DARWIN AND FEMALE MIMICRY 135 



led to believe that the first is the stronger. 

 Mimicry in the male would be no disadvantage 

 but an advantage, and when it appears would be 

 and is taken advantage of by selection. The 

 secondary sexual characters of males would be no 

 advantage but a disadvantage to females, and, as 

 Wallace thinks, are withheld from this sex by 

 selection. It is indeed possible that Mimicry has 

 been hindered and often prevented from passing 

 to the males by Sexual Selection. We know that 

 Darwin was much impressed l by Thomas Belt's 

 daring and brilliant suggestion that the white 

 patches which exist, although ordinarily concealed, 

 on the wings of mimetic males of certain Pierinae 

 (Dismorphia), have been preserved by preferential 

 mating. He supposed this result to have been 

 brought about by the females exhibiting a deep- 

 seated preference for males that displayed the 

 chief ancestral colour, inherited from periods 

 before any mimetic pattern had been evolved in 

 the species. But it has always appeared to me 

 that Belt's deeply interesting suggestion requires 

 much solid evidence and repeated confirmation 

 before it can be accepted as a valid interpretation 

 of the facts. 



In the present state of our knowledge, at any rate 

 of insects and especially of Lepidoptera, it is pro- 

 bable that the female is more apt to vary than the 

 male, and that an important element in the inter- 

 pretation of prevalent female Mimicry is provided 



1 Descent of Man, 825. 



