1866—1872] SEXUAL SELECTION 91 



I hope thai you will not think mc an intolerable bore. It Letter 455 

 is most improbable that you could get me an answer, but 



I ask on mere chance. M silenus 1 has a great mane 



of hair round neck, and passing into large whiskei 

 beard. Now what I want most especially to know is whether 

 these monkeys, when they fight in confinement and I have 

 seen it stated that they are sometimes kept in confinement), 

 are protected from bites by this mane and beard. Any one 

 who watched them fighting would, I think, be able to 

 judge on this head. My object is to find out with various 

 animals how far the mane is of any use, or a mere ornament. 

 Is the male Macacus silenus furnished with longer hair than 

 the female about the neck and face? As 1 said, it is a 

 hundred or a thousand to one against your finding out 

 any one who has kept these monkeys in confinement. 



To F. Miilli r. Le"" 456 



Down, August 28th [1S70]. 



I have to thank you very sincerely for two letters : one of 

 April 25th, containing a very curious account of the structure 

 and morphology of Bonatea. I f< el that it is quite a sin that 

 your letters should not all be published ! but, in truth, I have 

 no spare strength to undertake any extra work, which, though 

 slight, would follow from seeing your Utters in English 

 through the press — not but that you write alm< rly 



as any Englishman. This same letter also contained some 



ds for Mr. Farrer, which he was very .dad to recei\ . 



Your second letter, of July 5th, was chiefly devoted to 

 mimicry in lepidoptera: many of your remarks seem to me 

 so good, that 1 have forwarded your letter to Mr. Bates ; but 

 he is out of London having his summer holiday, and 1 i. . 

 not yet heard from him. Your remark about imitators and 

 imitated being of such different sizes, and the lower sun 

 of the wings not bring altered in colour, strike me as the m 

 curious points. I should not be at all surprised if your sug- 

 gestion about sexual selection ware to prove true ; but it 

 seems rather too speculative to be introduced in my book, 

 more especially as my book is already far too speculative. 

 The very same difficulty about brightly - coloured caterpillars 



1 Macacus silenus L., an Indian ape. 



