8 THE CANADIAN ENTOMOLOGIST. 



flies to believe that temperature exerts the greatest influence during the 

 turning into chrysalis, but nearly as much shortly afl:er that time ; and he 

 considers it very possible that a period may be fixed at which the original 

 tendency might be diverted more strongly. As related above, the chrysa. 

 lids of tharos which were subjected to cold three hours after forming 

 reached the same result as those which were exposed six and nine hours 

 after forming. The period of exposure, 7 days, did not seem to me at 

 the time very long for the purpose in view, especially as in Dr. Weismann's 

 experiments the exposure had been from 34 days to three months. This 

 too at a temperature of 2,Z° Far., while in case of tharos it was but 40°. 

 It is true, the greater part of the chrysalids of tharos which did not have 

 an exposure to this artificial temperature also produced the winter form 

 of the butterfly, but on the other hand some were not changed at all, 

 whereas in all the chrysalids subjected to ice the change was complete and 

 extreme. Nevertheless it would have been more satisfactory had chrysalids 

 of the summer brood been experimented with, and if I live to another 

 summer, I will test the matter. It seems to me very probable that a much 

 shorter exposure to cold immediately after the forming of the chrysalis 

 — a day or two, or even a {q\y hours — may be found to divert the direction 

 of the form, in this species. 



There is a very great range of variation in the winter form. 'It 

 exhibits at least four well marked types, and there are sub-varieties about 

 each of, and connecting, these. The first, A, has the basal area of under 

 side of hind wings (which area comprises half the wings, and is occupied 

 by the reticulated lines, while beyond is a clear field for a certain space) 

 whitened or silvered, as is also the whole series of sub-marginal crescents, 

 and there is either no marginal cloud, or bu' " e slightest ; the extra basal 

 space buff. A sub-var. of this has the basal area whitened, but the rest 

 of the wing clouded, and is between A and B. The second, B, has the 

 whole surface, except a narrow border along costal margin, dark brown, 

 running into blackish, but with a clear white or yellow belt formed of the 

 outer reticulated lines, across the disk. Its principal sub-variety has the 

 brown area broken, discovering a yellow ground, the belt remaining white, 

 and is between B and C. ^The third, C, is variegated and gay, the ground 

 being of a deep rich yellow, the marginal cloud extended quite to the belt, 

 and ferruginous in color ; a large patch on the disk and]|another on costal 

 margin, both ferruginous; the reticulated lines of same color and distance, 

 and a lilac flush over the whole hind margin. Sub-varieties of this have the 



