1914.] NATURAL SCIENCES OF PHILADELPHIA. 171 



The turnus female is a partially melanic variety, hut the lines of 

 the male pattern can be detected beneath the overspreading pigment. " 

 It also exhibits many features in its pattern which have received no 

 interpretation except that they are mimetic of philenor or secondarily 

 mimetic of the other Papilionine mimics of philenor (31, 467-471). 

 No doubt there are examples in which it is probable that melanic 

 females preserve something of an ancestral pattern, as in Argijnnis 

 (liana or the valesina form of our British ^. paphia (7, 103-5, 119-21), 

 but I "do not think that anyone has maintained that this is true of 

 the melanic females of Papilios. It is, I submit, unreasonable to 

 suppose that the male-like pattern first appeared almost hidden 

 under the melanism of the turnus female, and that the full pattern 

 became evident by the clearing up of the dark pigment; whereas 

 the opposite view, that the partial melanism appeared later, obscuring 

 but not completely hiding a pre-existing male-like pattern, seems to 

 me entirely probable. Such partial melanism, in my opinion, 

 provided the foundation on which the details of the mimetic resem- 

 blance were gradually built. 



As regard this same species, Dr. Skinner's final conclusions (34, 

 p. 26) are comprised in the following statement: ''The evidence in 

 favor of glaucus being brought about by mimicry is almost nil, while 

 the evidence against it is very considerable. The species swarms 

 in countless thousands in the north where glaucus does not exist." 

 When we add to these last words the fact that the model P. philenor 

 is also non-existent in the north. Dr. Skinner's argument seems to 

 support the view he is attacking. P. philenor only enters New 

 England and Southern Canada as a straggler and barely overlaps 

 the range of the northern subspecies of P. glaucus glaucus, which 

 Rothschild and Jordan distinguish under the name of P. glaucus 

 ■canadensis (20, p. 586). As regards the closely allied P. rutulus, the 

 ■same great authorities give reasons for considering it a distinct 

 species. The whole range of glaucus glaucus — Florida to New 

 England and westward to the Mississippi basin — lies within that 

 of P. philenor, and over this whole range the dark hmius female 

 occurs intermingled with male-like females — the latter preponderating 

 in the north, the former in the south. The evidence based on geo- 

 graphical distribution seems to me strongly to support Edwards' 

 conclusions. And we may add that there are, as I have already said, 

 details in the pattern of the dark females which are not explained 

 by any other hypothesis. Objections based on the great abundance 

 •of the non-mimetic ancestor are considered on pages 178, 179. 



