PROTECTIVE MIMICRY 237 



inhabiting the same land : Three well-known species 

 of Danais occur in Africa, each of which is mimicked 

 by a special variety of the female of Papilio merope ; 

 two of the Danaidce present two varieties in the range 

 over which they are accompanied by the P. merope, 

 and some females of the latter undergo corresponding 

 changes ; intermediate varieties occur and also connect 

 one of these forms with a fourth variety of the female. 

 Furthermore, in Madagascar, which in so many other 

 instances furnishes us with a glimpse of what the 

 ancestral African fauna must have been, a Papilio 

 is still living with a male like that of P. merope, and 

 having a female only differing in the rather greater 

 predominance of dark markings, a predominance 

 which is thus entirely in the direction of the far darker 

 African females. 



It requires a very slight exercise of the imagina- 

 tion to picture the steps by which these marvellous 

 changes have been produced ; for here the new forms 

 have arisen at so recent a date that many of the inter- 

 mediate stages can still be seen, while the parent form 

 has been preserved unchanged in a friendly land, where 

 the keener struggle of continental areas is unknown. 1 



1 Since the appearance of Mr. Trimen's important paper, the 

 interest and intricacy of the case have much increased. Mr. Mansel 

 Weale (Trans. Ent. Soc. Land. 1874, pp. 131 et scq.) found a number 

 of the larva feeding together in one locality, near King William's Town. 

 From these he bred seven males, four females of the Cenea form, one 

 of the Trophonius, and one of the Hippocoon form, thus confirming 

 Mr. Trimen's original suggestion, that all these belong to the same 

 species. The butterflies have furthermore been taken in coitu more 



