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%f butterflies than that of feathers. But there is a particular genus of the Lepirlopteræ, which Mr Lesser doe<> not mention, whose wings may be (hid to be composed of feathers, or at least of beurdeJ stems which very nearly resemble them. (Phalænæ Alucioe Lin.) These wings are not made like those of ordinary Lepidoptcræ, of a transparent membrane covered with a coloured dust which renders them, opake j thele barbed and divided stems themselves form the win?, just as the feathers form the wings of birds; but with this difference however, that the feathers of the wings in these Phalænæ are not laid over one another, and that being very Lr^e there are but few of them in each wing.
Page 162,1. 2*}k
Some with the figure of an arrow* All these representations which are generally very imperfect, merit but little attention; they are only sit to amuse the vulgar who are easily persuaded that there must be some concealed sense in the casual resemblance of a letter, or of some emblematic figure.
Pace 163,1. 14k
Lines Hie the furrows of a ploughed field* Tht furrows We observe in the elytra ot some beetles, *re often cha acter tiltic marks of the female; they are not always tound in the male.
Page 164, I. 11.
Hairs which change when the infctl grows old. It is fchiefly when larvae cease to eat, and prep*re themselves for undergoing a change, that there sometimes happen very considerable variations in their'hairs.. 1 know some caterpillars \viih hairs naturally white, which at that tin.e change from White to olatk, in the space of an hour or two.
. Page 165^ 1. 2.
Tlx hairs are weapons of defence. The hairs of infect* are generally si tfer, and more brittle than those of other animals, which renders t!ie wound they give so troublesome. Being so slender and fine, they insinuate themselves into the pores of the skin, where they break, and the broken part penetrates lull further, the more it is touched. This is the 3 £ 2 cause cause of that itching, and those small pustules which have made these caterpillars without any reason be supposed poisonous. This has already been observed by M. de Reaumur, and 1 have experienced it myself in repeated instances. Among the great number of smooth caterpillars of everykind which I have had occasion to handle, not one of them ever did me the smallest harm. But as to the hairy caterpillars, they have often afsected me with pain even without having touched them, and merely by opening with my lingers, the coques where they had left their hairs*
Page 166,1, io*
The skin covers many parts worthy of attention. Although from the manner in which this Chapter begins, we are led to expect an anatomical description of the principal parts which compose the bodies of insects, we must not expect 10 sind in it what will satisfy the curiosity of an intelligent anatomist. In order to give some just idea of the marvellous in the internal structure of these little animals, it would be necessary to enter into a detail which, alone, would surnisli materials for more than one volume, and which could not be interesting to any but connoisseurs. General reflections, such as those to which MrLesser has been here obliged to consind himself, give but a very impersect idea os the lubject. No author has treated it in such a masterly and satisfactory way as Swammerdam has done. His Biblia Naturae, which is almost entirely a collection of anatomical facts, shews clearly that there are not sewer parts required in the formation of an insect, than in the bodies of the larger animals; and, what supposes a much more admirable mechanism in the former is, that many of the internal parts in a great number of species, after having subsisted for a considerable time in one state, afterwards change their form, their sunctions, and their nature, and adapt themselves to those new uses which result from the disserent transformations which insects undergo.
Page I66, 1. last.
* It may well receive the name of Jlejh. This we must observe, contrary to Aristotle, who leems to have thought that insects have no flefli properly speaking, but merely a substance analogous to it, when he fays; H. A. L. r?. Cat. 7. Quod autem pro carne in iis habetur, id nec teftam imitatur, neque quod in testaceis genus camis contine
tur; sed mediara quandam inter h»c resert naturara. The author.
If the substance which composes the bodies of some insects be possessed of such a degree of consistence as to deserve the name of flesh, however improperly applied, that os which the bodies of the greatest part of them are formed, especially before their last change, is so soft or rather fluid, that the name.of viscid humour seems much more applicable to it. And accordingly M. Lesser in the foregoing note, might well have spared Aristotle for his remark on the subject.
Page 167,1. 291.
Afore elaboration than can be performed in a body so small. I doubt if ihis reason will satisfy the intelligent reader. The great apparatus observable in the internal structure of insects, of which however we can only see the most obvious and coarsest parts, the exceeding minuteness of some, several thousands of which united would not equal in si2e a grain of sand, and in which we must notwithstanding suppose parts analogous to those of the largest insects, Ihcw cviden:ly that it is not beyond the power of matter when in the hands of the divine Creator, to form in an insect however small, nil the vessels necessary for performing the requisite digestions and nitrations in order to convert the aliments into blood. It seems, on the contrary, still more evident, that if insects have not blood similar to ours, it is because that blood would be too gross to pass through vessels so delicate as theirs, and therefore it is necessary they should be provided for this purpose with fluids much more subtilised than those which enter into the composition of our blood,of which a single globule is sometimes larger than the whole body of lome of these animals. But without deciding positively cn the matter, we may at least consider as a certain fact, that it insects are not surnished with blood similar to ours, they have however fluids tbat perform the fame sunctions; and we cannot doubt that these fluids circulate in their veins when we attend to what passes in plants, and the larger animals; considering especially that there are insects in which we can discover pretty convincing proofs of this circulation. Such for instance are fleas: for when we examine their legs in a microscope, we distinctly see vcsselj which after hav
ing proceeded a certain length, return in another dire*i tion, towards the trunk of the body from which they set off.
Page 168,1. first,
This glutinous quality of the humours. 1 allow that the tenacity of the humours in insects may contribute to their tenacity of lise \ but what I belu-ve to contribute still n.oro to this quality is the circmstance of their vital principle, at least that of the far greater part of them, not residing solely in the head, but being dispersed over their Whole frame. 1 have lien a caterpillar continue to creep about sor some days after its hi-ad had been cut off. I have seen the body of the common earth-worm, which some aquatic insect had reduced to one third of its length, live in the Water for the space of a week after being thus maimed, and at both ends. I have seen motion in the abdomen of a wasp three days aster its separation from the thorax. If the vital principle of insects resided only in the head, we could conceive that the tenacity of their humours might contribute to detain lise for a certain time in that head and the part of the trunk attached to it: but how could the" mere tenacity of the humours preserve lise and motion in the other parts, which bei.ig then separated from the head, would be deprived of the vital principle, and the influence of the animal snirits? These parts ought immediately to perish; but as they do not, and preserve their activity for a considerable time, it seems natural to conclude that the principle of lise and motion does not reside solely in the head, but is distributed Over every other part of the body.
This is not all, it may be inserred from some experw ments I have made on the animals we have mentioned, that if insects have a foul, this soul is likewise extended over the whole body, so that when the body is divided, it too is divided of course. Every part of these divided animals appears to me capable of exhibiting marks of consciousness and sensation. When I touched the headless caterpillar; it made the fame motions which it used to make in the fame circumstances before it was maimed, and if I persisted for any time in annoying it, it ran awiy. The trunk of the earth worm when it seemed persectly at rest, was no sooner touched than it put itself in motion and made off with expedition. When I held the anterior part of the wasp, it bit into every thing I presented to it, and
when I'touched its trunk, although separated for some days from the head, it immediately put out its sting, and darted it on all sides, and m every direction, as if endeavouring to wound me. Is it not evident that all these different parts ot the animals, notwithstanding their separation, had still preserved not only life and motion, but the faculty of receiving impressions from objects, and the desire of self-preservation ; each, according to its nature, determining either for flight or resistance? And how is it possible to conceive that each of the parts separated from the same animal could retain that faculty, and that desire, if they had not at the same time preserved the principle in which both reside, that is, the foul? and the foul cannot be found in two separated parts ot the fame animal without being itself divided. Here then is the foul of insects, at least of some of them, divisible; what a itrange paradox!
Perhap> it may be thought, th^t in order to establish an opinion so singular, more decisive experiments than thole I have just related should be ma.'.e; take then the following which seem to me unanswerable, and appear to demonstrate that if insects are endowed with a lbul, there are some in which that soul is not only divisible, but such as that each of the parts into which it is divided, is sufficient to animate an entire body, and to preserve its life. The first of these experiments is made on that final' aquatic animal mentioned above, P. 300, whole body in bulk is about the size of a. feed »f Dandelion (Hydra polypus.) It is an ascertained fact, that when it is cut in two, or even in three parts, each part becomes an entire animal, which performs its (unctions as before. My second experiment goes still further; I have several times not only cut in two, but in four, eight, sixteen or more parts, a species of aquatic worm, of a reddish brown colour, about three or four inches long. The greater number of these divided parts, and often the whole of them, have not only preserved sensation and motion, but after ten or twelve days begun to push out at the two extremities, and became in three or four months each an entire animal ; so that thus a single worm sometimes furnished me with more than sixteen, which I have moreover caused to multiply in the same way, as often as I pleased After these experiments, it would seem difficult to with-hold our assent to the proposition that thr-re are infests whose soul, if they have one, is divisible and even intoa great miniberot parts, all