nished with two rigid roftrums. The Serphi firft become nymphs, and then change into Dytifci or Hemerobii.

The fixth clafs, called Bugones, confifts of fuch larve as have a round horny head, furnished with teeth fecking out; no feet. Thofe change into nymphs, and afterwards be come infects of the Hymenoptera order.

The feventh clafs, Rauce, have the head horny, and therefore unchangeable in its figure, but without exferted teeth. No horny feet. The Raucæ change into chryfalids or nymphs, and thefe into infects of the Diptera order.

The eighth and laft clafs is called Mida. The larvæ have a fmall membranaceous head, capable of changing its figure. Feet membranaceous, or none. All the Midæ pass through the state of nymph, into the order of Diptera, as far as is yet known.

PAGE 64, 1. 15.

Fleas, Onifci, &c. If we may believe Leuenhoeck, fleas, at iffuing from the egg, are worms which change into nymphs before affuming the form under which we know them; if this is fo, they belong to the third clafs, and not to the firft.

The onifci are viviparous, and suffer no transformation, confequently they belong to none of the four claffes. If any of them are oviparous as fome have affirmed, they may here find a place.

PAGE 64, 1. 26.

Ants. Ants do not belong to the fecond, but to the third clafs accordingly Swammerdain places them there in his HIST. GEN. P. 179. It is probable that Mr Leffer has claffed them thus by an overfight, for Swammerdam, at P. 176, which the author quotes, explains the fecond order of tranfformations by the example of dragon flies, and not by that of ants.

PAGE 64, 1. 27.

Aquatic flies. All aquatic flies do not belong to the fecond clafs. Many fpecies of them belong to the third as the different forts of Phryganeas; and many to the fourth, as all the Afili.

PAGE

PAGE 65, 1. 7.

This is the metamorpholis which flies and Ichneumons undergo. That is, the greater part of flies with two wings. I do not recollect of ever having obferved any with four wings which belonged to this clafs.

The Germans give the name of baftard wafps to those infects which the French call Ichneumons. I have obferved the transformations of many fpecies of thefe, but I never faw one that could be referred to the fourth clafs as it is here defcribed. Swammerdam to make this clafs, it would feem, more numerous, has comprehended in it many infects which properly belong to the third, and hence has arifen the error of the author.

PAGE 65, 1. 14.

Even fix times. There are infects which change their fkins ftill oftener. I know one caterpillar which does not become a chryfalis till it has caft its kin eight times; and another which changes its fkin nine times.

PAGE 66, 1. 5.

*Madame Merian relates of a caterpillar that feeds on the lime tree, that its chryfalis was as hard as a piece of wood, and that no force could bend it. P. II. n. 24. P. 47; but of the truth of this I am in doubt.

The hardness of this chryfalis is a fign that it was dead and dried. When the animals are alive, they are never so stiff and hard. Madame Merian seems to have been afterwards convinced of this; for my Latin Edition which mentions the fame caterterpillar takes no notice of this fingular circumstance.

PAGE 66, 1. 14.

The appearance of a child in fraddling clothes. All these reprefentations are very imperfect, and require the affistance of fancy to find them out. The most remarkable that I know is that of the chryfalis of the Papilio polychloros. There is actually on its back fome refemblance to a face; but what really deferves attention in these chryfalids is, that when we know in what manner the parts of the infect are arranged in them, it is not difficult to trace the head, the eyes, the antenpæ, the probofcis, the thorax, the legs and the abdomen. In

nymphs

nymphs all these parts appear more diftinctly, and in those I have called Semi-nymphs they are visible at first sight.

PAGE 66, 1. 23.

*Or producing the leaft confufion. This is obfervable in the nymph of the Chryfomela Afparagi. Its antennæ defcend along its shoulders: its four first legs are laid upon its breaft; the other two paffing between the wings, join towards the tail, and the wings themselves are applied clofe to the abdomen.

This difpofition of the members, is very common in the nymphs of all coleopterous infects.

*

PAGE 66, 1. 24.

Externally all the limbs. Thus in the nymph of the Scarabæus fimetarius we discover all the limbs of the future infect. The Author.

This is feen with the fame facility in the nymphs of all beetles, Tenthredos, Ichneumons and feveral other forts of flies. Lyonet.

PAGE 66, 1. 29.

The colour of chrysalids. The chefnut colour prevails in the cone-shaped chryfalids, but I have never obferved it in the angulated ones.

Befides the colours which the author enumerates, nothing is more common than to find a fort of gilding on the angulated chrysalids. I have even feen fome that were all over fo brilliant, that at firft fight, one would have taken them for a piece of pure gold.

I do not know that any gilding has been difcovered on the cone-shaped chryfalids; I have feen however a species of thofe caterpillars called Geometræ, which may be faid to be gilded, but with a gold much darker than that of the angulated chryfalids.

This gilding does not appear at firft on the chryfalids; it is only gradually affumed as they acquire by degrees their due confiftency. The Alchymifts oblerving this production did not fail to draw from it a conclufion favourable to their hopes; but nothing could prove more fallacious; this gilding fo beautiful and fhining, has nothing of gold but its gliftering. It owes all its fplendor to the luftrous white of the body of the animal, which fhining through the yellow, transparent

cover of the chryfalis, produces an effect so wonderful. This M. Reaumur difcovered, and he has given a very particular explanation of it in his first volume, Mem. X.

PAGE 67, 1. 8.

A very gaudy one. To give an example of this; the female of the Phalana antiqua is a very ugly, ill-fhaped animal; but its chryfalis, for the regular diftribution of the black and white marks with which it is generally adorned, is one of the most beautiful of any. On the other hand, the caterpillar Cloporte du Chene is one of the uglieft, and yet it produces a very elegant butterfly.

PAGE 67, 1. 29.

Take the leaft nourishment. Indeed it is perfectly impoffible that they can take any, not only because the animal in this ftate is too weak to be active, but because the fkin, which envelopes the chryfalis, covers all the parts of the body, and confines them as in a cafe from which the infect cannot extricate itself till the moment of its appearance in the perfect state arrives.

PAGE 68, 1. 12.

Thofe which have not the fame advantage. It is not always on account of the delicacy of their cover, that many infects are careful to fabricate very thick cones which are often impenetrable to the air. There are fome which are much harder and firmer than thofe which remain fufpended in the open air, which laft however make very solid The reafon of fuch a diffimilar method of preceeding feems to be that fome nymphs and chryfalids require a flower and more infenfible perfpiration than others, either for their developement in the proper feafon, or for taking the form of a perfect infect. What confirms me in this 'opinion is, that when I have taken thofe nymphs and chryfalids which form thick cones out of their lurking places, I have always obferved, either that they came forth fooner than ordinary, or that the infects which they produced were imperfect, or that they grew dry, and died without coming. forth.

PAGE 6, 1. 15.

* A fort of long wool. The Germans call thefe infects

wool-fuckers, as we learn from Frifch: what the fame author favs of the Cochineal is very remarkable. The pores of its back are very clofe, and there iffue from them little fhort hairs which cover the back in a fhort time with a kind of co ton; the abdomen which is defended by its fituation, produces no fuch hairs. If this coat is rubbed off, the infect foon acquires another. The Auhor.

Obferve that the infect here mentioned is not the Cocheneal, but the Kermes. Lyonet.

PAGE 68, 1. 21.

Outfide of their manfion. This is the practice of the infect called by the Germans the Camel, because it has two protuberances on its back. Reaumur and Linnæus call it the zic-zac, (Phalana zic-zac) because it commonly moves its body in a zig-zag direction.

PAGE 68, 1. 30.

Represent an egg. There are likewife chryfalids of other figures, as the conical, the cylindrical, the angulated. There are fome in the fhape of a boat, of a turnip, of a drop or tear of glass, the body of which is fwelled out, and the point incurvated. I have known fome compofed of two oval convex pieces, attached to each other by a plain furface, which is of equal breadth, and correfponds to the curvature of their outlines.

PAGE 69, 1. 3.

The period of change into chrysalids is fixed. Thefe periods are not fo conftant but that a degree more or less of heat or cold will fenfibly affect them. The fame infect which in the middle of fummer fhall have acquired its utmost fize in lefs than three weeks, will need as many months, and even much more if it comes forth in the end of the season. Such a nymph or chryfalis which in fummer will change into a winged infect in fifteen days, will employ fometimes fix, feven or eight months for the fame purpose, merely for having gone into the chryfalis ftate a few days later than those which have changed fo rapidly..

Thefe irregularities, caufed by the occafional prevalence of heat or cold, muft not be confidered as a diforder in nature; they are an effect of the infinite wisdom of the Creator, who by this means prevents infects which live lefs or

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