The Evidence from Sexual Characters. 215 



ing a numerous progeny, if better endowed males were 

 not present. We may infer that this would be the case, 

 for the females, which are unarmed and unornamented, 

 are able to survive and procreate their kind. Secondary 

 sexual characters of the kind just referred to will be 

 fully discussed in the following chapters, as they are, in 

 many respects, interesting, but more especially as they 

 depend on the will, choice, and rivalry of the individ- 

 uals of either sex. 



"When we behold two males fighting for the posses- 

 sion of the female, or several male birds displaying their 

 gorgeous plumage and performing the strangest antics 

 before an assembled body of females, we cannot doubt 

 that, though led by instinct, they know what they are 

 about, and consciously exert their mental and bodily 

 powers. In the same manner as man can improve the 

 breed of his game-cocks by the selection of those birds 

 which are victorious in the cock-pit, so it appears that 

 the strongest and most vigorous males, or those pro- 

 vided with the best weapons, have prevailed under na- 

 ture, and have led to the improvement of the natural 

 breed or species. Through repeated deadly contests, a 

 slight degree of variability, if it led to sgme advantage, 

 however slight, would suffice for the work of sexual se- 

 lection; and it is certain that secondary sexual charac- 

 ters are eminently variable. 



"In the same manner as man can give beauty, accord- 

 ing to his standard of taste, to his male poultry can 

 give to the Sebright bantam a new and elegant plumage, 

 an erect and peculiar carriage so it appears that in a 

 state of nature female birds, by having long selected the 

 more attractive males, have added to their beauty. . . . 

 It is certain that with almost all animals there is a 

 struggle between the males for the possession of the fe- 



