WCP4088

Letter (WCP4088.4035)

[1]

9, St. Mark’s Crescent1

May 1st. 1867

Dear Darwin2

I was afraid you had rather misunderstood my letter3 on first reading it; for I assure you I never for a moment imagined that any of the more obvious facts connected with sexual selection (which is altogether your own subject) could have been new to you. The remarkable coincidence, of so many of the birds which haveing females coloured as gayly as the males, making their nests so that the female is concealed during incubation, while almost all in which the female differs remarkably from the male in colour build exposed and uncovered nests; — appeared to me to get over one great difficulty in the way of explaining [2] the origin of colour in birds; and as it was so new & interesting to me I thought it might not possibly have occurred to you.

There are some exceptions which I cannot yet explain, but this is to be expected, for we cannot but suppose that many different causes have favoured or checked the developement of colour at different times. The exceptions are not I think numerous enough to upset the rule.

This view is I think also interesting as explaining the absence of much sexual difference of colour among [3] mammals or reptiles, in which the sexes are not very differently situated as regards danger from enemies.

The mode of nidification in birds is no doubt primaryily dependent on their structural peculiarities and their general habits (on which subject I have a paper written ten years ago,) and we may therefore conclude that the mode of nidification of Kingfishers[,] Toucans &c. has been the acting cause in determining or permitting the action of sexual selection on the female bird. In other cases however it is quite possible, that the colour being first produced by sex[ua]l. s[e]lect[io]n. has led to the modification of the nest for safety, as in the Australian finches [4] which make domed nests while our European species make open ones.4

On powerful and pugnacious birds, such as crows and hawks I do not expect the principle of protection has acted much in modifying colour.

I enclose you a copy of my notes on the subject, which I beg you to make what use of you like, in your proposed essay. I will merely allude to the subject in my paper on "mimicry", which is finished & sent to the "Westminster" to see if they will publish it.5 As you are going to treat fully the whole subject of "sexual selection" I hope you will not call it an "Essay on Man".6 I had thought of a short paper on "The connexion between the colours of female birds & their mode of nidification", — but had rather leave it for you to treat as part of the really great [5] subject of "sexual selection" which combined with "protective resemblances" and "differences" will I think when thoroughly worked out explain the whole colouring of the Animal Kingdom.7

Believe me Dear Darwin | Yours very faithfully | Alfred R. Wallace — [signature]8

1
ARW’s residence from March 1865-6/20 July 1867 and early July 1868-22 March 1870.
2
Darwin, Charles Robert (1809-1882). British naturalist, geologist and author, notably of On the Origin of Species (1859).
3
ARW's letter of 26 April [1867] is [WCP4087_L4034]. Darwin's reply to this letter, on 29 April [1867], is [WCP1878_L1768].
4
ARW shared this part about toucans and kingfishers in Wallace, A. R. 1868. A Theory of Birds' Nests: Shewing the Relation of Certain Sexual Differences of Colour in Birds to Their Mode of Nidification. Journal of Travel and Natural History. 1(2): 73-89, on 83: "When the confirmed habit of a group of birds was to build their nests in holes of trees, like the toucans, or in holes in the ground, like the kingfishers, the protection the female thus obtained, during the important and dangerous time of incubation, placed the two sexes on an equality as regards exposure to attack, and allowed 'sexual selection' to act unchecked in the development of gay colours and conspicuous markings in both sexes".
5
Wallace, A. R. 1867. Mimicry, and Other Protective Resemblances Among Animals. Westminster Review. New Series. 32(1): 1-43.
6
In Darwin's letter to ARW of 29 April [1867] [WCP1878_L1768], he had written "… 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". This "Essay on Man" of Darwin’s became part of Darwin, C. 1871. The Descent of Man, and Selection in Relation to Sex. 1st Ed. 2 vols. London, UK: John Murray.
7
ARW published the following on bird's nests: Wallace, A. R. 1867. The Philosophy of Birds' Nests. Intellectual Observer. 11(6): 413-420; Wallace, A. R. 1867. Birds' Nests and Plumage, Or the Relation Between Sexual Differences of Colour and the Mode of Nidification in Birds. The Gardeners' Chronicle and Agricultural Gazette. 12 October 1867: 1047-1048 (this was ARW’s paper he read at the BAAS meeting in Dundee on 9 September 1867); and Wallace, A. R. 1868. A Theory of Birds' Nests: Shewing the Relation of Certain Sexual Differences of Colour in Birds to Their Mode of Nidification. Journal of Travel and Natural History. 1(2): 73-89 (this is a greatly expanded version of the previous). ARW's arguments about bird’s nests were discussed in Darwin, C. 1871. The Descent of Man, and Selection in Relation to Sex. 1st Ed. 2 vols. London, UK: John Murray. [Vol. 2, pp. 166-180].
8
The remaining text of the letter is written vertically over the first layer of text on page four of the manuscript.

Editorial information

Status: Edited (but not proofed) transcription [Letter (WCP4088.4035)]

For more information about the transcriptions and metadata, see https://wallaceletters.myspecies.info/content/epsilon

Revision history

Transcribed by Darwin Correspondence Project [2012-07-02] Transcription checked by Costa, Leslie [2020-06-09]

Please cite as “WCP4088,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 20 April 2024, https://epsilon.ac.uk/view/wallace/letters/WCP4088