WCP1878

Letter (WCP1878.1768)

[1]

Down.

Bromley.

Kent. S.E.

Ap. 29. [1867]1

Dear Wallace

I have been greatly interested by your letter,2 but your view is not new to me. If you will look at p. 240 of 4th Ed. of Origin you will find it very briefly given with two extreme examples of the Peacock & Black grouse.3 A more general statement is given at p. 101 or at p. 89 of the 1st Ed.,4 for I have long entertained this view, though I have never had space to develope5 it. But I had not sufficient knowledge [2] to generalize as far as you do about colouring & nesting. In your paper6 perhaps you will just allude to my scanty remark in the 4th Ed, 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 & partly written my discussion & it w[oul]d 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 & Entomology that you will write a much better discussion than I c[oul]d, your paper [3] will be of great use to me.

Nevertheless I must discuss the subject fully in my essay on man. When we met at the Zoolog[ical]. Soc[iety]. & I asked you about the sexual differences in kingfishers I had this subject in view; as I had when I suggested to Bates7 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 a Mexican bird in which the female has long tailed plumes & which consequently builds a different nest from all its her allies. With respect to certain female birds being more brightly coloured than the males, & [4] the latter incubating I have gone a little into the subject & cannot say that I am fully satisfied. I remember mentioning to you the case of Rhynchaea, 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 I’s there is a Carrion hawk in which the female (as I ascertained by dissection) is the brightest coloured, & I doubt whether protection will here apply; but I wrote several months ago to the Falklands to make enquiries[.] [5] 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, & was transmitted to females alone, & 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 5 or 6 months, as I am fully employed in correcting dull proof sheets; when I return to the work I shall find it much better [6] done by you than I c[oul]d have succeeded in doing.

With many thanks for your very interesting note | believe me | dear Wallace | yours very sincerely | Ch. Darwin [signature]

It is curious how we hit on the same ideas.—8

[7]

I have endeavoured and show in my M.S. 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.—

[8]8

Down.—

Ap[ril] 29th [1867].

Post[s]cripts

My dear Wallace

On reading over your letter again & on further reflexion, I do not think (as far as I remember my words) that I expressed myself nearly strongly enough on the value & beauty of your generalisation, viz that all Birds, in [9] 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 sh[oul]d. ever have [one illeg. word crossed out] as to extended my view to your generalisation.— Forgive me troubling you with this. P.S.

yours | C. Darwin [signature]

"/67" is written in pencil in an unknown hand at the upper right-hand corner of pag 1. The date of 1867 has been established by the Darwin Correspondence Project see DCP-LETT-5517.
See ARW to Darwin, 26 April 1867 (WCP4087.4034).
Darwin, C. R. 1866. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, 4th edition. London, John Murray. p.240-241.
Darwin, C. 1859. On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life. London, UK: John Murray. p. 89.
Archaic form of develop.
Wallace, A. R. 1867. Mimicry, and Other Protective Resemblances Among Animals. Westminster Review. New Series. 32(1): 1-43.
Bates, Henry Walter (1825-1892). British naturalist, explorer and close friend of ARW.

Published letter (WCP1878.5961)

[1] [p. 183]

Down, Bromley, Kent, S E. April 29, 1867.

Dear Wallace, — I have been greatly interested by your letter;1 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.2 With respect [2] [p. 184] 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 Rhynchaea, 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. [3] [p. 185]

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.

A footnote here reads: "The letter to which this is a reply is missing. It evidently refers to Wallace's belief in the paramount importance of protection in the evolution of colour. See also Darwin's letter of February 26, 1867."
. A footnote here reads: "Menura superba. See "The Descent of Man" (1901), p 687 Rhynchaea, mentioned on p. 184, is discussed in the "Descent," p. 727. The female is more [continued on p. 184] brightly coloured than the male and has a convoluted trachea, elsewhere a masculine character. There seems some reason to suppose that "the male undertakes the duty of incubation.""

Please cite as “WCP1878,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 25 September 2022, https://epsilon.ac.uk/view/wallace/letters/WCP1878