Darwin s Theory of Sexual Selection 215 



since they will transmit the characters of all the males, it is 

 evident that the secondary sexual characters could not be 

 formed in the way imagined. 



3. If the female fails to select only the more ornamental 

 males, no result will follow. It has not been shown that she 

 is capable of making such a choice, and in the lower forms 

 particularly, it does not seem probable that this is done. 

 The argument that Darwin often employs, namely, that 

 unless she does select, the display of the males before her is 

 meaningless, is not to the point. So far as we can detect 

 the " cause " of the display of the male, it appears to be due 

 to his own excitement ; and even if we go so far as to admit 

 that the "purpose" is to attract the other sex, it still does 

 not in the least follow that the most ornamental male is se- 

 lected, and unless this occurs the display has no bearing on 

 the hypothesis of sexual selection. 



4. The two forms of sexual selection, namely, competition 

 of the males with one another (really one form of natural 

 selection), and the selection of the most ornamental or gifted 

 individuals, are both used by Darwin to explain secondary 

 sexual characters, the one for organs of offence and defence, 

 and the other for ornamental characters. If we fully appre- 

 ciate the difficulties that any theory of selection meets with, 

 we shall realize how extraordinarily complex the action must 

 be, when two such processes are carried out at the same 

 time, or even during alternating periods. 



5. It has been objected to Darwin's theory of sexual selec- 

 tion, that he suddenly reverses its mode of action to explain 

 those cases in which the female is the stronger and more 

 ornamented sex ; but if, as Darwin shows, the instincts of 

 the male have also changed, and have become more like those 

 of the female, I can see no inherent difficulty in this way of 

 applying the theory. A much more serious objection, it 

 seems to me, is that the male is supposed to select the female 

 for one set of characteristics, and the female to select the 



