between lepidopterous larve and their surroundings. 359 
From this date to the 29th the larve were fed upon 
Balsam Poplar, and then again upon Populus nigra. 
May 25th. Most of the larvee were changing the 3rd 
skin, and all were apparently dark. 
May 29th. All had changed the 3rd skin except 2, 
which were changing it. All were dark brown except 
the 2 latter, which, together with 1 which had just changed, 
were light brown. The average length was 14°25 mm. 
June 2nd. Four were changing the 4th skin; 5 were 
at various points in the 4th stage, with an average length 
of 20°75 mm.; 1 was in the Sth stage. All were brown, 
although not very dark. 
June 5th. Four were changing the 5th skin, 33:0 mm. 
long, and 1 at end of 5th stage. The latter was medium 
brown, the others 3 light brown and 1 green with light 
brown markings. The remaining 5 were much smaller, 
being all in the 4th stage, 8 dark brown and 2 light brown. 
June 14th. Five were nearly mature, 2 green sprinkled 
with distinct greyish dots much more numerous in the 
larger larva, which was practically mature and 55:0 mm. 
long. The ground-colour of this latter larva was bright 
green, the dorsal tubercles dark grey. Of the other 3 
large larvee, 1 was very light grey, almost whitish with 
darker dots and mottling, 2 were much darker, blackish 
rather than brown, with light grey markings. The largest 
of the set of smaller larvae was changing its 5th skin and 
ereenish-brown, 1 smaller in the 5th stage was green with 
dorsal brown line, 1 smaller still, chocolate brown. Two 
larve were still quite small, viz. 12°25 mm., and probably 
still in the 4th stage. Both were dark brown, but they 
appeared to be unhealthy. 
June 15th. The greenest, the whitish, and 1 dark larva 
had become mature and were removed. 
June 20th. One green larva mature and removed. Two 
in 6th stage, 1 dark with greyish markings not greatly 
developed, 1 intermediate, brownish-green ; 1 changing 
5th skin, green, 2 in 5th stage and lightish brown. 
June 22nd. The dark larva in 6th stage mature and 
was removed. Two larvie in 6th stage, 1 on green side of 
intermediate, viz. green clouded over but not entirely 
obscured by brown, 1 distinct green with a brown dorsal 
line and a little brown on the sides. Of the 2 smaller 
larvee, 1 was in the 5th stage and brownish-green, 1 in 
the 4th and lght brown. 
