LIFE HISTORIES OF CERTAIN BUTTERFLIES 89 
On September 20, 1915, it returned to a diet of cuticle, and 
very occasionally attacked the edge of a leaf. 
On September 22, 1915, it moulted again, and was inch 
long. 
On September 24, 1915, it again attacked pods, and began 
to feed up rapidly. 
It was full fed on September 28, 1915, when it was -J inch 
long. It kept its woodlouse shape and had few definite mark- 
ings ; the retractable head remained black and it was 
coloured almost exactly like the under-side of the leaf of 
the food-plant. It had a longitudinal darker dorsal stripe 
and a paler spiracular one with obscure diagonal stripes and 
specklings of paler green. 
On September 29, 1915, it spun up in the centre of the 
upper-side of a leaf of the food-plant on a small bed of silk 
with a very short girdle. At 6 p.m. on October 1 , 1915, it 
pupated after a larval existence of twenty-six days. 
Pupa . — The pupa is \ inch long and devoid of any peculiar 
markings or tubercles. The thorax is slightly keeled dor sally, 
and behind it there is a slight depression. It is coloured as 
the larva, only the wing-cases are a slightly darker green. 
There is a darker dorsal stripe running along its entire length. 
Near the insertion of the wings there are two tiny black dots, 
one above the other, followed by a longitudinal supra-spiracular 
row of seven black specks, the first two of which are much 
longer than the remainder. 
Imago . — The imago emerged at 9.45 a.m. on October 9, 1915, 
thus giving a pupal existence of about eight and a half days, 
and a total life cycle of thirty-eight days almost to the hour. 
Two days before emergence the wing-cases of the pupa became 
whitish and opaque, from which they passed into a faint salmon 
pink. They then rapidly darkened, and the colour of the 
imago was plainly visible the evening before emergence. 
The emergence itself is very rapid, and the little imago walks 
with considerable speed. It came to rest on a flower-head 
of grass with which I supplied it, and took post head 
downwards. In about three minutes it had pumped up 
its wings, which were then full-sized, and only required 
drying. 
