PSY CEH. 
EXPERIMENTS UPON THE EFFECT OF COLD APPLIED TO CHRYS- 
ALIDS OF BUTTERFLIES. 
BY WILLIAM HENRY EDWARDS, COALBURGH, W. VA. 
(Concluded from p. 19.) 
Between 26 Feb. and 19 March 1880, 
there emerged, in my house, 10 examples 
of Papilio ajax from the chrysalids sub- 
jected to cold for 14 and 20 days in 1879, 
as related on page 4. From the lot iced 
14 days emerged 2 %, 2 2; from that of 
20 days, 4 %, 2 9. 
From chrysalids of same laying of eggs, 
but which were not iced, emerged 4 % 8 
between 4 March and 30 March. Eight 
of the ten iced chrysalids gave butterflies 
before 2 March, and therefore 2 days be- 
fore any had come from the not iced lot. 
The other two emerged on 18 and 19 
March. 
On 4 April, I examined all these butter- 
flies and compared them with each other, 
and also with examples from same lot of 
eggs, the chrysalids of which had been 
iced and gave butterflies in 1879. 
1. Comparing with each other: all are 
telamonides. I found no difference in shape 
or coloration, between the examples iced 
and not iced. 
2. Comparing with examples from same 
lot of eggs, which emerged in 1879: these 
latter have the summer form (marcellus) 
with the coloration of the winter form 
(telamonides), wherever the change is 
complete ; and any change at all is in the 
direction of the winter form (p. 5, 6). 
The wings are all produced, the hind mar- 
gins of primaries concave ; the tails very 
long, averaging % 23.5 mm., 2 24.1 mm. 
The butterflies of 1880 have the wings 
much less produced, the hind margins 
straight or convex; the tails short, aver- 
aging, $ 18.1 mm., 2 20.3 mm. 
The icing apparently produced no effect 
on the chrysalids which passed the winter, 
except perhaps to hasten the appearance 
of the butterflies a few days. But the 
same treatment altered the markings of 
the butterflies which emerged in 1879. 
It does not appear that the effect of the 
cold was really to precipitate the emerging 
of any in 1879,—that is, to compel any 
which would naturally have emerged in 
1880, to do so in 1879. On examining 
the proportion of hibernating chrysalids 
from several broods of ajax, as recorded 
in Butterflies of N. A., v. 1, p. 11-13, I 
find that of all broods in and after May, 
about one-half the chrysalids gave butter- 
flies the same year. The figures are 14- 
39 [0.36], 10-17 [0.59], 6-10 [0.60], 40- 
