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PAGE 153, l. 11.

Furnished with a margin. One of the most effential diAinctions between these articulations, is, that some are placed end to end, while others inclofe the extremity of the one next them, and flip into one another, as in a groove.

PAGE 153, 1. 15.

All caterpillars have ten. They have twelve, counting the pofterior extremity, and the first articulation, which the author seems to take for the neck. It is not fo easy to explain how M. Andri was led into the mistake, as he counts only feven articulations in the filk worm, fixteen, and even more in other caterpillars, and twelve in the ant. One would not have expected to find fuch an affertion in a book written exprefsly on infects. If his obfervations on the worms which infeft the human inteftines, were all in the fame taste, his work would little deserve those encomiums which fill the first pages of his book.-See Andri de la Gener. des vers, dans le corps de l'homme.

PAGE 153, 1. 18.

A larva of a Tenthredo. Those which we have called pfeudo-caterpillars, as I think I have already faid, have properly but twelve articulations, like true caterpillars. But there are fome of thofe pfeudo-caterpillars, which have their articulations fubdivided into others, and thefe M. Lef fer feems to have counted as diftinct fegments.

PAGE 154, 1. 4.

The infect called Hippocampus. I have fhewn elsewhere, that this animal is not an infect, but a true fish.

PAGE 154, l. 7.

Furnished with a small bag. This has the appearance of a bag only on paper. Frisch gives the name of bag to the extremity of the abdomen, in the infects of the Genus, Sphex, Lin. which have that part of a different colour from the reft: and this, because the colour which diftinguishes it, makes it appear, as if it were inclofed in a bag. He gives thefe infects the name of fack-wefpen, or wafps with a bag, to distinguish them from other wafps. It is from him that

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Leffer

Leffer gives the name of bag, to the pofterior extremity of thefe infects.

PAGE 155, 1. 8.

The papilla, from which they draw their threads. Spiders, which M. Leffer has here in view, have each, according to M. Reaumur, (Mem. de l'Academie de Sciences, 1713,) fix of these papillæ. The extremity of a papilla, in one of the house fpiders, when magnified by the microscope, appeared divided into an infinity of protuberances, fmaller, but difpofed much in the fame way, with those that occupy the cornea in the eyes of Mufcæ. Each protuberance or convexity, in this cafe, undoubtedly affords a different thread, or rather, it is probable, that each concavity, fituated between those convexities, is pierced by a hole, through which the thread iffues; the fmall elevations feem intended to prevent the threads from joining at their exit. These convexities are not so apparent, at the extremities of the papillæ, in garden fpiders; but there is obfervable, a quantity of small hairs, which probably serve the fame purpose, that is, to feparate the threads from one another. However this may be, it is certain, that of every teat in a spider, threads may be drawn from a thousand different places; fo that the fpider, having fix of these papillæ, has holes to allow a paffage to fix thousand different threads; and what is ftill more wonderful, these threads are already formed, when they arrive at the papillæ, and they have each its own little tract, which conducts it thither. These little tracts are, moreover, inclofed in different fleshy tubes, which Reaumur supposes to be equal in number to the papillæ; these tubes terminate in winding veffels, which he calls the great refervoirs, and of which there are three on each fide of the fpider; these three unite at a very long branch, which takes a ferpentine course,and after having formed feveral turns, each terminates in a veffel which has the form of a tear of glass. These two veffels, are those which Reaumur confiders as the original fources of the threads of spiders. Who could have imagined, that the formation of a fpider's web required fuch apparatus; or, that the papillæ of fo vile an animal, was an object fo worthy of admiration!

PAGE 155, 1. 16.

A fort of horns. It is faid, that in fome infects, as for inftance,

inftance, in the aphides, thefe horns are the organs of refpiration.

PAGE 156, 1. 3.

*Forwards under the belly. As for inftance, in the large reddifh yellow fpider, of which Frifch gives the hiftory, (Aranea diadema.) The Author.

It appears from this note that the author is fpeaking of a particular fpecies of fpider. That fpecies I have not had an opportunity of obferving, but I have examined several other fpecies, and I can affirm, that I have found the male organs placed at the head, while thofe of the females were fituated in the belly, precifely in the spot where Frisch places thofe of the male in queftion. This would make me fufpect that the fpider he mentions was a female, and the more as he reprefents its body as exceedingly large, a property peculiar to the females of spiders, for I have always found the males with an abdomen proportionally slender. Lyonet.

PAGE 156, 1. 5.

Situated as in the males. This is in general the cafe, but there are however fome exceptions. The inftance of the fpider mentioned in the preceding note is fufficient to fhew, that there are infects whofe male organs are placed differently from thofe of the female.

PAGE 156, 1. 10.

Some likewife have a sting at the extremity. The author understands here by the word fting, not only that part which ferves as an inftrument of offence; but also that organ which serves as a conduit to their eggs when they introduce them into bodies which for that purpose they need to pierce. As thofe parts are very different, it would be better to distinguish them by different names; that which ferves them for introducing their eggs, might be called the tail, (Cauda Lin.) and the term fting (Aculeus Lin.) appropriated to that which is properly fo.

PAGE 157, 1. 3.

Often more than half an inch in length. There are ichneumons in my collection with tails near two inches long, and furpaffing greatly the length of the infect itself. It is fel

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dom

dom that the tails of infects, which have any, terminate in a pointed knob. The greater part of them have a cylind rical form without any fenfible thickness at the extremity.

PAGE 157, 1. 25.

*Thofe which depofite their eggs in other infects. Ichneu. mons depofite their eggs in the bodies of caterpillars where they are hatched, and produce larvæ; thefe larvæ maintain themselves there, and feed on the fubftance of the caterpil lars which thereby become weak and languishing. When the larvæ have attained their size, and neither find room nor food in the caterpillar, they make their way through its skin and then the caterpillar dies.

PAGE 157, 1. 31.

They use it as a pike or lance. The fting is by no means an organ peculiar to the male infects. Among bees for inftance the males have no fting; it is the fame with wafps. The females only and the neuters are provided with it.

PAGE 158, 1. firft.

Which they ufe as a fpiracle. There are fome aquatic infects which can elongate their tails to an aftonishing degree. The rat-tailed larvæ are well known, not indeed so much by that name given them by Reaumur, as by the form of their tail. This organ, though longer than the animal, is only the cafe of another tail longer ftill, which is capable of great contraction, and enters into the body of the larva. This laft tail is the organ of its refpiration. It raises it to the furface of the water to take in air, and while itself remains at the bottom, it can send this tail to the furface tho the water fhould be nearly five inches deep; fo that it can extend its tail nearly five inches, a very confiderable length for an animal only feven or eight lines long. See Reaumur, Toм. IV. and Scottish Regifter, VOL. II.

PAGE 158, 1. 12.

*Larva that have their feet on the back. This is an observation of M. de Reaumur, as may be feen in the Mem. of the Royal Academy of Sciences, 1714, P. 103, and Frifch, P. 11. N. 7. The author.

I am not surprised that the author fhould advance fo pofitively that there is a particular class of infects both aqua

tic and terreftrial, which before their transformation have their feet on the back; but which are no fooner divested of their skin, and begin to fly, than they have their feet under the belly. Frifch in the place here quoted, expreffes himself on this head in a manner fo decifive, that it would appear incredulity to hefitate a moment in believing that there were fuch infects. These are his words when speaking of the infect we shall immediately mention. "greatest fingularity in this larva is, that it has its fix legs 66 on its back. M. de Reaumur, in the Memoirs of the "Academy of Sciences, has well defcribed a fpecies of a"quatic larva, which has likewife its feet on the back; he " fays he is uncertain under what division of infects to class "it. For my part, I make a particular class of these "infects, whether aquatic or terreftrial, that is, of those "infects which before their transformation, have their "feet upon the back. To this class, belongs the infect def"cribed by Reaumur, and the beetle in queftion. &c." Would not one imagine from this paffage that Frisch had difcovered a great number of infects of this kind, and that it only remained to clafs them? He cites however only thefe two fpecies, and I do not remember that there is ano ther inftance in his work. I do not mean to deny that there may perhaps be infects, that have at first their feet upon the back, and which, after their transformation, have them then under the belly; yet I think the circumstance very unlikely, and it has never hitherto occurred to me. It ap pears however, that Mr Frifch has been rather precipitate in establishing a clafs for fuch. M. de Reaumur does not affirm as a well afcertained fact, that the fingular infect which he defcribes in the Memoirs of the Academy, has actually its feet on its back. He fays only that it has them on the back, or on the oppofite fide to its belly, fuppofing the belly to be on that fide where the mouth and the anus are fituated, and towards which the head generally inclines, So that if this infect had accidentally its head and the anus placed a little differently from what is the ordinary position in infects, a circumftance not altogether fingular, it might, notwithstanding these appearances to the contrary, ftill have its feet on the fide oppofite to the back. Befides, neither Reaumur nor Frifch had feen the transformation of this a nimal, at least they do not mention their having feen it; and

if

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