236 ANCESTR Y AND CLA SSIFICA TION. 



ingly different forms, which may be distin- 

 guished, not only by their coloring and markings, 

 but even by the form of the wings and the sculp- 

 ture of the hard parts of the abdomen ; in fact, 

 we have two forms, permanently distinct from 

 each other, to which we cannot apply the name 

 of species simply because we know they have the 

 same immediate parentage ; we can hardly doubt 

 that the separation of this species is nearly ac- 

 complished. 



The same may be affirmed of antigeny ; we find 

 melanic antigeny both partial and complete ; in 

 its partial condition in our Spring Azure it grows 

 more and more nearly perfect as we pass south- 

 ward ; we see its form fixed in some species, and 

 in others the melanic feature has been superin- 

 duced upon the male. The same is true of struc- 

 tural antigeny. Some species, which we can 

 hardly doubt have had a common ancestor, 

 scarcely differ from each other excepting in the 

 character of their antigenic peculiarities, and this 

 accounts for the close resemblance of the females 

 of allied species of skippers. Origin through 

 antigeny probably occurs with other animals, 

 but in butterflies it must be unusually common. 

 So too with mimicry. The Viceroy and the 

 Red-spotted Purple are nearly identical in all 

 their earlier stages, and yet utterly diverse in 

 the perfect butterfly ; both must have sprung 



