368 MR. E. B. POULTON ON THE COLOUR-RELATION BETWEEN EXPOSED 
Sept. 3, 11.30 a.m. . 
1 pinned np. 
1 pinned up. 
,, 1.5 P.M. . . 
55 
„ 4.45 p.m. 
55 
55 
2 pinned up. 
,, 6.15 p.m. 
55 
55 
1 fell off. 
4 pinned up. 
Sept. 4, 8.35 a.m. 
55 
55 
55 
2 pupated; some 
hours. 
„ 11.0 a.m. 
Pupated some 
55 
1 dead 
1 pupating. 
little time. 
. . 
„ 11.30 A.M. . 
Pupating 
* * 
No change. 
„ 1 p.m. . . 
* * 
1 pupating. 
Results:— 
Pupa was (3), 
Pupa was (5), 
2 first to pupate 
Compared Sept. 7. 
normal gold. 
golden, but not 
were dark (3) 
Thus Stage III. 
extreme for 
with rather 
very long, ap- 
this degree. 
unusually 
parently about 
Thus Stage III. 
bright gold for i 
22-23 hours. 
also very long, 
this degi'ee, but 1 
and at least 
the normal 
22 - 5 - hours. 
amount. 
2 next light (3), 
normal gold. 
The first two 
only passed 
about 8—9 hours 
in the light. 
The 3rd 16f 
hours, and the 
4th 18§ hours. 
The results of the experiment are certainly surprising, for I did not expect to find 
any indications of influence, and at the time of the experiment I did not think that 
there were any. I was then taking notes and making experiments every hour of the 
day, and had not time or opportunity to make allowance for the periods during which 
the larvae had been under any influence. However, when the notes are worked out 
in the above tabular form, there seems to be much reason for thinking; that some 
considerable effect was produced. The only two dark (3) among the pupae were those 
which were pinned up in the window long after the susceptible part of Stage III. had 
already passed, and the others, which were exposed for practically the whole of the 
stage, are certainly lighter than the normal forms. Had I realised these results at 
the time, I should have made other and much larger experiments, avoiding the source 
of error introduced by the proximity of the vertical light-coloured bar by suspending 
the pupae from fine threads. I hope to make such an experiment in the next season. 
The results are all the more remarkable because in Division A. it was shown that the 
powerful direct light had but little influence in opposition to the black surroundings. 
D. The rest of the larvae were almost entirely made use of in the conflicting colour 
experiments, towards which many other experiments had been leading. Two frames 
were made on precisely the same principle as a larger one, which will be described and 
illustrated in the next series, and therefore I need only give a mere outline of the 
