loured waters. Laftly fome like the camel have a protuberance on their back.

But we hall find as much diverfity in the parts that remain as in thofe we have already mentioned. The extremity of the abdomen is not alike in all. Some have it fmooth, in others it is fet with hairs, longer or fhorter according to the ufes they are def. tined for. In this place are fituated the papillæ from which they draw the threads they ufe in their different webs. Some like the caterpillar of the Phalana bucephala have this part covered with a fhort of fhield. Others have at the fame place a fliff membrane which affifts them as a rudder to turn when flying to this fide or that; and is to infects what the tail is to birds. Some have long flender briftles, one, two, three, or four; and others a fort of horns, ftraight, bent or crooked in various infects. When thefe horns are touched, fome like the caterpillar of the Sphinx Euphorbia can draw them in as fnails do theirs. Others have more flender horns, either fimple, or, as in the Blatta orientalis, articulated. These horns are of various ufe, for to fome infects as the Gryllus campestris, they give intelligence when any thing approaches them from behind, to others they are the organs of attachment to folid bodies, to others of progreffive motion. The extremity of the abdomen is likewife the fituation of the fting in those infects which poffefs it; fome have one, others two, which ferve as weapons of offence or defence. Some, as the Earwig, instead of a sting have a fort of pincers or forceps at the tail, with which they defend themselves, and feize their prey. Laftly fome like the caterpillar of the Phalana Vinula, have two tentacula, like a two-pronged fork.

I now come to the parts of generation in infects, which cannot be paffed over in filence. These are generally

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placed at the extremity of the abdomen in the males, though there are fome that have them placed forwards under the belly. Thefe parts in proportion to the body of the infect are larger in fome than in others. Those of the females are fituated, as in the males, generally towards the extremity of the abdomen, fometimes under it. They are covered with a fine down, that the male organs, which are exceedingly delicate, may not be hurt by the contact.

Some infects have likewife, at the extremity of the abdomen, a fting. In fome it lies within the body from which they can dart it forth when they have occafion to use it, in others it is altogether external. If fhort, it is placed under the belly, where it lies in a groove like that which receives the edge of the blade of a pocket knife. If long it flicks out behind, and is enclofed in a fort of cafe formed of two very flender laminæ like a tube cleft longitudinally. This tube terminates in a very sharp point, which opens to allow the fting to pafs when it is ufed. This fting is bearded with very fharp points like the beards of a hook. Thefe not only prevent the fting from being withdrawn, but make the wound more painful. It is formed of two fharp fpears, which, being once inferted into the fkin, penetrate further by means of their fharp points. At the bafe of the fting near the belly is found a fmall bag full of a strong and penetrating fluid. This the infect extracts when it has occafion, and injects it into the wound made by the tube of its fting, when tumour and pain fucceed in confequence of the fermentation of this fluid. The tube of the fting is fmooth in fome, in others when viewed through a magnifier, it appears hairy. At the bafe of the fting in the abdomen of the infect are found the muscles by which it acts.

All infects do not make the fame ufe of the fting.

In the female for inftance, it is the conduit through which the eggs are conveyed and depofited. It is of ten more than half an inch in length, hollow, and cleft in two: It terminates in a pointed knob, with which the infect makes a hole in the earth, or in a leaf large enough to hold her eggs. Thefe fhe depofites, through the hollow of her fting, that the rugged earth or other matters may not harm them. As it is open by means of the cleft at top, as well as at bottom, and as the eggs do not defcend by the preffure of the air, Nature has formed in it many half rings oppofite to one another, which facilitate its defcent. Infects contract thefe fucceffively, begining with that nearest the abdomen, and making the eggs defcend from one ring to another, by a fort of peristaltic motion. The cleft of this canal is almost invifible while the infects are alive, but it opens a little more when they are dead. The fting of the female is incapable of wounding; that of the males alone has this power.

The females of all infects are not provided with fuch a conduit: thofe which depofite their eggs on the furfaces of bodies, difcharge them immediately by the genital organs. None but those which depofite their eggs in the flesh, in other infects, in leaves, or in the earth, have occafion for such a tube, that they may introduce them as deep as is neceffary.

Although the fting of the males is extremely fine, it is, nevertheless, ftrong enough to pierce hard fubftances, and I have been ftung by a bee through a goat-skin glove. They ufe it as a pike or lance to annoy their enemies, or to defend themselves.

This tube or fting does not always ferve as a channel for the eggs. There are fome aquatic infects, fuch as the Nepa Cinerea, that have this part com

mon

mon to both fexes, and which they ufe as a fpiracle to inhale the fresh air. They are feen often pufhing the extremity of it to the furface of the water, and when they defcend, there rife little bubbles of air, which efcape from them.

We have had occafion to remark above, that infects which have feet, have not always the fame number of them, but that they vary according to the different fpecies. Thofe limbs are generally fituated under the abdomen: we find, however, a particular order of infects, aquatic as well as terreftrial, that before their transformation, have their feet on the back. But no fooner have they divested themselves of their fkin, and their feet, and are in a capacity to fly, than thefe appear under the abdomen.

All infects have not the legs of the fame length. Some have them very fhort, with but one articulation. Such are all caterpillars, whofe fix fore feet, are not, ftrictly speaking, any thing but hooked points, and the eight hind feet have but a fingle articulation, which gives them the appearance of being mutilated. Some infects are likewife found that have them longer, with three articulations, as fome fpiders, mentioned by Pliny; four, as the Scolopendra morfitans; five, as in the Tipula motitatrix; fix, as in the Aranea Diadema: and fometimes, even eight. The feet of the fame infect are not always of equal length. The hind legs of moft are longer than the reft.Bees have them fo long that they can carry them to their head, and put into their mouths the wax these legs are loaded with. This rule, however, is not fo general but that there are exceptions to it, the fore legs in fome being the longest.

Thefe legs are generally compofed of three parts, the firft is a kind of thigh, (femur.) It arifes im

mediately

thediately from the abdomen, and is thickeft at its origin, 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 ftrong and fharp fpines. 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 polished fubftances.→→ Between these, others have something like the fole of a foot, which enables them to flick to places where the hooks would be ufelefs. It produces the fame effect as the bit of moistened leather which children press upon a stone; 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 ufe them merely as hocks for faftening themfelves to objects, others for leaping. The leaps they make are fo great, that it is faid a flea will leap 200 times its own length. For this purpofe, thefe infects are furnifhed, not only with ftrong and flexible legs and thighs, but with vigorous mufcles, endowed with a power of elafticity, 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 pleasure of the animal. They receive the fame advantages from them that florks do from their long legs. They ftretch them out from the abdomen, and ufe them as