424 MR. E. B. POULTON ON THE COLOUR-RELATION BETWEEN EXPOSED 
Sept. 15, EVENING . 
Experiment began. 
,, 16, 7 p.m. 
5 P. B. girdled. 
„ 17, 7.30 p.m. 
2 P. B. pupated, 6 girdled; 2 P. R. 
girdled 
U nder 48 hours’ period for these 2 if it 
began with the experiment. 
„ 18, 7.52 p.m. 
8 P. B. pupated, 1 girdled ; 1 P. R. 
pupated, and 2 P. R. girdled 
So also under 72 hours for these addi¬ 
tional ones. 
,, 19, 8.52 p.m. 
9 P. B. pupated, 1 P. R. pupated; 
3 P. R. girdled, and 1 P. R. making- 
girdle. 
Results. —Nine pupae of P. brassicce were obtained, and— 
Of these, 1 was on the roof, and was. (1), /3, black patches normal, dusting rather 
less, and ground-colour rather more 
distinct than usual; yellowish-green, 
inclining to very pale orange in 
places. 
7 were on the side, fairly crowded, and 
all upon the upper f of the height 
of the cylinder ; of these .... 2 were (1),/3, 1 pale-greenish and 1 very pale orange; 
dusting less than usual; black spots 
normal on former, less than normal 
on latter. 
4 were (2), almost normal, but the ground-colour a 
little greener than usual. 
1 was (3), typical. 
1 was more isolated on the side, and was . . . (2), with normal ground-colour, but the black 
spots more developed than usual. 
Eight living pupae of P. rcipce were similarly compared, and— 
Of these, 2 were on the roof, of which .... 1 was a (5), very little pigment, and very pale greenish 
ground-colour; and 
1 „ (4), very little pigment, and a pale yellowish- 
pink ground-colour. 
1 pupa was on the side near the top, in 
the crowd of 7 P. brassicce described 
above, and it was a. (4), typical, with a greyish-yellow ground¬ 
colour. 
5 pupae were more isolated on the side, 
and of these.2 were (3), but both light for this degree, 1 with a 
yellowish - pink ground - colour, and 
1 with a dull, but distinct, greenish 
ground-colour. 
2 were (4), 1 typical, 1 with hardly any pigment; 
the ground-colour faintly yellowish-pink 
in both. 
1 was (5), of a distinct green ground-colour, but 
dull for this degree, and with the 
greyness and black patches of a light (3). 
