The Evidence from Sexual Characters. 227 



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in doubting, from the analogy of domesticated animals, 

 ■whether the excessive modiGcation of the males of wild 

 animals is due entirely to the fact that males are more 

 exposed than females to the action of selection. As the 

 study of domesticated races leads us to the conclusion 

 that something within the animal compels the male to 

 lead and the female to follow in the evolution of new 

 breeds, we must believe that a similar law regulates in 

 the same way the evolution of wild organisms. The 

 study of domesticated races, like the study of wild spe- 

 cies, also compels us to believe that this law is not im- 

 mutable, but that variations which originate in a female 

 may become hereditary, although this is somewhat rare, 

 as compared with the hereditary establishment of male 

 modifications. 



Tlie Vieiv that the Male is more Eccjiosed than the Female 

 to the Action of Selection. 



According to Darwin the excessive exposure of the 

 male to the action of selection, natural and sexual, is 

 the cause of his great modification. He points out that 

 the distinctive characters of the male are, in many cases 

 at least, of especial use to him, as a male, and he shows 

 that the individuals which possess these peculiarities are 

 benefited by them, and have therefore been preserved, 

 while the females, deriving no advantage from them, 

 have not been thus selected. 



No one can doubt the truth of this statement, but it 

 does not go to the root of the matter. The question is 

 not how peculiarities useful to the male alone have been 

 restricted to that sex, but why the female has not ac- 

 quired another set of characteristics to fit her for her 

 peculiar needs. No one can doubt that a hen might 

 have special organs, as useful to her for the care and pro- 



