LEPIDOPTEROUS PUPH1 AND THEIR SURROUNDING SURFACES. 
425 
These results are very uniform with those of Division A. The more numerous 
P. rapes in this division show that the green surroundings have some considerable 
effect, as one-fourth of the pupse were the green form (5). The bright yellowish-green 
variety of P. b?'assices, which was chiefly formed by the use of this background, is 
represented in Plate 26, fig. 28, X 2. 
C. 
September 13.—20 larvae of P. brassiccs and 10 of P. rapes were placed in a 
shallow wooden box (2'26 decimetres long, P3 decimetre wide, and 5’2 centimetres 
deep : all internal dimensions) lined internally with thick paper tinted with a pale 
bluish-green colour, which became whiter owing to the pigment being removed in 
many places. The box was made to stand on one of its long sides and covered with a 
sheet of clear glass, and it was placed close to the window, so that a strong north-east 
light was directed into the interior. Notes were taken at the following hours :— 
Sept. 13, 9.50 p.m. 
Experiment began. 
„ 16, 6.5 p.m. 
1 P. B. pupated ; 5 girdled. The box 
was inclined backwards at an angle of 
about 45°, so that the roof was illumi¬ 
nated to an extent equal to that of 
the rest of the box, for the larvse 
tended to collect on the roof for 
pupation. 
Under 72 hours for the 1 pupated, if 
the period began with the experiment. 
„ 17, 8.15 p.m. 
4 P. B. pupated, 8 girdled; 3 P. R. 
girdled 
Under 95 hours for these additional ones. 
,, 18, 9.15 p.m. 
7. P. B. pupated, 7 girdled; 3 P. R. 
pupated and 2 P. R. girdled. 
,, 19, 9.25 p.m. 
10 P. B. pupated, 2 girdled; 3 P. R. 
pupated and 2 P. R. girdled. 
Results .—11 living pupse of P. brassices were obtained. 
7 were crowded in a corner of the roof, 
and all. were (1), (3, 
1 pupa was isolated on another part of 
the roof, and. was (1), /3, 
3 pupse were isolated on the clear glass 
front, and of these.2 were (1), a, 
1 was (1), /3, 
3 I 
with normal black patches, but the ground-colour 
a peculiar greenish-white, very opaque-looking, 
much dusted with grey, as usual: with a slight 
orange tinge in 1 pupa, and 2 pupse rather 
more yellowish-green than the others. 
like the others, and especially resembling the 
2 last described. 
one of them faintly orange, the other pale 
greenish, rather unusually distinct, because 
the grey dusting, although very pronounced, 
was locally collected into bands and patches, 
leaving the colour comparatively undimmed 
between them. 
resembling the 3 last described of this degree, 
only a brighter colour than any others, because 
of the comparative absence of the grey dusting: 
a bright yellowish-green. 
MDCCCLXXX VII.—B. 
