who possibly never takes
food. We find in both the same very short oesophagus, the same
chylific ventricle, empty in the perfect insect, distended in the
larva with an abundant orange-coloured pulp; in both the same
gall-bladders, four in number, connected with the rectum by one of
their extremities. Like the perfect insect, the larva is devoid of
salivary glands or any other similar apparatus. Its nervous system
comprises eleven ganglia, not counting the oesophageal collar, whereas
in the perfect insect there are only seven: three for the thorax, of
which the last two are contiguous, and four for the abdomen.

When its rations are finished the larva remains a few days in a
motionless condition, ejecting from time to time a few reddish
droppings until the digestive canal is completely cleared of its
orange-coloured pulp. Then the creature contracts itself, huddles
itself together; and before long we see coming detached from its body
a transparent, slightly crumpled and extremely fine pellicle, forming
a closed bag, in which the successive transformations will take place
henceforth. On this epidermal bag, this sort of transparent leather
bottle, formed by the larva's skin detached all of a piece, without a
slit of any kind, we can distinguish the several well-preserved
external organs: the head, with its antennae, mandibles, paws and
palpi; the thoracic segments, with their vestiges of legs; the
abdomen, with its chain of breathing-holes still connected one to
another by tracheal threads.

Then beneath this pellicle, which is so delicate that it can hardly
bear the most cautious touch, we see a soft, white mass taking shape,
a mass which in a few hours acquires a firm, horny consistency and a
vivid yellow hue. The transformation is now complete. Let us tear the
fine gauze bag enclosing the organism which has just come into being
and direct our investigation to this third form of the Sitaris-larva.

It is an inert, segmented body, with an oval outline, a horny
consistency, just like that of pupae and chrysalids, and a
bright-yellow colour, which we can best describe by likening it to
that of a lemon-drop. Its upper surface forms a double inclined plane
with a very blunt ridge; its lower surface is at first flat, but, as
the result of evaporation, becomes more concave daily, leaving a
projecting rim all around its oval outline. Lastly, its two
extremities or poles are slightly flattened. The major axis of the
lower su