CATERPILLARS AND BUTTERFLIES
“Of all insects butterflies are the most graceful, the most worthy of
childhood’s eager desire. Oh, how beautiful they are! Poised on a
flower, they seem to form a part of it and to animate it with the
gentle beating of their wings. You cautiously draw near, you crouch
down and make a quick clutch with the hand, but the beautiful creature
is no longer there. It is waiting for you on another flower, quite
unconcerned at your designs on its freedom. Let us leave it, then, to
flit from one cluster of lilacs to another, and occupy ourselves a
while with an account of its structure and habits.
“All butterflies have four wings suitable for flying, two upper and
larger ones, and two lower ones half hidden under the others. Here we
find no horny sheaths such as are worn by the scarab and the June-bug,
no protecting case under which the membranous wings are folded to guard
against laceration. The scarab is a clod-hopper, well acquainted with
the harsh irregularities of the ground. He pursues his plodding course
on foot, and it is only rarely that he spreads his wings in flight. The
butterfly is a delicate creature of the air, very seldom using its legs
for walking, but finding them of service when it alights upon a flower.
It has, therefore, four broad wings, wide-spread and always ready for
flight.
“And what wings! Words are lacking to describe them fitly. Some are
white as if coated with flour, others sky-blue, and still others
sulphur-yellow. Again you find them of a flame-like red or dark
crimson. Some have round spots like eyes, which look at you with their
large pupils encircled by azure, mother-of-pearl, or gold; and you will
see others speckled with black, adorned with silver lace, or fringed
with carmine. If you touch them they leave on your fingers a brilliant
powder beside which the filings of the precious metals would look dull.
“This dust might be called the butterfly’s plumage. It consists of
scales of extreme delicacy, placed regularly side by side like the
tiles on a roof, and attached by one end to the membrane of the wing
just as a bird’s feathers have their quills implanted in its skin.
Grasped roughly between the fingers, the wing parts with its delicate
covering; it loses its ornamental scales and shows naked to the view.
It is then a fine, translucent membrane traversed by a network of tiny
ribs, or nervures, as they are called, which hold it expanded and give
it firmness.
“At rest, butterflies do not all carry their wings in the same manner.
Those that fly by day and go from flower to flower in full sunlight,
hold their wings erect on the back and folded against each other. These
butterflies are also recognized by their brilliant coloring, their
lightness on the wing, their grace of form. Those, [6] on the other
hand, that fly either by night or at evening twilight bear their wings,
in repose, either outspread or else lightly folded in a sort of
roof-shape. They are of bulkier form and heavier than the
first-mentioned, and sombre hues predominate in their costume.
“Whether friends of light or fond of darkness, whether courting the
sunshine or lovers of the night, butterflies are invariably very
abstemious, finding all the nourishment they require in the tiny drop
of honey exuding at the bottom of a flower. Many flowers have long and
narrow mouths; no insect muzzle is slender enough to reach into flasks
like these and lap up the syrup, and therefore butterflies must have a
special instrument adapted to the purpose.
“This instrument is the proboscis, as fine as a hair and long enough to
reach to the exquisite drop, however deeply it may be hidden. When not
in use, this proboscis is kept tightly coiled at the entrance to the
insect’s mouth. When it finds a flower to its taste, it uncoils this
spiral and extends the proboscis in a long thread which plunges into
the narrow-necked bottle and proceeds to suck up the coveted drop. If
we wished to drink from a flask of similar shape, we should use a straw
or reed. Its proboscis is the butterfly’s straw with which it takes its
refreshment from the flowers.
“As with other insects, the butterfly is at first a larva or worm, very
different, you understand, from what the creature will afterward
become. The larvæ of butterflies are nothing in the world but
caterpillars.”
“Oh, how disgusting!” cried Emile, making a wry face.
“But nevertheless so it is,” proceeded his uncle. “Caterpillars,
repugnant creatures to us, change into those magnificent butterflies
that we are never tired of admiring. What was ugly becomes beautiful,
what was frightful finds itself the proud possessor of grace and charm.
“There are some caterpillars that have the skin quite naked and mottled
with various colors in a manner not unpleasing to the eye. To touch
these worms, even to handle them, inspires little or no fear, so
harmless do they look. But there are others, of a larger size, which
carry on the back, toward the rear, a menacing horn, a sort of hook, of
which it seems prudent to beware. This apprehension, however, is
groundless: the horn is inoffensive, being not a weapon but a mere
ornament. Caterpillars thus equipped become large butterflies flying in
the late evening twilight.
“Still others have an even more repulsive look, bristling as they do
with clusters of prickles and with tufts of long hair. From these ugly
creatures, whose very touch would be so disagreeable to us and would
make us utter cries of fear, come some of the most beautiful
butterflies of our part of the world. Such is the caterpillar that
browses the leaves of the nettle and becomes the Vanessa Io or
peacock-butterfly. It is black with white spots, and wears a rough
armor of toothed prickles. The butterfly, the Vanessa, has wings of a
bright brick-red adorned with a large eye of mingled black, violet, and
blue. Who would ever imagine, unless he had seen the transformation or
heard about it, that so ravishing a creature has such an origin?
“But for all their hairs and prickles caterpillars need cause us no
alarm. Nothing about them justifies the fear they too often inspire. No
caterpillar is poisonous, no caterpillar seriously injures the hands
that touch it. Yet it is well not to repose full confidence in hairy
caterpillars: sometimes the hairs become detached and cling to the
fingers, causing rather lively itching sensations. But a little
scratching ordinarily ends the trouble. Accordingly any one who should
hereafter be afraid of caterpillars would not deserve the privilege of
chasing butterflies.
“Every larva is a gluttonous eater, because it must grow big and
accumulate the wherewithal for its subsequent changes of form. Nor are
caterpillars lacking in response to this serious duty. The future
butterfly’s welfare is at stake. Made solely for eating, the larvæ gnaw
and browse unceasingly. Each one has its own particular kind of
sustenance, its chosen plant, and nothing else meets the requirements.
The larva of the Vanessa selects the nettle and turns with aversion
from all substitutes; that of the Pieris, a white butterfly with black
spots, will have only the cabbage; that of the Machaon, a butterfly
with large wings that end in a sort of tail, feasts on fennel; and so
of others.
“After attaining the full size assigned to them by nature,
caterpillars, like other larvæ, prepare for their transformation. Some
shut themselves up in a cocoon made from a silken thread that they spin
from their mouth, while others content themselves with binding
together, by means of the small supply of thread at their disposal,
particles of earth, bits of wood, and hairs plucked from their own
body. Thus is obtained, at small expense, a sufficiently substantial
temporary abode. Finally, still others, especially among the
butterflies that fly in the daytime, merely seek a retreat on the side
of some wall or against a tree-trunk, and there suspend themselves in a
girdle of silk.
“These precautions taken, the caterpillar strips off its skin and
becomes a nymph, but very different from that which the stag-beetle
showed us. The coleopter, in its nymph stage, was already recognizable,
with its branching mandibles, its legs folded on its stomach, and its
wings enclosed in their sheaths. The butterfly, on the contrary, is not
at all discernible under the casing of the nymph. This nymph, with skin
as tough as parchment, is an object little indicative of its true
nature and much more suggestive of the kernel of some strange fruit
than of any animal form. Because of its shape, so different from that
shown to us by ordinary nymphs, it has received a special name, that of
chrysalis.
“This word means golden sheath. Sometimes, notably in the case of the
Vanessa, the chrysalis is adorned with gilding; but in the great
majority of instances the suggestive name is not deserved, a uniform
chestnut hue, darker or lighter, being the usual color of the
chrysalis. Ripened by long repose, this species of animal shell splits
down the back and releases the perfect insect, complete in all its
attributes. The butterfly passes a few festive days amid the flowers,
and before dying lays eggs whence will spring caterpillars to continue
the race.”