To A. R. Wallace 6 October [1868]1
Down. | Bromley. | Kent. S.E.
Oct 6th
My dear Wallace
Your letter is very valuable to me & in every way very kind. I will not inflict a long answer, but only answer your queries.2
There are breeds (viz Hamburgh) in which both sexes differ much from each other & from both sexes of G. bankiva; & both sexes are kept constant by selection.—
The comb of Spanish ♂ has been ordered to be upright & that of Spanish ♀ to lop over, & this has been effected. There are sub-breeds of Game Fowl, with ♀s very distinct & ♂s almost identical; but this apparently is result of spontaneous variation without special selection.—3
I am very glad to hear of case of ♀s Birds of Paradise.—4
I have never in the least doubted possibility of modifying female birds alone for protection; & I have long believed it for Butterflies: I have wanted only evidence for the females alone of Birds, having had their colour modified for protection.
But then I believe, that the variations by which a female bird or butterfly could get or has got protective colouring have probably from the first been variations limited in their transmission to the female sex;—& so with the variations of the male, where the male is more beautiful than the female, I believe the variations were sexually limited in their transmission to the males.5
I am delighted to hear that you have been hard at work on your M.S.6
Yours most sincerely | Ch. Darwin
Footnotes
Bibliography
Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.
Summary
Sexual selection, protection.
Letter details
- Letter no.
- DCP-LETT-6412
- From
- Charles Robert Darwin
- To
- Alfred Russel Wallace
- Sent from
- Down
- Source of text
- The British Library (Add MS 46434: 162–3)
- Physical description
- ALS 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 6412,” accessed on 19 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-6412.xml
Also published in The Correspondence of Charles Darwin, vol. 16