1909] Mimicry in the Butterflies of North America 223 



In tropical America not only are the species of Pharmaco- 

 phagiis extensively mimicked but Mimicry is also strongly devel- 

 oped within the limits of the section itself, viz., between the 

 two dominant groups Aeneas and Lysander. In these groups 

 the males are commonly very different in appearance from the 

 females and frequent more open habitats such as the banks of 

 rivers, etc., the females being found in the forest. In the inter- 

 nal Mimicry between Aeneas and Lysander the males resemble 

 the males, the females the females, but the female patterns are 

 alone extensively mimicked by other groups — Papilio, Cosmo- 

 desmiis and certain Pierinae. I have as yet only come across a 

 single example (a Cosmodesmiis) in which the pattern and green 

 markings of the males are mimicked. One or two species (e. g. 

 Ph. hahneli) of Pharmacoghagtis are themselves mimics of domi- 

 nant Ithomiine genera. 



It is well known that in the Papilio mimics of Pharma- 

 cophagiis the resemblance is often attained by the females alone, 

 a tendency exemplified in North America as shown on pp. 224-6. 

 In Cosmodesmns, on the other hand, where the Mimicry of these 

 models reaches a far higher level of perfection, it is equally pro- 

 nounced in both sexes. In Africa, on the other hand, where, 

 in default of Pharmacophagus models, the swallow-tails of both 

 groups frequently mimic Danainae and Acraeiiiae, the resem- 

 blances obtained by Cosmodesmns are far less striking than those 

 of the other section; yet the relationship of Mimicry to sex re- 

 mains unchanged. 



In the Oriental Region the female Mimicry of Pharmacophagus 

 is still characteristic of Papilio, also appearing in certain Cosmo- 

 desmns mimics of Danainae. Two remarkable features appear 

 in this Region: (i) the development within Pharmacophagus 

 of the gigantic Omithopteras which do not appear to be mim- 

 icked at all; (2) the appearance within the section Papilio of 

 groups which are mimicked as extensively, perhaps even more 

 extensively, than Pharmacophagus itself. Among the mimics of 

 these Papilios are not only species of other proups in the same 

 section but also, although in small proportion, Satyrine butter- 

 flies and day-flying moths. 



The fact that Pharmacophagus and certain groups of Papilio 

 should be mimicked pre-eminently by other Papilionidae is evi- 

 dence that Mimicry is most easily attained when there are initial 

 resemblances of size, shape, habits, and modes of flight upon 

 which to build. 



