II.] INCIPIENT STRUCTURES. 61 



attracted) to become the fathers of the next generation, to 

 which generation they tend to communicate their own 

 bright nuptial vesture. But there are peculiarities of color 

 and of form which it is exceedingly difficult to account for 

 by any such action. Thus, among apes, the female is no- 

 toriously weaker, and is armed with much less powerful 

 canine tusks than the male. When we consider what is 

 known of the emotional nature of these animals, and the 

 periodicity of its intensification, it is hardly credible that a 

 female would often risk life or limb through her admiration 

 of a trifling shade of color, or an infinitesimally greater 

 though irresistibly fascinating degree of wartiness. 24 



Yet the males of some kinds of ape are adorned with 

 quite exceptionally brilliant local decoration, and the male 

 orang is provided with remarkable, projecting, warty lumps 

 of skin upon the cheeks. As we have said, the weaker 

 female can hardly be supposed to have developed these by 

 persevering and long-continued selection, nor can they be 

 thought to tend to the preservation of the individual. On 

 the contrary, the presence of this enlarged appendage 

 must occasion a slight increase in the need of nutriment, 

 and in so far must be a detriment, although its detrimental 

 effect would not be worth speaking of except in relation to 

 " Darwinism," according to which, " selection " has acted 

 through unimaginable ages, and has ever tended to sup- 

 press any useless development by the struggle for life." 



84 Mr. A. D. Bartlett, of the Zoological Society, informs me that at 

 these periods female apes admit with perfect readiness the access of any 

 males of different species. To be sure this is hi confinement ; but the 

 fact is, I think, quite conclusive against any such sexual selection in a 

 state of nature as would account for the local coloration referred to. 



25 Mr. Darwin, in the last (fifth) edition of "Natural Selection," 1869, 

 p. 102, admits that all sexual differences are not to be attributed to the 

 agency of sexual selection, mentioning the wattle of carrier-pigeons, tuft 

 of turkey-cock, etc. These characters, however, seem less inexplicable 

 by sexual selection than those given in the text. 



