earth, should be of an uniform whitish colour, and that those which exist in the light should be arrayed in a great variety of tints, and sometimes the most brilliant on which the eye can dwell. The attentive observer of insects is frequently struck by special arrangements in structure, for the comfort and advantage of particular creatures; we may now instance two in that of the larvae of the dragonfly. If one be taken and placed in a large saucer of water, with some of the dead leaves or sticks it had for a covering, these will soon float towards its tail, and afterwards be driven back. How, then, do these results arise? It is from the caterpillar being gifted with a kind of pumping apparatus, by which it throws out a little stream; and this being resisted by the still water behind, the caterpillar is urged onwards. Nor is there merely the power of motion; the insect seems also partly to breathe by the same means, and to have small aquatic insects brought within its reach to serve for food. The other peculiarity in its structure is, if possible, still more remarkable. The under-lip of those caterpillars is usually small; but in that of the dragon-fly, as Kirby observes, 'It is by far the largest organ of the mouth, which, when closed, it entirely conceals, and it not only retains, but actually seizes the animal's prey, by means of a very singular pair of jaws, with which it is furnished. Conceive your underlip to be horny instead of fleshy, and to be elongated perpendicularly downwards, so as to wrap over your chin and extend to its bottom; that this elongation is there expanded into a triangularly-curved plate attached to it by a joint, so as to bend upwards again, and fold over the face as high as the nose, concealing not only the chin and the firstmentioned elongation, but the mouth and part of the cheeks; conceive, moreover, that to the end of this last-mentioned plate are fixed two other convex ones, so broad as to cover the whole nose and temples; that these can open, at pleasure, transversely, like a pair of jaws, so as to expose the nose and mouth; and that their inner edges, where they meet, are cut into numerous sharp teeth or spines, or armed with one or more sharp claws; you will then have as accurate an idea as my powers of description can give, of the strange conformation of the under-lip in the larvae of the tribes of Libellulina, which conceals the mouth and face precisely as I have supposed a similar construction of your lip would do yours. You will probably admit that your own visage would present an appearance not very engaging while concealed by such a mask; but it would strike still more awe into the spectators were they to see you first open the two upper jaw-like plates, which would project from each temple like the blinders of a horse; and next, having by means of the joint at your chin let down the above apparatus and uncovered your face, employ them in seizing any food that presented itself, and conveying it to your mouth. Yet this procedure is that adopted by the larva provided with this strange organ. While it is at rest, it applies close to, and covers the face. When the insects would make use of it, they unfold it like an arm, catch the prey at which they aim, by means of the mandibuliform plates, and then partly refold it, so as to hold the prey to the mouth in a convenient position for the operation of the two pair of jaws with which they are provided.' Reaumur once found a larva of a dragon-fly thus holding and devouring a large tadpole. This extraordinary under-lip varies considerably in the different genera of dragon-flies. Caterpillars are to be classed with those creatures who live to eat,' rather than with the temperate and rational who eat to live.' Shakespere drew, most appropriately, many of his metaphors from their voracity. Thus Bolingbroke styles the creatures of Richard 'the caterpillars of the commonwealth ;'* and the Duke of York, musing on his prostrate hopes, exclaims : Nor should the pathetic inquiry of the servant, addressed to the gardener, be omitted: Why should we, in the compass of a pate, But with these remarks on their condition generally, let us take a scene from the graphic pen of 'Acheta Domestica:' § 'We have ascended to a lofty eminence, whence, as a spectator of London looking from the summit of St. Paul's, we are taking a bird's-eye view over a populous city. In the highways swarm a motley multitude, passing and repassing, some on business, others on pleasure. Some are employed in the erection of solid habitations; others are raising shady tents upon the spots of verdure with which, above all other capitals, this city abounds. Others, again, are weaving for their occupation large silken hammocks, or are rocked within them by the breeze, while they take refreshment or repose. Of these, some are now issuing from their luxurious abode; and as if the footways (although of wood) were too rugged for their tender feet, are laying down silken carpets on the ways they are about to tread. Yonder, on one of the smooth green areas, slowly advances a compact militarylooking body, marshalled in files, dressed in uniform, and headed by a leader.' A friend of ours observed, some years ago, in the neighbourhood of Adelaide, South Australia, an extraordinary procession of this kind. The caterpillars noticed by this naturalist resembled those of the great tiger-moth; the body being about two inches and a quarter long, of a dark brown colour, with paler lines, and having a profusion of white hairs. They were seen crossing a road in single file, each so close to its predecessor as to convey the idea that they were united together, moving like a living cord, in a continuous undulating line. At about fifty from the end of the line, one having been ejected, for the sake of experiment, from its station, the caterpillar immediately before Richard II., Act ii. scene 4. + Second Part of Henry VI., Act iii. scene 1. § Episodes of Insect Life:' Second Series. it suddenly stood still, then the next, and so on to the leader; the same result took place to the other extremity. After a pause of a few moments, the first after the break in the line attempted to recover the communication; this was a work of time and difficulty, but the moment it was accomplished by its touching the one before it, this one communicated the fact to the next in advance, and so on till the information reached the leader, when the whole line was again put in motion. On counting the number of caterpillars, he found it to be 154, and the length of the line twenty-seven feet. He next took the one which he had abstracted from the line, and which remained coiled up, across the line; it immediately unrolled itself, and made every attempt to get into the procession; after many endeavours it succeeded. and crawled in, the one behind falling into the rear of the interloper. He subsequently took out two caterpillars, about the fiftieth from the head of the procession; and found, by his watch, that the intelligence was conveyed to the leader in thirty seconds, each caterpillar stopping at the signal of the one in the rear. The same effect was observable behind the break, each stopping at a signal from the one in advance; the leader of the second division then attempted to recover the lost connexion. That they were unprovided with the senses of sight and smell appeared evident, since the leader turned right and left, and often in a wrong direction, when within half an inch of the one immediately before it; when, at last, it touched the object of its search, the fact was communicated again by signal, and in thirty seconds the whole line was in quick march, leaving the two unfortunates behind, who remained perfectly quiet, without making any attempt to unroll themselves. It is said that these caterpillars feed on the Eucalyptus, and that when they have completely stripped a tree of its leaves, they congregate on the trunk, and repair in procession to another tree. 'And now,' (saysAcheta Domestica,') 'what have we here? A group, as it would seem, of pantomimic players, belonging to some strolling company. Truly, they are clever fellows in the art of posture-making. Ye Grimaldis of Greenwich, and balancers of St. Bartholomew's! hide your diminished heads behind your baize drop-curtains! Ye are but bunglers in your trade! 'Look at one of the performers. He grasps with his feet an upright pole, with which his body, extended horizontally, staf and motionless, forms a right angle, of which both sides, instead of only one, look as if formed of wood. What prodigious strength of muscle! He looks like a cataleptic patient under the hands of a mesmerist. See now one of his companions-head and feet nearly met upon the ground-back raised into an arch, or Greek . This strange position would seem but a part of his walking movement; for now, stretching forwards, he plants, as it were, with his hands, another step; then drawing up his rear, brings feet and head again almost together, and so progresses, looking as he goes, and measuring the ground he treads on. A third of his comrades, dressed in like manner, is sitting idle on a horizontal pole, raised a tremendous height above the ground. But now-powers of earth and air !—he throws himself off his station, and must be dashed to atoms! Not he! the rogue ! for there he hangs suspended by a slender rope, mid-air, like “one that gathers samphire !" Will he let himself drop, now, from that still fearful height, or has he yet more length of rope (hid nobody knows where), to let him down easy? No! neither. He's climbing up again by the line to which he dangles: and now he's reached the top-the place from whence he fell. Bravo! master tumbler! Bravo! most excellent posturemaster! You shall have my interest for a season at Vauxhall.' The structure of the legs of caterpillars is, indeed, well adapted for climbling up their rope; the six fore-legs being furnished with a curved claw, while those termed the pro-legs are equally well adapted for holding the insect family to the branch when they have regained it, as each one has an apparatus for forming a vacuum, like the school-boy's leather suckers, thus securing a stable adhesion. Nor is the rope itself less deserving attention. The spinning apparatus is situated near the mouth; it is connected with long, slender, floating vessels, containing a liquid gum, and these being closed at their lower extremity, become wider towards the middle, and more slender towards the head, where they unite to form the spinneret, the two tubes uniting in one. The larva fixes the first drop of gum that issues where she pleases, and drawing back its head, or letting itself fall, the gum continues to flow, and in its exposure to the air, it immediately becomes dry, and acquires consistence and strength. If the caterpillar of the common cabbage butterfly be observed climbing on a window, and the glass be minutely inspected, it will be found to have left behind it a visible track; and if this be examined by a suitable magnifying power, a silken ladder will be apparent, by which alone the ascent could be gained. If, on the other hand, the branches of a tree be suddenly shaken in summer, caterpillars may be seen descending by their silken cords. Nor is there any danger of their fall to the earth; for the larva descends gradually, dropping but little at a time, and pausing whenever it is desirable. If, moreover, one be placed in the hand, it will be seen to draw a thread as it advances; for the head is extended as far as the insect can stretch it; then fastening the thread there, it takes another step, but never moves onwards without its clue. Such, however, are only some of the occasions in which its spinning power is of service; it is especially so in numerous instances when a dwelling has to be fabricated by insect sagacity. Look at one, for example, that to defend itself from the attacks of birds, or predatory insects, has rolled up a lilac leaf; and it will be seen that the leaf is held fast in its circular form by means of silken threads. Take another instance: the long and narrow leaves of willows and osiers are naturally adapted to be placed parallel to one another, and, as if a little caterpillar were aware of this, it makes a dwelling by winding a thread around those leaves of which it is formed, from a little above their termination, to a very short distance from their extreme point. A third instance is thus given by 'Acheta Domestica:'— "The stone-mason is the caterpillar of a little moth, with wings of gilded bronze, smaller, but much resembling the clothes-moth, whose family name (Tinea) he also bears, athough in habits and locality, as well as the material of his workmanship, he stands widely contrasted with the destruction of the wardrobe. Instead of reposing, like the latter, in "Ladye's Bowre," encased in garment of wool, or silk, or down, and regaling on the same soft and delicate substances of animal derivation, our hardy little operative finds himself, on emerging from the egg, exposed, without protection, on the surface of some lichen-covered wall. Instructed however, by that kind Power which in this very lichen provides him with an ample store of provender, he knows perfectly well how to meet the other exigences of his exposed situation. Of what avail to him would be a silken or a leafen tent, liable to be overset and borne away by the summer breeze? A stone-built tower suits his purpose better; and such is the structure he proceeds forthwith to erect. By help of "tooth and nail," he detaches small particles of the stone or brick with which the wall supplies him,-binds them together with silk and a sort of natural cement, possessed in common with his kind,-and thus, after twenty-four hours of incessant labour, completes for himself a habitation of sugar-loaf form, just large enough for his comfortable accommodation, and under cover of which he proceeds to perambulate his world of wall, and regale on the vegetable viands with which, for him, it is bespread.' The inspired prophet suggests an impossibility by the charge, 'Let the Ethiopian change his skin,' but every keeper of silkworms is aware that four such changes occur in their history; while the entomologist regards the moulting of insects as one of the most astonishing circumstances in their truly marvellous economy. Most larvæ pass through this process only three or four times, but somewhat oftener; and one, according to Cuvier, casts its exuviæ ten times; the periods intervening between each change depending on the length or brevity of the insect's existence in the caterpillar state. When about to change its skin the larva ceases to eat, its colours fade, it becomes feeble, and it seeks some place of security. Spinning a slight web, it fixes its legs or pro-legs to the surface of its retreat, it turns and twists its body in various directions for some hours, with intervals of rest; the skin splits in the back, from the more violent swelling of the second or third segment; the opening is increased by successive swellings and contractions of the remaining segments; even the head itself is often divided into three triangular pieces, and the enclosed caterpillar gradually draws itself out of its old skin. Often is this skin cast off so entire, that it might be mistaken for the larva itself; comprising not only the covering of the main trunk with the hairs which clothed it, but of the very skull, eyes, antennæ, palpi, jaws, and legs; which, if examined from within, are now found to be hollow, and to have encased, like so many sheaths, similar parts in the new skin. Swammerdam says, speaking of the moult of the caterpillar of a beetle common in Holland : : 'Nothing in all nature is, in my opinion, a more wonderful sight than the change of skin in these and other the like worms. This matter, therefore, deserves the greatest consideration, and is worthy to be called a specimen of Nature's miracles; for it is not the external skin only that these worms cast like serpents, but the throat and a part of the stomach, and even the inward surface of the great gut, change their skins at the same time. But this is not the whole of these wonders, for at the same time, some hundreds of pulmonary pipes within the body of the worm casts also each its delicate and tender skin. These several skins are afterwards collected into eighteen thicker, and, as it were, compounded ropes, nine on each side of the body, which, when the skin is cast, slip gently and by degrees from within the body through the eighteen apertures or orifices of the pulmonary tubes before described, having their tops or ends directed upwards towards the head. Two other branches of the pulmonary tubes that are smaller, 3 G VOL. VII. |