SEXUAL SELECTION 59 



ural selection will then preserve the vigorous offspring of 

 the vigorous parents, and the males among these will be 

 highly ornamented like their fathers. This is but conjec- 

 ture. The relations suggested have not been established by 

 observation. It is clear, however, that Wallace's statement 

 is not self-evident. 



Morgan keenly suggests an interesting objection. He 

 says, " If in order to bring about, or even maintain, the 

 results of sexual selection, such a tremendous elimination 1 

 of individuals must take place, it is surprising that natural 

 selection would not counteract this by destroying those 

 species in which a process, so useless for the welfare of the 

 species, is going on." ... " If, in nature, competition be- 

 tween species takes place on the scale that the Darwinian 

 theory of natural selection postulates, such forms, if they are 

 much exposed, would be needlessly reduced in numbers in 

 the process of acquiring these [ornamental] structures " in 

 the male. This objection of Morgan's is based upon the 

 same assumption as that of Wallace which is criticised in 

 the preceding paragraph. 



Prolonged and careful observation, on a large scale, of 

 the courting and mating of animals is needed to give us a 

 sound basis for judging of the reality and degree of impor- 

 tance of sexual selection. We do not even know from obser- 

 vation whether the highly ornamented males are more suc- 

 cessful in finding mates than are their less adorned fellows. 

 Such observation is very difficult, for it involves keeping 

 large numbers of individuals under as nearly natural condi- 

 tions as possible, and observing them continuously, as well 

 as keeping complete records of the mating and offspring. 



1 Elimination from the breeding process. 



