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those crustaceous infects, whose wings are longer than the elytra.

Mary fpec'es of insects are covered with hairs; sometimes these are so fine that they escape the naked eye, and are visible o: iy with a good glass. But in others thsy are sufficiently obvious. They do not cover the whole body . i me have them on the head where they look like a plume of feathers, some on the thorax, on the extremity of the abdomen, on the wings, both upper and under, and on the legs.

These hairs are of different colours which change however when the infects grow old, and are about to form their cone. They are thiniy scattered on some, on others thickly set. There we alio insects where the hairs form tufts, like a brush, (fasciculi) as in the Phalæna pudibuuda; some square, others round, often equal at top as if cut over like the egrets in the turban of a Turk, and often terminating in a point Kke a pencil. Sometimes the hairs are so gross and strong that they may justly be called spines; each of these spines sometimes dividing into many rigid branches, and so small as to be with difficulty seen. They too are of different colours, as may be seen in the different species of the thorny caterpillars and the number of their branches varies, some having three, four or more. Their position is also very different. In some the spines are placed round each sing in one line as in the caterpillar of the Papilio lo; in others they are placed in two lines, n6t opposite to one another but alternate, and always at such equal distan- , ces, that one would fay they had been measured with the greatest care; an instance of this may be seen in the caterpillar of the Papilio Urticae

These hairs and spines answer more than one pur• pose. They preserve some from two great friction, which could not but injure their {kin; they are likewise weapons of offence, others striking their enemieswith them very forcibly. Lastly, in -those that live under water, there are some that encompass their hairs with a bubble of air which serves them to come up more easily to the surface. The water beetles have hairs on the belly between which there are little particles of air. When these are numerous they descend to the bottom with difficulty, and when they reach it, they are obliged to hold by some substance to keep themselves there: but when they loose their hold, the air carries them up to the surface.

. Nature has endowed some insects with horns different from the antennæ, having no articulations. Some have but one placed on the head, and rising straight or recurved like a hook. Some have two placed on the forehead bending to the. sides or rising in a straight line. These horns are either short, smooth, or a little incurved like hooks, or branched like those of the flying stag. Sometimes they are of equal length, sometimes one is longer than the other. There are likewise insects which have three of these horns rising perpendicularly. They are not always situated on the head, but sometimes on the shoulder* near the head. Lastly, in some insects they are imrnoveable, but moveable in others. - These last cart by their means hold their prey as with pincers, and t.he former can remove any obstacle from their way.

CHAP. IL.

CHAP. II.
Section it.

Of Thf Internal Farts Of Insects*

Let Us now come to the internal parts of insects, anc? let Jus scrutinize the inmost recesses of their structure in order to penetrate into the mysteries of nature. The task is full of difficulty. Many of those parts are so small as to escape our sight. To discover them we must use the highest magnisiers. Besides, the eye is weakened by the continued contemplation of one object, and we feel this sensibly when we force ourselves to the task. Notwithstanding these disficulties, however, Naturalists have discovered many things on our present subject; these I shall detail, and add what I have learnt from my own observations.

If we separate the external skin from an insect witi| instruments, or throw it into warm water, that the skin may come away of itself, we shall find that it covers many parts worthy of attention. And first in the head we discern the brain, the substance of which is so soft that it is not easily examined even with a glass. When we pierce the eyes of infects with a pin there issues out a fluid, in some clear like water, in others red like blood. Under the skin is the flesh. Jt may well receive the name since it consists of fibrous T6us pasts soft and sometimes reddish as in other animals. The fibres are oblong parts, thin and slender like the finest thread; their use is to connect the other parts with one another, and to put them in motion. They resemble wrinkles in the form of rings, and are distinctly observable in insects when the muscles are inactive; but when these are in motion they stretch the fibres, and make them invisible. The ex~ ceffive delicacy of the fibres in insects has prevented hitherto our discovering whether they are enveloped with a fine membrane, like those of quadrupeds. . Ia some insects these fibres are so short that their length is hardly equal to the breadth of three hairs; and therefore, they are not always to be seen, even with a glass. As they serve to extend, and to contract the muscles, their structure must resemble that of a wire wound round a cylinder, when that cylinder is withdrawn. They vary their motion, folding themselves in a semi-circle, sometimes to the right, sometimes to the left, nearly like a number of small worms. This motion, however, is very inconsiderable, and the fibres hardly change their situation. After these, the flesh of insects appears, as in other animals. There are likewise small veins, which, joined to the nervous and fleshy fibres, compose the muscles.

Insects are destitute of blood, properly so called; because, the composition of that substance demands snore preparation and elaboration than can be performed in a body so small as theirs; but, in place of blood, they have certain viscid humours that serve the purposes of it. These humours contain their animal spirits, and from them insects draw their nourishment. However subtile they may be, they are, nevertheless, endowed with considerable tenacity. In consequence of this quality, the head of a fly, after being cut off, will adhere again to its body, if stuck

on, on, without, however, restoring it to life. This glutinous quality of the humours enables infects to lire for a time, after having been cut into two or more pieces; it prevents a rapid evaporation, it retains the humours which still continue to circulate for a time in the members, which would not happen without this quality. And, that this quality actually resides in the humours of insects, we may be convinced, by exposing them, when drawn from the animal, to the air, when they will so dry, in a few minutes, as to become brittle like glue.

Infects have an artery, which is observable, riming along their back, and in which pulsation may be seen. The air produces in this artery the fame effect that blood does in circulation.

Infects eat and drink like other animals, a stomach k therefore necessary to them. This is nothing but an extremely thin and hollow bag. The aliments of insects pass from the gullet fnto this stomach, where they are digested and changed into a nutritive juice. Among quadrupeds, those that ruminate need more 4han one stomach, formed of several folds. It is the fame with insects; some of them are found to ruminate, and consequently, have more than one stomach. It is of this fort of insects that God permitted the Jews to eat. See Levit. Ch. xi. 21. and 22.

Many persons, not having observed a heart in insects, have denied that they have any: but this is rash. These animals have many parts, so very' minute, that they cannot be discovered; may this not be the cafe with the heart? Besides, there are many species, in which this organ may be distinctly seen. Lastly, the humours circulate in insects, and the arteries have a sort of pulsation; they must, therefore, either have a heart or something analogous to it.

Lungs

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