significance of wing -markings. 119 



rarely reaching forwards to the subcostal nervure ; in P. 

 atalanta as a similar but blunter process, easily visible 

 on the under side (fig. 42), but on the upper reduced to a 

 mere irregularity of the dark inner boundary of the red 

 streak. I. 5 is closely apposed to the disco-cellular 

 nervules, with an occasional intercalated patch of lighter 

 ground colour (as often in A. adippe), and forms the 

 innermost portion of the middle dark costal patch in the 

 Vanessas and Graptas. 



The markings in the discoidal cell of the hind wing 

 (I. 6 — 9) are normally four, or corresponding to I. 1, 2, 

 3 and 5. I. 6, like I. 1, occupies the angle between the 

 principal nervures of the wing, i. e., the subcostal and 

 the median ; I. 7 and 8 are often united into a more or 

 less regular ring ; I. 9, when present, consists of a 

 narrow dark border to the disco-cellular nervules (fig. 44). 

 These markings are, as we should expect, best seen in 

 the Argynnids ; in the Vanessas they are mostly merged 

 in the dark ground tint that pervades the base of the 

 wing. I. 6, 7 and 8, however, may be distinguished 

 on the under surface of V. polychloros, V. urticce, V. io, 

 and other species. 



7. Phylogenetic conclusions. — It now remains to put 

 together the results of the preceding investigation, and 

 to draw from them what conclusions seem possible as to 

 the phylogeny of the forms examined. 



It would appear, then, that all the lines which we 

 have been able to trace converge in the direction of a 

 dark olive or blue-coloured Argynnid like the female of 

 the recent A. diana* Possibly, were we able to go 

 back further still, we should find a type in which the 

 dark coloration was absolutely uniform, as it is over the 

 basal region of the wings in A. diana, no differentiation 

 into ground colour and spots having yet taken place. 

 From such a type as the last mentioned, the earliest 

 step in advance would be taken by the lightening of the 

 ground colour in patches between the nervures, the 

 original dark tint remaining as ill-defined streaks and 



* " The stem-form of the Nymphalidce must have possessed a 

 caterpillar approximately of the form that is now presented to us 

 by Acrcea . . . AcrcBa, the Heliconince, Argynnis still remain in 

 this stage of development." W. Mliller, " Siidamerikanische 

 Nymphalidenraupen," Zool. Jahrbllcher, Bd. i., p. 621. This is 

 confirmatory of the primitive character of Argynnis, 



