THE METAMORPHOSIS
“ONCE inclosed in its cocoon, the caterpillar withers and shrivels up,
as if dying. First, the skin splits on the back; then, by repeated
convulsions that pull it this way and that, the worm with much
difficulty tears off its skin. With the skin comes everything: the case
of the skull, jaws, eyes, legs, stomach and the rest. It is a general
tearing-off. The ragged covering of the old body is finally pushed into
a corner of the cocoon.
“What do they find then in the cells of silk? Another caterpillar, a
butterfly? Neither. They find an almond shaped body, rounded at one end,
pointed at the other, of a leathery appearance, and called a chrysalis.
It is an intermediate state between the caterpillar and the butterfly.
There can be seen certain projections which already indicate the shape
of the future insect: at the large end can be distinguished the antennæ
and the wings tightly folded crosswise on the chrysalis.
“The larvæ of the June bug, capricorn, stag-beetle, and other beetles
pass through a similar state, but with more accentuated forms. The
different parts of the head, wings, legs delicately folded at their
sides, are very recognizable. But all is immobile, soft, white, or even
transparent as crystal. This insect in outline is called a nymph. The
name of chrysalis used for butterflies and that of nymph used for the
other insects signify the same thing under somewhat different
appearances. Both the chrysalis and the nymph are insects in process of
formation—insects closely wrapped in swaddling-clothes, under which is
finished the mysterious operation that will change their first structure
from top to bottom.
“In a couple of weeks, if the temperature is favorable, the chrysalis of
the silkworm opens like a ripe fruit, and from its burst shell the
butterfly escapes, all ragged, moist, scarcely able to stand on its
trembling legs. Open air is necessary for it to gain strength, to spread
and dry its wings. It must get out of the cocoon. But how? The
caterpillar has made the cocoon so solid and the butterfly is so weak!
Will it perish in its prison, the poor little thing? It would not be
worth the trouble of going through so much to stifle miserably in the
close cell, just as the end is attained!”
“Could it not tear the cocoon open with its teeth?” asked Emile.
“But, my innocent child, it has none, nor anything like them. It has
only a proboscis, incapable of the slightest effort.”
“With its claws then?” suggested Jules.
“Yes, if it had any strong enough. The trouble is, it is not provided
with any.”
“But it must be able to get out,” persisted Jules.
“Doubtless it will get out. Has not every creature resources in the
difficult moments of life! To break the hen’s egg that imprisons it, the
tiny little chicken has at the end of its beak a little hard point made
on purpose; and the butterfly is to have nothing to open its cocoon? Oh,
yes! But you would never guess the singular tool that it will use. It
will use its eyes—”
“Its eyes?” interrupted Claire in amazement.
“Yes. Insects’ eyes are covered with a cap of transparent horn, hard and
cut in facets. A magnifying glass is needed in order to distinguish
these facets, they are so fine; but, fine as they are, they have sharp
bones which all together can, in time of need, be used as a grater. The
butterfly begins then by moistening with a drop of saliva the point of
the cocoon it wishes to attack, and then, applying an eye to the spot
thus softened, it writhes, knocks, scratches, files. One by one the
threads of silk succumb to the rasping. The hole is made, the butterfly
comes out. What do you think about it? Do not animals sometimes have
intelligence enough for four? Which of us would have thought of forcing
the prison walls by striking them with the eye?”
“The butterfly must have studied a long time to think of that ingenious
way?” queried Emile.
“The butterfly does not study, does not reflect; it knows at once what
to do and how to do well whatever concerns it. Another has reflected for
it.”
“Who?”
“God himself! God, the great wise one. The silkworm butterfly is not
pretty. It is whitish, tun-bellied, heavy. It does not fly like the
others from flower to flower, for it takes no nourishment. As soon as it
is out of the cocoon, it sets to work laying eggs; then it dies.
Silkworm eggs are commonly called seed, a very good term, for the egg is
the seed of the animal as the seed is the egg of the plant. Egg and seed
correspond. They do not stifle all the cocoons in the vapor to wind them
afterwards; they keep out a certain number so as to obtain butterflies
and consequently eggs or seeds. These are the seeds which, the following
year, produce the fresh brood of worms.
“All insects that are metamorphosed pass through the four states that I
have just told you about: egg, larva, chrysalis or nymph, perfect
insect. The perfect insect lays its eggs, and the series of
transformations begins again.”
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