lemdopterous larvae and pupae and their surroundings. 143 
Il. Transference experiments. 
In order to find out to what extent the larvae were 
susceptible after hibernation, some were taken from the 
black surroundings in B, and given white sticks as in C. 
In the same way some were taken from C and put into a 
case containing black sticks. The results are best shown 
by a table. One curious point is that the white sticks 
produced their full effect sooner than the dark ones, 
whereas in the experiments on the early stages the reverse 
was the case. 
TABLE II. 
DATE IN Bl cl 
1910. WHITE STICKS. BLACK STICKS, 
March 11. | 8 introduced from B. 5 introduced from C. 
April 27. | 1 lightest form (as in C). | 2 still as light as C. 1 of 
3 nearly light, as C.| thesesmall. 2lightpink- 
1 slightly darker. ish brown. 2 smaller 
and rather darker. 
April 28. | All but 1 as light as C. 
This one nearly so. 
April 30. | Retwrned to black sticks. All as before. 
May 5. 4still as light as C. 1 much | 
darker. | 
June 13. | No change. All pupating.| All pupating. | 
Ill. Eaperiments on the pupa of U. sambucaria. 
When the first of the larvae used on the previous 
experiments began to spin, all were arranged in various 
environments with a view to testing the susceptibility of 
the pupae. In the first set (Table III) the larvae were 
left in the same environments that they had hitherto 
occupied. The results of this set show clearly enough 
that when the same conditions are continued, the pupae 
are as well adapted to them as were the larvae. What 
they do not show is to what period of susceptibility the 
adjustment is due. Prof. Poulton thinks that it is effected 
just before pupation, and independently of the previous 
environment of the larvae. The results shown in Table 
