176 MIMIOEY IN N. AMEEICAN BUTTERFLIES 



(' Purple Emperors') and the later brood ofArasch- 

 nia levana} Furthermore, the close allies of Li- 

 menitis in South America, the abundant Adelphas, 

 are beautifully mimicked, not only by females of 

 the genus Chlorippe, which represents Apatura, but 

 also by Erycinidae. In another point the facts are 

 at variance with Bates's interpretation but har- 

 monize with Miiller's. Bates supposed Mimicry to 

 be an adaptation by which a scarce, hard-pressed 

 form is enabled to hold its own in the struggle 

 for existence. But L. arthemis, which represents 

 with little or no change the species from which 

 the mimics were derived, persists as a very abun- 

 dant and flourishing species, while its mimetic 

 descendant arcMppus has gained an immensely 

 extended range and become almost universally 

 commoner than any other species of its group 

 (Scudder, Lc, 266). L. arcMppus extends from 

 Hudson's Bay to the Gulf of Mexico; over this vast 

 area it is only rare in the west, and only unknown 

 in Colorado, Arizona, and New Mexico (I.e., 278). 

 It is to be observed that the range of arcMppus 

 includes the whole of the area (Canada and the 

 north-eastern States) occupied by the ancestral 

 form arthemis. 



The facts indicate that the changes produced 

 by the invaders were wrought in the conspicuous 

 pattern of a dominant indigenous species, and 

 that the transformed butterfly having adopted the 



' See also the mimetic resemblance to L. astyanax described on 

 pp. 189-91. 



