166 Proceedings of the Royal Physical Society. 
Three or four micropyles indicate the cephalic end of the ego A 
glandular secretion supplied at the time of ovi-position ensures adherence 
to the leaf. If the egg be detached the impression of the guard-cells of the 
stomata is plainly visible on its under surface. When the envelopes 
of the egg are removed under a dissecting microscope it is found that 
closely investing the yolk is still another coat, the serosa, consisting 
of a firm layer of epithelial-like cells with large nuclei. The orange- 
coloured appearance of the yolk is largely due to the tint of the serosa. — 
The envelopes are so impervious that eggs which had been placed for six 
hours in 80 per cent. alcohol hatched out afterwards; and an egg a few hours 
old was seen to go through the usual early embryonic changes while lying in 
Bles’s fixative. 
The Larva emerges from the egg by gnawing an exit hole in the chorion, 
a process lasting from half an hour to one hour. When first hatched the 
larva is under 2 mm. in length, of a yellow colour with a blackish head. 
The yellow colour is maintained through the first and second instars. The 
newly emerged caterpillars wander away at once in search of food, and soon 
reach the opening buds. The little larve are, however, quite able to eat leaves 
of the last year’s growth, as was proved by depriving a small plant of all its 
buds. The larvee which hatched from eggs on this tree made their way to the 
ends of the shoots, and finding no buds nourished themselves quite well upon 
the leaves of the previous year. 
For the first few days the larve crawl about the outermost leaves 
of the buds, which at the time when the eggs of #. nevana are hatching 
out are still very small. A careful scrutiny of buds, with a 
hand lens, will reveal the presence of frass, and the fact that minute 
depredations are already being wrought on the outermost leaves. When 
the larvee have reached a length of 24 mm., having gained also proportionately 
in girth (usually in about a week), they moult for the first time. Larvee 
about to moult stop eating and encase themselves in a very delicate sheath 
of threads. At each subsequent moult the sheath woven for the occasion 
is thicker than that spun for the previous ecdysis. There are four instars 
of larval life; and after each moult, except the fourth, the larva devours its 
cast skin, leaving only the mask. I have a micro-preparation of a newly- 
moulted larva of the second instar, in the alimentary canal of which can be 
clearly seen the exuvia, with all six legs still attached. | 
In the second instar, the larva, except in the matter of size, has changed 
little in appearance. During this instar, which lasts: about twelve days, 
1 The more intimate observations on the habits of the larva: were made on specimens 
reared on pot plants, kept under observation in a cool greenhouse. 
