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of butterflies than that of feathers. But there is a particular genus of the Lepidopteræ, which Mr Leffer does not mention, whofe wings may be faid to be compofed of feathers, or at leaft of bearded stems which very nearly refemble them. (Phalænæ Alucite Lin.) Thefe wings are not made like thofe of ordinary Lepidopteræ, of a transparent membrane covered with a coloured duft which renders them opake; thefe barbed and divided ftems themselves form the wing, juft as the feathers form the wings of birds; but with this difference however, that the feathers of the wings in thefe Phalaænæ are not laid over one another, and that being very large there are but few of them in each wing.

PAGE 162, 1. 27.

Some with the figure of an arrow. All thefe reprefentations which are generally very imperfect, merit but little attention; they are only fit to amufe the vulgar who are eafily perfuaded that there must be fome concealed fenfe in the cafual refemblance of a letter, or of fome emblematic figure.

PAGE 163, 1. 14.

Lines like the furrows of a ploughed field. The furrows we obferve in the eltra of fome beetles, are often characteriftic marks of the female; they are not always found in the male.

PAGE 164, 1. 11.

Hairs which change when the infect grows old. It is chiefly when larvæ ceafe to eat, and prepare themfelves for undergoing a change, that there fometimes happen very confiderable variations in their hairs. I know fome caterpillars with hairs naturalty white, which at that time change from white to plack, in the fpace of an hour or two.

PAGE 165, 1. 2.

The hairs are weapons of defence. The hairs of infects are generally ft ffer, and more brittle than those of other animais, which renders the wound they give fo troublesome. Being fo slender and fine, they infinuate themselves into the pores of the fkin, where they break, and the broken part penetrates ftill further, the more it is touched. This is the

3 E 2

caufe

cause of that itching, and those small puftules which have made these caterpillars without any reafon be fuppofed poifonous. This has already been obferved by M. de Reaumur, and I have experienced it myfelf in repeated inftances. Among the great number of smooth caterpillars of everykind which I have had occafion to handle, not one of them ever did me the fmalleft harm. But as to the hairy caterpillars, they have often affected me with pain even without having touched them, and merely by opening with my fingers, the coques where they had left their hairs.

PAGE 166, 1. 19.

The skin covers many parts worthy of attention. Although from the manner in which this Chapter begins, we are led to expect an anatomical defcription of the principal parts which compose the bodies of infects, we muft not expect to find in it what will fatisfy the curiofity of an intelligent anatomist. In order to give fome juft idea of the marvellous in the internal ftructure of thefe little animals, it would be neceffary to enter into a detail which, alone, would furnish materials for more than one volume, and which could not be interefting to any but connoiffeurs. General reflections, fuch as thofe to which MrLeffer has been here obliged to confine himself, give but a very imperfect idea of the subject. No author has treated it in fuch a mafterly and fatisfactory way as Swammerdam has done. His Biblia Naturæ, which is al moft entirely a collection of anatomical facts, thews clearly that there are not fewer parts required in the formation of an infect, than in the bodies of the larger animals; and, what fuppofes a much more admirable mechanifm in the former is, that many of the internal parts in a great number of species, after having subsisted for a confiderable time in one state, afterwards change their form, their functions, and their nature, and adapt themselves to thofe new uses which result from the different transformations which infects undergo.

PAGE 166, 1. laft.

It may well receive the name of flesh. This we must obferve, contrary to Ariftotle, who feems to have thought that infects have no flesh properly speaking, but merely a fubftance analogous to it, when he fays; H. A. L. iv. CAP. 7. Quod autem pro carne in iis habetur, id nec teftam imitatur, neque quod in teftaceis genus carnis contine

tur;

tur; fed mediam quandam inter hæc refert naturam. The author.

If the fubftance which compofes the bodies of fome infects be poffeffed of fuch a degree of confiftence as to deferve the name of flesh, however improperly applied, that of which the bodies of the greateft part of them are formed, efpecially before their laft change, is fo foft or rather fluid, that the name of vifcid humour feems much more applicable to it. And accordingly M. Leffer in the foregoing note, might well have fpared Ariftotle for his remark on the fubject.

PAGE 167, 1. 29.

More elaboration than can be performed in a body fo fmall. I doubt if this reafon will fatisfy the intelligent reader. The great apparatus obfervable in the internal structure of infects, of which however we can only fee the most obvious and coarfeft parts, the exceeding minutenefs of fome, feveral thousands of which united would not equal in fize a grain of fand, and in which we muft notwithstanding fuppofe parts analogous to thofe of the largest infects, fhew evidently that it is not beyond the power of matter when in the hands of the divine Creator, to form in an infect however small, all the veffels neceflary for performing the requifite digeftions and filtrations in order to convert the aliments into blood. It feems, on the contrary, still more evident, that if infects have not blood fimilar to ours, it is becaufe that blood would be too grofs to pafs through veffels fo delicate as theirs, and therefore it is neceffary they fhould be provided for this purpose with fluids much more fubtilifed than thofe which enter into the compofition of our blood,of which a fingle globule is fometimes larger than the whole body of fome of thefe animals. But without deciding pofitively on the matter, we may at least confider as a certain fact, that if infects are not furnished with blood fimilar to ours, they have however fluids that perform the fame functions; and we cannot doubt that thefe fluids circulate in their veins when we attend to what paffes in plants, and the larger animals; confidering especially that there are infects in which we can discover pretty convincing proofs of this circulation. Such for inftance are fleas for when we examine their legs in a microfcope, we diftinctly fee veffels which after hav

ing

ing proceeded a certain length, return in another direstion, towards the trunk of the body from which they fet off.

PAGE 168, 1. first.

This glutinous quality of the humours. I allow that the tenacity of the humours in infects may contribute to their tenacity of life; but what I believe to contribute ftill more to this quality is the circmftance of their vital principle, at leaft that of the far greater part of them, not refiding folely in the head. but being difperfed over their whole frame. I have fen a caterpillar continue to creep about for fome days after its head had been cut off. I have feen 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 feen motion in the abdomen of a wafp three days after its feparation from the thorax. If the vital principle of infects refided only in the head, we could conceive that the tenacity of their humours might contribute to detain life 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 preferve life and motion in the other parts, which being then feparated from the head, would be deprived of the vital principle, and the influence of the animal foirits? Thefe parts ought immediately to pe rifh; but as they do not, and preferve their activity for a confiderable time, it seems natural to conclude that the principle of life and motion does not refide folely in the head, but is diftributed over every other part of the body.

This is not all, it may be inferred from fome experi ments I have made on the animals we have mentioned, that if infects have a foul, this foul is likewife extended over the whole body, fo that when the body is divided, it too is divided of courfe. Every part of thefe divided animals appears to me capable of exhibiting marks of consciousnefs and fenfation. When I touched the headlefs caterpillar; it made the fame motions which it ufed to make in the fame circumftances before it was maimed, and if I perfifted for any time in annoying it, it ran away. The trunk of the earth worm when it seemed perfectly at rest, was no fooner touched than it put itfelf in motion and made off with expedition. When I held the anterior part of the wafp, it bit into every thing I prefented to it, and when

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when I touched its trunk, although feparated for fome days from the head, it immediately put out its fting, and darted it on all fides, and in every direction, as if endeavouring to wound me. Is it not evident that all these different parts of the animals, notwithstanding their feparation, had still preferved not only life and motion, but the faculty of receiving impreffions from objects, and the defire of felf-prefervation; each, according to its nature, determining either for flight or refiftance? And how is it poffible to conceive that each of the parts feparated from the fame animal could retain that faculty, and that detire, if they had not at the fame time preferved the principle in which both refide, that is, the foul? and the foul cannot be found in two separated parts of the fame animal without being itself divided. Here then is the foul of infects, at least of some of them, divifible; what a itrange paradox!

Perhaps it may be thought, that in order to establish an opinion fo fingular, more decifive experiments than thofe I have just related should be made; take then the following which feem to me unanswerable, and appear to demonstrate that if infects are endowed with a foul, there are some in which that foul is not only divifible, but fuch as that each of the parts into which it is divided, is fufficient to animate an entire body, and to preferve 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 fize of a feed of 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 functions as before. My fecond experiment goes ftill further; I have feveral times not only cut in two, but in four, eight, fixteen or more parts, a fpecies of aquatic worm, of a reddish brown colour, about three or four inches long. The greater number of thefe divided parts, and often the whole of them, have not only preferved fenfation 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; fo that thus a fingle worm fometimes furnished me with more than fixteen, which I have moreover caused to multiply in the fame way, as often as I pleafed After these experiments, it would feem difficult to with-hold our affent to the propofition that there are infects whofe foul, if they have one, is divifible and even into a great number of parts, all fufficient

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