552 The Descent of Man. I'aet II 



pretty ; the orange-tinted face is surrounded by long whiskers 

 of glossy whiteness, with a line of chcsnut-red over the eye- 

 brows ; the fur on the back is of a delicate grey, with a square 

 patch on the loins, the tail and the fore-arms being of a pure 

 white ; a gorget of chesnut surmounts the chest ; the thighs are 

 black, with the legs chesnut-red. I will mention only two other 

 monkeys for their beauty; and I have selected these as pre- 

 senting slight sexual differences in colour, which renders it 

 in some degi-ee probable that both sexes owe their elegant 

 appearance to sexual selection. In the moustache-monkey 

 {(.'ercopitherus ceplius)\he general colour of the fur is mottled- 

 greenish with the throat white ; in the male the end of the tail 

 is chesnut, but the face is the most ornamented part, the skin 

 being chiefly bluish- grey, shading into a blackish tint beneath 

 the eyes, with the upper lip of a delicate blue, clothed on the 

 lower edge with a thin black moustache; the whiskers are 

 orange-coloured, with the upper part black, forming a band 

 which extends backwards to the ears, the latter being clothtd 

 with whitish hairs. In the Zoological Society's Gardens I have 

 often overheard visitors admiring the beauty of another monkey, 

 deservedly called Gercopithecus diana (fig. 78) ; the general 

 colour of the fur is grey ; the chest and inner surface of the 

 forelegs are white; a large triangular defined space on the 

 hinder part of the back is rich chesnttt ; in the male the inner 

 sides of the thighs and the abdomen are delicate fawn-coloured, 

 and the top of the head is black ; the face and ears are intensely 

 black, contrasting finely with a white transverse crest over the 

 eye-brows and a long white peaked beard, of which the basal 

 portion is black.*' 



In these and many other monkeys, the beauty and singular 

 arrangement of their colours, and still more the diversified and 

 elegant arrangement of the crests and tufts of hair on their 

 heads, force the conviction on my mind that these characters 

 have been acquired through sexual selection exclusively as 

 ornaments. 



Summary. — The law of battle for the possession of the femalo 

 appears to prevail throughout the whole great class of mammals. 

 Most naturalists will admit that the greater size, strength, 

 courage, and pugnacity of the male, his special weapons of 

 offence, as well as his special means of defence, have been 



" I have seen most of thi ibove Mr. W. C. Martin's 'Nat. Hist, of 



monlieys in the Zoological Society's Mammalia,' 1S41, p. 4-60; sec alsc 



Gardeus. The description of the pp. 470, .")2y 

 Semno.Jt/itJcuf vem,i'us is taken from 



