1867.] 149 
and examined by a low power, is found to contain a newly hatched 
larva ; some may be observed extended at full length in the egg-shell, 
whilst others are in a coiled position. 
The young larva has a very hyaline look, the mouth with a pinkish 
tinge, with a small white spot on each side of the back of the second 
segment, the dorsal vessel is white, but only visible on the 7th — 10th 
segments ; the head is somewhat wedge-shaped. As soon as the larva 
is sufficiently developed, it quits the egg-shell and pierces the cuticle of 
the leaf, and commences feeding on the parenchyma, where it is after- 
wards joined by its fellow larvae, and they continue feeding side by side 
in little communities, varying in numbers from two to twelve. The 
part of the leaf where the larvae are feeding becomes slightly dis- 
coloured, in consequence of the tissues having been devoured by the 
larvae, and thus gives the first outward indication of their presence.* 
If we take up a larva at this early period of its life, we find that, 
when dropped, it has not a silken cord ready to break its fall, but falls 
helplessly to the ground. 
After the first moult the head of the larva becomes roundish, and 
is slightly suiFused with pale brownish, and it has three minute dark 
brown marks on each side ; the mouth is brown, the body is white, but 
without its previously glassy look, the dorsal vessel is darker, and is 
traceable as far as the penultimate segment. 
When arrived at this stage of its development the larva is not 
content, as previously, with eating the mere surface juices of the 
parenchyma, but eats large trenches in the cellular tissues of the leaf 
always, however, taking care not to pierce the outer cuticle 
At the expiration of three or four days the 4th— 9th segments 
become dvill yellowish, the anterior and posterior segments still retaining 
their previous appearance. After the interval of one day the mouth 
of the larva becomes of a dull red, the whole of the body becomes 
white, and the dorsal vessel turns pale green ; in doing so, however, it 
imparts a greenish tinge to the body ; the larva now, for the first time, 
possesses the power of spinning a silken cord. 
By this time the leaf on which the larva and its companions have 
been feeding has become much blotched ; the larvae now enter upon a 
new phase of their existence, for, quitting the mine in w^hich they have 
hitherto lived by biting holes in the upper surface of the leaf, they 
[• It is at this period of its existence we can most easily check the ravages of this insect; we have 
but to pick the leaves that are just blotched, and we destroy all the larvse within thera. Each individual 
larva, if allowed to grow to its full size, would have destroyed or discoloured two or three Ulac leaves.— 
H.T. S.] 
