between lepidopterous larve and their surroundings. 363 
of black twigs. The larve were of a very uniform length 
of 85 mm. 
May 25th. Six were found on the black twigs, the rest 
on the leaves. Ten larvie, all about 140 mm. long, at the 
end of the 3rd_ stage, and mostly changing the 38rd skin, 
were transferred to green surroundings (C). The remain- 
ing larvie were fed on Balsam Poplar from May 20th until 
the 29th. Green forms had begun to appear among the 
brown. 
May 29th. Only 1 on black twigs. Seven larvee were at 
the beginning of the 4th stage, 6 dark and 1 greenish. 
Two were changing the 3rd skin and 1 nearly mature in 
the 3rd stage. 
June 2nd. Four larvee on the twigs. Two were chang- 
ing 4th skin, and 8 at various degrees of development in 
the 4th stage. All brown and the largest larvee very dark 
brown. 
June 3rd. Only 1 on the twigs. Two had now changed 
4th skin on the 2nd, and were transferred to green sur- 
roundings (C1): 1 was very black, the other a medium 
brown. 
June 4th. Three on twigs. All larvee in 4th stage, all 
brown of various shades: those on the twigs very black. 
June 5th. Only 1 on twigs and that a hght brown one. 
One light brown larva changing 4th skin and transferred to 
green surroundings (C'). Five in the 4th stage, including 
1 dark brown larva which had just died, 1 in 3rd stage. 
All brown (more or less dark). 
June Tth. 'Two on twigs, dark and medium brown. The 
latter was changing its 4th skin and was transferred to 
green (C1), together with another dark brown larva 
which had just entered the 5th stage. The remainder 
were as last described, and all were advancing in the 4th 
stage. 
June 14th. Two were on the twigs; both in the 5th 
stage, one dark greyish-brown and the other dark chocolate- 
brown. ‘Two were on the leaves, both in the 5th stage and 
greyish-brown, lighter than the former two. 
June 20th. Two large in the 6th stage and very dark. 
June 26th. Four in the 6th stage and all very dark 
indeed. 
July 2nd. Two of the dark larvee had become mature 
and were removed. The remaining larvee were very black 
and nearly mature. 
