SOME NOTES ON MELANISM. 243 



it would seem to have divided very near the base ; but of the 

 latter (in which, as a rule, it can scarcely be traced) I have one 

 specimen, in which not merely a fold but an actual nervure 

 (representing the main stem and the upper part of the primary 

 fork) is visible, where the branch could only have sprung from 

 quite near the outer edge of the discoidal cell. The outer (as 

 opposed to the basal) ends of the primary fork are just visible at 

 the secondary branching in northern -parthenie, and in aurelia 

 and berisalensis (the upper one only in the last two), and more 

 conspicuously, as a rule, in dictynna, as well as in some species 

 of both the other groups. 



The four central cross nervules are really the secondary 

 bifurcations of iii, and join iiij to iii2, and iiig to iiig. 



iiii and iii^ are more nearly parallel — i. e. nearer to Dryas 

 papilla — in britomartis than in any other species of this group, 

 though perhaps not more so than in aurinia, in which, however, 

 they are much more curved, iii^ springs from near the corner 

 of the discoidal cell, the short cross nervule coming outwards 

 from the base at a sharp angle, in partlienie, deionc, herisalensis, 

 and dictyiinoides, and generally in athalia and dictynna ; in brito- 

 martis the cross nervule is more nearly, and sometimes quite, 

 at right angles with ii ; in asteria and varia iiij^ springs from the 

 corner of the cell or close to it, and almost as close in aurelia ; 

 this point of departure is also by no means unusual in atJialia 

 and dictynna. 



iiio is basally very close to iii^ in asteria and aurelia, less so 

 in deione, rather farther away in parthenie, and still more so in 

 athalia and berisalensis, more nearly parallel in varia, dictynna, 

 and dictynnoides, most widely separated in britomartis ; but it is 

 impossible to base any conclusion whatever on this characteristic, 

 as there is considerable variety in the matter in the specimens 

 of each species. 



iiig is perceptibly less curved at its basal end (even without a 

 lens) in aurelia than in any other species ; the curve is slightly 

 more abrupt in asteria, varia, and dictynna, and less so in deione, 

 berisalensis, and britomartis. 



(To be continued.) 



SOME NOTES ON MELANISM. 



By a. M. Stewart. 



. Recently while passing along the edge of a small wood, in 

 conversation with a gamekeeper friend, some remarks were 

 passed on the occasional appearance of a black rabbit amongst 

 those we saw around us. " Yes," my friend remarked, " wher- 

 ever you see so many black ones you may depend upon it the 

 stock is getting too much inbred. You see," he continued, " I 



