The Wallace-Darwin Correspondence 



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



Dear Wallace, — I have been greatly interested by your 

 letter;' 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 suflficient knowledge to general- 

 ise 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, ex- 

 plaining, 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 entomo- 

 logy that you will write a much better discussion than I 

 could, your paper will be of great use to me. Neverthe- 

 less, 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 sub- 

 ject in view; as I had when I suggested to Bates the diffi- 

 culty 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.* With respect 



1 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. 



« 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 



183 



