90 THE ENTOMOLOGIST. 



is simpl)'' that the ground colour of the wings is black, on which 

 ground colour the chestnut has been evolved by the same pro- 

 cesses which produced a similar chestnut on the whitish wing of 

 urticce. 



In another respect, also, I consider urticre an important link, 

 for the colour — in superficial appearance — is, as it were, interme- 

 diate between such dull colours as those of S. megcera, &c., on 

 the one hand, and the brilliant copper of the Lycsenidae, on the 

 other. Some hesitation might be felt in classing together such, 

 apparently, very different colours as those of P. virgaurea, 

 S. megcei'a, or C. pamphilus ; but very little violence to our 

 prejudices is done by classing together such colours as those of 

 virgaurea and urticce ; and from tirticce we have coloric transitions, 

 by easy stages, through Argyn7iis, Melifcea, and Epinephele, down 

 to the palest and dullest of colours. Moreover, the contrast of 

 virgaurea and pamphilus is no more than that of cardamines or 

 C. edusa and Abrax-as grossulariata, or the species of Terias. 



The remaining species (column 1) call, I think, for no further 

 remark at present. I will merely add that the species of Danais 

 are so richly endowed with the chestnut pigment, that one hour 

 is insufficient time for the total solution thereof. 



Now, as to the evolution of red from chestnut. My readers 

 are already pretty well aware of the grounds for holding that 

 atalanta red has not been evolved — as almost all other reds— 

 from yellow, but is descended from the chestnut of cardui. The 

 proofs are, I think, very conclusive ; indeed, we have a concursus 

 of both entomological and chemical evidence. 



The red does not — like all other reds— instantly turn yellow, 

 but becomes of a " cardui-hvovin " ; there is no reversion ; but 

 the pigment dissolves, just as does the chestnut of the other 

 Vanessa species. Moreover, from the entomological side, atalanta 

 and cardui are exceedingly closely allied — as the most cursory 

 inspection will show ; there is an intermediate Asiatic species, 

 V. indica, maiked like atalanta, but ivith the scarlet band replaced 

 by one of cardui-broivn ; and, lastly, in cardui itself we find a 

 delicate pink colour developed on the under surface. It seems 

 to me, therefore, very clear that atalanta-red is a derivative 

 of chestnut, and in this fact we have — as already pointed out — a 

 very strong proof of the intimate relationship in constitution between 

 the two pigments, chestnut and yellow. But why so conspicuous 

 and presumably serviceable colour as red, which is so constantly 

 developed by yellow species, has been so rarely developed by the 

 far more numerous chestnuts, is a puzzling problem that I must 

 confess myself totally unable to even conjecturally solve.* Some- 



* One experiment with atalanta has not yet been recorded. I treated several 

 ■wings with a strong solution of silver nitrate. The effect was to change the red of 

 atalanta into a very deep chocolate. It was this that induced me to experiment on 

 so many species — but unsuccessfully — with a (probably weaker) solution of this 

 reagent. See Entom. xxiii. p. 185. 



