364 Professor E. B. Poulton on colour-relation 



July 12th. The 2 last larvae had forced their way through 

 the hole in the plate and were drowned. Their appearance 

 had not changed, and it is probable that they had become 

 mature and began to wander. 



CONCLUSIONS. 



In the final result we probably see the full and cliar- 

 acteristic effect of the black twigs unmodified by the green 

 environment in which the two youngest stages were 

 passed. 



B-. A. Ijctularia. 



May 25th. Fifteen hcfnlaria larvag transferred from green 

 to black ; all chanoino- the 3rd .skin and 140 mm. lono-. 

 Some were becoming greenish, but most were brown. 



May 29th. All examined : the colour varied very greatly, 

 but none were altocjether oreen althouodi there was much 

 green ground-colour on some. All were in the 4th stage ; 

 1 only on the black twigs and that happened to be a 

 particularly green one. Many light brown and many dark 

 brown. 



Jnne 2nd. Five on twigs, 3 in the 5th stage, 1 chan^- 

 ing 4th skin, and 1 nearly at end of 4th stage. The 

 latter and 1 in the oth stag^e dark grreenish-brown. the 

 remaining 3 very dark brown. On the leaves and green 

 stems there were in the 5th stage, 1 green, 3 light brownish- 

 green, and 2 light brown (1 slightly greenish) ; in the 4th 

 stage, 2 brownish-green and 2 medium brown. 



June 5th. On the black twigs there were 8 larvae, 7 in 

 the 5th stage (3 of them changing the 5th skin), 5 dark 

 brown, 1 bright green (changing skin), and 1 brownish- 

 green (half-grown in stage) ; 1 in 4th stage and brownish- 

 green. On the light brown stem of P. nigra was a single 

 larva which harmonized with it very exactly. On the 

 leaves were 5 larva;, 2 small in the 5th stage and light 

 brown, 3 in the 4th, 1 dark (changing the 4th skin), 1 

 brownish-crreen, and 1 orreenish-brown. 



June 14:th. Six larva; in the 6th stage were on the 

 twigs and very deep black, some of them with a small 

 amount of greyish markings. One similar larva on 

 greeu : 1 larva in the 6th stage on green was of a 

 uniform dull light grey tint : of 2 larva? in the 5th stage, 

 1 was changing the 5th skin and light brown overspread 



