ANTIGENY; Oil SEXUAL DIVERSITY. 531 



EXCURSUS XVL — ANTIGENY; OR SEXUAL DIVERSITY IN 



BUTTERFLIES. 



Papillon, qui viens tic paraitre 

 Loi^quc ie soleil va pAlir, 

 Je plains le sort qui te fit naitro 

 Pour briller uiie lieure et muurir. 

 En vain tes ailes sont parses 

 Du reflet de niille couleurs, 

 Elles n' orncront pas les flours, 

 Depuls longtem]Js d6color6es. 

 Jamais tu ne boiras les pleurs 

 Que 1' aurorc venait r6pandre 

 Dans leur calices pleins de iniel, 

 Et jamais tu u' iras suspendre 

 A leur feuillaj^e d' un vert tendre 

 Ta robe oil se pcint 1' arc-en-ciel. 



Anon. 



If male and female butterflies of the same species always resembled 

 each other more than either resembled the same sex of an allied species, 

 the work of the systematist would be easy, and we may perhaps add, — 

 stupid. No such simplicity, no such stupidity is in store for him. Nature 

 is constantly perplexing him, piquing his curiosity, testing the sharpness 

 of his wit, and leading him on from one comparison or one conclusion to 

 another, till he finds himself confronted with questions of deepest interest 

 and wide purport. It matters little what branch of zoology a student 

 may follow ; modern science, with its new questions born of evolution, 

 will not leave the mind to stagnate. 



By secondary sexual diversity, or antigeny, as it may be more briefly 

 termed, is meant all such accessory peculiarities of one sex or the other as 

 are not directly connected with generation. They are multiform and multi- 

 tudinous. The lines of erect hairs on the upper surface of the wings of 

 some Satyrinae and Arynnidi, the gland-like spot at the base of the wings 

 or the powdery band at the margin in some Rhodoceridi, the little oval disk 

 near the middle of the front edge of the upper surface of the fore Avings of 

 most Theclidi, the pocket beside the first median nervule of the hind wings of 

 Anosia, the iimschlag or fold of the front edge of the fore wings in many 

 Hesperidi, and the velvety dash in the middle of the fore wings of nearly 

 all the Pamphilidi, always confined to the males, — these are all accessory 

 sexual peculiarities found on the wings alone, and are quite on a par with 

 the characteristic plumage of the males in many birds. Or, if one seek 

 something still closer, he may find it in the bristling front of the head of 

 the Theclidi. 



So when we come to color, and, to a certain very limited extent, to its 

 distribution in definite arrangement upon the surface of the wing, we find the 

 same thing. Here w-e may pass from the simplest imaginable distinctions 

 to those which are quite extraordinary. In Vanessa huntera, for example, 

 a slender, short, transverse stripe near the apex of the upper wings is white 

 in one sex and orange in the other ; nothing could be simpler than this, 



