kind. The true wing of the animal is a light transparent membrane, finer than the finest gauze, and not unlike it. It is also, when expanded, in proportion to the size of the animal, very large. In order to protect this delicate structure, and perhaps also to preserve it in a due state of suppleness and humidity, a strong hard case is given to it, in the shape of the horny wing which we call the elytron.* When the animal is at rest, the guaze wings lie folded up under this impenetrable shield. When the beetle prepares for flying, he raises the integument, and spreads out his thin membrane to the air. And it cannot be observed without admiration, what a tissue of cordage, i. e. of muscular tendons, must run in various and complicated, but determinate directions, along this fine surface, in order to enable the animal, either to gather it up into a certain precise form, whenever it desires to place its wing under the shelter which nature hath given to them; or to expand again their folds, when wanted for action.

In some insects, the elytra cover the whole body; in others, half;t in others, only a small

* TAB. XXXI. Fig. 1. Is an instance of this sort in one of the most beautiful of the beetle class of this country, the scarabæus auratus, or rose chafer; shewing the expanded elytra, a, a: the true wings, b, b.

Fig. 2. A specimen of this kind of elytron in the ear-wig, (forficula auricularia :) one of the elytra is extended, and the membranous wing unfolded.

part of it; but in all, they completely hide and cover the true wings. Also,

Many or most of the beetle species lodge in holes in the earth, environed by hard rough substances, and have frequently to squeeze their way through narrow passages; in which situation, wings so tender, and so large, could scarcely have escaped injury, without both a firm covering to defend them, and the capacity of collecting themselves up under its protection.

II. Another contrivance, equally mechanical and equally clear, is the awl, or borer, fixed at the tails of various species of flies; and with which they pierce, in some cases, plants; in others, wood; in others, the skin and flesh of animals; in others, the coat of the chrysalis of insects of a different species from their own; and in others, even lime, mortar, and stone. I need not add, that having pierced the substance, they deposit their eggs in the hole. The descriptions which naturalists give of this organ, are such as the following: It is a sharp-pointed instrument, which, in its inactive state, lies concealed in the extremity of the abdomen, and which the animal draws out at pleasure, for the purpose of making a puncture in the leaves, stem, or bark, of the particular plant which is suited to the nourishment of its young. In a sheath, which divides and opens whenever the organ is used, there is enclosed a compact, solid, dentated stem, along which runs a gutter or groove, by which groove, after the penetration is

effected, the egg, assisted in some cases by a peristaltic motion, passes to its destined lodgement. In the œstrum or gad-fly, the wimble draws out like the pieces of a spy-glass; the last piece is armed with three hooks, and is able to bore through the hide of an ox.* Can any thing more be necessary to display the mechanism, than to relate the fact?

III. The stings of insects, though for a different purpose, are, in their structure, not unlike the piercer. The sharpness to which the point in all of them is wrought; the temper and firmness of the substance of which it is composed; the strength of the muscles by which it is darted out, compared with the smallness and weakness of the insect, and with the soft and friable texture of the rest of the body; are properties of the sting to be noticed, and not a little to be admired. The sting of a bee will pierce through a goat-skin glove. It penetrates the human flesh more readily than the finest point of a needle. The action of the sting affords an example of the union of chymistry and mechanism, such as, if it be not a proof of contrivance, nothing is. First, as to the chymistry; how highly concentrated must be the venom, which, in so small a quantity, can produce such powerful effects! And in the bee we may observe, that this venom is made from honey, the only food

* Fig. 3. The awl of the astrum bovis, or gad-fly, highly magnified. Fig. 4. One of the hooks,