MIMICRY OF OLD WORLD DANAIDAS 161 



Danaida. In addition to the extraordinary degree 

 to which the Mimicry of D. chrysippm is carried 

 in Africa, it is mimicked in the Oriental Eegion 

 by the females of Hypolimnas misippus and of 

 Argynnis niphe, and by the males of certain species 

 of Cethosia. Danaida genutia and the forms related 

 to it are also mimicked by male Cethosias and 

 extensively by the females of species of Elymniinae, 

 while incipient Mimicry is seen in the males of 

 some of them. With the exception of Hypolimnas 

 misippus, common to both Regions, the Oriental 

 mimics of Danaida do not approach the degree of 

 resemblance attained by the best African mimics 

 of D. chrysippus. It has already been pointed out 

 that the Oriental mimics of this genus are far 

 less numerous than the African. On the other 

 hand, it is a curious fact that the only North 

 American mimic of D. plexippus, Limenitis 

 (Basilarchia) archippus reaches a far higher 

 degree of resemblance than that attained by 

 any of the characteristically Oriental mimics of 

 Danaida. 



The evidence as a whole enables us to decide 

 that Danaida is an Old World genus and a com- 

 paratively recent intruder into America, while 

 the perfection of the likeness attained by an 

 indigenous American mimic proves that, under 

 favourable circumstances, such resemblances may 

 be rapidly produced. I do not, of course, mean 

 to imply that the transformation was in any way 

 sudden, or by other than minute transitional 



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