fly, 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 mandible-form 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 pairs of jaws with which they are provided. Reaumur once found one of them thus holding and devouring a large tadpole."

These lively writers, in speaking of the mask-like appearance of this apparatus, jocosely add, "If entomologists ever went to masquerades, they could not more effectually relieve the insipidity of such amusements, and attract the attention of the demoiselles,* [ladies,] than by appearing at the supper-table with a mask of this construction, and serving themselves by its assistance." For my part, I am inclined to take a more serious view, and consider these varied and wonderful contrivances and adaptations, as new proofs of Creative Wisdom.

SIXTH WEEK-WEDNESDAY.

INSECT TRANSFORMATIONS.-THEIR PUPA OR CHRYSALIS

STATE.

"COUNTRY fellows, for a prize," says Kirby, "sometimes amuse the assembled inhabitants of a village by running races in sacks: take one of the most active and adroit of these, bind him hand and foot, suspend him by the bottom of his sack, head downward, to the branch of a lofty tree; make an opening in one side of the sack, and set him to extricate himself from it, to detach it from its hold, and suspend himself by his feet in its place. Though endowed with the suppleness of an Indian juggler, and promised his sack full of gold for a reward, you would set him on an absolute impossibility; yet this is

* Alluding to the French name of the dragon-fly.

what our caterpillars, instructed by a beneficent Creator, easily perform."*

I have already shown how the silkworm prepares for its pupa state, by weaving for itself a shroud; and this may be taken as an example of the process pursued by several other species of larvæ, such as those of the pressmoth, the tentmakers, &c. ; but the curious operations alluded to by Kirby, in the passage I have quoted, are most commonly employed by the insect tribes in the stage of transformation we are now considering. They suspend themselves by means of almost invisible silken filaments, formed into a little button thickly interlaced and strong, which they weave for themselves, and among the meshes of which they thrust their hinder pair of prolegs; taking secure hold by the numerous hooks with which these are fringed, and then fearlessly swinging themselves into the air with their heads downward. The most difficult part of the process still remains; for the insect has to throw off its skin while thus suspended, together with the hooks by which it is attached, and this without losing its hold. The old skin is rent by the forcible bending round of the upper part of the body, a tedious and probably painful operation, in which it is engaged for a day, or sometimes even more. The rent being made, the included insect, by successively contracting and dilating the rings of its body, pushes off the skin by degrees from the head towards the tail, as the sack-racers mentioned by Kirby would disengage themselves from the sacks in which they are enclosed.

In this position the excluded insect is at a considerable distance from the point of attachment to the meshes of silk, hanging on the empty slough. It has to reach that point, fix itself there, and disengage and cast away the sloughed skin. This operation, says Bonnet, causes a spectator to tremble for the consequences, for every moment seems to render its fall almost certain. It is, however, provided with means which enable it to effect its purpose it can elongate and contract, at pleasure, the

* Introduction, iii. p. 209.

rings of its body. Laying hold of the nearest portion of the skin between two of its rings, as with a pair of pincers, it securely crawls along it, till it reaches the silk button. Having arrived at this station, it feels about with its tail for the silk, and inserts into its meshes the delicately formed hooks with which that part of its body is furnished; when, finding itself securely fixed, it again throws itself into the air, and hangs as formerly, with its head downward. It yet remains that the old skin be got rid of, the neighborhood of which appears to be annoying. This it effects by repeated wrigglings, gyrations, and contortions of its body, which disengage the hooks of the prolegs from the silk, and cause it to fall to the ground.

There are other insects, which, manifesting the variety of resources belonging to the Author of Nature, make use of other expedients. Some of these not only fix themselves by the tail, but throw around their body, by a curious process, a girdle of silk, which binds them firmly to the spot selected, frequently in a horizontal position. But instead of stopping to detail this difficult operation, which is performed in a different manner by distinct classes, I shall select an order whose plan of proceeding is altogether dissimilar. I allude to the numerous species of what are called common flies. Unlike most other larvæ, these never cast the skin, not even when they change into pupæ. The maggot of the common blow-fly, for example, when about to undergo its transformation, quits the carrion on which it has been feeding, and burrows, for an inch or two, into the first soft earth it can meet with. Here it draws its body into a shorter compass, and the soft skin being thus condensed, it acquires in thickness what it loses in length. In this state it becomes hard and tough, like thin parchment, and of a dull reddish-brown color. Within this skin, now converted into a leathern case, it undergoes its transformations, which have been minutely traced by Reaumur, but which I shall not enumerate, as this would lead into a somewhat tedious detail.

We are so apt to consider the processes of insect transformation as insignificant, merely on account of the small

ness of the animal, that it is sometimes desirable to suppose a case in which bulk would appear to add to their importance. Mr. Rennie has, in the present instance, successfully availed himself of this device.

"Were

such an extraordinary transformation as this," says he, "to happen to one of the larger animals, it would be held forth as altogether miraculous. Were a lion or an elephant, for example, to coil itself up into a ball, compressing its skin into twice the thickness, and half the extent, while it remained uniform in shape, and without joinings or openings; and, at the same time, were it entirely to separate its whole body from this skin, and lie within it as a kernel does in a nut, or a chick in an egg, throwing off its now useless tusks into a corner; and then, after a space, should it acquire wings, break through the envelope, and take its flight through the air, there would be no bounds to our admiration. Yet the very same circumstances, in miniature, take place every day during sum mer, almost under the eye of every individual, in the case of the blow-fly, without attracting the attention of one person in a million.”*

Were we to follow up this idea, by supposing the various tribes of the insect world magnified to the dimensions of man, and the vertebrated animals, with which he is immediately associated, we should acquire more distinct views of their relative powers; but what a scene of wonders would be disclosed to our view. It would be pleasant to give way to our fancy in peopling the world with the monsters, strange and diverse, which would then meet us on every side. Looking only to one of the species. we have been considering, we should see a creature large and fearful as a crocodile, for a time consuming every thing before it with the voracity of a hundred cattle, but presently becoming sick and refusing to eat; and then climbing the highest trees, spinning ropes from its bowels, weaving a net, and hanging itself up by the feet to the winds of heaven; and then again bursting its natural covering, coming forth to the open air, naked and in a new shape, and, in resuming its position, discovering a tact

* Insect Transformations, p. 282.

and agility which neither man nor quadruped could equal; once more we would observe this wonderful animal voluntarily suspended at the giddy height it had first assumed, and remaining exposed to the changing season till a new metamorphosis took place. Again it bursts its external covering; and now it comes forth a glorious being, shining with sapphire, emeralds, and gold, expanding its painted wings in the sun, and soaring joyously through the yielding air. Such would be the history of one class of existences; and a hundred more, equally surprising and extraordinary, would meet our view on every side.

But instead of pursuing this train, let us look at some of the faculties and operations of the insect tribes as compared with those of higher species. The flea can draw seventy or eighty times its own weight,* and it can leap to the distance of two hundred times its own length. It is, therefore, immensely stronger than a horse, in proportion to its size; and were a man able to equal the agility of this little animal, he could leap between three and four hundred yards. But the cuckoo-spit froghopper has still greater elasticity of limbs, being able to leap more than two hundred and fifty times its own length; and to vie with this, a man of ordinary stature should vault through the air to the distance of a quarter of a mile! It has been remarked, that according to a similar mode of comparison, a cockchafer is six times stronger than a horse; and Linnæus observes, that if an elephant were as strong in proportion as a stag-beetle, it would be able to tear up rocks and level mountains. The architecture of insects is not less remarkable than their strength and agility. It has been said, that the community of white ants erect a building five hundred times their own height. Were our

* Many wonderful exhibitions of the strength of the flea have been made, one of the first of which was in Cox's museum, about sixty or seventy years ago. Mr. Boverich, a London watchmaker, constructed a minute landau, which opened and shut by springs, with the figures of six horses harnessed to it, and of a coachman on the box, a dog between his legs, four persons inside, two footmen behind it, and a postilion riding on one of the four horses, which were all easily dragged along by a single flea. Goldsmith remarks, that the feats of Samson would not, to a community of fleas, appear to be at all miraculous.