mediately from the abdomen, and is thickeft at its órigin, although there are fome infects which have it thicker below than above. The fecond is the leg, properly fo called, (tibia.) The articulations of thefe parts in fome infects are furnished with strong and fharp spines. The third part is the foot, (tarfus,} which deferves more attention than the other two.

It is generally articulated, the parts fometimes round or heart fhaped. Some have two articulations, fome more, the length of five. At the extremity of thefe, fome have two hooked appendices, by which they attach themselves to the most polifhed fubftances.→→→→ Between these, others have something like the fole of a foot, which enables them to stick to places where the hooks would be ufelefs. It produces the fame effect as the bit of moistened leather which children prefs upon a ftone; it adheres fo ftrongly, that a very heavy stone may be lifted by it. Some have, a fort of cup at the knee joint, by which they affix themfelves ftrongly to the bodies they want to hold by

The legs of infects likewife ferve various purposes, and chiefly for walking. But there are fome, which use them merely as hooks for fastening themfelves to objects, others for leaping. The leaps they make are fo great, that it is faid a flea will leap 200 timest its own length. For this purpose, these infects are furnished, not only with ftrong and flexible legs and thighs, but with vigorous mufcles, endowed with a power of elasticity, which raifes the animal high in the air. The feet ferve as a rudder to those infects which fwim, directing them to the place they want to reach. They hold in equilibrium, the body of thofe that fly, and direct it at the pleafure of the a nimal. They receive the fame advantages from them that ftorks do from their long legs. They ftretch them out from the abdomen, and ufe them: as

a rudder to fteer them. Others, which are fhortfighted, use them for exploring the road, both before and behind them. Some employ them in cleaning their eyes, their antennæ, and their. wings, and in clearing them of the duft and earth which might incommode them. Thofe which dig in the earth, ufe their legs as pick-axes, to make cavities and fubterraneous paffages. As men ufe their arms, and some animals their feet; as weapons of defence, there are infects which make the fame ufe of theirs. I believe I have already mentioned that fome use them for feizing and holding their prey. Laftly, by the ftruc. ture of the legs, the species of infects are often diễ ftinguishable.

>. The wings are the principal things to be noticed in winged infects. I have already spoken above of the number which the different kinds of infects poffefs; and have obferved, that fome have two, others four. They are fo delicate, and their ftructure difcovers fo much art, that they may well pafs for one of those objects that moft clearly demonftrate the wisdom of the Creator. They are provided with different nerves, which, like thofe of leaves, are diftributed in different directions. The pofition of them is also different, in different infects. In fome they are horizontal, in others they decline a little towards the fides, and in others, they stand erect. The remarks which I have had occafion to make in fome of the preceding articles, fufficiently fhew, that the wings of infects are very various. Some have a kind of a covering over them, while others are bare. Some of thefe laft are exceedingly thin, fhining, and tranfparrent, like parchment or fine gauze; others are o paque, and covered with a fort of farina or powder: I have alfo already examined the different forts: of butterflies and winged beetles, fo that I have only here to treat of the wings themselves.

The

The wings of infects, which are bare, whether they have two or four, are exceedingly thin, and their nerves are ramified in different directions. In fome, these ramifications extend from the body to the half of the wings only, where they are loft and disappear, as in the Hippobofca equina. In others they reach the margin of the wings, where they join and form a spot, which Frifch calls the marginal fpot, as in the Hemerobius Chryfops. Thefe ramifications affume various figures. Sometimes they are fquares, which, at the fuperior extremity divide into three branches, as in fome Libellulas, in others they are rhomboidical, as in the grafshoppers, pentagonal, or irregularly pentagonal, as in the Sphex fabulofa: the membrane that fills up the interftices of these nerves is fò thin, that it can hardly be perceived, and the whole wing appears like thin gauze.

There is great diverfity in the figure of the farinaceous wings. They may be compared to the leaves of different trees; whatever connection there may be among them, there is not one of them like another. They are round, long, heart-fhaped, indented, or intire in the margins, oval, or nearly oval, their ends terminating in a point; in others they form triangles, the ends being either pointed or rounded. The margin of the wings is often indented like the edge of a faw, or undulated, forming femicircles like the figure of a ferpent in motion; and sometimes between these circles there are fmall elevations. Some at the extremity of the wings have a fort of tail, like that of a swallow, fome have it ornamented with fine fringes like lace.

When the duft which covers the wings of infects is looked at with the naked eye, one would take it for nothing but fine farina or powder; but, if it is feen through a magnifier, this pretended duft appears

in the form of very delicate feathers, which easily come off on being touched. The fmall feathers are of very different figures; fome have the form of a a battledore with a short handle, others are almost oval, except at the bafe, where they are a little notched; fome are like the leaves of a willow, except that they are sometimes indented at top: fome refemble a fan, a fquare with rounded angles, but waved at top; others are pointed at the bafe, and enlarge gradually, terminating in two, three, four, and even five long points like a finger; some resemble the heart-fhaped leaves of trees, and terminate in two or three hook ed points; others are oblong, and pointed at their origin, where they are oval, and have at the extremity, three, four, and even a greater number of fhort points; laftly, fome are long, thickening at the base, flender in the middle, and are twice as broad at the top, as at the bottom.

Without taking into account, the different colours of thefe wings, of which we fhall hereafter take notice, many are marked with fingular characters. On the wings of fome, are marks which refemble Hebrew letters, on others a Roman C, a Greek upfilon, a V, or an O. Madame Merian obferved, on the wings of a butterfly, characters refembling the letters BCY M; this I have not myself feen. Others are marked with a St Andrew's cross, and fome with the figure of an arrow.

The wings that have cafes are not lefs worthy of attention than the others; thefe cafes are hard as horn, and are easily broken. They are like a fheath to the delicate wings, which they cover and preferve from injury. As infects have no bones, these ferve inftead of them externally. They are not of equal hardness in all infects, the genus of Cantharis has them thin and flexible, and Frifch fays of the Cantha

up.

ris fufca, that when it dies, the elytra shrivel There is likewife great diverfity in their length; in fome, they cover only a fmall part of the body below the thorax, in others they cover the half of it; in fome they hardly reach the extremity of the abdomen, in others they cover the whole of it. Sometimes these cafes are nearly opaque, and hard as horn; in others thin and nearly tranfparent. Not less variety is observable in their fhape. Some, when joined together, are round, like the fection of a fphere, others oval, oblong, or ftraight. Some are exceedingly smooth and polifhed, others have a border, or are dotted with little depreffions, as if made with a pin. Some have longitudinal lines like the furrows of a ploughed field, and others are fet with hairs, or adorned with little tubercles, covering the furface..

The wings to which these cases ferve as covers are very fine and transparent. In fome fpecies they are not longer than the cafes themselves and may be covered therefore without being folded. But there are others which have them much longer, and must fold them up when they are not flying to put them under the elytra. For this purpose they have at the external margin an articulation or a kind of fpring to fold up what is longer than the cafes. When thefe wings are laid on the back, their largest nerves are without fupport, and the two ends which are too long hang down. But when the elytra are laid down to cover them, they lower at the fame time these nerves, and then the two ends drawn by their mufcles are folded in, and take their proper place. In order to accomplish this, the beetle has nothing to do but to leave a small fpace between the elytra and abdomen that what remains of the wing may the more eafily be folded: and this happens with all

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