350 
MR. E. B. POULTON ON THE COLOUR-RELATION BETWEEN EXPOSED 
A. The 12 larvte were made use of for this experiment, of which an account is given 
below : — 
Dates, &c. 
(a) Blinded larvae. 
(13) Unblinded larvae. 
Aug. 26, 9.35 p.m. . 
6 larvae blinded and placed in left com- 
6 normal larvae placed in the right com- 
partment of the gilt box already 
described 
partment. 
,, 10.55 p.m. . 
No change. 
2 on roof, resting, and another wandering 
(Stage I. ended about 10.15 p.m.). 
,, 11.25 p.m. . 
4 on roof, resting, and 1 wandering 
(Stage I. of 2 more ended about 
11.10 P.M.). 
Aug. 27, 9.40 a.m. . 
5 on sides or roof, 1 feeding .... 
4 still on roof, resting; 1 on back, 1 on 
food-plant. 
„ 12 NOON . 
4 on roof, 1 on side. 
5 on roof (Stage I. of 1 more ended 
about 10.50 a.m.) . 
„ 1.15 P.M. . 
6 on roof (1 changed position later) . . 
2 suspended (about 12.37 p.m.), 1 on 
food-plant. 
„ 4.7 p.m. . 
4 suspended (about 2.40 p.m.) .... 
5 suspended ; 1 of them is the larva on 
the food-plant. (3 about 2.40 p.m.) 
,, 5.55 p.m. . 
5 suspended (about 5 p.m.). 
All 6 suspended (1 about 5 p.m.). 
„ 10.58 p.m. . 
5 suspended . 
All 6 suspended. 
Aug. 28, 10 a.m. 
5 pupated some few hours (about 7 A.M.), 
All pupated some few hours (about 
the 6th died. Hence Stage III. lasted 
about 16 houi’S in the case of 4 larvae, 
7 a.m.). Results will be given below. 
and about 14 hours in the case of the 5th 
Results, pupa3 com- 
1 pupa, isolated on side, was very light 
4 pupae were arranged in an irregular 
pared Aug. 29. 
(3), nearly (4) 
(not crowded) line along one side of 
4 near together on roof, but not crowded ; 
roof: of these 3 were (4), normal. 
of these 1 external pupa is (4), normal. 
1 was very light (3). 
The other, external, is light (3). 
The 2 internal ones are light (3). 
5 
The whole period may have lasted about 
pink, not unusual 
gold. 
1 was isolated on other side 
30 hours, but the position of the com- 
of roof, and was . . . (5), typical. 
mencement cannot be estimated with 
1 was hanging from food- 
any accuracy. 
plant, and was .... (4). 
6 
Although the (a) subdivisions are not so brilliant as the (/3), they are none of them 
dark pupae, and there is nothing in the difference which can justify the theory that 
the ocelli are the larval organs influenced by the surrounding colours in the pre¬ 
paratory period. 
The experiment also throws much light on the duration of the preparatory period 
and its stages. In the (a) subdivision the process of blinding probably disturbed the 
larvae and prevented the normal beginning of Stage I., until it was too late to observe 
it, and hence the length of Stage III. is alone obtained with any degree of accuracy 
from these larvae. But the normal larvae yielded far more precise results, which are 
shown below :— 
