ON MELANISM. 85 



wings. The nervures are blackish on the margins of all the 

 wings, but most distinctly so on the posterior pair, where they 

 project more or less into the white fringes. In females from the 

 Simplon there is scarcely a trace of a discoidal spot, no orange 

 markings on the fore wings, and but the slightest vestige of 

 orange on the hind wings ; whilst in other female examples from 

 the Valais the orange bands are bright and well-defined. 



In some specimens the under side coloration is similar to 

 that of icarus, whilst in others it more nearly approaches that of 

 bellargus. The basal ocelli are absent, and in the remaining 

 eyed-spots of some examples the black pupils are very large, but 

 in several others are not a whit larger than the black spots of 

 some Irish icarus. The white streak is present, but sometimes, 

 as in the other species previously noted, indistinct. 



Larva unknown. An alpine species, occurring in France, 

 Switzerland, Savoy, Piedmont, Spain, and Portugal. 



(To be continued.) 



ON MELANISM. 

 By J. Jenner Weir, F.L.S., F.Z.S., F.E S. 



I HAVE read and carefully studied Mr. Dobree's ver}' 

 instructive paper on this subject, which appeared in the 

 February number of the ' Entomologist,' pp. 25-28. 



So far as my limited knowledge extends there is no 

 connection between the tendency to melanic variation in 

 Lepidoptera and the high latitude they may have been produced 

 in, but, on the contrary, I find that, so far as the Lepidoptera of 

 Kussia in Europe are concerned, of the 300 sj^ecies I have 

 received from the neighbourhood of St. Petersburg, from the late 

 Mr. Field and Mr. Erschoif, none show the slightest melanism. 

 I am, not, however, disposed to think that this point " destroys 

 Lord Walsingham's latest and ingenious theory" on this subject, 

 as Mr. Dobree states, but modifies it, and confines the 

 phenomenon to the higher latitudes of the British Isles, and to 

 high altitudes. 



Lord Walsingham's theory of melanism in Le^jidoptera was 

 embodied in his address, as President of the Yorkshire Naturalists' 



