yS MAN [Chap. VIII 



Letter 443 put sexual selection as an equal, or perhaps as even a more 

 important agent in giving colour than Natural Selection for 

 protection. As I get on in my work I hope to get clearer 

 and more decided ideas. Working up from the bottom of 

 the scale, I have as yet only got to fishes. What I rather 

 object to in your articles is that I do not think any one 

 would infer from them that you place sexual selection even 

 as high as No. 4 in your summary. It was very natural that 

 you should give only a line to sexual selection in the summary 

 to the Westminster Review, but the result at first to my 

 mind was that you attributed hardly anything to its power. 

 In your penultimate note you say " in the great mass of 

 cases in which there is great differentiation of colour between 

 the sexes, I believe it is due almost wholly to the need of 

 protection to the female." Now, looking to the whole 

 animal kingdom, I can at present by no means admit this 

 view ; but pray do not suppose that because I differ to a 

 certain extent, I do not thoroughly admire your several 

 papers and your admirable generalisation on birds' nests. 

 With respect to this latter point, however, although, following 

 you, I suspect that 1 shall ultimately look at the whole case 

 from a rather different point of view. 



You ask what I think about the gay-coloured females of 

 Pieris} I believe I quite follow you in believing that the 

 colours are wholly due to mimicry ; and I further believe 

 that the male is not brilliant from not having received 

 through inheritance colour from the female, and from not 

 himself having varied ; in short, that he has not been 

 influenced by selection. 



I can make no answer with respect to the elephants. 

 With respect to the female reindeer, I have hitherto looked 

 at the horns simply as the consequence of inheritance not 

 having been limited by sex. 



Your idea about colour being concentrated in the smaller 

 males seems good, and I presume that you will not object 

 to my giving it as your suggestion. 



1 See Westminster Review, July, 1867, p. yj ; also Letter 440. 



