366 MR. E. B. POULTON ON THE COLOUR-RELATION BETWEEN EXPOSED 
surfaces, which this experiment shows to be decidedly efficacious, although not quite 
equal to the same surface in darkness. 
B. The object of this experiment was to test the effect of gilt surroundings on 
larvae when they were exposed to its influence for the whole of the preparatory 
period as compared with exposure during Stage III. only. This was accomplished by 
placing eight mature larvae with food in one compartment of the gilt box, and trans¬ 
ferring recently suspended larvae to the same compartment, where they were pinned 
against the gilt side. Both subdivisions were taken from the stock under clear glass 
in large cylinders. The experiment was conducted as follows :— 
Dates, &c. 
(a) 8 larvae exposed to gilt surroundings 
for preparatory period. 
(/3) 3 larvae exposed to gilt surroundings for Stage III. 
Sept. 3, MORNING 
2 suspended larvae pinned in compartment 
„ 11.27 A.M. 
8 larvae placed in the compartment 
within few minutes of beginning of suspen¬ 
sion. 
No change. 
,, 3 P.M. . . 
1 suspended, 3 resting on roof, 1 
55 
„ 6.15 P.M. . 
wandering, 3 feeding 
No change . 
„ 11 P.M. 
3 suspended, 4 resting on roof . 
59 
Sept. 4, 8.35 a.m. . 
4 „ 3 „ „ . . 
2 have pupated 2 or 3 
„ 1 P.M. . . 
,, 1.10 P.M. . 
3 ,, 2 ,, ,, 
55 59 55 * 
hours. (Hence about 
20 hours were passed 
in the compartment.) 
Another suspended 
„ 1.35 p.m. . 
1 has just pupated. (Hence Stage 
larva added. 
No change. 
„ 4.15 p.m. . 
III. is probably very nearly 24 
hours long.) 
1 has just pupated. (Hence Stage 
55 
,, 8.50 p.m. . 
III. probably about 19-20 hours.) 
It has just pupated. 
Results: compared 
1 pupa suspended to side, near the 
Both pupae were light 
It is a dark (3). 
Sept. 7. 
pinned ones, was (4), with normal 
(3), 1 of them very 
Red in lower part of 
gold. 
red and black in 
abdomen. 
Of 5 pupae suspended on roof, 1 was 
lower part of abdo- 
This larva, having 
very dark (3). 
men (? diseased). 
been only about 7-| 
2 were light (3) with little gold. 
These larvae must have 
hours in the box, 
2 were (4), 1 with normal gold, 
spent very nearly all 
appears to have been 
and 1 with little. 
Stage III. in the 
unaffected. 
There is no note of pupations later 
than the above 2. 2 larvae died. 
box, and seem to 
have been somewhat 
affected. 
