190 DIVERSITY OF THE SEXES 



longs [Fig. 159 ; see also Figs. 113-116, etc.], the 

 prevailing colors, at least in the temperate zone, 

 are certainly tawny and black or brown, the lat- 

 ter marginal ; this is the case with the male of 

 Brettus, while the female diverges from the type 

 in becoming wholly brown. 



In the Tiger Swallow-tail [see Fig. 153], where 

 we sometimes have a black female, it is more 

 difficult to decide what should be considered the 

 normal color, owing to diversity of view upon the 

 relationship of many of the swallow-tails ; but 

 ^4 jx*- to judge only from those 



^^^tijjjri&jjSS agreed by all to be most near- 

 ly allied to it, there is no 

 question whatever that the 



Jft&1JStittfi stri P ed character prevails. 



It will be noticed in this 

 case and others I have given that wherever partial 

 antigeny or dimorphism is confined to one sex, it 

 is always to the female ; and I am not aware of any 

 exception to the rule, excepting in the case of the 

 Spring Azure. In these instances, on my hypoth- 

 esis, half of the females depart from the type ; on 

 Darwin's, half of the females and all of the males. 

 But if, on Darwin's theory, sometimes half and 

 sometimes three-fourths of a species have diverged 

 from the type, why does it never happen that 

 only one-fourth of them diverge ? This seems to 

 me a very pertinent and damaging inquiry. 



