12 BUTTERFLIES IN DISGUISE 



same region. Now, as mimicry is clearly only a 

 protective device, or rather outcome, we should 

 naturally inquire whether either sex was more in 

 need than the other of protection from those foes 

 against wliich mimicry could avail anything^ 

 Plainly, it would be the female, since, were she 

 lost before oviposition, just so many eggs would be 

 lost with her ; and besides this, her heavier, more 

 sluggish flight — a necessity from her burden of 

 eggs — makes her an easier prey to insectivorous 

 creatures against which mimicry is aimed. Ac- 

 cordingly, we find many instances in wliich the 

 female is mimetic and the male normal. Probably 

 they are far more numerous than we imagine, and 

 many of the exceedingly common differences be- 

 tween the sexes, which since Darwin's day we have 

 been wont to set down to sexual selection, doubt- 

 less are to be attributed to something of this na- 

 ture. But there is no known case of parastatic 

 mimicry confined to the male sex. On the other 

 hand, some of the most vivid and striking exam- 

 ples of mimicry are to be found confined to the 

 females. There is one example brought forward 

 by Trimen which is the most surprising yet pub- 

 lished, where not only have two kinds of African 

 swallow-tail butterflies, one with, the other with- 



