More Letters of Charles Darwin Volume I Part 45

LETTER 295. TO E.S. MORSE. Down, October 21st, 1879.

Although you are so kind as to tell me not to write, I must just thank you for the proofs of your paper, which has interested me greatly.

(295/1. See "The Sh.e.l.l Mounds of Omori" in the "Memoirs of the Science Department of the Univ. of Tokio," Volume I., Part I., 1879. The ridges on Arca are mentioned at page 25. In "Nature," April 15th, 1880, Mr.

Darwin published a letter by Mr. Morse relating to the review of the above paper, which appeared in "Nature," XXI., page 350. Mr. Darwin introduces Mr. Morse's letter with some prefatory remarks. The correspondence is republished in the "American Naturalist," September, 1880.) The increase in the number of ridges in the three species of Arca seems to be a very noteworthy fact, as does the increase of size in so many, yet not all, the species. What a constant state of fluctuation the whole organic world seems to be in! It is interesting to hear that everywhere the first change apparently is in the proportional numbers of the species. I was much struck with the fact in the upraised sh.e.l.ls of Coquimbo, in Chili, as mentioned in my "Geological Observations on South America."

Of all the wonders in the world, the progress of j.a.pan, in which you have been aiding, seems to me about the most wonderful.

LETTER 296. TO A.R. WALLACE. Down, January 5th 1880.

As this note requires no sort of answer, you must allow me to express my lively admiration of your paper in the "Nineteenth Century." (296/1.

"Nineteenth Century," January 1880, page 93, "On the Origin of Species and Genera.") You certainly are a master in the difficult art of clear exposition. It is impossible to urge too often that the selection from a single varying individual or of a single varying organ will not suffice.

You have worked in capitally Allen's admirable researches. (296/2. J.A.

Allen, "On the Mammals and Winter Birds of East Florida, etc." ("Bull.

Mus. Comp. Zoolog. Harvard," Volume II.) As usual, you delight to honour me more than I deserve. When I have written about the extreme slowness of Natural Selection (296/3. Mr. Wallace makes a calculation based on Allen's results as to the very short period in which the formation of a race of birds differing 10 to 20 per cent. from the average in length of wing and strength of beak might conceivably be effected. He thinks that the slowness of the action of Natural Selection really depends on the slowness of the changes naturally occurring in the physical conditions, etc.) (in which I hope I may be wrong), I have chiefly had in my mind the effects of intercrossing. I subscribe to almost everything you say excepting the last short sentence. (296/4. The pa.s.sage in question is as follows: "I have also attempted to show that the causes which have produced the separate species of one genus, of one family, or perhaps of one order, from a common ancestor, are not necessarily the same as those which have produced the separate orders, cla.s.ses, and sub-kingdoms from more remote common ancestors. That all have been alike produced by 'descent with modification' from a few primitive types, the whole body of evidence clearly indicates; but while individual variation with Natural Selection is proved to be adequate for the production of the former, we have no proof and hardly any evidence that it is adequate to initiate those important divergences of type which characterise the latter." In this pa.s.sage stress should be laid (as Mr. Wallace points out to us) on the word PROOF. He by no means a.s.serts that the causes which have produced the species of a genus are inadequate to produce greater differences. His object is rather to urge the difference between proof and probability.)

LETTER 297. TO J.H. FABRE.

(297/1. A letter to M. Fabre is given in "Life and Letters," III., page 220, in which the suggestion is made of rotating the insect before a "homing" experiment occurs.)

Down, February 20th, 1880.

I thank you for your kind letter, and am delighted that you will try the experiment of rotation. It is very curious that such a belief should be held about cats in your country (297/2. M. Fabre had written from Serignan, Vaucluse: "Parmi la population des paysans de mon village, l'habitude est de faire tourner dans un sac le chat que l'on se propose de porter ailleurs, et dont on veut empecher le retour. J'ignore si cette pratique obtient du succes."), I never heard of anything of the kind in England. I was led, as I believe, to think of the experiment from having read in Wrangel's "Travels in Siberia" (297/3. Admiral Ferdinand Petrovich von Wrangell, "Le Nord de la Siberie, Voyage parmi les Peuplades de la Russie asiatique, etc." Paris, 1843.) of the wonderful power which the Samoyedes possess of keeping their direction in a fog whilst travelling in a tortuous line through broken ice. With respect to cats, I have seen an account that in Belgium there is a society which gives prizes to the cat which can soonest find its way home, and for this purpose they are carried to distant parts of the city.

Here would be a capital opportunity for trying rotation.

I am extremely glad to hear that your book will probably be translated into English.

P.S.--I shall be much pleased to hear the result of your experiments.

LETTER 298. TO J.H. FABRE. Down, January 21st, 1881.

I am much obliged for your very interesting letter. Your results appear to me highly important, as they eliminate one means by which animals might perhaps recognise direction; and this, from what has been said about savages, and from our own consciousness, seemed the most probable means. If you think it worth while, you can of course mention my name in relation to this subject.

Should you succeed in eliminating a sense of the magnetic currents of the earth, you would leave the field of investigation quite open.

I suppose that even those who still believe that each species was separately created would admit that certain animals possess some sense by which they perceive direction, and which they use instinctively.

On mentioning the subject to my son George, who is a mathematician and knows something about magnetism, he suggested making a very thin needle into a magnet; then breaking it into very short pieces, which would still be magnetic, and fastening one of these pieces with some cement on the thorax of the insect to be experimented on.

He believes that such a little magnet, from its close proximity to the nervous system of the insect, would affect it more than would the terrestrial currents.

I have received your essay on Halictus (298/1. "Sur les Moeurs et la Parthenogese des Halictes" ("Ann. Sc. Nat." IX., 1879-80).), which I am sure that I shall read with much interest.

LETTER 299. TO T.H. HUXLEY.

(299/1. On April 9th, 1880, Mr. Huxley lectured at the Royal Inst.i.tution on "The Coming of Age of the Origin of Species." The lecture was published in "Nature" and in Huxley's "Collected Essays," Volume II., page 227. Darwin's letter to Huxley on the subject is given in "Life and Letters," III., page 240; in Huxley's reply of May 10th ("Life and Letters of T.H. Huxley," II., page 12) he writes: "I hope you do not imagine because I had nothing to say about 'Natural Selection' that I am at all weak of faith on that article...But the first thing seems to me to be to drive the fact of evolution into people's heads; when that is once safe, the rest will come easy.")

Down, May 11th, 1880.

I had no intention to make you write to me, or expectation of your doing so; but your note has been so far "cheerier" (299/2. "You are the cheeriest letter-writer I know": Huxley to Darwin. See Huxley's "Life,"

II., page 12.) to me than mine could have been to you, that I must and will write again. I saw your motive for not alluding to Natural Selection, and quite agreed in my mind in its wisdom. But at the same time it occurred to me that you might be giving it up, and that anyhow you could not safely allude to it without various "provisos" too long to give in a lecture. If I think continuously on some half-dozen structures of which we can at present see no use, I can persuade myself that Natural Selection is of quite subordinate importance. On the other hand, when I reflect on the innumerable structures, especially in plants, which twenty years ago would have been called simply "morphological" and useless, and which are now known to be highly important, I can persuade myself that every structure may have been developed through Natural Selection. It is really curious how many out of a list of structures which Bronn enumerated, as not possibly due to Natural Selection because of no functional importance, can now be shown to be highly important.

Lobed leaves was, I believe, one case, and only two or three days ago Frank showed me how they act in a manner quite sufficiently important to account for the lobing of any large leaf. I am particularly delighted at what you say about domestic dogs, jackals, and wolves, because from mere indirect evidence I arrived in "Varieties of Domestic Animals" at exactly the same conclusion (299/3. Mr. Darwin's view was that domestic dogs descend from more than one wild species.) with respect to the domestic dogs of Europe and North America. See how important in another way this conclusion is; for no one can doubt that large and small dogs are perfectly fertile together, and produce fertile mongrels; and how well this supports the Pallasian doctrine (299/4. See Letter 80.) that domestication eliminates the sterility almost universal between forms slowly developed in a state of nature.

I humbly beg your pardon for bothering you with so long a note; but it is your own fault.

Plants are splendid for making one believe in Natural Selection, as will and consciousness are excluded. I have lately been experimenting on such a curious structure for bursting open the seed-coats: I declare one might as well say that a pair of scissors or nutcrackers had been developed through external conditions as the structure in question.

(299/5. The peg or heel in Cucurbita: see "Power of Movement in Plants"

page 102.)

LETTER 300. TO T.H. HUXLEY. Down, November 5th, 1880.

On reading over your excellent review (300/1. See "Nature," November 4th, 1880, page 1, a review of Volume I. of the publications of the "Challenger," to which Sir Wyville Thomson contributed a General Introduction.) with the sentence quoted from Sir Wyville Thomson, it seemed to me advisable, considering the nature of the publication, to notice "extreme variation" and another point. Now, will you read the enclosed, and if you approve, post it soon. If you disapprove, throw it in the fire, and thus add one more to the thousand kindnesses which you have done me. Do not write: I shall see result in next week's "Nature."

Please observe that in the foul copy I had added a final sentence which I do not at first copy, as it seemed to me inferentially too contemptuous; but I have now pinned it to the back, and you can send it or not, as you think best,--that is, if you think any part worth sending. My request will not cost you much trouble--i.e. to read two pages, for I know that you can decide at once. I heartily enjoyed my talk with you on Sunday morning.

P.S.--If my ma.n.u.script appears too flat, too contemptuous, too spiteful, or too anything, I earnestly beseech you to throw it into the fire.

LETTER 301. CHARLES DARWIN TO THE EDITOR OF "NATURE."

(301/1. "Nature," November 11th, 1880, page 32.)

Down, November 5th, 1880.

Sir Wyville Thomson and Natural Selection.

I am sorry to find that Sir Wyville Thomson does not understand the principle of Natural Selection, as explained by Mr. Wallace and myself.

If he had done so, he could not have written the following sentence in the Introduction to the Voyage of the "Challenger": "The character of the abyssal fauna refuses to give the least support to the theory which refers the evolution of species to extreme variation guided only by Natural Selection." This is a standard of criticism not uncommonly reached by theologians and metaphysicians, when they write on scientific subjects, but is something new as coming from a naturalist. Professor Huxley demurs to it in the last number of "Nature"; but he does not touch on the expression of extreme variation, nor on that of evolution being guided only by Natural Selection. Can Sir Wyville Thomson name any one who has said that the evolution of species depends only on Natural Selection? As far as concerns myself, I believe that no one has brought forward so many observations on the effects of the use and disuse of parts, as I have done in my "Variation of Animals and Plants under Domestication"; and these observations were made for this special object. I have likewise there adduced a considerable body of facts, showing the direct action of external conditions on organisms; though no doubt since my books were published much has been learnt on this head.

If Sir Wyville Thomson were to visit the yard of a breeder, and saw all his cattle or sheep almost absolutely true--that is, closely similar, he would exclaim: "Sir, I see here no extreme variation; nor can I find any support to the belief that you have followed the principle of selection in the breeding of your animals." From what I formerly saw of breeders, I have no doubt that the man thus rebuked would have smiled and said not a word. If he had afterwards told the story to other breeders, I greatly fear that they would have used emphatic but irreverent language about naturalists.

(301/2. The following is the pa.s.sage omitted by the advice of Huxley: see his "Life and Letters," II., page 14:--

"Perhaps it would have been wiser on my part to have remained quite silent, like the breeder; for, as Prof. Sedgwick remarked many years ago, in reference to the poor old Dean of York, who was never weary of inveighing against geologists, a man who talks about what he does not in the least understand, is invulnerable.")

LETTER 302. TO G.J. ROMANES.

(302/1. Part of this letter has been published in Mr. C. Barber's note on "Graft-Hybrids of the Sugar-Cane," in "The Sugar-Cane," November 1896.)

Down, January 1st, 1881.

I send the MS., but as far as I can judge by just skimming it, it will be of no use to you. It seems to bear on transitional forms. I feel sure that I have other and better cases, but I cannot remember where to look.

I should have written to you in a few days on the following case. The Baron de Villa Franca wrote to me from Brazil about two years ago, describing new varieties of sugar-cane which he had raised by planting two old varieties in apposition. I believe (but my memory is very faulty) that I wrote that I could not believe in such a result, and attributed the new varieties to the soil, etc. I believe that I did not understand what he meant by apposition. Yesterday a packet of MS.

arrived from the Brazilian Legation, with a letter in French from Dr.

Gla.s.s, Director of the Botanic Gardens, describing fully how he first attempted grafting varieties of sugar-cane in various ways, and always failed, and then split stems of two varieties, bound them together and planted them, and then raised some new and very valuable varieties, which, like crossed plants, seem to grow with extra vigour, are constant, and apparently partake of the character of the two varieties.

The Baron also sends me an attested copy from a number of Brazilian cultivators of the success of the plan of raising new varieties. I am not sure whether the Brazilian Legation wishes me to return the doc.u.ment, but if I do not hear in three or four days that they must be returned, they shall be sent to you, for they seem to me well deserving your consideration.