VAEIATION AND ABEERATION IN BUTTERFLIES. 143 



The three bla-ik spots formhig a diagonal band across the 

 fore wing become considerably reduced, and in many individuals 

 the whole of the dorsal margin is coloured red, besides which 

 the base of the wing, which is usually conspicuously darker, is 

 rendered much lighter by the prevalence of red scales. 



In the same way the hind wing becomes predominantly red- 

 dish brown. The four or five spots which correspond to the 

 ocelli on the under surface never show, in this form, blue scales 

 in their centres. 



Under side. — Here also, as on the upper surface, all the 

 blackish-brown colouring is diminished in consequence of an 

 increase in the tints of red and reddish brown. 



The pattern of the apex of the fore wing and of the whole of 

 the hind wing, which both follow the same scheme, also becomes 

 considerably lighter, but there is no noteworthy difference in the 

 individual features of the pattern. 



h. Cold. (Larvae again all from Zurich.) 



(1) Twenty-three days refrigerator, then 12 days longer at 

 the normal temperature. 



This gave rise to a very recognisable darkening of the whole 

 insect, on both surfaces of each pair of wings. 



Most of the specimens resemble a form received by me from 

 Lapland, from the natural history dealer Kricheldorff, of Berlin, 

 now dead. 



A number of specimens go further than this form along the 

 same line of development. 



Upper surface. — The blackish-brown constituents of the pat- 

 tern in the fore wing encroach far upon the red area, this latter 

 in many specimens acquiring a tinge of light carmine. More- 

 over, those parts of the wing that remain red become shaded 

 over with a rich besprinkling of blackish-brown scales, only one 

 red spot before the end of the central cell being unaffected by 

 this overclouding. 



The large white costal spot is also in some specimens darkened 

 by a powdering of blackish-grey scales. 



The hind wings correspond in character to the fore wings. A 

 small spot before the end of the central cell is the only one in the 

 basal region that invariably remains red ; the portion of the 

 wing, however, between the row of [submarginal] spots and the 

 outer margin does the same. 



There is in these forms a frequent centring of the spots with 

 greyish-blue scales, especially towards the anal angle. 



Under side. — In most specimens the elements of the pattern 

 are changed very slightly, or scarcely at all ; the whole of the 

 yellowish and light brown colouring, however, becomes much 

 darker, whilst those parts that are almost white remain un- 



N 2 



