VI] "MIMICRY RINGS" 69 



Variations in the direction of a more conspicuous 

 pattern would for that reason tend to be preserved 

 by natural selection, until eventually was evolved 

 through its means the well-marked pattern so charac- 

 teristic of the model to-day. If in the meantime 

 variations in the same direction occurred among the 

 females of E. undularis these would tend to be preserved 

 through their resemblance to the developing warning 

 pattern of the distasteful Danaine model. The develop- 

 ment of model and mimic would proceed pari passu, 

 but if the sexes of the mimic differ, as in this case, 

 we must suppose the starting-point to have been the 

 condition exhibited by the male of the mimicking 

 species. 



But Argynnis hyperbhis is also a species in which 

 the female mimics D. plexippus ; and by using the 

 same argument as that just detailed for Elymnias 

 undularis we can shew that the Danaine model, D. 

 plexippus, must also have been like the male of Argynuis 

 hyperbius. And if the resemblance of A. hyperbius 

 was developed subsequently to that of E. undularis, 

 then both D. plexippus and E. undularis must at one 

 time have been like the male of A. hyperbius, a pro- 

 position to which few entomologists are likely to assent. 

 Further, since the female of H. misippus also comes 

 into the plexippus-chrysippus combine we must suppose 

 that these species must at some time or another have 

 passed through a pattern stage Uke that of the misippus 

 male. 



It is scarcely necessary to pursue this argument 



