of facts; but the statement, if fully established, would

no doubt be an important step in our knowledge. But I had better say

nothing more on the subject, otherwise I shall perhaps blunder again.

I assure you that I regret much that I have fallen into two such grave

errors.

LETTER 253. A. HYATT TO CHARLES DARWIN.

(253/1. Mr. Hyatt replied in a long letter, of which only a small part

is here given.

Cannstadt bei Stuttgart, November 1872.

The letter with which you have honoured me, bearing the date of October

10th, has just reached here after a voyage to America and back.

I have long had it in mind to write you upon the subject of which you

speak, but have been prevented by a very natural feeling of distrust in

the worthiness and truth of the views which I had to present.

There is certainly no occasion to apologise for not having quoted

my paper. The law of acceleration and retardation of development was

therein used to explain the appearance of other phenomena, and might, as

it did in nearly all cases, easily escape notice.

My relations with Prof. Cope are of the most friendly character; and

although fortunate in publishing a few months ahead, I consider that

this gives me no right to claim anything beyond such an amount

of participation in the discovery, if it may be so called, as the

thoroughness and worth of my work entitles me to...

The collections which I have studied, it will be remembered, are fossils

collected without special reference to the very minute subdivisions,

such as the subdivisions of the Lower or Middle Lias as made by the

German authors, especially Quenstedt and Oppel, but pretty well defined

for the larger divisions in which the species are also well defined.

The condition of the collections as regards names, etc., was chaotic,

localities alone, with some few exceptions, accurate. To put this in

order they were first arranged according to their adult characteristics.

This proving unsatisfactory, I determined to test thoroughly the theory

of evolution by following out the developmental history of each species

and placing them within their formations, Middle or Upper Lias, Oolite

or so, according to the extent to which they represented each other's

characteristics. Thus an adult of simple structure being taken as the

starting-point which we will call a, another species which was a in

its young stage and became b in the adult was placed above it in the

zoological series. By this process I presently found that a, then a b

and a b c, c representing the adult stage, were very often found; but

that practically after passing these two or three stages it did not

often happen that a species was found which was a b c in the young and

then became d in the adult. But on the other hand I very frequently

found one which, while it was a in the young, skipped the stages b and

c and became d while still quite young. Then sometimes, though more

rarely, a species would be found belonging to the same series, which

would be a in the young and with a very faint and fleeting resemblance

to d at a later stage, pass immediately while still quite young to the

more advanced characteristics represented by e, and hold these as its

specific characteristics until old age destroyed them. This skipping is

the highest exemplification, or rather manifestation, of acceleration in

development. In alluding to the history of diseases and inheritance of

characteristics, you in your "Origin of Species" allude to the ordinary

manifestation of acceleration, when you speak of the tendency of

diseases or characteristics to appear at younger periods in the life of

the child than of its parents. This, according to my observations, is

a law, or rather mode, of development, which is applicable to all

characteristics, and in this way it is possible to explain why the young

of later-occurring animals are like the adult stages of those which

preceded them in time. If I am not mistaken you have intimated something

of this sort also in your first edition, but I have not been able to

find it lately. Of course this is a very normal condition of affairs

when a series can be followed in this way, beginning with species a,

then going through species a b to a b c, then a b d or a c d, and then

a d e or simply a e, as it sometimes comes. Very often the acceleration

takes place in two closely connected series, thus:

a--ab--abd--ae---ad

in which one series goes on very regularly, while another lateral

offshoot of a becomes d in the adult. This is an actual case which can

be plainly shown with the specimens in hand, and has been verified in

the collections here. Retardation is entirely Prof. Cope's idea, but I

think also easily traceable. It is the opponent of acceleration, so to

speak, or the opposite or negative of that mode of development. Thus

series may occur in which, either in size or characteristics, they

return to former characteristics; but a better discussion of this point

you will find in the little treatise which I send by the same mail as

this letter, "On Reversions among the Ammonites."

LETTER 254. TO A. HYATT. Down, December 4th, 1872.

I thank you sincerely for your most interesting letter. You refer much

too modestly to your own knowledge and judgment, as you are much better

fitted to throw light on your own difficult problems than I am.

It has quite annoyed me that I do not clearly understand yours and Prof.

Cope's views (254/1. Prof. Cope's views may be gathered from his "Origin

of the Fittest" 1887; in this book (page 41) is reprinted his "Origin

of Genera" from the "Proc. Philadelph. Acad. Nat. Soc." 1868, which was

published separately by the author in 1869, and which we believe to be

his first publication on the subject. In the preface to the "Origin of

the Fittest," page vi, he sums up the chief points in the "Origin

of Genera" under seven heads, of which the following are the most

important:--"First, that development of new characters has been

accomplished by an ACCELERATION or RETARDATION in the growth of the

parts changed...Second, that of EXACT PARALLELISM between the adult of

one individual or set of individuals, and a transitional stage of one or

more other individuals. This doctrine is distinct from that of an exact

parallelism, which had already been stated by von Baer." The last point

is less definitely stated by Hyatt in his letter of December 4th, 1872.

"I am thus perpetually led to look upon a series very much as upon an

individual, and think that I have found that in many instances these

afford parallel changes." See also "Lamarck the Founder of Evolution, by

A.S. Packard: New York, 1901.) and the fault lies in some slight degree,

I think, with Prof. Cope, who does not write very clearly. I think I

now understand the terms "acceleration" and "retardation"; but will

you grudge the trouble of telling me, by the aid of the following

illustration, whether I do understand rightly? When a fresh-water

decapod crustacean is born with an almost mature structure, and

therefore does not pass, like other decapods, through the Zoea stage,

is this not a case of acceleration? Again, if an imaginary decapod

retained, when adult, many Zoea characters, would this not be a case of

retardation? If these illustrations are correct, I can perceive why I

have been so dull in understanding your views. I looked for something

else, being familiar with such cases, and classing them in my own mind

as simply due to the obliteration of certain larval or embryonic stages.

This obliteration I imagined resulted sometimes entirely from that law

of inheritance to which you allude; but that it in many cases was

aided by Natural Selection, as I inferred from such cases occurring

so frequently in terrestrial and fresh-water members of groups, which

retain their several embryonic stages in the sea, as long as fitting

conditions are present.

Another cause of my misunderstanding was the assumption that in your

series

a--ab--abd--ae,--------ad

the differences between the successive species, expressed by the

terminal letter, was due to acceleration: now, if I understand rightly,

this is not the case; and such characters must have been independently

acquired by some means.

The two newest and most interesting points in your letter (and in,

as far as I think, your former paper) seem to me to be about senile

characteristics in one species appearing in succeeding species during

maturity; and secondly about certain degraded characters appearing in

the last species of a series. You ask for my opinion: I can only send

the conjectured impressions which have occurred to me and which are

not worth writing. (It ought to be known whether the senile character

appears before or after the period of active reproduction.) I should be

inclined to attribute the character in both your cases to the laws of

growth and descent, secondarily to Natural Selection. It has been an

error on my part, and a misfortune to me, that I did not largely discuss

what I mean by laws of growth at an early period in some of my books. I

have said something on this head in two new chapters in the last edition

of the "Origin." I should be happy to send you a copy of this edition,

if you do not possess it and care to have it. A man in extreme old age

differs much from a young man, and I presume every one would account for

this by failing powers of growth. On the other hand the skulls of some

mammals go on altering during maturity into advancing years; as do the

horns of the stag, the tail-feathers of some birds, the size of fishes

etc.; and all such differences I should attribute simply to the laws of

growth, as long as full vigour was retained. Endless other changes of

structure in successive species may, I believe, be accounted for by

various complex laws of growth. Now, any change of character thus

induced with advancing years in the individual might easily be inherited

at an earlier age than that at which it first supervened, and thus

become characteristic of the mature species; or again, such changes

would be apt to follow from variation, independently of inheritance,

under proper conditions. Therefore I should expect that characters of

this kind would often appear in later-formed species without the aid

of Natural Selection, or with its aid if the characters were of any

advantage. The longer I live, the more I become convinced how ignorant

we are of the extent to which all sorts of structures are serviceable

to each species. But that characters supervening during maturity in

one species should appear so regularly, as you state to be the case, in

succeeding species, seems to me very surprising and inexplicable.

With respect to degradation in species towards the close of a series,

I have nothing to say, except that before I arrived at the end of your

letter, it occurred to me that the earlier and simpler ammonites must

have been well adapted to their conditions, and that when the species

were verging towards extinction (owing probably to the presence of some

more successful competitors) they would naturally become re-adapted to

simpler conditions. Before I had read your final remarks I thought also

that unfavourable conditions might cause, through the law of growth,

aided perhaps by reversion, degradation of character. No doubt many new

laws remain to be discovered. Permit me to add that I have never been

so foolish as to imagine that I have succeeded in doing more than to lay

down some of the broad outlines of the origin of species.

After long reflection I cannot avoid the conviction that no innate

tendency to progressive development exists, as is now held by so many

able naturalists, and perhaps by yourself. It is curious how seldom

writers define what they mean by progressive development; but this is a

point which I have briefly discussed in the "Origin." I earnestly hope

that you may visit Hilgendorf's famous deposit. Have you seen Weismann's

pamphlet "Einfluss der Isolirung," Leipzig, 1872? He makes splendid use

of Hilgendorf's admirable observations. (254/2. Hilgendorf, "Monatsb.

K. Akad." Berlin, 1866. For a semi-popular account of Hilgendorf's and

Hyatt's work on this subject, see Romanes' "Darwin and after Darwin,"

I., page 201.) I have no strength to spare, being much out of health;

otherwise I would have endeavoured to have made this letter better

worth sending. I most sincerely wish you success in your valuable and

difficult researches.

I have received, and thank you, for your three pamphlets. As far as I

can judge, your views seem very probable; but what a fearfully intricate

subject is this of the succession of ammonites. (254/3. See various

papers in the publications of the "Boston Soc. Nat. Hist." and in the

"Bulletin of the Harvard Museum of Comp. Zoology.")

LETTER 255. A. HYATT TO CHARLES DARWIN. Cannstadt bei Stuttgart,

December 8th, 1872.

The quickness and earnestness of your reply to my letter gives me

the greatest encouragement, and I am much delighted at the unexpected

interest which your questions and comments display. What you say about

Prof. Cope's style has been often before said to me, and I have remarked

in his writings an unsatisfactory treatment of our common theory. This,

I think, perhaps is largely due to the complete absorption of his

mind in the contemplation of his subject: this seems to lead him to be

careless about the methods in which it may be best explained. He has,

however, a more extended knowledge than I have, and has in many ways a

more powerful grasp of the subject, and for that very reason, perhaps,

is liable to run into extremes. You ask about the skipping of the Zoea

stage in fresh-water decapods: is this an illustration of acceleration?

It most assuredly is, if acceleration means anything at all. Again,

another and more general illustration would be, if, among the marine

decapods, a series could be formed in which the Zoea stage became less

and less important in the development, and was relegated to younger and

younger stages of the development, and finally disappeared in those to

which you refer. This is the usual way in which the accelerated mode

of development manifests itself; though near the lowest or earliest

occurring species it is also to be looked for. Perhaps this to which

you allude is an illustration somewhat similar to the one which I have

spoken of in my series,

a--ab--abc--ae--------ad,

which like "a d" comes from the earliest of a series, though I should

think from the entire skipping of the Zoea stage that it must be, like

"a e," the result of a long line of ancestors. In fact, the essential

point of our theory is, that characteristics are ever inherited by the

young at earlier periods than they are assumed in due course of growth

by the parents, and that this must eventually lead to the extinction or

skipping of these characteristics altogether...

Such considerations as these and the fact that near the heads of series

or near the latest members of series, and not at the beginning, were

usually found the accelerated types, which skipped lower characteristics

and developed very suddenly to a higher and more complex standpoint in

structure, led both Cope and [myself] into what may be a great error. I

see that it has led you at least into the difficulty of which you very

rightly complain, and which, I am sorry to see, has cost you some

of your valuable time. We presumed that because characteristics were

perpetually inherited at earlier stages, that this very concentration

of the developed characteristics made room for the production of

differences in the adult descendants of any given pair. Further, that in

the room thus made other different characteristics must be produced, and

that these would necessarily appear earlier in proportion as the

species was more or less accelerated, and be greater or less in the same

proportion. Finally, that in the most accelerated, such as "a c" or "a

d," the difference would be so great as to constitute distinct genera.

Cope and I have differed very much, while he acknowledged the action of

the accumulated mode of development only when generic characteristics or

greater differences were produced, I saw the same mode of development to

be applicable in all cases and to all characteristics, even to diseases.

So far the facts bore us out, but when we assumed that the adult

differences were the result of the accelerated mode of development,

we were perhaps upon rather insecure ground. It is evidently this

assumption which has led you to misunderstand the theory. Cope founded

his belief, that the adult characteristics were also the result of

acceleration, if I rightly remember it, mainly upon the class of facts

spoken of above in man where a sudden change into two organs may produce

entirely new and unexpected differences in the whole organisation,

and upon the changes which acceleration appeared to produce in the

development of each succeeding species. Your difficulty in understanding

the theory and the observations you have made show me at once what my

own difficulties have been, but of these I will not speak at present, as

my letter is spinning itself out to a fearful length.

(255/1. After speaking of Cope's comparison of acceleration and

retardation in evolution to the force of gravity in physical matters Mr.

Hyatt goes on:--)

Now it [acceleration] seems to me to explain less and less the origin of

adult progressive characteristics or simply differences, and perhaps now

I shall get on faster with my work.

LETTER 256. TO A. HYATT. Down, December 14th [1872].

(256/1. In reply to the above letter (255) from Mr. Hyatt.)

Notwithstanding the kind consideration shown in your last sentence, I

must thank you for your interesting and clearly expressed letter. I

have directed my publisher to send you a copy of the last edition of the

"Origin," and you can, if you like, paste in the "From the Author"

on next page. In relation to yours and Professor Cope's view on

"acceleration" causing a development of new characters, it would, I

think, be well if you were to compare the decapods which pass and do not

pass through the Zoea stage, and the one group which does (according to

Fritz Muller) pass through to the still earlier Nauplius stages, and see

if they present any marked differences. You will, I believe, find that

this is not the case. I wish it were, for I have often been perplexed at

the omission of embryonic stages as well as the acquirement of peculiar

stages appearing to produce no special result in the mature form.

(256/2. The remainder of this letter is missing, and the whole of the

last sentence is somewhat uncertainly deciphered. (Note by Mr. Hyatt.))

LETTER 257. TO A. HYATT. Down, February 13th, 1877.

I thank you for your very kind, long, and interesting letter. The case

is so wonderful and difficult that I dare not express any opinion on it.

Of course, I regret that Hilgendorf has been proved to be so greatly

in error (257/1. This refers to a controversy with Sandberger, who had

attacked Hilgendorf in the "Verh. der phys.-med. Ges. zu Wurzburg," Bd.

V., and in the "Jahrb. der Malakol. Ges." Bd. I., to which Hilgendorf

replied in the "Zeitschr. d. Deutschen geolog. Ges." Jahrb. 1877.

Hyatt's name occurs in Hilgendorf's pages, but we find no reference to

any paper of this date; his well-known paper is in the "Boston. Soc.

Nat. Hist." 1880. In a letter to Darwin (May 23rd, 1881) Hyatt regrets

that he had no opportunity of a third visit to Steinheim, and goes on:

"I should then have done greater justice to Hilgendorf, for whom I have

such a high respect."), but it is some selfish comfort to me that I

always felt so much misgiving that I never quoted his paper. (257/2. In

the fifth edition of the "Origin" (page 362), however, Darwin speaks of

the graduated forms of Planorbis multiformis, described by Hilgendorf

from certain beds in Switzerland, by which we presume he meant the

Steinheim beds in Wurtemberg.) The variability of these shells is quite

astonishing, and seems to exceed that of Rubus or Hieracium amongst

plants. The result which surprises me most is that the same form should

be developed from various and different progenitors. This seems to show

how potent are the conditions of life, irrespectively of the variations

being in any way beneficial.

The production of a species out of a chaos of varying forms reminds me

of Nageli's conclusion, as deduced from the study of Hieracium, that

this is the common mode in which species arise. But I still continue to

doubt much on this head, and cling to the belief expressed in the first

edition of the "Origin," that protean or polymorphic species are those

which are now varying in such a manner that the variations are neither

advantageous nor disadvantageous. I am glad to hear of the Brunswick

deposit, as I feel sure that the careful study of such cases is highly

important. I hope that the Smithsonian Institution will publish your

memoir.

LETTER 258. TO A. DE CANDOLLE. Down, January 18th [1873].

It was very good of you to give up so much of your time to write to me

your last interesting letter. The evidence seems good about the tameness

of the alpine butterflies, and the fact seems to me very surprising, for

each butterfly can hardly have acquired its experience during its own

short life. Will you be so good as to thank M. Humbert for his note,

which I have been glad to read. I formerly received from a man, not

a naturalist, staying at Cannes a similar account, but doubted about

believing it. The case, however, does not answer my query--viz., whether

butterflies are attracted by bright colours, independently of the

supposed presence of nectar?

I must own that I have great difficulty in believing that any temporary

condition of the parents can affect the offspring. If it last long

enough to affect the health or structure of the parents, I can quite

believe the offspring would be modified. But how mysterious a subject

is that of generation! Although my hypothesis of pangenesis has been

reviled on all sides, yet I must still look at generation under this

point of view; and it makes me very averse to believe in an emotion

having any effect on the offspring. Allow me to add one word about

blushing and shyness: I intended only to say the habit was primordially

acquired by attention to the face, and not that each shy man now

attended to his personal appearance.

LETTER 259. TO J.D. HOOKER. Down, June 28th, 1873.

I write a line to wish you good-bye, as I hear you are off on Wednesday,

and to thank you for the Dionoea, but I cannot make the little creature

grow well. I have this day read Bentham's last address, and must

express my admiration of it. (259/1. Presidential address to the Linnean

Society, read May 24th, 1873.) Perhaps I ought not to do so, as he

fairly crushes me with honour.

I am delighted to see how exactly I agree with him on affinities, and

especially on extinct forms as illustrated by his flat-topped tree.

(259/2. See page 15 of separate copy: "We should then have the present

races represented by the countless branchlets forming the flat-topped

summit" of a genealogical tree, in which "all we can do is to map out

the summit as it were from a bird's-eye view, and under each cluster, or

cluster of clusters, to place as the common trunk an imaginary type of a

genus, order, or class according to the depth to which we would go.")

My recent work leads me to differ from him on one point--viz., on the

separation of the sexes. (259/3. On the question of sexuality, see

page 10 of Bentham's address. On the back of Mr. Darwin's copy he has

written: "As long as lowest organisms free--sexes separated: as soon as

they become attached, to prevent sterility sexes united--reseparated as

means of fertilisation, adapted [?] for distant [?] organisms,--in the

case of animals by their senses and voluntary movements,--with plants

the aid of insects and wind, the latter always existed, and long

retained." The two words marked [?] are doubtful. The introduction

of freedom or attachedness, as a factor in the problem also occurs in

"Cross and Self-fertilisation," page 462. I strongly suspect that sexes

were primordially in distinct individuals; then became commonly united

in the same individual, and then in a host of animals and some few

plants became again separated. Do ask Bentham to send a copy of his

address to "Dr. H. Muller, Lippstadt, Prussia," as I am sure it will

please him GREATLY.

...When in France write me a line and tell me how you get on, and how

Huxley is; but do not do so if you feel idle, and writing bothers you.

LETTER 260. TO R. MELDOLA.

(260/1. This letter, with others from Darwin to Meldola, is published in

"Charles Darwin and the Theory of Natural Selection," by E.B. Poulton,

pages 199 et seq., London, 1896.)

Southampton, August 13th, 1873.

I am much obliged for your present, which no doubt I shall find at Down

on my return home. I am sorry to say that I cannot answer your question;

nor do I believe that you could find it anywhere even approximately

answered. It is very difficult or impossible to define what is meant

by a large variation. Such graduate into monstrosities or generally

injurious variations. I do not myself believe that these are often or

ever taken advantage of under nature. It is a common occurrence that

abrupt and considerable variations are transmitted in an unaltered

state, or not at all transmitted, to the offspring, or to some of them.

So it is with tailless or hornless animals, and with sudden and great

changes of colour in flowers. I wish I could have given you any answer.

LETTER 261. TO E.S. MORSE. [Undated.]

I must have the pleasure of thanking you for your kindness in sending me

your essay on the Brachiopoda. (261/1. "The Brachiopoda, a Division of

Annelida," "Amer. Assoc. Proc." Volume XIX., page 272, 1870, and "Annals

and Mag. Nat. Hist." Volume VI., page 267, 1870.) I have just read

it with the greatest interest, and you seem to me (though I am not a

competent judge) to make out with remarkable clearness an extremely

strong case. What a wonderful change it is to an old naturalist to have

to look at these "shells" as "worms"; but, as you truly say, as far as

external appearance is concerned, the case is not more wonderful than

that of cirripedes. I have also been particularly interested by your

remarks on the Geological Record, and on the lower and older forms in

each great class not having been probably protected by calcareous valves

or a shell.

P.S.--Your woodcut of Lingula is most skilfully introduced to compel one

to see its likeness to an annelid.

LETTER 262. TO H. SPENCER.

(262/1. Mr. Spencer's book "The Study of Sociology," 1873, was published

in the "Contemporary Review" in instalments between May 1872 and October

1873.)

October 31st [1873].

I am glad to receive to-day an advertisement of your book. I have been

wonderfully interested by the articles in the "Contemporary." Those were

splendid hits about the Prince of Wales and Gladstone. (262/2. See "The

Study of Sociology," page 392. Mr. Gladstone, in protest against some

words of Mr. Spencer, had said that the appearance of great men "in

great crises of human history" were events so striking "that men would

be liable to term them providential in a pre-scientific age." On this

Mr. Spencer remarks that "in common with the ancient Greek Mr. Gladstone

regards as irreligious any explanation of Nature which dispenses with

immediate Divine superintendence." And as an instance of the

partnership "between the ideas of natural causation and of providential

interference," he instances a case where a prince "gained popularity

by outliving certain abnormal changes in his blood," and where "on the

occasion of his recovery providential aid and natural causation were

unitedly recognised by a thanksgiving to God and a baronetcy to the

doctor." The passage on Toryism is on page 395, where Mr. Spencer, with

his accustomed tolerance, writes: "The desirable thing is that a growth

of ideas and feelings tending to produce modification shall be joined

with a continuance of ideas and feelings tending to preserve stability."

And from this point of view he concludes it to be very desirable that

"one in Mr. Gladstone's position should think as he does." The matter

is further discussed in the notes to Chapter XVI., page 423.) I never

before read a good defence of Toryism. In one place (but I cannot for

the life of me recollect where or what it exactly was) I thought that

you would have profited by my principle (i.e. if you do not reject it)

given in my "Descent of Man," that new characters which appear late

in life are those which are transmitted to the same sex alone. I have

advanced some pretty strong evidence, and the principle is of great

importance in relation to secondary sexual likenesses. (262/3. This

refers to Mr. Spencer's discussion of the evolution of the mental traits

characteristic of women. At page 377 he points out the importance of

the limitation of heredity by sex in this relation. A striking

generalisation on this question is given in the "Descent of Man,"

Edition I., Volume II., page 285: that when the adult male differs from

the adult female, he differs in the same way from the young of both

sexes. Can this law be applied in the case in which the adult female

possesses characters not possessed by the male: for instance, the high

degree of intuitive power of reading the mental states of others and of

concealing her own--characters which Mr. Spencer shows to be accounted

for by the relations between the husband and wife in a state of

savagery. If so, the man should resemble "the young of both sexes" in

the absence of these special qualities. This seems to be the case with

some masculine characteristics, and childishness of man is not without

recognition among women: for instance, by Dolly Winthrop in "Silas

Marner," who is content with bread for herself, but bakes cake for

children and men, whose "stomichs are made so comical, they want a

change--they do, I know, God help 'em.") I have applied it to man and

woman, and possibly it was here that I thought that you would have

profited by the doctrine. I fear that this note will be almost

illegible, but I am very tired.

LETTER 263. G.J. ROMANES TO CHARLES DARWIN.

(263/1. This is, we believe, the first letter addressed by the late Mr.

Romanes to Mr. Darwin. It was put away with another on the same subject,

and inscribed "Romanes on Abortion, with my answer (very important)."

Mr. Darwin's answer given below is printed from his rough draft, which

is in places barely decipherable. On the subject of these letters

consult Romanes, "Darwin and after Darwin," Volume II., page 99, 1895.)

Dunskaith, Parkhill, Ross-shire, July 10th, 1874.

Knowing that you do not dissuade the more attentive of your readers from

communicating directly to yourself any ideas they may have upon subjects

connected with your writings, I take the liberty of sending the enclosed

copy of a letter, which I have recently addressed to Mr. Herbert

Spencer. You will perceive that the subject dealt with is the same as

that to which a letter of mine in last week's "Nature" [July 2nd,

page 164] refers--viz., "Disuse as a Reducing Cause in Species."

In submitting this more detailed exposition of my views to your

consideration, I should like to state again what I stated in "Nature"

some weeks ago, viz., that in propounding the cessation of selection as

a reducing cause, I do not suppose that I am suggesting anything which

has not occurred to you already. Not only is this principle embodied

in the theory set forth in the article on Rudimentary Organs ("Nature,"

Volume IX.); but it is more than once hinted at in the "Origin," in

the passages where rudimentary organs are said to be more variable than

others, because no longer under the restraining influence of Natural

Selection. And still more distinctly is this principle recognised in

page 120.

Thus, in sending you the enclosed letter, I do not imagine that I am

bringing any novel suggestions under your notice. As I see that you

have already applied the principle in question to the case of

artificially-bred structures, I cannot but infer that you have pondered

it in connection with naturally-bred structures. What objection,

however, you can have seen to this principle in this latter connection,

I am unable to divine; and so I think the best course for me to pursue

is the one I adopt--viz., to send you my considerations in full.

In the absence of express information, the most natural inference is

that the reason you refuse to entertain the principle in question, is

because you show the backward tendency of indiscriminate variability

[to be] inadequate to contend with the conservative tendency of long

inheritance. The converse of this is expressed in the words "That the

struggle between Natural Selection on the one hand, and the tendency to

reversion and variability on the other hand, will in the course of

time cease; and that the most abnormally developed organs may be made

constant, I see no reason to doubt" ("Origin," page 121). Certainly not,

if, as I doubt not, the word "constant" is intended to bear a relative

signification; but to say that constancy can ever become absolute--i.e.,

that any term of inheritance could secure to an organ a total immunity

from the smallest amount of spontaneous variability--to say this would

be unwarrantable. Suppose, for instance, that for some reason or other a

further increase in the size of a bat's wing should now suddenly

become highly beneficial to that animal: we can scarcely suppose that

variations would not be forthcoming for Natural Selection to seize upon

(unless the limit of possible size has now been reached, which is an

altogether distinct matter). And if we suppose that minute variations on

the side of increase are thus even now occasionally taking place, much

more is it probable that similar variations on the side of decrease are

now taking place--i.e., that if the conservative influence of Natural

Selection were removed for a long period of time, more variations would

ensue below the present size of bat's wings, than above it. To this it

may be added, that when the influence of "speedy selection" is removed,

it seems in itself highly probable that the structure would, for this

reason, become more variable, for the only reason why it ever ceased to

be variable (i.e., after attaining its maximum size), was because of the

influence of selection constantly destroying those individuals in which

a tendency to vary occurred. When, therefore, this force antagonistic

to variability was removed, it seems highly probable that the latter

principle would again begin to assert itself, and this in a cumulative

manner. Those individuals in which a tendency to vary occurred being no

longer cut off, they would have as good a chance of leaving progeny to

inherit their fluctuating disposition as would their more inflexible

companions.

LETTER 264. TO G.J. ROMANES. July 16th, 1874.

I am much obliged for your kind and long communication, which I have

read with great interest, as well as your articles in "Nature." The

subject seems to me as important and interesting as it is difficult.

I am much out of health, and working very hard on a very different

subject, so thus I cannot give your remarks the attention which they

deserve. I will, however, keep your letter for some later time, when I

may again take up the subject. Your letter makes it clearer to me than

it ever was before, how a part or organ which has already begun from any

cause to decrease, will go on decreasing through so-called spontaneous

variability, with intercrossing; for under such circumstances it is very

unlikely that there should be variation in the direction of increase

beyond the average size, and no reason why there should not be

variations of decrease. I think this expresses your view. I had intended

this summer subjecting plants to [illegible] conditions, and observing

the effects on variation; but the work would be very laborious, yet I am

inclined to think it will be hereafter worth the labour.

LETTER 265. TO T. MEEHAN. Down, October 9th, 1874.

I am glad that you are attending to the colours of dioecious flowers;

but it is well to remember that their colours may be as unimportant to

them as those of a gall, or, indeed, as the colour of an amethyst or

ruby is to these gems. Some thirty years ago I began to investigate

the little purple flowers in the centre of the umbels of the carrot.

I suppose my memory is wrong, but it tells me that these flowers are

female, and I think that I once got a seed from one of them; but

my memory may be quite wrong. I hope that you will continue your

interesting researches.

LETTER 266. TO G. JAGER. Down, February 3rd, 1875.

I received this morning a copy of your work "Contra Wigand," either

from yourself or from your publisher, and I am greatly obliged for

it. (266/1. Jager's "In Sachen Darwins insbesondere contra Wigand"

(Stuttgart, 1874) is directed against A. Wigand's "Der Darwinismus

und die Naturforschung Newtons und Cuviers" (Brunswick, 1874).) I had,

however, before bought a copy, and have sent the new one to our best

library, that of the Royal Society. As I am a very poor german scholar,

I have as yet read only about forty pages; but these have interested

me in the highest degree. Your remarks on fixed and variable species

deserve the greatest attention; but I am not at present quite convinced

that there are such independent of the conditions to which they are

subjected. I think you have done great service to the principle of

evolution, which we both support, by publishing this work. I am the more

glad to read it as I had not time to read Wigand's great and tedious

volume.

LETTER 267. TO CHAUNCEY WRIGHT. Down, March 13th, 1875.

I write to-day so that there shall be no delay this time in thanking you

for your interesting and long letter received this morning. I am sure

that you will excuse brevity when I tell you that I am half-killing

myself in trying to get a book ready for the press. (267/1. The MS. of

"Insectivorous Plants" was got ready for press in March, 1875. Darwin

seems to have been more than usually oppressed by the work.) I

quite agree with what you say about advantages of various degrees of

importance being co-selected (267/2. Mr. Chauncey Wright wrote (February

24th, 1875): "The inquiry as to which of several real uses is the one

through which Natural Selection has acted...has for several years seemed

to me a somewhat less important question than it seemed formerly, and

still appears to most thinkers on the subject...The uses of the rattling

of the rattlesnake as a protection by warning its enemies and as a

sexual call are not rival uses; neither are the high-reaching and the

far-seeing uses of the giraffe's neck 'rivals.'"), and aided by

the effects of use, etc. The subject seems to me well worth further

development. I do not think I have anywhere noticed the use of the

eyebrows, but have long known that they protected the eyes from sweat.

During the voyage of the "Beagle" one of the men ascended a lofty

hill during a very hot day. He had small eyebrows, and his eyes became

fearfully inflamed from the sweat running into them. The Portuguese

inhabitants were familiar with this evil. I think you allude to the

transverse furrows on the forehead as a protection against sweat; but

remember that these incessantly appear on the foreheads of baboons.

P.S.--I have been greatly pleased by the notices in the "Nation."

LETTER 268. TO A. WEISMANN. Down, May 1st, 1875.

I did not receive your essay for some days after your very kind letter,

and I read german so slowly that I have only just finished it. (268/1.

"Studien zur Descendenz-Theorie" I. "Ueber den Saison-Dimorphismus,"

1875. The fact was previously known that two forms of the genus Vanessa

which had been considered to be distinct species are only SEASONAL forms

of the same species--one appearing in spring, the other in summer. This

remarkable relationship forms the subject of the essay.) Your work has

interested me greatly, and your conclusions seem well established. I

have long felt much curiosity about season-dimorphism, but never could

form any theory on the subject. Undoubtedly your view is very important,

as bearing on the general question of variability. When I wrote the

"Origin" I could not find any facts which proved the direct action of

climate and other external conditions. I long ago thought that the time

would soon come when the causes of variation would be fully discussed,

and no one has done so much as you in this important subject. The recent

evidence of the difference between birds of the same species in the N.

and S. United States well shows the power of climate. The two sexes of

some few birds are there differently modified by climate, and I have

introduced this fact in the last edition of my "Descent of Man." (268/2.

"Descent of Man," Edition II. (in one volume), page 423. Allen showed

that many species of birds are more strongly coloured in the south of

the United States, and that sometimes one sex is more affected than

the other. It is this last point that bears on Weismann's remarks (loc.

cit., pages 44, 45) on Pieris napi. The males of the alpine-boreal form

bryoniae hardly differ from those of the German form (var. vernalis),

while the females are strikingly different. Thus the character of

secondary sexual differences is determined by climate.) I am, therefore,

fully prepared to admit the justness of your criticism on sexual

selection of lepidoptera; but considering the display of their beauty, I

am not yet inclined to think that I am altogether in error.

What you say about reversion (268/3. For instance, the fact that

reversion to the primary winter-form may be produced by the disturbing

effect of high temperature (page 7).) being excited by various causes,

agrees with what I concluded with respect to the remarkable effects

of crossing two breeds: namely, that anything which disturbs the

constitution leads to reversion, or, as I put the case under my

hypothesis of pangenesis, gives a good chance of latent gemmules

developing. Your essay, in my opinion, is an admirable one, and I thank

you for the interest which it has afforded me.

P.S. I find that there are several points, which I have forgotten. Mr.

Jenner Weir has not published anything more about caterpillars, but

I have written to him, asking him whether he has tried any more

experiments, and will keep back this letter till I receive his answer.

Mr. Riley of the United States supports Mr. Weir, and you will

find reference to him and other papers at page 426 of the new and

much-corrected edition of my "Descent of Man." As I have a duplicate

copy of Volume I. (I believe Volume II. is not yet published in german)

I send it to you by this post. Mr. Belt, in his travels in Nicaragua,

gives several striking cases of conspicuously coloured animals (but not

caterpillars) which are distasteful to birds of prey: he is an excellent

observer, and his book, "The Naturalist in Nicaragua," very interesting.

I am very much obliged for your photograph, which I am particularly glad

to possess, and I send mine in return.

I see you allude to Hilgendorf's statements, which I was sorry to

see disputed by some good German observer. Mr. Hyatt, an excellent

palaeontologist of the United States, visited the place, and likewise

assured me that Hilgendorf was quite mistaken. (268/4. See Letters

252-7.)

I am grieved to hear that your eyesight still continues bad, but anyhow

it has forced your excellent work in your last essay.

May 4th. Here is what Mr. Weir says:--

"In reply to your inquiry of Saturday, I regret that I have little

to add to my two communications to the 'Entomological Society

Transactions.'

"I repeated the experiments with gaudy caterpillars for years, and

always with the same results: not on a single occasion did I find richly

coloured, conspicuous larvae eaten by birds. It was more remarkable

to observe that the birds paid not the slightest attention to gaudy

caterpillars, not even when in motion,--the experiments so thoroughly

satisfied my mind that I have now given up making them."

LETTER 269. TO LAWSON TAIT.

(269/1. The late Mr. Lawson Tait wrote to Mr. Darwin (June 2nd, 1875):

"I am watching a lot of my mice from whom I removed the tails at birth,

and I am coming to the conclusion that the essential use of the tail

there is as a recording organ--that is, they record in their memories

the corners they turn and the height of the holes they pass through by

touching them with their tails." Mr. Darwin was interested in the idea

because "some German sneered at Natural Selection and instanced the

tails of mice.")

June 11th, 1875.

It has just occurred to me to look at the "Origin of Species" (Edition

VI., page 170), and it is certain that Bronn, in the appended chapter

to his translation of my book into german, did advance ears and tail of

various species of mice as a difficulty opposed to Natural Selection. I

answered with respect to ears by alluding to Schobl's curious paper (I

forget when published) (269/2. J. Schobl, "Das aussere Ohr der Mause als

wichtiges Tastorgan." "Archiv. Mik. Anat." VII., 1871, page 260.) on the

hairs of the ears being sensitive and provided with nerves. I presume

he made fine sections: if you are accustomed to such histological work,

would it not be worth while to examine hairs of tail of mice? At page

189 I quote Henslow (confirmed by Gunther) on Mus messorius (and other

species?) using tail as prehensile organ.