fects, the greater number feem to be as little allied to the vegetable kingdom, as other animals, it must, however, be confeffed, that there are fome, which, in external appearance, or in fome other refpect, appear to have a nearer relation to it. Such, for instance, are the lea anemones (actinia) which have rather the figure of a fungus, than of an animal, and which ftir fo little from the ftone they adhere to, that one would think they were rooted in it. Not that they are incapable of progreffive motion; but, it is so flow, as to be almoft imperceptible, and they hardly move over a space of half an inch in a quarter of an hour.

Such, likewife, is the female of thofe animals, called by Reaumur, gall-infects, and which have always been taken in Europe, for real galls. When the female of this infect is with young, he becomes incapable of changing place, the, lofes the figure of an animal, and affumes that of thofe excrefcences, commonly called by the name of galls.

Such, likewife, is that fpecies of tænia, or flat and articulated worm of the human body, whofe head has not been obferved, and which, it is faid, is incapable of motion.Laftly, fuch is that animal, common in ditches, the form of which, has fome refemblance to the feed of the dandelion, (Hydra polypus.)

It is generally fixed by its extremity, to fome other body, without changing place, except very rarely. It has not the appearance of an animated being: if it is cut in two, and even into three parts, each part recovers, and affumes the figure of the whole, and thus, there are two or three animals made out of one. The young iffue from its fides, by a fort of flow and infenfible vegetation, and having grown in this manner, for a certain time, like branches, and having, even themfelves, puthed out young in the fame way, they are detached from the mother, and live apart. By the greater part of these circumftances, one could fcarcely hefitate to rank it among common vegetables; but, when it is more narrowly examined, we perceive, that, when the water around it is agitated, it contracts and draws itself in, then expands itfelf again, so that we begin to think it ought to be claffed above ordinary vegetables, and to be considered as a fenfitive plant. But, upon ftill narrower infpection, from time to time, when we find, that it is capable of voJuntary motion, and that it does not always continue in the fame ipot, but that it tranfports itfelf from one place to a

nother,

nother, by a motion, which, though very flow, is evident, that it even endeavours to get towards the places which are moft enlightened, that the beards which are placed round its anterior extremity, furnish it, by their vifcidity, with the means of catching the fmall water infects that come in its way, that these beards ferve it for arms to carry the infects to its mouth, and that afterwards it fwallows them; we are sensible, that it is not enongh to place it with the fenfitive plants, but that it must be acknowledged as a true animal. Befides, the vegetable and animal kingdoms approach each other fo nearly, by means of this equivocal being, that M. Trembley, a very attentive obferver, and who had verified the facts I have just mentioned, before me, was not able, till after a diligent obfervation of it, for many months, to determine, that it was actually an animal.

PAGE 39, 1. 21.

They are not furnished with bones. This obfervation of the author, that infects are deftitute of bones, appears to me pretty juft: I even believe, that one of the beft characters for diftinguifhing infects from other animals, would be their want of an internal skeleton. It cannot be denied, however, that, if infects have not bones, many of them have parts that answer the purpofe of bones. The fnail, for inftance, has, within its body, according to Swammerdam, a ftony tubercle, in which many of the nerves of that animal terminate. Caterpillars, and many other creeping infects have their head defended by a hard thell-like covering, and often too, a fimilar part above their firft ring or fegment, many of the larvae that change into beetles, and even the beetles themselves, the fea eggs, lobsters, crabs, &c. are `all armed with a fhell. Lepidopterous infects and all flies have the thorax hard enough to refift moderate preffure. The ichneumons in general, have it very hard; I have seen fome of thefe, whofe thorax was fo hard, that it bent very ftrong pins I wanted to pierce them with. Thefe parts, however, differ from true bones. 1. By being rather fhell`like, stony or cruftaceous, than offeous. 2. By being placed, (except in the flug) on the outfide of the body, and not in the infide. 3. By being forined in many, if not in all infects, not by a fap which circulates in thefe fhells, but by a fimple appofition of particles, which tranfpire from the body of the animal, and afterwards grow hard. 4. By thefe

fhells

fhells being apparently given for a covering or defence. And 5. By their being fo little effential to the internal conftruction of the body of infects, that it is in a manner demonftrated, that the covers of fhell fish are loofened, whenever their enlargement requires that the muscles they are attached by change their place; it is alfo certain, that many often caft their fhells, and that a great number of thofe that are beft armed, exist and act all the time which has preceded their ultimate transformation, without having had any thing of the kind on their body. It would feem, therefore, that the name of bone, cannot be given, with propriety, to thofe fhells or cruftaceous coverings. Indeed, this matter is liable to fome difficulty, in the cafe of the flug. Its ftony part has been bestowed on it, neither for a covering nor a defence. It feems to exift within the body, merely as a fixed point for the mufcles to reft on, and to perform the function of a bone. However, when we confider on one fide, that this mafs has lefs the form and fubstance of a bone, than it has of fomething lapideous; that befides, it is fingle in the body of the flug, and only occupies there, a very small space, while the bones, in every animal poffeffed of them, are found in great numbers, and form, almost always, a skeleton of connected pieces, which fupport, internally, the whole mafs of the body, it does not appear, that this fingularity, which takes place in the flug, is fufficient to make it an exception to the rule. 1 make the fame obfervation, with refpect to thofe cartilaginous parts, which are found internally attached to the calcareous covers of lobsters, and which they quit, when they caft their fhells; being nothing but cartilages, and by no means true bones.

I know, that fome curious obfervers, when tearing away from the leg of a flea, the hard part, which covers the arti culation next the body, have thought they perceived a bone, in the place which the removal of the hard part had left bare; but I know likewife, that the leg of a flea is an object too finall, to allow us to affirm, even with the aid of a microfcope, that what we there fee, is a bone, and not a nerve, or rather, a part of the very fubftance of the leg. If there was a bone in the leg of a flea, we fhould much rather expect to find it in the leg of fome larger infect, efpecially among thofe whofe legs refemble thofe of the flea, as the grafhopper; but nobody has hitherto difcovered any

1

thing like one in it. Add to this, that the legs of a flea being armed with hard fhells, it is not eafy to conceive, of what use bones would be to them, thefe fhells being alone more than fufficient for fupporting the action of the nerves and muscles, and for preventing their limbs from folding between two articulations.

But if, after all, experiment, fuperior to any reafoning, fhould enable us to difcover true bones in an infect, this fingularity, which would approximate the ftructure of it to that of other animals, would not be fufficient to remove it from the clafs of infects; but, as it feems established in nature, that in every kind of created beings, whofe extremi ties approach each other, there are always limits which feparate them, and that one of the chief, and most conftant of thofe limits between infects and other animals, feems to be the internal skeleton given to the one, and not to the others, it would feem, that we cannot, without confounding the claffes of beings really diftinét, rank among infects, any animal, poffeffed internally of a skeleton formed by a contiguity of bones. I conclude, therefore, that this contiguity alone, is fufficient to exclude every a imal in which it is found, from the number of infects.

PAGE 39, 1. 27.

Whofe fubftance is not flesh. What the author remarks here in pafling, to wit, that the fubftance of infects, properly speaking, is not flesh, may furnish a fecond mark for diftinguishing infects from other animals, that is, that if we find an animal, whofe fubftance does not resemble flesh, we may conclude, that it is an infect. But we muft not carry this too far; we would fall into mistakes, were we to conclude, that an animal is not an infect, because it has a fubftance fimilar to flefh; for crabs, lobsters, and fome other animals of the fame order have actually flesh, though they are undoubtedly infects. Befides, as the question is, how infects are to be diftinguished from all other animals, and confequently alfo, from fifhes, it is evident, that the expreffions, flesh and bones, made ufe of by us, must be taken in a very extended fenfe, in order to comprehend the fubtance and bones of fishes.

PAGE 39, 1. 30.

Infects are deftitute of blood. The blood of infects is not

red,

red, and this is a third diftinctive character. But, as it is very rare to find in Natural Hiftory, any rules without exceptions, the rule that infects want red blood, fuffers an exception, both in the earth worm, whose blood has a tinge of red, and in a certain thelled fnail, very common in the ditches in Holland, whofe blood is purple. Perhaps too, it may be thought another exception to the rule, that many files, when they are killed, produce large fpots, of a very bright and deep red. But it must be remarked, that thefe are by no means the blood of the fly. When they were in the maggot ftate, nothing fimilar was to be observed in them; and when changed into flies, this red matter is not found in their bodies, as it ought neceffarily to be, were it blood which circulates in their veins. It is only found in their eyes, where it affifts most probably the organ of fight, I know, that blood is fometimes remarked in the bodies of gnats, and of fome flies; but, if we attend accurately to the circumstance, we fhall find, that it is not to be found, except in the bodies of thofe gnats and flies, which fuck the blood of animals; and this blood will be found, only in their ftomachs, or in their inteftines: an evident proof, that this blood is that of the animals they attack, as the author has obferved,

PAGE 40, l. 1,

If we compare infes. Here is a fourth character, very ufeful as a diftinguifhing mark of infects; for though fome of them equal, and even furpafs in fize, the smallest of the other animals, it may, however, be faid, confidering things in general, that, to defcend from the greatest animals to the fmalleft, infects begin nearly where the others end.

To thefe four characters, which refpect the bodies of infects, as to fubftance and extenfion, we may add five others, which have a reference to their external form, and which are not lefs proper for distinguishing infects from the other animals, than the preceding characters. The first is men, tioned by Mr Leffer, and confifts in this, that the bodies of the greater part of infects are, as it were, divided by incifures, which has given rife to the name they bear. The fecond, is, that no infect without wings has only four feet, nor any flying infect but two. The third, that they have no vifible noftril, or external ears: but, that they have their organs of refpiration, either in their thorax or abdomen.

The