108 THE ENTOMOLOGIST. 



reddish brown ; one portion of the blue on the apex of the wings 

 is deficient, and the black ground colour here becomes evident. 



On the hind wings the pale annulus surrounding the ocellus 

 disappears from the outer margin, and the dark ground colour 

 accordingly extends inwards. The under side of both fore and 

 hind wing becomes darker and more uniform in tint, whilst 

 nearly all the Fanessa-pattern, which is still indicated in the 

 normal form, is lost. 



h. Cold. 



(1) Pupse kept in the refrigerator 35 days produced the perfect 

 insect in 12 — 1-1 days afterwards, in the room ; 25 per cent, of the 

 butterflies were crippled. I have described this form in the 

 present Journal for Dec. 1st, 1892, as V. io, ab. Jischeri, and 

 have in the same place already drawn attention to the fact that 

 it is of especial interest as affording an insight into the way in 

 which the derivation of V. io from V. urtica, L., and its nearest 

 relatives has taken place, — an insight, that is to say, into phylo- 

 genetic relations. 



The chief characteristics of this form are : the reduction in 

 number of the blue scales on both fore and hind wings, and the 

 darker appearance of the outer margin in both wings. 



Besides this there occur on the fore wings, at the junction of 

 the outer border with the reddish brown ground colour, some 

 small isolated groups of deep black scales, mingled with which 

 appear a few detached blue scales. 



The black costal patch lying close to the root of the wing 

 undergoes a further extension inwards. 



On the under side the pattern is much more sharply defined 

 than in the normal, the elements of the pattern being largely 

 marked out in brown scales. 



All these characters of the pattern betoken an approach to 

 the type of V. urtica. 



(2) In addition to these features there occurred others in the 

 case of pupse kept for 42 days in the refrigerator, the butterflies 

 (of which only 10 per cent, were good specimens) emerging in 

 the room from 14 — 18 days later. These were as follows : — 



«. The ground colour of the wings showed a strong admixture 

 of yellow. 



13. In some individuals there appeared a black spot on the 

 dorsal margin of the fore wing, in exactly the same place as the 

 corresponding spot in V. urticce. 



7. The ocehus on the hind wing was frequently much reduced, 

 in some almost to the point of complete disappearance. 



S. The region which constitutes the middle of the ocellus at 

 the apex of the fore wing acquired numerous black scales, thus 

 resembling the corresponding black spot in F. urticce. 



e. In a number of individuals the brown scales on the under 

 side of both wings increased to such an extent that the character 



