THE EARLIER STAGES OF COLIAS HECLA. 85 
take it out of doors, so that it might get some approach to its 
natural home conditions in winter, and afterwards to force it, 
but the winter turned out to be exceptionally mild, and by 
January 23th, there not having been any frost, I brought the 
larva up and placed itin a warm room. I didnot have a plant of 
A. alpinus in leaf, and so offered the larva young leaves of Colutea 
arborescens, which I had ascertained the previous summer it 
would eat. On January 22nd it commenced to feed upon 
these, and fed very slowly for several weeks, so slowly, however, 
that its daily meal, which was usually taken when the sun was 
shining, did not exceed a notch in a leaflet the size of an average 
pin’s head. In the beginning of March it sickened and died. 
During the time it was feeding in the winter the size only in- 
creased a very little, not more than a millimeter in length. In all 
probability, to successfully rear this larva would entail its being 
kept at a temperature below freezing point for several months. 
In its natural habitat the snow would probably be gone by 
the middle of May. Staudinger mentions that at Bossekop the 
first male was taken on June 18th, 1860, but it certainly was not 
out there on the day I left, June 22nd, 1912. On my arrival at 
Laxely on July 11th, fully one-third of the specimens flying 
about were more or less worn. The season was rather a late 
one, and I should say that June 20th, as the first date of emer- 
gence on an average season, is probably not far wrong. 
Astragalus alpinus in Lapland entirely loses all trace of 
foliage in the winter, and until the middle of June, or rather 
later, it does not develop sufficient new leaves to feed the larva 
upon; this being the case, there seem to be three possible 
theories of its behaviour after hibernation :— 
(1) That it has an alternative food-plant. Ido not think this 
probable for, as before stated, I could not find another leguminous 
plant in its haunts, and one cannot imagine it feeding upon 
anything else. 
(2) That it feeds upon the roots of A. alpinus. This is pos- 
sible, for this plant has long succulent roots, very much after the 
style of Lotus corniculatus. 
(3) That it feeds very slowly through the summer on the 
leaves of A. alpinus, hibernating a second time, either as a full- 
fed larva or as a pupa. Iam inclined to think that this latter 
theory will prove the correct one. The larva I had in confine- 
ment seemed perfectly healthy and satisfied with its daily 
minute meal for weeks, which is just what one would expect it 
to do in a state of nature if this theory be correct, for the leaves 
until the middle of June are very minute and would not suflice 
to satisfy a more vigorous appetite. But, of course, my larva 
had not been subjected to its natural low winter temperature for 
many months, and one does not know what effect the unusual 
treatment received might have had upon its appetite. 
Youlgreave, South Croydon: January 13th, 1914. 
