COLOURS PRODUCED BY COURTSHIP 305 



Such facts point towards the existence of a wide-spread 

 aesthetic sense in the higher animals 



All such facts taken together seem to me to sup- 

 port the opinion that an aesthetic sense exists in the 

 females of all groups in which courtship is accompanied 

 by display of any kind, and that the males vie in 

 gratifying this sense as far as possible with whatever 

 endowments they may possess. I believe that more 

 extended observations like those upon spiders will 

 prove that any variation of the male in the direction 

 of greater adornment will, if not disadvantageous to 

 the species, increase the chances of success in court- 

 ship. As such new points arise the attitudes and 

 movements will be modified in order to show them off 

 to the greatest perfection. 



Mr. Wallace, while admitting the display and the 

 pleasure given by it to the females, considers that it 

 by no means follows that slight differences of shape, 

 pattern, or colour would lead a female to prefer one 

 male to another, ' still less that all the females of a 

 species, or the great majority of them, over a wide 

 area of country, and for many successive generations, 

 prefer exactly the same modification of the colour or 

 ornament.' 



If, however, we consider a hypothetical case in the 

 light of ascertained facts, the probabilities do not 

 seem to favour Mr. Wallace's opinion. Let us sup- 



