igoQJ Mhnicry in the Butterflies of North America 239 



15. The fact that the ancestral pattern of a species indige- 

 nous in the temperate zone of the New World should be wholly 

 transformed by a recent invader from the Old World tropics — 

 the invader meanwhile retaining its original characteristic pat- 

 tern, is demonstrative of the inadequacy of the theory which 

 refers these likenesses to the influence of soil, climate, etc. 



16. The poison-eating "Aristolochia swallow-tail" Phar- 

 macophagus (Papilio) philcnor belongs structurally to the Ameri- 

 can division of this tropical section, and is probably an intruder 

 into North America from the south. 



17. Just as tropical species of Pharmacophagus are mimicked, 

 especially by other sections of swallow-tails, so the invading 

 philenor is mimicked by three species of the section ''Papilio.'" 



18. Of these three — Papilio troiliis, mimetic in both sexes, 

 is probably the oldest; P. asterius, mimetic in female and on under 

 surface of male, the next; and P. glaiicus, mimetic in one out of 

 the two forms of female (the mimetic form becoming more num- 

 erous in the south of the range) , the youngest. 



19. The ancestors of these mimics persist with little or no 

 change — in the two last-named species, the non-mimetic sex or 

 form, in the first-named the allied palamedes. By their aid we 

 can reconstruct the history of the transformation. 



20. In asterius and glaucus partially melanic forms of the 

 female probably supplied a tinted background on which the new 

 and mimetic picture was gradually built up by the modification 

 of elements in the original non-mimetic pattern. 



21. The close resemblance between the three mimicking 

 species cannot be entirely explained by their convergence upon a 

 single model, but seems to imply the existence of Secondary 

 Mimicry between them. 



22. Limenitis astyanax has arisen as a very recent modifica- 

 tion of arthemis in Mimicry of philenor, and especially in Second- 

 ary Mimicry of the three Papilio mimics. 



23. The female of Argynnis {Semnopsyche) diana has arisen 

 as a tertiary mimic, on the upper surface, of L. astyanax. Its 

 under surface, inconspicuous with that of the male when contract- 

 ed, suggests that the species is palatable as compared with the 

 rest of this combination and that its Mimicry is Batesian. 



24. The dark ground and pale markings of the female diana 

 are probably analogous with those of other dark female forms 

 in Argynnidae, while the blue colouring is an additional feature 

 of purely mimetic significance. 



