1876.1 m 



111 its general figure, the egg is semi-spherical, convex above and flattish beneath, 

 its surface very finely reticulated ; creamy-wliite in colour, with the margin at the 

 base of the shell colourless and pellucid in contrast to the opacity of the rest, over 

 which the shell is glistening. On the evening of the 1st of June, without the eggs 

 showing any previous change of colour, the larva; began to hatch, four of them 

 within half an hour of dusk, the others in course of the night ; the young larvae were 

 nearly one-eighth of an inch long, of a pale pellucid-straw colour, inclining a little to 

 greenish, the segmental folds sliowing pale yellow ; by June 5th, they were three- 

 sixteenths of an inch long, and one or two had, by this time, united the poplar 

 leaves by short, thick, silken attachments, and they were all feeding on the green 

 cuticle. By the 12th, the most forward were half an inch in length, and others 

 about three-eighths, these last showed a black dot on each side of the second segment, 

 while those half an inch long had a black dot on each side of the second, third, 

 fourth, eleventh, and twelfth segments ; the head buff colour, and body of greenish- 

 buff, with a broad green velvety interior sliowing through the semi-transparent skin ; 

 up to this time, they had been eating away the cuticle from both upper- and under- 

 sides of the leaves fastened by detached threads one upon the other; henceforward, 

 they began and continued to eat quite through the substance of the leaves from the 

 edges, but each larva Avas always concealed between two leaves united by a couple of 

 strong, broad based, short, stud-like fastenings of white silk ; in this retreat, when 

 not feeding, the larva reposes with its body curved round ; — and here, also, when 

 the time for a moult approaches, it lies in a close coil, its head resting on the middle 

 of one side of the body. 



Particularly noticing a larva, which moulted on June 27th, I observed the body 

 to be very soft and delicate, velvety in appearance, of a pale buff tint ; the head of 

 pale honey-yellow, rather glistening, with black ocelli, and black on each side the 

 mouth ; two black dots, one above the other, on the side of the second and third 

 segments, and one on the fourth, another also on the twelfth segment. After the 

 last moult, when the larvae measured full an inch long, their heads were pale brownish- 

 orange, broadly marked with black at the sides of the mouth, and round the papillae, 

 the skin of the body still soft in texture, without the least gloss excepting a narrow 

 shining plate behind the head, which is slightly glistening, and the anal flap and 

 legs ; the colour of the body delicate greyish-green, showing through a pale buff 

 skin, the dorsal vessel seen pulsating distinctly, the spiracles flesh colour, and the 

 colouring along their region pale yellowish, the black dots just as before. 



By the 4th of July, two larvae had spun up, the two others were still feeding — 

 the rest having died off one at a time at different stages, probably from being so often 

 interrupted by my investigations. Even at the last, when mature, the habit of the 

 lai-va is still to lie curled round, with its head inwards, and towards, or in contact 

 with, the seventh or eighth segment of its body ; I found also that when turned 

 out from its domicile between two leaves, the larva, when placed on a fresh leaf and 

 another laid over, would quickly spin new fastenings, but it was not easy to watch 

 its proceedings, for, when I raised the upper leaf, but a very little, in order to peep, 

 the larva would directly strengthen and shorten the silk stud that I had probably 

 stretched ; and it did so by taking the middle or thinnest part between its two front 

 legs, and pulling it inwards towards its body, and holding it there dextei'ously, 

 whilst it spun shorter threads in a moment or two to the surface of the leaves, bring- 



