Selection by Females 



the males, or selection by the female of one 

 among several admirers. Thirdly, that the 

 female selects, as a rule, the most attractive of 

 her suitors. 



The evidence upon which Darwin founds this 

 theory may be thus summarised : 



1. In cases where the sexes differ in appear- 

 ance, or power of song, it is almost invariably 

 the cock who is the more beautiful or the better 

 singer, as the case may be. 



2. All male birds that possess accessory plumes 

 or other attractions, make a most elaborate dis- 

 play of these before the females at the mating 

 season, hence "it is obviously probable that 

 these appreciate the beauty of their suitors." 



3. Darwin was able to cite specific instances 

 in which the hens showed preference. 



In the case of polygamous species there can 

 be no doubt that there is considerable competition 

 among males for their wives. It cannot be said 

 that the contention is so well established in the 

 case of monogamous species. D. Dewar suggests 

 that circumstances may occur in which the hens 

 have to fight for the cock, or in which the male is 

 in the happy position of being able to select his 

 mate. He states his belief that in many cases 

 the selection is mutual, as in the case of human 

 beings. 



"I have seen," he writes, on page 13 of 

 Birds of the Plains, " one hen Paradise Fly- 



303 



