382 GENERAL SUMMARY [Part II. 



ways. It is to be especially observed that the males dis- 

 play their attractions with elaborate care in the presence 

 of the females ; and that they rarely or never display them 

 excepting during the season of love. It is incredible that 

 all this display should be purposeless. Lastly, we have 

 distinct evidence with some quadrupeds and birds that the 

 individuals of the one sex are capable of feeling a strong 

 antipathy or preference for certain individuals of the oppo- 

 site sex. 



Bearing these facts in mind, and not forgetting the 

 marked results of man's unconscious selection, it secms'to 

 me almost certain that if the individuals of one sex were 

 during a long series of generations to prefer pairing with 

 ceitain individuals of the other sex, characterized in some 

 peculiar manner, the offspring would slowly but surely 

 become modified in this same manner. I have not at- 

 tempted to conceal tliat, excepting when the males are 

 more numerous than the females, or when polygamy pre- 

 vails, it is doubtful how the more attractive males succeed 

 in leaving a larger number of offspring to inherit their 

 superiority in ornaments or other charms than the less 

 attractive males ; but I have shown that this would prob- 

 ably follow from the females — especially the more vigor- 

 ous females, which would be the first to breed — preferring 

 not only the more attractive but at the same time the 

 more vigorous and victorious males. 



Although we have some positive evidence that birds 

 appreciate bright and beautiful objects, as with the Bower- 

 birds of Australia, and although they certainly appreciate 

 the power of song, yet I fully admit that it is an astonish- 

 ing fact that the females of many birds and some mam- 

 mals should be endowed with suflicient taste for what has 

 apparently been effected through sexual selection ; and 

 this is even more astonishing in the case of reptiles, fish, 

 and insects. But we really know very little about the 



