f to be tempted by the
adjacent green stuff before finishing the ritual repast whereat skin
bottles furnish forth the feast. It is the first time that I have seen
a larva make a meal of the sack in which it was born. Of what use can
this singular fare be to the budding caterpillar? I suspect as follows:
the leaves of the cabbage are waxed and slippery surfaces and nearly
always slant considerably. To graze on them without risking a fall,
which would be fatal in earliest childhood, is hardly possible unless
with moorings that afford a steady support. What is needed is bits of
silk stretched along the road as fast as progress is made, something
for the legs to grip, something to provide a good anchorage even when
the grub is upside down. The silk-tubes, where those moorings are
manufactured, must be very scantily supplied in a tiny, new-born
animal; and it is expedient that they be filled without delay with the
aid of a special form of nourishment. Then what shall the nature of the
first food be? Vegetable matter, slow to elaborate and niggardly in its
yield, does not fulfil the desired conditions at all well, for time
presses and we must trust ourselves safely to the slippery leaf. An
animal diet would be preferable: it is easier to digest and undergoes
chemical changes in a shorter time. The wrapper of the egg is of a
horny nature, as silk itself is. It will not take long to transform the
one into the other. The grub therefore tackles the remains of its egg
and turns it into silk to carry with it on its first journeys.

If my surmise is well-founded, there is reason to believe that, with a
view to speedily filling the silk-glands to which they look to supply
them with ropes, other caterpillars beginning their existence on smooth
and steeply-slanting leaves also take as their first mouthful the
membranous sack which is all that remains of the egg.

The whole of the platform of birth-sacks which was the first
camping-ground of the White Butterfly's family is razed to the ground;
naught remains but the round marks of the individual pieces that
composed it. The structure of piles has disappeared; the prints left by
the piles remain. The little caterpillars are now on the level of the
leaf which shall henceforth feed them. They are a pale orange-yellow,
with a sprinkling of white bristles. The head is a shiny black and
remarkably powerful; it already gives signs of the coming gluttony. The
little animal measures scarcely tw