I fully admit the probability of "protective adaptation" having come

into play with female butterflies as well as with female birds. I have a

good many facts which make me believe in sexual selection as applied to

man, but whether I shall convince anyone else is very doubtful.--Dear

Wallace, yours very sincerely,

CH. DARWIN.

* * * * *

LETTER VIII

C. DARWIN TO A.R. WALLACE

_Down, Bromley, Kent. May 18, 1860._

My dear Mr. Wallace,--I received this morning your letter from Amboyna

dated Feb. 16th, containing some remarks and your too high approbation

of my book. Your letter has pleased me very much, and I most completely

agree with you on the parts which are strongest and which are weakest.

The imperfection of the geological record is, as you say, the weakest of

all; but yet I am pleased to find that there are almost more geological

converts than of pursuers of other branches of natural science. I may

mention Lyell, Ramsay, Jukes, Rogers, Keyerling, all good men and true.

Pictet of Geneva is not a convert, but is evidently staggered (as I

think is Bronn of Heidelberg), and he has written a perfectly fair

review in the _Bib. Universelle_ of Geneva. Old Bronn has translated my

book, well done also into German, and his well-known name will give it

circulation. I think geologists are more converted than simple

naturalists because more accustomed to reasoning.

Before telling you about the progress of opinion on the subject, you

must let me say how I admire the generous manner in which you speak of

my book: most persons would in your position have felt bitter envy and

jealousy. How nobly free you seem to be of this common failing of

mankind. But you speak far too modestly of yourself; you would, if you

had had my leisure, have done the work just as well, perhaps better,

than I have done it. Talking of envy, you never read anything more

envious and spiteful (with numerous misrepresentations) than Owen is in

the _Edinburgh Review_. I must give one instance; he throws doubts and

sneers at my saying that the ovigerous frena of cirripedes have been

converted into branchiæ, because I have not found them to be branchiæ;

whereas _he himself_ admits, before I wrote on cirripedes, without the

least hesitation, that their organs are branchiæ. The attacks have been

heavy and incessant of late. Sedgwick and Prof. Clarke attacked me

savagely at the Cambridge Philosophical Society, but Henslow defended me

well, though not a convert. Phillips has since attacked me in a lecture

at Cambridge; Sir W. Jardine in the _Edinburgh New Philosophical

Journal_, Wollaston in the _Annals of Nat. History_, A. Murray before

the Royal Soc. of Edinburgh, Haughton at the Geological Society of

Dublin, Dawson in the _Canadian Nat. Magazine_, and _many others_. But I

am getting case-hardened, and all these attacks will make me only more

determinedly fight. Agassiz sends me personal civil messages, but

incessantly attacks me; but Asa Gray fights like a hero in defence.

Lyell keeps as firm as a tower, and this autumn will publish on the

Geological History of Man, and will then declare his conversion, which

now is universally known. I hope that you have received Hooker's

splendid essay. So far is bigotry carried that I can name three

botanists who will not even read Hooker's essay!! Here is a curious

thing: a Mr. Pat. Matthews, a Scotchman, published in 1830 a work on

Naval Timber and Arboriculture, and in the appendix to this he gives

_most clearly_ but very briefly in half-dozen paragraphs our view of

Natural Selection. It is a most complete case of anticipation. He

published extracts in the _Gardeners' Chronicle_. I got the book, and

have since published a letter acknowledging that I am fairly

forestalled. Yesterday I heard from Lyell that a German, Dr.

Schaffhausen, has sent him a pamphlet published some years ago, in

which the same view is nearly anticipated, but I have not yet seen this

pamphlet. My brother, who is a very sagacious man, always said, "You

will find that someone will have been before you." I am at work at my

larger work, which I shall publish in separate volumes. But for

ill-health and swarms of letters I get on very, very slowly. I hope that

I shall not have wearied you with these details.

[Illustration: A.R. WALLACE SOON AFTER HIS RETURN FROM THE EAST]

With sincere thanks for your letter, and with most deeply-felt wishes

for your success in science and in every way, believe me your sincere

well-wisher,

C. DARWIN.

* * * * *

Of the letters from Wallace to Darwin which have been preserved, the

earliest is the following:

_5 Westbourne Grove Terrace, W. April 7, 1862._

My dear Mr. Darwin,--I was much pleased to receive your note this

morning. I have not yet begun work, but hope to be soon busy. As I am

being doctored a little I do not think I shall be able to accept your

kind invitation at present, but trust to be able to do so during the

summer.

I beg you to accept a wild honeycomb from the island of Timor, not quite

perfect but the best I could get. It is of a small size, but of

characteristic form, and I think will be interesting to you. I was quite

unable to get the honey out of it, so fear you will find it somewhat in

a mess; but no doubt you will know how to clean it. I have told Stevens

to send it to you.

Hoping your health is now quite restored and with best wishes, I remain,

my dear Mr. Darwin, yours very sincerely,

ALFRED R. WALLACE.

* * * * *

_5 Westbourne Grove Terrace, W. May 23, 1862._

My dear Mr. Darwin,--Many thanks for your most interesting book on the

Orchids. I have read it through most attentively, and have really been

quite as much staggered by the wonderful adaptations you show to exist

in them as by the _Eye_ in animals or any other complicated organs. I

long to get into the country and have a look at some orchids guided by

your new lights, but I have been now for ten days confined to my room

with what is disagreeable though far from dangerous--boils.

I have been reading several of the Reviews on the "Origin," and it seems

to me that you have assisted those who want to criticise you by your

overstating the difficulties and objections. Several of them quote your

own words as the strongest arguments against you.

I think you told me Owen wrote the article in the _Quarterly_. This

seems to me hardly credible, as he speaks so much of Owen, quotes him as

such a great authority, and I believe even calls him a profound

philosopher, etc. etc. Would Owen thus speak of himself?

Trusting your health is good, I remain, my dear Mr. Darwin, yours very

faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. May 24, 1862._

My dear Mr. Wallace,--I write one line to thank you for your note and to

say that the Bishop of Oxford[35] wrote the _Quarterly Review_ (paid

£60), aided by Owen. In the _Edinburgh_ Owen no doubt praised himself.

Mr. Maw's Review in the _Zoologist_ is one of the best, and staggered me

in parts, for I did not see the sophistry of parts. I could lend you any

which you might wish to see; but you would soon be tired. Hopkins and

Pictet in France are two of the best.

I am glad you approve of my little Orchid book; but it has not been

worth, I fear, the ten months it has cost me: it was a hobby-horse, and

so beguiled me.

I am sorry to hear that you are suffering from boils; I have often had

fearful crops: I hope that the doctors are right in saying that they are

serviceable.

How puzzled you must be to know what to begin at. You will do grand

work, I do not doubt.

My health is, and always will be, very poor: I am that miserable animal

a regular valetudinarian.--Yours very sincerely,

C. DARWIN.

* * * * *

_5 Westbourne Grove Terrace, W. August 8, 1862._

My dear Mr. Darwin,--I sincerely trust that your little boy is by this

time convalescent, and that you are therefore enabled to follow your

favourite investigations with a more tranquil mind.

I heard a remark the other day which may not perhaps be new to you, but

seemed to me a fact, if true, in your favour. Mr. Ward (I think it was),

a member of the Microscopical Society, mentioned as a fact noticed by

himself with much surprise that "the muscular fibres of the whale were

no larger than those of the bee!"--an excellent indication of community

of origin.

While looking at the ostriches the other day at the Gardens, it occurred

to me that they were a case of special difficulty, as, inhabiting an

ancient continent, surrounded by numerous enemies, how did their wings

ever become abortive, and if they did so before the birds had attained

their present gigantic size, strength and speed, how could they in the

transition have maintained their existence? I see Westwood in the

_Annals_ brings forward the same case, arguing that the ostriches should

have acquired better wings within the historic period; but as they are

now the swiftest of animals they evidently do not want their wings,

which in their present state may serve some other trifling purpose in

their economy such as fans, or balancers, which may have prevented their

being reduced to such rudiments as in the cassowaries. The difficulty

to me seems to be, how, if they once had flight, could they have lost

it, surrounded by swift and powerful carnivora against whom it must have

been the only defence?

This probably is all clear to you, but I think it is a point you might

touch upon, as I think the objection will seem a strong one to most

people.

In a day or two I go to Devonshire for a few weeks and hope to lay in a

stock of health to enable me to stick to work at my collections during

the winter. I begin to find that large collections involve a heavy

amount of manual labour which is not very agreeable.

Present my compliments to Mrs. and Miss Darwin, and believe me yours

very faithfully,

ALFRED R. WALLACE.

* * * * *

_1 Carlton Terrace, Southampton. August 20, 1862._

My dear Mr. Wallace,--You will not be surprised that I have been slow in

answering when I tell you that my poor boy[36] became frightfully worse

after you were at Down; and that during our journey to Bournemouth he

had a slight relapse here and my wife took the scarlet fever rather

severely. She is over the crisis. I have had a horrid time of it, and

God only knows when we shall be all safe at home again--half my family

are at Bournemouth.

I have given a piece of the comb from Timor to a Mr. Woodbury (who is

working at the subject), and he is _extremely_ interested by it (I was

sure the specimen would be valuable) and has requested me to ascertain

whether the bee (_A. testacea_) is domesticated when it makes its combs.

Will you kindly inform me?

Your remarks on ostriches have interested me, and I have alluded to the

case in the Third Edition. The difficulty does not seem to me so great

as to you. Think of bustards, which inhabit wide open plains, and which

so seldom take flight: a very little increase in size of body would make

them incapable of flight. The idea of ostriches acquiring flight is

worthy of Westwood; think of the food required in these inhabitants of

the desert to work the pectoral muscles! In the rhea the wings seem of

considerable service in the first start and in turning.[37] ...

* * * * *

_5 Westbourne Grove Terrace, W. September 30, 1862._

My dear Mr. Darwin,--Many thanks for the third edition of the "Origin,"

which I found here on my return from Devonshire on Saturday. I have not

had time yet to read more than the Historical Sketch, which is very

interesting, and shows that the time had quite come for your book.

I am now reading Herbert Spencer's "First Principles," which seems to me

a truly great work, which goes to the root of everything.

I hope you will be well enough to come to Cambridge.

I remain, my dear Mr. Darwin, yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_5 Westbourne Grove Terrace, W. January 14 [1863?]._

My dear Mr. Darwin,--I am very sorry indeed to hear you are still in

weak health. Have you ever tried mountain air? A residence at 2,000 or

3,000 ft. elevation is very invigorating.

I trust your family are now all in good health, and that you may be

spared any anxiety on that score for some time. If you come to town I

shall hope to have the pleasure of seeing you.

I am now in much better health, but find sudden changes of weather

affect me very much, bringing on ague and fever fits. I am now working a

little, but having fresh collections still arriving from correspondents

in the East, it is principally the drudgery of cleaning, packing, and

arrangement.

On the opposite page I give all the information I can about the Timor

fossils, so that you can send it entire to Dr. Falconer.

With best wishes for the speedy recovery of your health, I remain, my

dear Mr. Darwin, yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. January 1, 1864._

Dear Wallace,--I am still unable to write otherwise than by dictation.

In a letter received two or three weeks ago from Asa Gray he writes: "I

read lately with gusto Wallace's exposé of the Dublin man on Bee cells,

etc."[38]

Now though I cannot read at present, I much want to know where this is

published, that I may procure a copy. Further on Asa Gray says (after

speaking of Agassiz's paper on Glaciers in the _Atlantic Magazine_ and

his recent book entitled "Method of Study"): "Pray set Wallace upon

these articles." So Asa Gray seems to think much of your powers of

reviewing, and I mention this as it assuredly is _laudari a laudato_.

I hope you are hard at work, and if you are inclined to tell me I should

much like to know what you are doing.

It will be many months, I fear, before I shall do anything.

Pray believe me yours very sincerely,

CH. DARWIN.

* * * * *

_5 Westbourne Grove Terrace, W. January 2, 1864._

My dear Darwin,--Many thanks for your kind letter. I was afraid to write

because I heard such sad accounts of your health, but I am glad to find

that you can write, and I presume read, by deputy. My little article on

Haughton's paper was published in the _Annals of Natural History_ about

August or September last, I think, but I have not a copy to refer to. I

am sure it does not deserve Asa Gray's praises, for though the matter

may be true enough, the manner I know is very inferior. It was written

hastily, and when I read it in the _Annals_ I was rather ashamed of it,

as I knew so many could have done it so much better.

I will try and see Agassiz's paper and book. What I have hitherto seen

of his on Glacial subjects seems very good, but in all his Natural

History _theories_, he seems so utterly wrong and so totally blind to

the plainest deduction from facts, and at the same time so vague and

obscure in his language, that it would be a very long and wearisome task

to answer him.

With regard to work, I am doing but little--I am afraid I have no good

habit of systematic work. I have been gradually getting parts of my

collections in order, but the obscurities of synonymy and descriptions,

the difficulty of examining specimens, and my very limited library, make

it wearisome work.

I have been lately getting the first groups of my butterflies in order,

and they offer some most interesting facts in variation and

distribution--in variation some very puzzling ones. Though I have very

fine series of specimens, I find in many cases I want more; in fact if I

could have afforded to have all my collections kept till my return I

should, I think, have found it necessary to retain twice as many as I

now have.

I am at last making a beginning of a small book on my Eastern journey,

which, if I can persevere, I hope to have ready by next Christmas. I am

a very bad hand at writing anything like narrative. I want something to

argue on, and then I find it much easier to go ahead. I rather despair,

therefore, of making so good a book as Bates's, though I think my

subject is better. Like every other traveller, I suppose, I feel

dreadfully the want of copious notes on common everyday objects, sights

and sounds and incidents, which I imagined I could never forget but

which I now find it impossible to recall with any accuracy.

I have just had a long and most interesting letter from my old companion

Spruce. He says he has had a letter from you about Melastoma, but has

not, he says, for three years seen a single melastomaceous plant! They

are totally absent from the Pacific plains of tropical America, though

so abundant on the Eastern plains. Poor fellow, he seems to be in a

worse state than you are. Life has been a burden to him for three years

owing to lung and heart disease, and rheumatism, brought on by exposure

in high, hot, and cold damp valleys of the Andes. He went down to the

dry climate of the Pacific coast to die more at ease, but the change

improved him, and he thinks to come home, though he is sure he will not

survive the first winter in England. He had never been able to get a

copy of your book, though I am sure no one would have enjoyed or

appreciated it more.

If you are able to bear reading, will you allow me to take the liberty

of recommending you a book? The fact is I have been so astonished and

delighted with the perusal of Spencer's works that I think it a duty to

society to recommend them to all my friends who I think can appreciate

them. The one I particularly refer to now is "Social Statics," a book

which is by no means hard to read; it is even amusing, and owing to the

wonderful clearness of its style may be read and understood by anyone. I

think, therefore, as it is quite distinct from your special studies at

present, you might consider it as "light literature," and I am pretty

sure it would interest you more than a great deal of what is now

considered very good. I am utterly astonished that so few people seem to

read Spencer, and the utter ignorance there seems to be among

politicians and political economists of the grand views and logical

stability of his works. He appears to me as far ahead of John Stuart

Mill as J.S.M. is of the rest of the world, and, I may add, as Darwin is

of Agassiz. The range of his knowledge is no less than its accuracy. His

nebular hypothesis in the last volume of his essays is the most masterly

astronomical paper I have ever read, and in his forthcoming volume on

Biology he is I understand going to show that there is something else

besides Natural Selection at work in nature. So you must look out for a

"foeman worthy of your steel"! But perhaps all this time you have read

his books. If so, excuse me, and pray give me your opinion of him, as I

have hitherto only met with one man (Huxley) who has read and

appreciated him.

Allow me to say in conclusion how much I regret that unavoidable

circumstances have caused me to see so little of you since my return

home, and how earnestly I pray for the speedy restoration of your

health.--Yours most sincerely,

ALFRED R. WALLACE.

* * * * *

_Malvern Wells. Tuesday, March, 1864._

My dear Mr. Wallace,--Your kindness is neverfailing. I got worse and

worse at home and was sick every day for two months; so came here, when

I suddenly broke down and could do nothing; but I hope I am now very

slowly recovering, but am very weak.

Sincere thanks about Melastoma: these flowers have baffled me, and I

have caused several friends much useless labour; though, Heaven knows, I

have thrown away time enough on them myself.

The gorse case is very valuable, and I will quote it, as I presume I

may.

I was very glad to see in the _Reader_ that you have been giving a

grand paper (as I infer from remarks in discussion) on Geographical

Distribution.

I am very weak, so will say no more.--Yours very sincerely,

C. DARWIN.

* * * * *

In Vol. I., p. 93, of the "Life and Letters of Charles Darwin," Darwin

states the circumstances which led to his writing the "Descent of Man."

He says that his collection of facts, begun in 1837 or 1838, was

continued for many years without any definite idea of publishing on the

subject. The letter to Wallace of May 28, 1864, in reply to the latter's

of May 10, shows that in the period of ill-health and depression about

1864 he despaired of ever being able to do so.

_5 Westbourne Grove Terrace, W. May 10, 1864._

My dear Darwin,--I was very much gratified to hear by your letter of a

month back that you were a little better, and I have since heard

occasionally through Huxley and Lubbock that you are not worse. I

sincerely hope the summer weather and repose may do you real good.

The Borneo Cave exploration is to go on at present without a

subscription. The new British consul who is going out to Sarawak this

month will undertake to explore some of the caves nearest the town, and

if anything of interest is obtained a good large sum can no doubt be

raised for a thorough exploration of the whole country. Sir J. Brooke

will give every assistance, and will supply men for the preliminary

work.

I send you now my little contribution to the _theory_ of the origin of

man. I hope you will be able to agree with me. If you are able, I shall

be glad to have your criticisms.

I was led to the subject by the necessity of explaining the vast mental

and cranial differences between man and the apes combined with such

small structural differences in other parts of the body, and also by an

endeavour to account for the diversity of human races combined with

man's almost perfect stability of form during all historical epochs.

It has given me a settled opinion on these subjects, if nobody can show

a fallacy in the argument.

The Anthropologicals did not seem to appreciate it much, but we had a

long discussion which appears almost verbatim in the _Anthropological

Review_.[39]

As the _Linnean Transactions_ will not be out till the end of the year I

sent a pretty full abstract of the more interesting parts of my

Papilionidæ paper[40] to the _Reader_, which, as you say, is a splendid

paper.

Trusting Mrs. Darwin and all your family are well, and that you are

improving, believe me yours most sincerely,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent. May 28, 1864._

Dear Wallace,--I am so much better that I have just finished a paper for

the Linnean Society; but as I am not yet at all strong I felt much

disinclination to write, and therefore you must forgive me for not

having sooner thanked you for your paper on Man received on the 11th.

But first let me say that I have hardly ever in my life been more struck

by any paper than that on variation, etc. etc., in the _Reader_. I feel

sure that such papers will do more for the spreading of our views on the

modification of species than any separate treatises on the single

subject itself. It is really admirable; but you ought not in the Man

paper to speak of the theory as mine; it is just as much yours as mine.

One correspondent has already noticed to me your "high-minded" conduct

on this head.

But now for your Man paper, about which I should like to write more than

I can. The great leading idea is quite new to me, viz. that during late

ages the mind will have been modified more than the body; yet I had got

as far as to see with you that the struggle between the races of man

depended entirely on intellectual and _moral_ qualities. The latter part

of the paper I can designate only as grand and most eloquently done. I

have shown your paper to two or three persons who have been here, and

they have been equally struck with it.

I am not sure that I go with you on all minor points. When reading Sir

G. Grey's account of the constant battles of Australian savages, I

remember thinking that Natural Selection would come in, and likewise

with the Esquimaux, with whom the art of fishing and managing canoes is

said to be hereditary. I rather differ on the rank under the

classificatory point of view which you assign to Man: I do not think any

character simply in excess ought ever to be used for the higher

division. Ants would not be separated from other hymenopterous insects,

however high the instinct of the one and however low the instincts of

the other.

With respect to the differences of race, a conjecture has occurred to me

that much may be due to the correlation of complexion (and consequently

hair) with constitution. Assume that a dusky individual best escaped

miasma and you will readily see what I mean. I persuaded the

Director-General of the Medical Department of the Army to send printed

forms to the surgeons of all regiments in tropical countries to

ascertain this point, but I daresay I shall never get any returns.

Secondly, I suspect that a sort of sexual selection has been the most

powerful means of changing the races of man. I can show that the

different races have a widely different standard of beauty. Among

savages the most powerful men will have the pick of the women, and they

will generally leave the most descendants.

I have collected a few notes on Man, but I do not suppose I shall ever

use them. Do you intend to follow out your views, and if so would you

like at some future time to have my few references and notes?

I am sure I hardly know whether they are of any value, and they are at

present in a state of chaos.

There is much more that I should like to write but I have not

strength.--Believe me, dear Wallace, yours very sincerely,

CH. DARWIN.

Our aristocracy is handsomer? (more hideous according to a Chinese or

negro) than the middle classes, from pick of women; but oh what a scheme

is primogeniture for destroying Natural Selection! I fear my letter will

be barely intelligible to you.

* * * * *

_5 Westbourne Grove Terrace, W. May 29 [1864]._

My dear Darwin,--You are always so ready to appreciate what others do,

and especially to overestimate my desultory efforts, that I cannot be

surprised at your very kind and flattering remarks on my papers. I am

glad, however, that you have made a few critical observations, and am

only sorry you were not well enough to make more, as that enables me to

say a few words in explanation.

My great fault is haste. An idea strikes me, I think over it for a few

days, and then write away with such illustrations as occur to me while

going on. I therefore look at the subject almost solely from one point

of view. Thus in my paper on Man[41] I aim solely at showing that brutes

are modified in a _great variety_ of ways by Natural Selection, but that

in _none of these particular_ ways can man be modified, because of the

superiority of his intellect. I therefore no doubt overlook a few

smaller points in which Natural Selection may still act on men and

brutes alike. Colour is one of them, and I have alluded to this in

correlation to constitution in an abstract I have made at Sclater's

request for the _Natural History Review_.[42] At the same time, there is

so much evidence of migrations and displacements of races of man, and so

many cases of peoples of distinct physical characters inhabiting the

same or similar regions, and also of races of uniform physical

characters inhabiting widely dissimilar regions, that the external

characteristics of the chief races of man must I think be older than his

present geographical distribution, and the modifications produced by

correlation to favourable variations of constitution be only a secondary

cause of external modification.

I hope you may get the returns from the Army. They would be very

interesting, but I do not expect the results would be favourable to your

view.

With regard to the constant battles of savages leading to selection of

physical superiority, I think it would be very imperfect, and subject to

so many exceptions and irregularities that it could produce no

_definite_ result. For instance, the strongest and bravest men would

lead, and expose themselves most, and would therefore be most subject to

wounds and death. And the physical energy which led to any one tribe

delighting in war might lead to its extermination by inducing quarrels

with all surrounding tribes and leading them to combine against it.

Again, superior cunning, stealth and swiftness of foot, or even better

weapons, would often lead to victory as well as mere physical strength.

Moreover this kind of more or less perpetual war goes on among all

savage peoples. It could lead therefore to no differential characters,

but merely to the keeping up of a certain average standard of bodily and

mental health and vigour. So with selection of variations adapted to

special habits of life, as fishing, paddling, riding, climbing, etc.

etc., in different races: no doubt it must act to some extent, but will

it be ever so rigid as to induce a definite physical modification, and

can we imagine it to have had any part in producing the distinct races

that now exist?

The sexual selection you allude to will also, I think, have been equally

uncertain in its results. In the very lowest tribes there is rarely much

polygamy, and women are more or less a matter of purchase. There is also

little difference of social condition, and I think it rarely happens

that any healthy and undeformed man remains without wife and children. I

very much doubt the often-repeated assertion that our aristocracy are

more beautiful than the middle classes. I allow that they present

_specimens_ of the highest kind of beauty, but I doubt the average. I

have noticed in country places a greater average amount of good looks

among the middle classes, and besides, we unavoidably combine in our

idea of beauty, intellectual expression and refinement of _manner_,

which often make the less appear the more beautiful. Mere physical

beauty--that is, a healthy and regular development of the body and

features approaching to the _mean_ or _type_ of European man--I believe

is quite as frequent in one class of society as the other, and much more

frequent in rural districts than in cities.

With regard to the rank of man in zoological classification, I fear I

have not made myself intelligible. I never meant to adopt Owen's or any

other such views, but only to point out that from _one_ point of view he

was right. I hold that a distinct _family_ for man, as Huxley allows, is

all that can possibly be given him zoologically. But at the same time,

if my theory is true--that while the animals which surrounded him have

been undergoing modification in _all_ parts of their bodies to a

_generic_ or even _family_ degree of difference, he has been changing

almost wholly in the brain and head--then, in geological antiquity the

_species_ of man may be as old as many mammalian _families_, and the

origin of the _family_ man may date back to a period when some of the

orders first originated.

As to the theory of Natural Selection itself, I shall always maintain it

to be actually yours and yours only. You had worked it out in details I

had never thought of, years before I had a ray of light on the subject,

and my paper would never have convinced anybody or been noticed as more

than an ingenious speculation, whereas your book has revolutionised the

study of natural history, and carried away captive the best men of the

present age. All the merit I claim is the having been the means of

inducing _you_ to write and publish at once.

I may possibly some day go a little more into this subject (of Man),

and, if I do, will accept the kind offer of your notes. I am now,

however, beginning to write the "Narrative of my Travels" which will

occupy me a long time, as I hate writing narrative, and after Bates's

brilliant success rather fear to fail. I shall introduce a few chapters

on geographical distribution and other such topics.

Sir C. Lyell, while agreeing with my main argument on Man, thinks I am

wrong in wanting to put him back into Miocene times, and thinks I do not

appreciate the immense interval even to the later Pliocene. But I still

maintain my view, which in fact is a logical result of my theory, for if

man originated in later Pliocene times, when almost all mammalia were of

closely allied species to those now living, and many even identical,

then man has _not_ been stationary in bodily structure while animals

have been varying, and my theory will be proved to be all wrong.

In Murchison's address to the Geographical Society just delivered he

points out Africa, as being the _oldest_ existing land. He says there is

_no_ evidence of its having been ever submerged during the tertiary

epoch. Here, then, is evidently the place to find _early man_. I hope

something good may be found in Borneo, and that then means may be found

to explore the still more promising regions of tropical Africa, for we

can expect nothing of man _very_ early in Europe.

It has given me great pleasure to find that there are symptoms of

improvement in your health. I hope you will not exert yourself too soon

or write more than is quite agreeable to you. I think I made out every

word of your letter though it was not always easy.--Believe me, my dear

Darwin, yours very sincerely,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. June 15, 1864._

Dear Wallace,--You must not suppose from my delay that I have not been

much interested by your long letter. I write now merely to thank you,

and just to say that probably you are right on all the points you touch

on except, as I think, about sexual selection, which I will not give up.

My belief in it, however, is contingent on my general beliefs in sexual

selection. It is an awful stretcher to believe that a peacock's tail was

thus formed; but believing it, I believe in the same principle somewhat

modified applied to man.

I doubt whether my notes would be of any use to you, and as far as I

remember they are chiefly on sexual selection.

I am very glad to hear that you are on your Travels. I believe you will

find it a very convenient vehicle for miscellaneous discussion. With

your admirable powers of writing, I cannot doubt that you will make an

excellent book.--Believe me, dear Wallace, yours sincerely,

CH. DARWIN.

P.S.--A great gun, Flourens, has written a little dull book against me;

which pleases me much, for it is plain that our good work is spreading

in France. He speaks of the _engouement_ about this book, "so full of

empty and presumptuous thoughts."

* * * * *

_Down, Bromley, Kent, S.E. January 29, 1865._

My dear Wallace,--I must ease my mind by saying how much I admire the

two papers you have sent me.

That on parrots[43] contained most new matter to me, and interested me

_extremely_; that in the _Geographical Journal_[44] strikes me as an

epitome of the whole theory of geographical distribution: the comparison

of Borneo and New Guinea, the relation of the volcanic outbursts and the

required subsidence, and the comparison of the supposed conversion of

the Atlantic into a great archipelago, seemed to me the three best hits.

They are both indeed excellent papers.--Believe me yours very sincerely,

CHARLES DARWIN.

Do try what hard work will do to banish painful thoughts.[45]

P.S.--During one of the later French voyages, a _wild_ pig was killed

and brought from the Aru Islands to Paris. Am I not right in inferring

that this must have been introduced and run wild? If you have a clear

opinion on this head, may I quote you?

* * * * *

_5 Westbourne Grove Terrace, W. January 31, [1865?]._

Dear Darwin,--Many thanks for your kind letter. I send you now a few

more papers. One on Man is not much in your line. The other three are

bird lists, but in the introductory remarks are a few facts of

distribution that may be of use to you, and as you have them already in

the _Zoological Proceedings_, you can cut these up if you want

"extracts."

I hope you do not very much want the Aru pig to be a domestic animal run

wild, because I have no doubt myself it was the species peculiar to the

New Guinea fauna (_Sus papuensis_, Less.), a very distinct form. I have

no doubt it is this species, though I did not get it myself there,

because I was told that on a small island near, called there Pulo babi

(Pig Island), was a race of pigs (different from and larger than those

of the large islands) which had originated from the wreck of a large

ship near a century ago. The productions of the Aru Islands closely

resemble those of New Guinea, more than half the species of birds being

identical, as well as about half of the few known mammals.

I am beginning to work at some semi-mechanical work, drawing up

catalogues of parts of my collection for publication.

I enclose my "carte." Have you a photograph of yourself of any kind you

can send me? When you come to town next, may I beg the honour of a

sitting for my brother-in-law, Mr. Sims, 73 Westbourne Grove?--Yours

very sincerely,

ALFRED R. WALLACE.

P.S.--Your paper on _Lythrum salicaria_[46] is most beautiful. What a

wonderful plant it is! I long to hear your paper on Tendrils and hear

what you have got out of them. My old friend Spruce, a good botanist and

close observer, could probably supply you with some facts on that or

other botanical subjects if you would write to him. He is now at Kew,

but almost as ill as yourself.--A.R.W.

* * * * *

_Down, Bromley, Kent, S.E. February 1, 1865._

My dear Wallace,--I am much obliged for your photograph, for I have

lately set up a scientific album; and for the papers, which I will read

before long. I enclose my own photo, taken by my son, and I have no

other.

I fear it will be a long time before I shall be able to sit to a

photographer, otherwise I should be happy to sit to Mr. Sims.

Thanks for information about the Aru pig, which will make me very

cautious.

It is a perplexing case, for Nathusius says the skull of the Aru

resembles that of the Chinese breed, and he thinks that _Sus papuensis_

has been founded on a young skull; D. Blainville stating that an old

skull from New Guinea resembles that of the wild pigs of Malabar, and

these belong to the _S. scrofa_ type, which is different from the

Chinese domestic breed. The latter has not been found in a wild

condition.--Believe me, dear Wallace, yours very sincerely,

CH. DARWIN.

* * * * *

_9 St. Mark's Crescent, Regent's Park, N.W. Sept. 18, 1865._

Dear Darwin,--I should have written before to thank you for the copy of

your paper on climbing plants, which I read with great interest; I can

imagine how much pleasure the working out must have given you. I was

afraid you were too ill to make it advisable that you should be bothered

with letters.

I write now, in hopes you are better, to communicate a curious case of

_variation_ becoming at once _hereditary_, which was brought forward at

the British Association. I send a note of it on the other side, but if

you would like more exact particulars, with names and dates and a

drawing of the bird, I am sure Mr. O'Callaghan would send them to you.

I hope to hear that you are better, and that your new book is really to

come out next winter.--Believe me yours very faithfully,

ALFRED R. WALLACE.

NOTE.--Last spring Mr. O'Callaghan was told by a country boy that he had

seen a blackbird with a topknot; on which Mr. O'C. very judiciously told

him to watch it and communicate further with him. After a time the boy

told him he had found a blackbird's nest, and had seen this crested bird

near it and believed he belonged to it. He continued watching the nest

till the young were hatched. After a time he told Mr. O'C. that two of

the young birds seemed as if they would have topknots. He was told to

get one of them as soon as it was fledged. However, he was too late, and

they left the nest, but luckily he found them near and knocked one down

with a stone, which Mr. O'C. had stuffed and exhibited. It has a fine

crest, something like that of a Polish fowl, but _larger_ in proportion

to the bird, and very regular and well formed. The male must have been

almost like the Umbrella bird in miniature, the crest is so large and

expanded.--A.R.W.

* * * * *

_Down, Bromley, Kent, S.E. September 22, 1865._

Dear Wallace,--I am much obliged for your extract; I never heard of such

a case, though such a variation is perhaps the most likely of any to

occur in a state of nature and be inherited, inasmuch as all

domesticated birds present races with a tuft or with reversed feathers

on their heads. I have sometimes thought that the progenitor of the

whole class must have been a crested animal.

Do you make any progress with your Journal of travels? I am the more

anxious that you should do so as I have lately read with much interest

some papers by you on the ouran-outang, etc., in the _Annals_, of which

I have lately been reading the latter volumes, I have always thought

that Journals of this nature do considerable good by advancing the taste

for natural history; I know in my own case that nothing ever stimulated

my zeal so much as reading Humboldt's Personal Narrative. I have not yet

received the last part of _Linnean Transactions_, but your paper[47] at

present will be rather beyond my strength, for though somewhat better I

can as yet do hardly anything but lie on the sofa and be read aloud to.

By the way, have you read Tylor and Lecky?[48] Both these books have

interested me much. I suppose you have read Lubbock?[49] In the last

chapter there is a note about you in which I most cordially concur.[50] I

see you were at the British Association, but I have heard nothing of it

except what I have picked up in the _Reader_. I have heard a rumour that

the _Reader_ is sold to the Anthropological Society. If you do not

begrudge the trouble of another note (for my sole channel of news

through Hooker is closed by his illness), I should much like to hear

whether the _Reader_ is thus sold. I should be very sorry for it, as the

paper would thus become sectional in its tendency. If you write, tell me

what you are doing yourself.

The only news which I have about the "Origin" is that Fritz Müller

published a few months ago a remarkable book[51] in its favour, and

secondly that a second French edition is just coming out.--Believe me,

dear Wallace, yours very sincerely,

CH. DARWIN.

* * * * *

_9 St. Mark's Crescent, Regents Park. October 2, 1865._

Dear Darwin,--I was just leaving town for a few days when I received

your letter, or should have replied at once.

The _Reader_ has no doubt changed hands, and I am inclined to think for

the better. It is purchased, I believe, by a gentleman who is a Fellow

of the Anthropological Society, but I see no signs of its being made a

special organ of that Society. The Editor (and, I believe, proprietor)

is a Mr. Bendyshe, the most talented man in the Society, and, judging

from his speaking, which I have often heard, I should say the articles

on "Simeon and Simony," "Metropolitan Sewage," and "France and Mexico,"

are his, and these are in my opinion superior to anything that has been

in the _Reader_ for a long time; they have the point and brilliancy

which are wanted to make leading articles readable and popular. The

articles on Mill's Political Economy and on Mazzini are also first-rate.

He has introduced also the plan of having two, and now three, important

articles in each number--one political or social, one literary, and one

scientific. Under the old regime they never had an editor above

mediocrity, except Masson (? Musson); there was a want of unity among

the proprietors as to the aims and objects of the journal; and there was

a want of capital to secure the services of good writers. This seems to

me to be now all changed for the better, and I only hope the rumour of

that _bête noire_, the Anthropological Society, having anything to do

with it may not cause our best men of science to withdraw their support

and contributions.

I have read Tylor, and am reading Lecky. I found the former somewhat

disconnected and unsatisfactory from the absence of any definite result

or any decided opinion on most of the matters treated of.

Lecky I like much, though he is rather tedious and obscure at times.

Most of what he says has been said so much more forcibly by Buckle,

whose work I have read for the second time with increased admiration,

although with a clear view of some of his errors. Nevertheless, his is I

think unapproachably the grandest work of the present century, and the

one most likely to liberalise opinion. Lubbock's book is very good, but

his concluding chapter very weak. Why are men of science so dreadfully

afraid to say what they think and believe?

In reply to your kind inquiries about myself, I can only say that I am

ashamed of my laziness. I have done nothing lately but write a paper on

Pigeons for the _Ibis_, and am drawing up a Catalogue of my Collection

of Birds.

As to my "Travels," I cannot bring myself to undertake them yet, and

perhaps never shall, unless I should be fortunate enough to get a wife

who would incite me thereto and assist me therein--which is not likely.

I am glad to hear that the "Origin" is still working its revolutionary

way on the Continent. Will Müller's book on it be translated?

I am glad to hear you are a little better. My poor friend Spruce is

still worse than you are, and I fear now will not recover. He wants to

write a book if he gets well enough.--With best wishes, believe me yours

very faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. January 22, 1866._

My dear Wallace,--I thank you for your paper on Pigeons,[52] which

interested me, as everything that you write does. Who would ever have

dreamed that monkeys influenced the distribution of pigeons and parrots!

But I have had a still higher satisfaction; for I finished yesterday

your paper in the _Linnean Transactions_.[53] It is admirably done. I

cannot conceive that the most firm believer in Species could read it

without being staggered. Such papers will make many more converts among

naturalists than long-winded books such as I shall write if I have

strength.

I have been particularly struck with your remarks on dimorphism; but I

cannot quite understand one point (p. 22), and should be grateful for an

explanation, for I want fully to understand you.[54] How can one female

form be selected and the intermediate forms die out, without also the

other extreme form also dying out from not having the advantages of the

first selected form? for, as I understand, both female forms occur on

the same island. I quite agree with your distinction between dimorphic

forms and varieties; but I doubt whether your criterion of dimorphic

forms not producing intermediate offspring will suffice; for I know of

a good many varieties, which must be so called, that will not blend or

intermix, but produce offspring quite like either parent.

I have been particularly struck with your remarks on geological

distribution in Celebes. It is impossible that anything could be better

put, and [it] would give a cold shudder to the immutable naturalists.

And now I am going to ask a question which you will not like. How does

your Journal get on? It will be a shame if you do not popularise your

researches.

My health is so far improved that I am able to work one or two hours a

day.--Believe me, dear Wallace, yours very sincerely,

CH. DARWIN.

* * * * *

_9 St. Mark's Crescent, Regent's Park, N.W. February 4, 1866._

My dear Darwin,--I am very glad to hear you are a little better, and

hope we shall soon have the pleasure of seeing your volume on "Variation

under Domestication." I do not see the difficulty you seem to feel about

two or more female forms of one species. The _most common_ or _typical_

female form must have certain characters or qualities which are

sufficiently advantageous to it to enable it to maintain its existence;

in general, such as vary much from it die out. But occasionally a

variation may occur which has special advantageous characters of its own

(such as mimicking a protected species), and then this variation will

maintain itself by selection. In no less than three of my _polymorphic_

species of Papilio, one of the female forms mimics the _Polydorus_

group, which, like the _Æneas_ group in America, seems to have some

special protection. In two or three other cases one of the female forms

is confined to a restricted locality, to the conditions of which it is

probably specially adapted. In other cases one of the female forms

resembles the male, and perhaps receives a protection from the

abundance of the males, in the crowd of which it is passed over. I think

these considerations render the production of two or three forms of

female very conceivable. The physiological difficulty is to me greater,

of how each of two forms of female produces offspring like the other

female as well as like itself, but no intermediates?

If you "know varieties that will not blend or intermix, but produce

offspring quite like either parents," is not that the very physiological

test of a species which is wanting for the _complete proof_ of the

origin of species?

I have by no means given up the idea of writing my Travels, but I think

I shall be able to do it better for the delay, as I can introduce

chapters giving popular sketches of the subjects treated of in my

various papers.

I hope, if things go as I wish this summer, to begin work at it next

winter. But I feel myself incorrigibly lazy, and have no such system of

collecting and arranging facts or of making the most of my materials as

you and many of our hard-working naturalists possess in

perfection.--With best wishes, believe me, dear Darwin, yours most

sincerely,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, S.E. Tuesday, February, 1866._

My dear Wallace,--After I had dispatched my last note, the simple

explanation which you give had occurred to me, and seems satisfactory. I

do not think you understand what I mean by the non-blending of certain

varieties. It does not refer to fertility. An instance will explain. I

crossed the Painted Lady and Purple sweet peas, which are very

differently coloured varieties, and got, even out of the same pod, both

varieties perfect, but none intermediate. Something of this kind, I

should think, must occur at first with your butterflies and the three

forms of Lythrum; though these cases are in appearance so wonderful, I

do not know that they are really more so than every female in the world

producing distinct male and female offspring.

I am heartily glad that you mean to go on preparing your

Journal.--Believe me yours very sincerely,

CH. DARWIN.

* * * * *

_Hurstpierpoint, Sussex. July 2, 1866._

My dear Darwin,--I have been so repeatedly struck by the utter inability

of numbers of intelligent persons to see clearly, or at all, the

self-acting and necessary effects of Natural Selection, that I am led to

conclude that the term itself, and your mode of illustrating it, however

clear and beautiful to many of us, are yet not the best adapted to

impress it on the general naturalist public. The two last cases of this

misunderstanding are (1) the article on "Darwin and his Teachings" in

the last _Quarterly Journal of Science_, which, though very well written

and on the whole appreciative, yet concludes with a charge of something

like blindness, in your not seeing that Natural Selection requires the

constant watching of an intelligent "chooser," like man's selection to

which you so often compare it; and (2) in Janet's recent work on the

"Materialism of the Present Day," reviewed in last Saturday's _Reader_,

by an extract from which I see that he considers your weak point to be

that you do not see that "thought and direction are essential to the

action of Natural Selection." The same objection has been made a score

of times by your chief opponents, and I have heard it as often stated

myself in conversation. Now, I think this arises almost entirely from

your choice of the term Natural Selection, and so constantly comparing

it in its effects to man's selection, and also to your so frequently

personifying nature as "selecting," as "preferring," as "seeking only

the good of the species," etc., etc. To the few this is as clear as

daylight, and beautifully suggestive, but to many it is evidently a

stumbling-block. I wish, therefore, to suggest to you the possibility of

entirely avoiding this source of misconception in your great work (if

not now too late), and also in any future editions of the "Origin," and

I think it may be done without difficulty and very effectually by

adopting Spencer's term (which he generally uses in preference to

Natural Selection), viz. "Survival of the Fittest." This term is the

plain expression of the _fact_; "Natural Selection" is a metaphorical

expression of it, and to a certain degree _indirect_ and _incorrect_,

since, even personifying Nature, she does not so much select special

variations as exterminate the most unfavourable ones.

Combined with the enormous multiplying powers of all organisms, and the

"struggle for existence," leading to the constant destruction of by far

the largest proportion--facts which no one of your opponents, as far as

I am aware, has denied or misunderstood--"the survival of the fittest,"

rather than of those which were less fit, could not possibly be denied

or misunderstood. Neither would it be possible to say that to ensure the

"survival of the fittest" any _intelligent chooser_ was necessary,

whereas when you say "Natural Selection" acts so as to choose those that

are fittest it _is_ misunderstood, and apparently always will be.

Referring to your book, I find such expressions as "Man selects only for

his own good; Nature only for that of the being which she tends." This,

it seems, will always be misunderstood; but if you had said, "Man

selects only for his own good; Nature, by the inevitable survival of the

fittest, only for that of the being she tends," it would have been less

liable to be so.

I find you use the term Natural Selection in two senses--(1) for the

simple preservation of favourable and rejection of unfavourable

variations, in which case it is equivalent to "survival of the fittest";

(2) for the _effect or change_ produced by this preservation, as when

you say, "To sum up the circumstances favourable or unfavourable to

natural selection," and, again, "Isolation, also, is an important

element in the process of natural selection": here it is not merely

"survival of the fittest," but _change_ produced by survival of the

fittest, that is meant. On looking over your fourth chapter, I find that

these alterations of terms can be in most cases easily made, while in

some cases the addition of "or survival of the fittest" after "natural

selection" would be best; and in others, less likely to be

misunderstood, the original term might stand alone.

I could not venture to propose to any other person so great an

alteration of terms, but you, I am sure, will give it an impartial

consideration, and, if you really think the change will produce a better

understanding of your work, will not hesitate to adopt it. It is

evidently also necessary not to personify "nature" too much, though I am

very apt to do it myself, since people will not understand that all such

phrases are metaphors. Natural Selection is, when understood, so

necessary and self-evident a principle that it is a pity it should be in

any way obscured; and it therefore occurs to me that the free use of

"survival of the fittest", which is a compact and accurate definition of

it, would tend much to its being more widely accepted and prevent its

being so much misrepresented and misunderstood.

There is another objection made by Janet which is also a very common

one. It is that the chances are almost infinite against the particular

kind of variation required being coincident with each change of external

conditions, to enable an animal to become modified by Natural Selection

in harmony with such changed conditions; especially when we consider

that, to have produced the almost infinite modifications of organic

beings, this coincidence must have taken place an almost infinite number

of times.

Now it seems to me that you have yourself led to this objection being

made by so often stating the case too strongly against yourself. For

example, at the commencement of Chapter IV. you ask if it is "improbable

that useful variations should sometimes occur in the course of thousands

of generations"; and a little further on you say, "unless profitable

variations do occur, natural selection can do nothing." Now, such

expressions have given your opponents the advantage of assuming that

_favourable_ variations are _rare accidents_, or may even for long

periods never occur at all, and thus Janet's argument would appear to

many to have great force. I think it would be better to do away with all

such qualifying expressions, and constantly maintain (what I certainly

believe to be the fact) that _variations of every kind_ are _always

occurring_ in _every part_ of _every species_, and therefore that

favourable variations are _always ready_ when wanted. You have, I am

sure, abundant materials to prove this, and it is, I believe, the grand

fact that renders modification and adaptation to conditions almost

always possible. I would put the burthen of proof on my opponents to

show that any one organ, structure, or faculty does _not vary_, even

during one generation, among all the individuals of a species; and also

to show any _mode or way_ in which any such organ, etc., does not vary.

I would ask them to give any reason for supposing that any organ, etc.,

is ever _absolutely identical_ at any _one time in all the individuals_

of a species, and if not, then it is always varying, and there are

always materials which, from the simple fact that the "fittest survive,"

will tend to the modification of the race into harmony with changed

conditions.

I hope these remarks may be intelligible to you, and that you will be so

kind as to let me know what you think of them.

I have not heard for some time how you are getting on. I hope you are

still improving in health, and that you will be able now to get on with

your great work, for which so many thousands are looking with

interest.--With best wishes, believe me, my dear Darwin, yours very

faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. July 5, [1866]._

My dear Wallace,--I have been much interested by your letter, which is

as clear as daylight. I fully agree with all that you say on the

advantages of H. Spencer's excellent expression of "the survival of the

fittest." This, however, had not occurred to me till reading your

letter. It is, however, a great objection to this term that it cannot be

used as a substantive governing a verb; and that this is a real

objection I infer from H. Spencer continually using the words "Natural

Selection."

I formerly thought, probably in an exaggerated degree, that it was a

great advantage to bring into connection natural and artificial

selection; this indeed led me to use a term in common, and I still think

it some advantage. I wish I had received your letter two months ago, for

I would have worked in "the survival," etc., often in the new edition of

the "Origin," which is now almost printed off, and of which I will, of

course, send you a copy. I will use the term in my next book on Domestic

Animals, etc., from which, by the way, I plainly see that you expect

_much_ too much. The term Natural Selection has now been so largely used

abroad and at home that I doubt whether it could be given up, and with

all its faults I should be sorry to see the attempt made. Whether it

will be rejected must now depend on the "survival of the fittest."

As in time the term must grow intelligible, the objections to its use

will grow weaker and weaker. I doubt whether the use of any term would

have made the subject intelligible to some minds, clear as it is to

others; for do we not see, even to the present day, Malthus on

Population absurdly misunderstood? This reflection about Malthus has

often comforted me when I have been vexed at the misstatement of my

views.

As for M. Janet,[55] he is a metaphysician, and such gentlemen are so

acute that I think they often misunderstand common folk. Your criticism

on the double sense in which I have used Natural Selection is new to me

and unanswerable; but my blunder has done no harm, for I do not believe

that anyone excepting you has ever observed it. Again, I agree that I

have said too much about "favourable variations," but I am inclined to

think you put the opposite side too strongly; if every part of every

being varied, I do not think we should see the same end or object gained

by such wonderfully diversified means.

I hope you are enjoying the country and are in good health, and are

working hard at your Malay Archipelago book, for I will always put this

wish in every note I write to you, like some good people always put in a

text. My health keeps much the same, or rather improves, and I am able

to work some hours daily.--With many thanks for your interesting letter,

believe me, my dear Wallace, yours sincerely,

CH. DARWIN.

P.S.--I suppose you have read the last number of H. Spencer; I have been

struck with astonishment at the prodigality of original thought in it.

But how unfortunate it is that it seems scarcely ever possible to

discriminate between the direct effect of external influences and the

"survival of the fittest."

* * * * *

_9 St. Mark's Crescent, Regent's Park, N.W. Nov. 19, 1866._

Dear Darwin,--Many thanks for the fourth edition of the "Origin," which

I am glad to see grows so vigorously at each moult, although it

undergoes no metamorphosis. How curious it is that Dr. Wells should so

clearly have seen the principle of Natural Selection fifty years ago,

and that it should have struck no one that it was a great principle of

universal application in nature!

We are going to have a discussion on "Mimicry, as producing Abnormal

Sexual Characters," at the Entomological to-night. I have a butterfly

(Diadema) of which the female is metallic blue, the male dusky brown,

contrary to the rule in all other species of the genus, and in almost

all insects; but the explanation is easy--it mimics a metallic

_Euploea_, and so gets a protection perhaps more efficient than its

allies derive from their sombre colours, and which females require much

more than males. I read a paper on this at the British Association. Have

you the report published at Nottingham in a volume by Dr. Robertson? If

so, you can tell me if my paper is printed in full.

I suppose you have read Agassiz's marvellous theory of the Great

Amazonian glacier, 2,000 miles long! I presume that will be a _little_

too much, even for you. I have been writing a little popular paper on

"Glacial Theories" for the _Quarterly Journal of Science_ of January

next, in which I stick up for glaciers in North America and icebergs in

the Amazon!

I was very glad to hear from Lubbock that your health is permanently

improved. I hope therefore you will be able to give us a volume per

annum of your _magnum opus_, with all the facts as you now have them,

leaving additions to come in new editions.

I am working a little at another family of my butterflies, and find the

usual interesting and puzzling cases of variation, but no such phenomena

as in the Papilionidæ.--With best wishes, believe me, my dear Darwin,

yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_6 Queen Anne Street, W. Monday, January, 1867._

My dear Wallace,--I return by this post the _Journal_.[56] Your résumé of

glacier action seems to me very good, and has interested my brother

much, and as the subject is new to him he is a better judge. That is

quite a new and perplexing point which you specify about the freshwater

fishes during the glacial period.

I have also been very glad to see the article on Lyell, which seems to

me to be done by some good man.

I forgot to say when with you--but I then indeed did not know so much as

I do now--that the sexual, i.e. _ornamental_, differences in fishes,

which differences are sometimes very great, offer a difficulty in the

wide extension of the view that the female is not brightly coloured on

account of the danger which she would incur in the propagation of the

species.

I very much enjoyed my long conversation with you; and to-day we return

home, and I to my horrid dull work of correcting proof-sheets.--Believe

me, my dear Wallace, yours very sincerely,

CHARLES DARWIN.

P.S.--I had arranged to go and see your collection on Saturday evening,

but my head suddenly failed after luncheon, and I was forced to lie down

all the rest of the day.

* * * * *

_Down, Bromley, Kent, S.E. February 23, 1867._

Dear Wallace,--I much regretted that I was unable to call on you, but

after Monday I was unable even to leave the house. On Monday evening I

called on Bates and put a difficulty before him, which he could not

answer, and, as on some former similar occasion, his first suggestion

was, "You had better ask Wallace." My difficulty is, why are

caterpillars sometimes so beautifully and artistically coloured? Seeing

that many are coloured to escape danger, I can hardly attribute their

bright colour in other cases to mere physical conditions. Bates says the

most gaudy caterpillar he ever saw in Amazonia (of a Sphinx) was

conspicuous at the distance of yards from its black and red colouring

whilst feeding on large green leaves. If anyone objected to male

butterflies having been made beautiful by sexual selection, and asked

why should they not have been made beautiful as well as their

caterpillars, what would you answer? I could not answer, but should

maintain my ground. Will you think over this, and some time, either by

letter or when we meet, tell me what you think? Also, I want to know

whether your _female_ mimetic butterfly is more beautiful and brighter

than the male?

When next in London I must get you to show me your Kingfishers.

My health is a dreadful evil; I failed in half my engagements during

this last visit to London.--Believe me, yours very sincerely,

C. DARWIN.

* * * * *

The answer to this letter is missing, but in Vol. II. of "My Life," p.

3, Wallace writes:

"On reading this letter I almost at once saw what seemed to be a

very easy and probable explanation of the facts. I had then just

been preparing for publication (in the _Westminster Review_) my

rather elaborate paper on 'Mimicry and Protective Colouring,' and

the numerous cases in which specially showy and slow-flying

butterflies were known to have a peculiar odour and taste which

protected them from the attacks of insect-eating birds and other

animals led me at once to suppose that the gaudily coloured

caterpillars must have a similar protection. I had just

ascertained from Mr. Jenner Weir that one of our common white

moths (_Spilosoma menthastri_) would not be eaten by most of the

small birds in his aviary, nor by young turkeys. Now, as a _white_

moth is as conspicuous in the dusk as a coloured caterpillar in

the daylight, this case seemed to me so much on a par with the

other that I felt almost sure my explanation would turn out

correct. I at once wrote to Mr. Darwin to this effect."

* * * * *

_Down, Bromley, Kent, S.E. February 26, 1867._

My dear Wallace,--Bates was quite right, you are the man to apply to in

a difficulty. I never heard anything more ingenious than your

suggestion, and I hope you may be able to prove it true. That is a

splendid fact about the white moths; it warms one's very blood to see a

theory thus almost proved to be true.[57] With respect to the beauty of

male butterflies, I must as yet think that it is due to sexual

selection; there is some evidence that dragonflies are attracted by

bright colours; but what leads me to the above belief is so many male

Orthoptera and Cicadas having musical instruments. This being the case,

the analogy of birds makes me believe in sexual selection with respect

to colour in insects. I wish I had strength and time to make some of the

experiments suggested by you; but I thought butterflies would not pair

in confinement; I am sure I have heard of some such difficulty. Many

years ago I had a dragonfly painted with gorgeous colours, but I never

had an opportunity of fairly trying it.

The reason of my being so much interested just at present about sexual

selection is that I have almost resolved to publish a little essay on

the Origin of Mankind, and I still strongly think (though I failed to

convince you, and this to me is the heaviest blow possible) that sexual

selection has been the main agent in forming the races of man.

By the way, there is another subject which I shall introduce in my

essay, viz. expression of countenance. Now, do you happen to know by any

odd chance a very good-natured and acute observer in the Malay

Archipelago who, you think, would make a few easy observations for me on

the expression of the Malays when excited by various emotions. For in

this case I would send to such person a list of queries.--I thank you

for your most interesting letters, and remain yours very sincerely,

CH. DARWIN.

* * * * *

_9 St. Mark's Crescent, N.W. March 11, 1867._

Dear Darwin,--I return your queries, but cannot answer them with any

certainty. For the Malays I should say Yes to 1, 3, 8, 9, 10 and 17, and

No to 12, 13 and 16; but I cannot be _certain_ in any one. But do you

think these things are of much importance? I am inclined to think that

if you could get good direct observations you would find some of them

often differ from tribe to tribe, from island to island, and sometimes

from village to village. Some no doubt may be deep-seated, and would

imply organic differences; but can you tell beforehand which these are?

I presume the Frenchman shrugs his shoulders whether he is of the

Norman, Breton, or Gaulish stock. Would it not be a good thing to send

your List of Queries to some of the Bombay and Calcutta papers? as there

must be numbers of Indian judges and other officers who would be

interested and would send you hosts of replies. The Australian papers

and New Zealand might also publish them, and then you would have a fine

basis to go on.

Is your essay on Variation in Man to be a supplement to your volume on

Domesticated Animals and Cultivated Plants? I would rather see your

second volume on "The Struggle for Existence, etc.," for I doubt if we

have a sufficiency of fair and accurate facts to do anything with man.

Huxley, I believe, is at work upon it.

I have been reading Murray's volume on the Geographical Distribution of

Mammals. He has some good ideas here and there, but is quite unable to

understand Natural Selection, and makes a most absurd mess of his

criticism of your views on oceanic islands.

By the bye, what an interesting volume the whole of your materials on

that subject would, I am sure, make.--Yours very sincerely,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. March, 1867._

My dear Wallace,--I thank you much for your two notes. The case of Julia

Pastrana[58] is a splendid addition to my other cases of correlated teeth

and hair, and I will add it in correcting the proof of my present

volume. Pray let me hear in course of the summer if you get any evidence

about the gaudy caterpillars. I should much like to give (or quote if

published) this idea of yours, if in any way supported, as suggested by

you. It will, however, be a long time hence, for I can see that sexual

selection is growing into quite a large subject, which I shall introduce

into my essay on Man, supposing that I ever publish it.

I had intended giving a chapter on Man, inasmuch as many call him (not

_quite_ truly) an eminently _domesticated_ animal; but I found the

subject too large for a chapter. Nor shall I be capable of treating the

subject well, and my sole reason for taking it up is that I am pretty

well convinced that sexual selection has played an important part in the

formation of races, and sexual selection has always been a subject which

has interested me much.

I have been very glad to see your impression from memory on the

expressions of Malays. I fully agree with you that the subject is in no

way an important one: it is simply a "hobby-horse" with me about

twenty-seven years old; and after thinking that I would write an essay

on Man, it flashed on me that I could work in some "supplemental remarks

on expression." After the horrid, tedious, dull work of my present huge

and, I fear, unreadable book, I thought I would amuse myself with my

hobby-horse. The subject is, I think, more curious and more amenable to

scientific treatment than you seem willing to allow. I want, anyhow, to

upset Sir C. Bell's view, given in his most interesting work, "The

Anatomy of Expression," that certain muscles have been given to man

solely that he may reveal to other men his feelings. I want to try and

show how expressions have arisen.

That is a good suggestion about newspapers; but my experience tells me

that private applications are generally most fruitful. I will, however,

see if I can get the queries inserted in some Indian paper. I do not

know names or addresses of any other papers.

I have just ordered, but not yet received, Murray's book: Lindley used

to call him a blunder-headed man. It is very doubtful whether I shall

ever have strength to publish the latter part of my materials.

My two female amanuenses are busy with friends, and I fear this scrawl

will give you much trouble to read.--With many thanks, yours very

sincerely,

CH. DARWIN.

* * * * *

_Down, Bromley, Kent, S.E. April 29, 1867._

Dear Wallace,--I have been greatly interested by your letter;[59] but

your view is not new to me. If you will look at p. 240 of the fourth

edition of the "Origin," you will find it very briefly given with two

extremes of the peacock and black grouse. A more general statement is

given at p. 101, or at p. 89 of the first edition, for I have long

entertained this view, though I have never had space to develop it. But

I had not sufficient knowledge to generalise as far as you do about

colouring and nesting. In your paper, perhaps you will just allude to my

scanty remark in the fourth edition, because in my essay upon Man I

intend to discuss the whole subject of sexual selection, explaining, as

I believe it does, much with respect to man. I have collected all my old

notes and partly written my discussion, and it would be flat work for me

to give the leading idea as exclusively from you. But as I am sure from

your greater knowledge of ornithology and entomology that you will write

a much better discussion than I could, your paper will be of great use

to me. Nevertheless, I must discuss the subject fully in my essay on

Man. When we met at the Zoological Society and I asked you about the

sexual differences in kingfishers, I had this subject in view; as I had

when I suggested to Bates the difficulty about gaudy caterpillars which

you have so admirably (as I believe it will prove) explained. I have got

one capital case (genus forgotten) of an [Australian] bird in which the

female has long-tailed plumes and which consequently builds a different

nest from all her allies.[60] With respect to certain female birds being

more brightly coloured than the males, and the latter incubating, I have

gone a little into the subject and cannot say that I am fully satisfied.

I remember mentioning to you the case of Rhynchæa, but its nesting seems

unknown. In some other cases the difference in brightness seemed to me

hardly sufficiently accounted for by the principle of protection. At the

Falkland Islands there is a carrion hawk in which the female (as I

ascertained by dissection) is the brightest coloured, and I doubt

whether protection will here apply; but I wrote several months ago to

the Falklands to make inquiries. The conclusion to which I have been

leaning is that in some of these abnormal cases the colour happened to

vary in the female alone, and was transmitted to females alone, and that

her variations have been selected through the admiration of the male.

It is a very interesting subject, but I shall not be able to go on with

it for the next five or six months, as I am fully employed in correcting

dull proof-sheets; when I return to the work I shall find it much better

done by you than I could have succeeded in doing.

With many thanks for your very interesting note, believe me, dear

Wallace, yours very sincerely,

CH. DARWIN.

It is curious how we hit on the same ideas. I have endeavoured to show

in my MS. discussion that nearly the same principles account for young

birds _not_ being gaily coloured in many cases--but this is too complex

a point for a note.

_Postscript. Down. April 29._

My dear Wallace,--On reading over your letter again, and on further

reflection, I do not think (as far as I remember my words) that I

expressed myself _nearly strongly_ enough as to the value and beauty of

your generalisation, viz. that all birds in which the female is

conspicuously or brightly coloured build in holes or under domes. I

thought that this was the explanation in many, perhaps most cases, but

do not think I should ever have extended my view to your generalisation.

Forgive me troubling you with this P.S.--Yours,

CH. DARWIN.

* * * * *

_Down, Bromley, Kent, S.E. May 5, 1867._

My dear Wallace,--The offer of your valuable notes is _most_ generous,

but it would vex me to take so much from you, as it is certain that you

could work up the subject very much better than I could. Therefore I

earnestly and without any reservation hope that you will proceed with

your paper, so that I return your notes.

You seem already to have well investigated the subject. I confess on

receiving your note that I felt rather flat at my recent work being

almost thrown away, but I did not intend to show this feeling. As a

proof how little advance I had made on the subject, I may mention that

though I had been collecting facts on the colouring and other sexual

differences in mammals, your explanation with respect to the females had

not occurred to me. I am surprised at my own stupidity, but I have long

recognised how much clearer and deeper your insight into matters is than

mine.

I do not know how far you have attended to the laws of inheritance, so

what follows may be obvious to you. I have begun my discussion on sexual

selection by showing that new characters often appear in one sex and are

transmitted to that sex alone, and that from some unknown cause such

characters apparently appear oftener in the male than in the female.

Secondly, characters may be developed and be confined to the male, and

long afterwards be transferred to the female. Thirdly, characters may,

again, arise in either sex and be transmitted to both sexes, either in

an equal or unequal degree. In this latter case I have supposed that the

survival of the fittest has come into play with female birds and kept

the female dull-coloured. With respect to the absence of spurs in female

gallinaceous birds, I presume that they would be in the way during

incubation; at least, I have got the case of a German breed of fowls in

which the hens were spurred, and were found to disturb and break their

eggs much.

With respect to the females of deer not having horns, I presume it is to

save the loss of organised matter.

In your note you speak of sexual selection and protection as sufficient

to account for the colouring of all animals; but it seems to me doubtful

how far this will come into play with some of the lower animals, such as

sea anemones, some corals, etc. etc.

On the other hand, Haeckel has recently well shown that the transparency

and absence of colour in the lower oceanic animals, belonging to the

most different classes, may be well accounted for on the principle of

protection.

Some time or other I should like much to know where your paper on the

nests of birds has appeared, and I shall be extremely anxious to read

your paper in the _Westminster Review_.

Your paper on the sexual colouring of birds will, I have no doubt, be

very striking.

Forgive me, if you can, for a touch of illiberality about your paper,

and believe me yours very sincerely,

CH. DARWIN.

* * * * *

_Down, Bromley, Kent, S.E. July 6, 1867._

My dear Wallace,--I am very much obliged for your article on Mimicry,[61]

the whole of which I have read with the greatest interest. You certainly

have the art of putting your ideas with remarkable force and clearness;

now that I am slaving over proof-sheets it makes me almost envious.

I have been particularly glad to read about the birds' nests, and I must

procure the _Intellectual Observer_; but the point which I think struck

me most was about its being of no use to the Heliconias to acquire in a

slight degree a disagreeable taste. What a curious case is that about

the coral snakes. The summary, and indeed the whole, is excellent, and I

have enjoyed it much.--With many thanks, yours very sincerely,

CH. DARWIN.

* * * * *

_9 St. Mark's Crescent, N.W. Wednesday, [August or September, 1867]._

Dear Darwin,--I am very sorry I was out when you called yesterday. I had

just gone to the Zoological Gardens, and I met Sir C. Lyell, who told me

you were in town.

If you should have time to go to Bayswater, I think you would be pleased

to see the collections which I have displayed there in the form of an

_exhibition_ (though the public will not go to see it).

If you can go, with any friends, I should like to meet you there if you

can appoint a time.

I am glad to find you continue in tolerable health.--Believe me yours

very faithfully,

ALFRED R. WALLACE.

What do you think of the Duke of Argyll's criticisms, and the more

pretentious one in the last number of the _North British Review_?

I have written a little article answering them both, but I do not yet

know where to get it published.--A.R.W.

* * * * *

_76-1/2 Westbourne Grove, Bayswater, W. October 1, 1867._

Dear Darwin,--I am sorry I was not in town when your note came. I took a

short trip to Scotland after the British Association Meeting, and went

up Ben Lawers. It was very cold and wet, and I could not find a

companion or I should have gone as far as Glen Roy.

My article on "Creation by Law," in reply to the Duke of Argyll and the

_North British_ reviewer, is in the present month's number of the

_Quarterly Journal of Science_. I cannot send you a copy because they do

not allow separate copies to be printed.

There is a nice illustration of the _predicted_ Madagascar moth and

_Angræcum sesquipedale_.

I shall be glad to know whether I have done it satisfactorily to you,

and hope you will not be so very sparing of criticism as you usually

are.

I hope you are getting on well with your great book. I hear a rumour

that we are to have _one_ vol. of it about Christmas.

I quite forget whether I told you that I have a little boy, now three

months old, and have named him Herbert Spencer (having had a brother

Herbert). I am now staying chiefly in the country, at Hurstpierpoint,

but come up to town once a month at least. You may address simply,

"Hurstpierpoint, Sussex."

Hoping your health is tolerable and that all your family are well,

believe me, dear Darwin, yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. October 12 and 13, 1867._

My dear Wallace,--I ordered the journal a long time ago, but by some

oversight received it only yesterday and read it. You will think my

praise not worth having from being so indiscriminate, but if I am to

speak the truth, I must say I admire every word.

You have just touched on the points which I particularly wished to see

noticed. I am glad you had the courage to take up _Angræcum_[62] after

the Duke's attack; for I believe the principle in this case may be

widely applied. I like the figure, but I wish the artist had drawn a

better sphinx.

With respect to beauty, your remarks on hideous objects and on flowers

not being made beautiful except when of practical use to them strike me

as very good.

On this one point of beauty, I can hardly think that the Duke was quite

candid. I have used in the concluding paragraph of my present book

precisely the same argument as you have, even bringing in the

bulldog,[63] with respect to variations not having been specially

ordained. Your metaphor of the river[64] is new to me, and admirable;

but your other metaphor, in which you compare classification and complex

machines, does not seem to me quite appropriate, though I cannot point

out what seems deficient. The point which seems to me strong is that all

naturalists admit that there is a _natural_ classification, and it is

this which descent explains. I wish you had insisted a little more

against the _North British_[65] reviewer assuming that each variation

which appears is a strongly marked one; though by implication you have

made this _very_, plain. Nothing in your whole article has struck me

more than your view with respect to the limit of fleetness in the

racehorse and other such cases; I shall try and quote you on this head

in the proof of my concluding chapter. I quite missed this explanation,

though in the case of wheat I hit upon something analogous. I am glad

you praise the Duke's book, for I was much struck with it. The part

about flight seemed to me at first very good, but as the wing is

articulated by a ball-and-socket joint, I suspect the Duke would find it

very difficult to give any reason against the belief that the wing

strikes the air more or less obliquely. I have been very glad to see

your article and the drawing of the butterfly in _Science Gossip_. By

the way, I cannot but think that you push protection too far in some

cases, as with the stripes on the tiger. I have also this morning read

an excellent abstract in the _Gardeners' Chronicle_ of your paper on

nests;[66] I was not by any means fully converted by your letter, but I

think now I am so; and I hope it will be published somewhere _in

extenso_. It strikes me as a capital generalisation, and appears to me

even more original than it did at first.

I have had an excellent and cautious letter from Mr. Geach of Singapore

with some valuable answers on expression, which I owe to you.

I heartily congratulate you on the birth of "Herbert Spencer," and may

he deserve his name, but I hope he will copy his father's style and not

his namesake's. Pray observe, though I fear I am a month too late, when

tears are first secreted enough to overflow; and write down date.

I have finished Vol. I. of my book, and I hope the whole will be out by

the end of November; if you have the patience to read it through, which

is very doubtful, you will find, I think, a large accumulation of facts

which will be of service to you in your future papers, and they could

not be put to better use, for you certainly are a master in the noble

art of reasoning.

Have you changed your house to Westbourne Grove?

Believe me, my dear Wallace, yours very sincerely,

CH. DARWIN.

This letter is so badly expressed that it is barely intelligible, but I

am tired with proofs.

P.S.--Mr. Warington has lately read an excellent and spirited abstract

of the "Origin" before the Victoria Institute, and as this is a most

orthodox body he has gained the name of the devil's advocate. The

discussion which followed during three consecutive meetings is very rich

from the nonsense talked. If you would care to see the number I could

lend it you.

I forgot to remark how capitally you turn the table on the Duke, when

you make him create the _Angræcum_ and moth by special creation.

* * * * *

_Hurstpierpoint. October 22, 1867._

Dear Darwin,--I am very glad you approve of my article on "Creation by

Law" as a whole.

The "machine metaphor" is not mine, but the _North British_ reviewer's.

I merely accept it and show that it is on our side and not against us,

but I do not think it at all a good metaphor to be used as an _argument_

either way. I did not half develop the argument on the limits of

variation, being myself limited in space; but I feel satisfied that it

is the true answer to the very common and very strong objection, that

"variation has strict limits." The fallacy is the requiring variation in

domesticity to go beyond the limits of the same variation under nature.

It does do so sometimes, however, because the conditions of existence

are so different. I do not think a case can be pointed out in which the

limits of variation under domestication are not up to or beyond those

already marked out in nature, only we generally get in the _species_ an

amount of change which in nature occurs only in the whole range of the

_genus_ or _family_.

The many cases, however, in which variation has gone far beyond nature

and has not yet stopped are ignored. For instance, no wild pomaceous

fruit is, I believe, so large as our apples, and no doubt they could be

got much larger if flavour, etc., were entirely neglected.

I may perhaps push "protection" too far sometimes, for it is my hobby

just now, but as the lion and the tiger are, I think, the only two

non-arboreal cats, I think the tiger stripe agreeing so well with its

usual habitat is at least a probable case.

I am rewriting my article on Birds' Nests for the new _Natural History

Review_.

I cannot tell you about the first appearance of _tears_, but it is very

early--the first week or two, I think. I can see the _Victoria Institute

Magazine_ at the London Library.

I shall read your book, _every word_. I hear from Sir C. Lyell that you

come out with a grand new theory at the end, which even the _cautious_

(!) Huxley is afraid of! Sir C. said he could think of nothing else

since he read it. I long to see it.

My address is Hurstpierpoint during the winter, and, when in town,

76-1/2 Westbourne Grove.

I suppose you will now be going on with your book on Sexual Selection

and Man, by way of relaxation! It is a glorious subject, but will

require delicate handling,--Yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_10 Duchess Street, W. February 7, 1868._

Dear Darwin,--I have to thank you for signing the Memorial as to the

East London Museum, and also for your kindness in sending me a copy of

your great book, which I have only just received. I shall take it down

in the country with me next week, and enjoy every line at my leisure.

Allow me also to congratulate you on the splendid position obtained by

your second son at Cambridge.

You will perhaps be glad to hear that I have been for some time

hammering away at my Travels, but I fear I shall make a mess of it. I

shall leave most of the Natural History generalisation, etc., for

another work, as if I wait to incorporate all, I may wait for

years.--Hoping you are quite well, believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. February 22, [1868?]._

My dear Wallace,--I am hard at work on sexual selection and am driven

half mad by the number of collateral points which require investigation,

such as the relative numbers of the two sexes, and especially on

polygamy. Can you aid me with respect to birds which have strongly

marked secondary sexual characters, such as birds of paradise,

humming-birds, the rupicola or rock-thrush, or any other such cases?

Many gallinaceous birds certainly are polygamous. I suppose that birds

may be known not to be polygamous if they are seen during the whole

breeding season to associate in pairs, or if the male incubates, or aids

in feeding the young. Will you have the kindness to turn this in your

mind? but it is a shame to trouble you now that, as I am _heartily_ glad

to hear, you are at work on your Malayan Travels. I am fearfully puzzled

how far to extend your protective views with respect to the females in

various classes. The more I work, the more important sexual selection

apparently comes out.

Can butterflies be polygamous?--i.e. will one male impregnate more than

one female?

Forgive me troubling you, and I daresay I shall have to ask your

forgiveness again, and believe me, my dear Wallace, yours most

sincerely,

CH. DARWIN.

P.S.--Baker has had the kindness to set the Entomological Society

discussing the relative numbers of the sexes in insects, and has brought

out some very curious results.

Is the orang polygamous? But I daresay I shall find that in your papers

in (I think) the _Annals and Magazine of Natural History_.

* * * * *

The following group of letters deals with the causes of the sterility of

hybrids (_see_ note in "More Letters," p. 287). Darwin's final view is

given in the "Origin," 6th edit., 1900, p. 384. He acknowledges that it

would be advantageous to two incipient species if, by physiological

isolation due to mutual sterility, they could be kept from blending; but

he continues: "After mature reflection, it seems to me that this could

not have been effected through Natural Selection." And finally he

concludes (p. 386): "But it would be superfluous to discuss this

question in detail; for with plants we have conclusive evidence that the

sterility of crossed species must be due to some principle quite

independent of Natural Selection. Both Gäartner and Kolreuter have

proved that in genera including numerous species a series can be formed

from species which, when crossed, yield fewer and fewer seeds, to

species which never produce a single seed, but yet are affected by the

pollen of certain other species, for the germen swells. It is here

manifestly impossible to select the more sterile individuals, which have

already ceased to yield seeds; so that this acme of sterility, when the

germen alone is affected, cannot have been gained through selection; and

from the laws governing the various grades of sterility being so uniform

throughout the animal and vegetable kingdoms, we may infer that the

cause, whatever it may be, is the same or nearly the same in all cases."

Wallace still adhered to his view (_see_ "Darwinism," 1889, p. 174,

_also_ p. 292 of "More Letters," note 1, and Letter 211, p. 299). The

discussion of 1868 began with a letter from Wallace, written towards the

end of February, giving his opinion on the "Variation of Animals and

Plants"; the discussion on the sterility of hybrids is at p. 185, Vol.

II., 1st edit.

* * * * *

(_Second and third sheets of a letter from Wallace, apparently of

February, 1868._)

I am in the second volume of your book, and I have been astonished at

the immense number of interesting facts you have brought together. I

read the chapter on Pangenesis first, for I could not wait. I can hardly

tell you how much I admire it. It is a positive _comfort_ to me to have

any feasible explanation of a difficulty that has always been haunting

me, and I shall never be able to give it up till a better one supplies

its place, and that I think hardly possible. You have now fairly beaten

Spencer on his own ground, for he really offered no solution of the

difficulties of the problem. The incomprehensible minuteness and vast

numbers of the physiological germs or atoms (Which themselves must be

compounded of numbers of Spencer's physiological units) is the only

difficulty, but that is only on a par with the difficulties in all

conceptions of matter, space, motion, force, etc. As I understood

Spencer, his physiological units were identical throughout each species,

but slightly different in each different species; but no attempt was

made to show how the identical form of the parent or ancestors came to

be built up of such units.

The only parts I have yet met with where I somewhat differ from your

views are in the chapter on the Causes of Variability, in which I think

several of your arguments are unsound: but this is too long a subject to

go into now.

Also, I do not see your objection to _sterility_ between allied species

having been aided by Natural Selection. It appears to me that, given a

differentiation of a species into two forms, each of which was adapted

to a special sphere of existence, every slight degree of sterility would

be a positive advantage, not to the _individuals_ who were sterile, but

to _each form_. If you work it out, and suppose the two incipient

species A, B to be divided into two groups, one of which contains those

which are fertile when the two are crossed, the other being slightly

sterile, you will find that the latter will certainly supplant the

former in the struggle for existence, remembering that you have shown

that in such a cross the offspring would be _more vigorous_ than the

pure breed, and would therefore certainly soon supplant them, and as

these would not be so well adapted to any special sphere of existence as

the pure species A and B, they would certainly in their turn give way to

A and B.

I am sure all naturalists will be disgusted at the malicious and

ignorant article in the _Athenæum_. It is a disgrace to the paper, and I

hope someone will publicly express the general opinion of it. We can

expect no good reviews of your book till the quarterlies or best

monthlies come out.... I shall be anxious to see how Pangenesis is

received.--Believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_Down, Bromley, Kent, S.E. February 27, 1868._

My dear Wallace,--You cannot well imagine how much I have been pleased

by what you say about Pangenesis. None of my friends will speak out,

except, to a certain extent, Sir H. Holland,[67] who found it very tough

reading, but admits that some view "closely akin to it" will have to be

admitted. Hooker, as far as I understand him, which I hardly do at

present, seems to think that the hypothesis is little more than saying

that organisms have such and such potentialities. What you say exactly

and fully expresses my feeling, viz. that it is a relief to have some

feasible explanation of the various facts, which can be given up as soon

as any better hypothesis is found. It has certainly been an immense

relief to my mind; for I have been stumbling over the subject for years,

dimly seeing that some relation existed between the various classes of

facts. I now hear from H. Spencer that his views quoted in my footnote

refer to something quite distinct, as you seem to have perceived.

I shall be very glad to hear, at some future day, your criticisms on the

causes of variability.

Indeed, I feel sure that I am right about sterility and Natural

Selection. Two of my grown-up children who are acute reasoners have two

or three times at intervals tried to prove me wrong, and when your

letter came they had another try, but ended by coming back to my side. I

do not quite understand your case, and we think that a word or two is

misplaced. I wish some time you would consider the case under the

following point of view. If sterility is caused or accumulated through

Natural Selection, then, as every degree exists up to absolute

barrenness, Natural Selection must have the power of increasing it. Now

take two species, A and B, and assume that they are (by any means)

half-sterile, i.e. produce half the full number of offspring. Now try

and make (by Natural Selection) A and B absolutely sterile when crossed,

and you will find how difficult it is. I grant, indeed it is certain,

that the degree of sterility of the individuals of A and B will vary,

but any such extra-sterile individuals of, we will say, A, if they

should hereafter breed with other individuals of A, will bequeath no

advantage to their progeny, by which these families will tend to

increase in number over other families of A, which are not more sterile

when crossed with B. But I do not know that I have made this any clearer

than in the chapter in my book. It is a most difficult bit of reasoning,

which I have gone over and over again on paper with diagrams.

I shall be intensely curious to see your article in the _Journal of

Travel_.

Many thanks for such answers as you could give. From what you say I

should have inferred that birds of paradise were probably polygamous.

But after all, perhaps it is not so important as I thought. I have been

going through the whole animal kingdom in reference to sexual selection,

and I have just got to the beginning of Lepidoptera, i.e. to end of

insects, and shall then pass on to Vertebrata. But my ladies next week

are going (ill-luck to it) to take me nolens-volens to London for a

whole month.

I suspect Owen wrote the article in the _Athenæum_, but I have been told

that it is Berthold Seeman. The writer despises and hates me.

Hearty thanks for your letter--you have indeed pleased me, for I had

given up the great god Pan as a stillborn deity. I wish you could be

induced to make it clear with your admirable powers of elucidation in

one of the scientific journals.

I think we almost entirely agree about sexual selection, as I now follow

you to large extent about protection to females, having always believed

that colour was often transmitted to both sexes; but I do not go quite

so far about protection.--Always yours most sincerely,

CH. DARWIN.

* * * * *

_Hurstpierpoint. March 1, 1868._

My dear Darwin,--I beg to enclose what appears to me a demonstration,

_on your own principles_, that Natural Selection _could_ produce

_sterility of hybrids_.

If it does not convince you I shall be glad if you will point out where

the fallacy lies. I have taken the two cases of a slight sterility

overcoming a perfect fertility, and of a perfect sterility overcoming a

partial fertility--the beginning and end of the process. You admit that

variations in fertility and sterility occur, and I think you will also

admit that if I demonstrate that a considerable amount of sterility

would be advantageous to a variety, that is sufficient proof that the

slightest variation in that direction would be useful also, and would go

on accumulating.

Sir C. Lyell spoke to me as if he greatly admired pangenesis. I am very

glad H. Spencer at once acknowledges that his view was something quite

distinct from yours. Although, as you know, I am a great admirer of his,

I feel how completely his view failed to go to the root of the matter,

as yours does. His explained nothing, though he was evidently struggling

hard to find an explanation. Yours, as far as I can see, explains

everything in _growth and reproduction_, though of course the mystery of

_life_ and _consciousness_ remains as great as ever.

Parts of the chapter on Pangenesis I found hard reading, and have not

quite mastered yet, and there are also throughout the discussions in

Vol. II. many bits of hard reading on minute points which we, who have

not worked experimentally at cultivation and crossing as you have done,

can hardly see the importance of, or their bearing on the general

question.

If I am asked, I may perhaps write an article on the book for some

periodical, and if so shall do what I can to make pangenesis

appreciated.

I suppose Mrs. Darwin thinks you _must_ have a holiday, after the

enormous labour of bringing out such a book as that. I am sorry I am not

now staying in town. I shall, however, be up for two days on Thursday,

and shall hope to see you at the Linnean, where Mr. Trimen has a paper

on some of his wonderful South African mimetic butterflies.

I hope this will reach you before you leave.--Believe me yours very

faithfully,

ALFRED R. WALLACE.

* * * * *

_Hurstpierpoint. March 8, 1868._

Dear Darwin,--I am very sorry your letter came back here while I was

going to town, or I should have been very pleased to have seen you.

Trimen's paper at the Linnean was a very good one, but the only

opponents were Andrew Murray and B. Seeman. The former talked utter

nonsense about the "harmony of nature" produced by "polarisation," alike

in "rocks, plants and animals," etc. etc. etc. And Seeman objected that

there was mimicry among plants, and that our theory would not explain

it.

Lubbock answered them both in his best manner.

Pray take your rest, and put my last notes by till you return to Down,

or let your son discover the fallacies in them.

Would you like to see the specimens of pupæ of butterflies whose colours

have changed in accordance with the colour of the surrounding objects?

They are very curious, and Mr. T.W. Wood, who bred them, would, I am

sure, be delighted to bring them to show you. His address is 89 Stanhope

Street, Hampstead Road, N.W.--Believe me yours very faithfully,

ALFRED R. WALLACE.

Darwin had already written a short note to Wallace expressing a general

dissent from his views.

* * * * *

_4 Chester Place, Regent's Park, N.W. March 17, 1868._

My dear Wallace,--Many thanks about Pieridæ. I have no photographs up

here, but will remember to send one from Down. Should you care to have a

large one, of treble or quadruple common size, I will with pleasure send

you one under glass cover, to any address you like in London, either now

or hereafter. I grieve to say we shall not be here on April 2nd, as we

return home on the 31st. In summer I hope that Mrs. Wallace and

yourself will pay us a visit at Down, soon after you return to London;

for I am sure you will allow me the freedom of an invalid.

My paper to-morrow at the Linnean Society is simply to prove, alas! that

primrose and cowslip are as good species as any in the world, and that

there is no trustworthy evidence of one producing the other. The only

interesting point is the frequency of the production of natural hybrids,

i.e. oxlips, and the existence of one kind of oxlip which constitutes a

third good and distinct species. I do not suppose that I shall be able

to attend the Linnean Society to-morrow.

I have been working hard in collecting facts on sexual selection every

morning in London, and have done a good deal; but the subject grows more

and more complex, and in many respects more difficult and doubtful. I

have had grand success this morning in tracing gradational steps by

which the peacock tail has been developed: I quite feel as if I had seen

a long line of its progenitors.

I do not feel that I shall grapple with the sterility argument till my

return home; I have tried once or twice and it has made my stomach feel

as if it had been placed in a vice. Your paper has driven three of my

children half-mad--one sat up to twelve o'clock over it. My second son,

the mathematician, thinks that you have omitted one almost inevitable

deduction which apparently would modify the result. He has written out

what he thinks, but I have not tried fully to understand him. I suppose

that you do not care enough about the subject to like to see what he has

written?

I hope your book progresses.

I am intensely anxious to see your paper in _Murray's Journal_.--My dear

Wallace, yours very sincerely,

CH. DARWIN.

* * * * *

_Hurstpierpoint. March 19, 1868._

Dear Darwin,--I should very much value a _large_ photograph of you, and

also a carte for my album, though it is too bad to ask you for both, as

you must have so many applicants.

I am sorry I shall not see you in town, but shall look forward with

pleasure to paying you a visit in the summer.

I am sorry about the Primulas, but I feel sure some such equally good

case will some day be discovered, for it seems impossible to understand

how all natural species whatever should have acquired sterility. Closely

allied forms from adjacent islands would, I should think, offer the best

chance of finding good species fertile _inter se_; since even if Natural

Selection induces sterility I do not see how it could affect them, or

why they should _always_ be sterile, and varieties _never_.

I am glad you have got good materials on sexual selection. It is no

doubt a difficult subject. One difficulty to me is, that I do not see

how the constant _minute_ variations, which are sufficient for Natural

Selection to work with, could be _sexually_ selected. We seem to require

a series of bold and abrupt variations. How can we imagine that an inch

in the tail of a peacock, or a quarter of an inch in that of the bird of

paradise, would be noticed and preferred by the female?

Pray let me see what your son says about the sterility selection

question. I am deeply interested in all that concerns the powers of

Natural Selection, but, though I admit there are a few things it cannot

do, I do not yet believe sterility to be one of them.

In case your son has turned his attention to mathematical physics, will

you ask him to look at the enclosed question, which I have vainly

attempted to get an answer to?--Believe me yours very faithfully,

ALFRED R. WALLACE.

* * * * *

_4 Chester Place, Regent's Park, N.W. March 19-24, 1868._

My dear Wallace,--I have sent your query to Cambridge to my son. He

ought to answer it, for he got his place of Second Wrangler chiefly by

solving very difficult problems. I enclose his remarks on two of your

paragraphs: I should like them returned some time, for I have not

studied them, and let me have your impression.

I have told E. Edwards to send one of my large photographs to you

addressed to 76-1/2 Westbourne Grove, not to be forwarded. When at home

I will send my carte.

The sterility is a most [? puzzling] problem. I can see so far, but I am

hardly willing to admit all your assumptions, and even if they were all

admitted, the process is so complex and the sterility (as you remark in

your note) so universal, even with species inhabiting quite distinct

countries (as I remarked in my chapter), together with the frequency of

a difference in reciprocal unions, that I cannot persuade myself that it

has been gained by Natural Selection, any more than the difficulty of

grafting distinct genera and the impossibility of grafting distinct

families. You will allow, I suppose, that the capacity of grafting has

not been directly acquired through Natural Selection.

I think that you will be pleased with the second volume or part of

Lyell's Principles, just out.

In regard to sexual selection. A girl sees a handsome man, and without

observing whether his nose or whiskers are the tenth of an inch longer

or shorter than in some other man, admires his appearance and says she

will marry him. So, I suppose, with the pea-hen; and the tail has been

increased in length merely by, on the whole, presenting a more gorgeous

appearance. Jenner Weir, however, has given me some facts showing that

birds apparently admire details of plumage.--Yours most sincerely,

C. DARWIN.

* * * * *

_Hurstpierpoint. March 24, [1868?]._

Dear Darwin,--Many thanks for the photo, which I shall get when I go to

town.

I return your son's notes with my notes on them.

Without going into any details, is not this a strong general argument?--

1. A species varies occasionally in two directions, but owing to their

free intercrossing they (the variations) never increase.

2. A change of conditions occurs which threatens the existence of the

species, but the _two varieties_ are adapted to the changing conditions,

and, if accumulated, will form two new _species adapted to the new

conditions_.