714 THE DESCENT OF MAN 



There is another and more peaceful kind of contest, in 

 which the males endeavor to excite or allure the females 

 by various charios. This is probably carried on in soma 

 cases by the powerful odors emitted by the males during 

 the breeding season, the odoriferous glands having been ac- 

 quired through sexual selection. Whether the same view 

 can be extended to the voice is doubtful, for the vocal 

 organs of the males must have been strengthened by use 

 during maturity, under the powerful excitements of love, 

 jealousy, or rage, and will consequently have been trans- 

 mitted to the same sex. Various crests, tufts, and mantles 

 of hair, which are either confined to the male or are more 

 developed in this sex than in the female, seem in most cases 

 to be merely ornamental, though they sometimes serve as a 

 defence against rival males. There is even reason to sus- 

 pect that the branching horns of stags, and the elegant 

 horns of certain antelopes, though properly serving as 

 weapons of o£Fence or defence, have been partly modified 

 for ornament. 



When the male differs in color from the female, he gen- 

 erally exhibits darker and more strongly contrasted tints. 

 We do not in this class meet with the splendid red, blue, 

 yellow, and green tints, so common with male birds and 

 many other animals. The naked parts, however, of certain 

 Quadrumiana must be excepted; for such parts, often oddly 

 situated, are brilliantly colored in some species. The colors 

 of the male in other cases may be due to simple variation, 

 without the aid of selection. But when the colors are diver- 

 sified and strongly pronounced, when they are not developed 

 until near maturity, and when they are lost after emascula- 

 tion, we can hardly avoid the conclusion that they have been 

 acquired through sexual selection for the sake of ornament, 

 and have been transmitted exclusiv>ely, or almost exclu- 

 sively, to the same sex. When both sexes are colored in 

 the same manner, and the colors are conspicuous or curi- 

 ously arranged, without being of the least apparent use as 

 a protection, and especially when they are associated with 



