vn] THE CASE OF PAPILIO POLYTES 79 



which the two polytes females that are unlike the male 

 have been built up by natural selection. 



The suggestion of mimicry in this case is supported 

 by the fact that there is a general correspondence 

 between the areas of distribution of model and mimic. 

 P. hector is not found outside India and Ceylon, and 

 the H female of P. polytes is also confined to this area. 

 P. aristolochiae, on the other hand, has a much wider 

 range, almost as wide indeed as that of P. polytes 

 itself. Generally speaking the A female accompanies 

 P. aristolochiae wherever the latter species is found. 

 Beyond the range of P. aristolochiae, in northern China, 

 the M female alone is said to occur. On the other 

 hand, as the matter comes to be more closely studied 

 exceptions are beginning to turn up. The H female, 

 for instance, is found on the lower slopes of the Hima- 

 layas, far north of the range of P. hector, and there 

 are indications that a careful study of the distribution 

 in China and Japan may prove of importance. 



Moreover, the investigation of a smaller area may 

 also bring to light points of difficulty. In Ceylon, for 

 example, P. polytes is common up to several thousand 

 feet, while P. hector is rare at half the height to which 

 polytes ascends. Nevertheless the H form of female is 

 relatively just as abundant up-country where hector 

 is rarely found as it is low down where hector is plenti- 

 ful 1 . On the other hand, P. aristolochiae may be exceed- 

 ingly abundant at altitudes where hector is scarce. Yet 

 the A form of polytes is no more relatively abundant 



1 Spolia Zeylanica, 1910. 



