286 THE COLOURS OF ANIMALS 



account of the subject; and furthermore there are 

 certain recent observations which seem to me to yield 

 strong support to Darwin's theory. 



Insufficient evidence for existence of aesthetic preferences 



Mr. Wallace's chief objection is the lack of evi- 

 dence that the female has any aesthetic preferences at 

 all in the selection of her mate. When, however, he 

 admits that display of their decorative plumage by 

 male birds is ' demonstrated,' and that the females are 

 in all probability ' pleased or excited by the display,' 

 he certainly admits the possession of an aesthetic 

 sense ; while the insufficient evidence that the final 

 choice of the female is frequently determined by the 

 gratification of this sense, may, I think, be chiefly due 

 to want of patient or discriminating observations upon 

 wild animals in their natural conditions. 



Reasons for the lack of evidence 



It is a very remarkable fact that the great impetus 

 given to biological inquiry by the teachings of Darwin 

 has chiefly manifested itself in the domain of Com- 

 parative Anatomy, and especially in that of Embry- 

 ology, rather than in questions which concern the 

 living animal as a whole and its relations to the organic 

 world. And yet these were the questions in which 

 Darwin himself was principally interested. 



