between lepidojpteroVjS lain:iB and their surroundings. 363 



of black twigs. The larvte were of a very uniform length 

 of 8'5 mm. 



May 2oth. Six were found on the black twigs, the rest 

 on the leaves. Ten larvae, all about 140 mm. long, at the 

 end of the 3rd stage, and mostly changing the 3rd skin, 

 were transferred to green surroundings (C). The remain- 

 ing larva? 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 larva; 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. 



'Tune 2nd. Four larvas on the twigs. Tvro were chang- 

 ing 4th skin, and 8 at various degrees of development in 

 the 4th stage. All brown and the largest larvae verv dark 

 brown. 



'June 'Srd. Onlv 1 on the twias. Two had now chiinofed 

 4th skin on the 2nd, and were transferred to orreen sur- 

 roundings (C^) : 1 was very black, the other a medium 

 brown. 



J'une 4th. Three on twigs. All larva? in 4th stage, all 

 bro"«Ti of various shades : those on the twigs very black. 



'Tune oth. Only 1 on twigs and that a light 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 7th. Two on twigs, dark and medium bro%\Ti. The 

 latter was changing its 4th skin and was transferred to 

 green (C^), together with another dark brown larva 

 which had just entered the oth stage. The remainder 

 were as last described, and all were advancingr in the 4th 

 stage. 



June l-ith. Two were on the twigs ; both in the -5th 

 stage, one dark greyish-brown and the other dark chocolate- 

 bro^^-n. Two were on the leaves, both in the oth stage and 

 grevish-brown, lio-hter than the former two. 



Ju/u: 20th. Two large in the 6th stage and very dark. 



'June 26th. Four in the 6 th stage and all veiy dark 

 indeed. 



'July 2nd. Two of the dark larva? had become mature 

 and were removed. The remaining larva? were very black 

 and nearlv mature. 



