1909] Mimicry in the Butterflies of North America 229 



whether the Mendehan proportions appear in the offspring of the 

 hybrids. The pairing of astyanax and archipptts, although in 

 this case failure is probable, ought also to be attempted. 



The Female of Argyxxis (Semnopsyche) diaxa (Cr.) a 

 Mimic of Limenitis astyanax. 



The comparatively narrow range of this species is, as Scudder 

 points out, wholly included within that of astyanax (1. c. 1802). 

 The Mimicry is confined to the upper surface, where the blue 

 tint has even less sheen than that of any other member of the 

 group clustered round the brilliant philenor. Apart from the 

 blue expanse, which he admits to be mimetic, Dr. F. A. Dixey 

 considers that the female of diana belongs to a set of dark female 

 forms w^ell-known in Argynnis, forms which he believes to be 

 ancestral.^'' It is probable that 'the recent evolution of L. 

 astyanax provided this ancestral form with a model which it could 

 approach by small and easy steps of variation.'^** 



The Bearing upon Theories of Mimicry of Pharm. 

 philenor and Its Mimics. 



Haase, who always shows an imperfect appreciation of the 

 scope of Fritz Miiller's principle, apparently regarded all the 

 species mentioned in the preceding section as simple Batesian 

 mimics, of philenor, neglecting the mimetic relationships between 

 the mimics themselves. This interpretation is unconvincing, 

 and most naturalists will agree with Scudder in his hesitation to 

 accept the two Nymphalines, astyanax and diana (female), 

 as simple mimics of philenor. The Miillerian hypothesis at once 

 explains relationships that are mere coincidences under that of 

 Bates. 



Pharm. philenor, a probable intruder from the American 

 tropics, produced its eft'ect upon the three large Papilios — butter- 

 fiies with a conspicuous under surface pattern, in large part 

 reproducing that of the upper surface, butterflies belonging to a 

 section that provides models for extensive Mimicry in the Oriental 

 Region. They may be regarded as Miillerian mimics of the pri- 

 mary Pharmacophagiis model, exhibiting a certain amount of 

 Secondary Mimicry of one another. 



The four above-named Papilionidae, but especially the three 

 mimics acting as secondary models, then proudced an effect upon 



29 Trans. Ent. Sac. Lond. (1890), 89-129. 

 ^° Ibid., (1908), 475. 



