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Annals Entomological Society of America [Vol. II. 



The facts indicate that the changes produced by the invaders 

 were wrought in the conspicuous pattern of a dominant indi- 

 genous species, and that the transformed butterfly having adopted 

 the advertisement of the still more unpalatable Danaida, became 

 even more dominant and gained a far wider range than before. 

 The mimetic resemblance arose in a species which we have reason 

 to believe possessed warning colours and some form of special 

 protection before the change occurred. There is no evidence that 

 the special protection was diminished after the assumption of 

 Mimicry, and, if it remain, the new" appearance is still a warning 

 character, only one that is learnt by enemies more readily than 

 the old because of the wide advertisement given to it by Danaida 

 plexippiis. The facts harmonize with the theory of Fritz Miiller 

 rather than with that of H. W. Bates. 



The 'Poisox-Eating' Swallow-Tail Butterflies (Phar- 

 macophagus) as models for mimicry. 



The late Erich Haase gave the name of Pharmacophagiis or 

 "Poison-eater" to the section of swallow-tail butterflies whose 

 larvae feed upon Aristolochia or allied species, and he made the 

 probable suggestion that the qualities which render them dis- 

 tasteful are derived from the juices of the food-plant. The poi- 

 son-eating swallow-tails are abundant in tropical America and 

 the Oriental Region, but with the exception of antenor in Mada- 

 gascar are wanting from the Ethiopian Region. They are exten- 

 sively mimicked by swallow-tails of the other two sections: 

 Papilio, of which machaon may be taken as a type, and Cosmo- 

 desmns, of which podalirins serves as an example. The distinc- 

 tion between these three sections of Papilionidae extends to lar- 

 val and pupal stages, as was originally discovered by Horsfield. 

 It was made the basis of Haase's classification,-^ recently confirmed 

 and amplified by Rothschild and Jordan.--^ The latter authorities 

 propose the names "Aristolochia Swallow-tails," "Fluted Swal- 

 lows-tails," and "Kite Swallow-tails," respectively for Haase's 

 sections Pharmacophagiis , Papilio and Cosmodesmus. 



The Pharmacophagiis swallow-tails are not so well-known as 

 models for Mimicry as are the Danainae, Acraeinae, etc., and it is 

 therefore expedient to say a few words about the section before 

 considering the effect produced by one of its members in North 

 America. 



2^ Researches on Mimicry, Pt. ii, Stuttgart, 1896, English translation. 

 ^'Nov. Zool. xiii (190G), 411-752. 



