52 SOME CRITICISMS [ch. 



But though mimic and model may be found together 

 in the same locahty, they do not always occupy the 

 same station in the sense that they fly together. 

 According to Seitz^ the Dismorphias themselves do 

 not fly with the Ithomiines which they mimic. The 

 occurrence of butterflies is largely conditioned by the 

 occurrence of the plants on which the larva feeds, 

 and this is especially true of the female, which, as has 

 already been noticed, is more commonly mimetic 

 than the male. The female of Papilio polytes, for 

 instance, is found flying where are to be found the 

 wild citronaceous plants on which its larva feeds. 

 On the other hand, its so-called models, Papilio hector 

 and P. aristolochiae, are generally in the proximity 

 of the Aristolochias on which their larvae feed. The 

 two plants are not always foxmd together, so that 

 one frequently comes across areas where P. polytes 

 is very abunda'nt while the models are scarce or absent. 

 Though in the great majority of cases the imitator 

 and the imitated occur in the same locahty, this is 

 not always so. The female of the Fritillary Argynnis 

 hyperhius (PI. IV, fig. 3), for instance, is exceedingly 

 difiicult to distinguish from Danais plexippus when 

 flying, although when at rest the difference between 

 the two is sufficiently obvious. Both insects are 

 plentiful in Ceylon but inhabit different stations. 

 The Danaid is a low-country insect, while the Fritillary 

 is not found until several thousand feet up. The two 

 species affect entirely different stations and hardly 



^ Macrdlepidoptera o/ the World. Fauna Americana, p. 98. 



