CHAPTER VII 



THE CASE OF PAPILIO POLYTES 



Many instances of mimicry are known to-day, but 

 comparatively few of them have been studied in any 

 detail. Yet a single carefully analysed case is worth 

 dozens which are merely superficially recorded. In 

 trying to arrive at some conception of the way in which 

 the resemblance has come about we want to know the 

 nature and extent of the likeness in the living as well 

 as in the dead; the relative abundance of model and 

 mimic ; what are likely enemies and whether they could 

 be supposed to select in the way required, whether the 

 model is distasteful to them; whether intermediate 

 forms occur among the mimics ; how the various forms 

 behave when bred together, etc., etc. Probably the 

 form that from these many points of view has, up to 

 the present, been studied with most care is that of the 

 Swallow-tail, Papilio polytes. It is a common butterfly 

 throughout the greater part of India and Ceylon, and 

 closely allied forms, probably to be reckoned in the 

 same species, reach eastwards through China as far as 

 Hongkong. P. polytes is one of those species which 

 exhibit polymorphism in the female sex. Three dis- 

 tinct forms of female are known, of which one is like the 

 male, while the other two are very different. Indeed 



