374 



thopterae (fig. i6), and these ofíer a good opportunity for drawing 

 attention to the great frequency, throughout the whole family of 

 PapilionidcB, of the forewing bearing the unmodified primitive 

 pattern, while the hindwing shows it in a much more differentiated 

 and therefore less typical form. This observation agrees with 

 the general fact that the hindwing shows more traces of having 

 undergone modifications in the course of phylogenetic develop- 

 ment than the forewing. In primitive Lepidoptera, such as 

 Hepialus, fore- and hindwing are more ahke than in genera 

 standing higher in the phylogenetic scale, and this similarity is 

 caused by the hindwing still showing the same structure as the 

 forewing, not by the forewing having acquired the structure of 

 the hindwing. 



A second remark refers to the comparison of male with female 

 Ornithopterae, when it is seen that the latter often show a com- 

 plication and disturbance of the primitive pattern by the breaking 

 up of the colour in the different internervural areas into alter- 

 nately dark and light patches, and the confluence of the colour- 

 figures of adjacent wing-spaces. In this, however, the female 

 must be considered as the more modified sex of the two.^ 



This same conclusion is independently reached by a study 

 of those Papilionidœ which possess polymorphic females. The 

 male form of P. mefnnon wears a simple uniform of primitive 

 design ; its different females all show various modifications of 

 this pattern, chiefly depending on changes in the hindwings, 

 but also more or less embracing the forewings. As the poly- 

 gynomorphism most probably has arisen by secondary modi- 

 fication of an originally monomorphic ancestral type, it seems 

 only logical to assume that the male did preserve this type, 

 while in the females it became modified in various degrees and 

 directions. 



P. ucalegon furnishes us with an example of a mimetic form, 

 and, besides, shows a general resemblance in wing-pattern to 

 P. Zenobia. Without in the least desiring to discuss the merits 



^ The figure given in illustration of this remark was taken from a 

 figure in Seitz's Atlas, which bears the name " aeacus $ ." So in this 

 case the female does not show a pattern of her own, but one of the kind 

 which in other species of Omithoptera is characteristic for the male, 

 that is to say, according to my opinion, the original or primitive one. 



