222 Darwin, and after Darwin. 



theory of Natural Selection ; fyr the f)Ossessors of ^^reatest vital 

 ixrwer being those most frequently produced and reproduced^ thi 

 external signs of it would go on developing in an ever increas- 

 ing exaggeration, only to be checked where it became really 

 detrimental in some respect or other to the individual *." 



Here then the idea is. as more fully expressed by 

 Mr. Wallace in the context, that all the innumerable, 

 frequently considerable, and generally elaborate " pe- 

 culiarities of form, structure, colour, and ornament," 

 which Darwin attributed to sexual selection, are really 

 due to '• the laws of growth." Diverse, definite, and 

 constant though these specific peculiarities be. they 

 are all but the accidental or adventitious accompani- 

 ments of " vigour," or '• vital power," due to natural 

 selection. Now. without waiting to dispute this view, 

 which has already been dealt with in the chapter 

 on Sexual Selection in Part I, it necessarily follows 

 that " a large proportional number of specific char- 

 acters," which, while presenting "no imaginable use," 

 are very much less remarkable, less considerable, less 

 elaborate, &c., must likewise be due to this 'correlation 

 with vital power." But if the principle of correlation 

 is to be extended in this vague and general manner, it 

 appears to me that the difference between Mr. Wallace 

 and myself, with respect to the principle of utility, is 

 abolished. For of course no one will di.spute that 

 the prime condition to the occurrence of " specific 

 characters," whether useful or useless, is the existence 

 of some form which has been denominated a "species" 

 to present them ; and this is merely another way of 

 saying that such characters cannot arise except in 

 correlation with a general fitness due to natural 



' Darwinism, pp 296-7 : italics mine. 



