and moths. In the laft fort of transformation, the infect, after having arrived at the nymph ftate, like those before mentioned, does not diveft itself of its fkin in order to enter into that ftate, but affumes the form of a nymph under its fkin, where it continues thut up, till quitting two fkins at once, it comes forth in its perfect ftate. This is the metamorphofis which flies, Ichneumons, &c, undergo.

Befides thefe changes, infects feveral times cat their skins; but this does not happen to them all at the fame time or in the fame way. Some, as fpiders, change their fkins only once a-year; others as grafshoppers, and the cabbage caterpillars change it four times; and others even fix times. The greater part quit it entirely, but fome retain it attached to the extremity of the abdomen, and carry it over their head to defend them from bad weather, or other infects their enemies. This is the cafe, as Frifch obferves, with the Caffida nebulofa. The manner in which they diveft themselves of it, varies alfo according to the diverfity of fpecies. In fome it is rent near the top of the head, and the infect puts it off as one draws off a stocking. In others it is firft torn under the belly, and they throw it over their head as one does a flirt. The fpoils of many infects preferve exactly the figure of the animal, which is particularly remarkable in thofe of fpiders. Some of thefe cait fkins, are lined internally with a white membrane much more delicate than the outer one. When thrown off, they are fometimes fo contracted as not to retain a third of their former length; at other times they appear fwollen, and difcover nothing b the hole through which the infect made its exit. in

not

When the infect has thrown off its laft fkiy the pears in the state of a nymph or chryfali, rench

I

method of

are only covers under which the animal is formed, and which it preferves till it has taken its natural fhape. Thefe nymphs are foft at firft, and contain fome liquid matter which in time evaporates, and they acquire more confiftence; but in general they are very thin and fragile.

Infects in this ftate may be divided into two claffes. There are fome of a conical fhape, almoft of the figure of a date; others of an angulated form, with fharp corners at the rings and anterior part, and little elevations at thefe corners. There is a great diverfity in their figure. Without mentioning thofe that are of the form of a date, fome have the appearance of a child in fwaddling cloaths laid in a cradle; others have the face of a man. Others refemble the head of a dog, a cat, a bird, a moufe with its tail, and even of the Infect itself which is to proceed from it.

The limbs of infects are not folded with lefs art in chryfalids and nymphs than they are in the egg. It is wonderful to fee the artifice with which they are difpofed, and the wildom which has contrived to lodge in so small a space, fo many different members without hurting them, or producing the leaft confufion. In fome we may perceive externally all the limbs of the animal it enclofes; others are fo tranfparent that the infect is eafily difcoverable upon looking through it but others must be opened before we can judge of the infect they contain.

Great variety is remarkable, in the colour of chrythelids. Brown, yellow, red, green, white, violet and undeck are the chief; but it must be obferved that nymple colours appear in various degrees, and that the fupe different fhades of them may be perceived in ftate, wnt forts of chryfalids, and in fome mingled includes much art, that the eye is aftonished in viewThe ancients imagined that the beauty of

the

the colours in a chryfalis was a proof of the beauty of the infect it contained; but nothing is more deceitful; we might as well fay that the beauty of a cradle was an indication of the beauty of the child that flept in it. Befides, experience teaches us that a plain infect very often iffues from a gilded chryfalis, while another with a lefs fpecious appearance often produces a véry gaudy one.

No motion is perceived in fome of those infects while they continue in this ftage of transformation; but as this incapacity of moving themselves might expose them to be devoured by their enemies, they fhelter themfelves under a ftone, a root, or a piece of wood. This is not all, they make that fide which is expofed, fo round and tenfe, that worms cannot lay hold of them. They are not however all motionlefs. Some spontaneously agitate themfelves, and others do not move except they are touched. These last, on fuch occafions move their abdomen and fhake their heads as if to defend themselves, and intimidate their enemy. There are likewife fome (as the Dytifcus latiflimus) which when turned upon their back, inftantly replace themfelves, in their first fituation. Others, (as the Coccinella feptempunctata,) turn themfelves round for fome time. Others though they are in general motionlefs, if they are taken into the hand, feem to be revived by the heat which puts their humours in circulation, and makes them perform various contorfions. But. neither the one nor the other take the leaft nourifh

ment during the time they continue in the pupa ftate.

The precaution of choofing a convenient place in order to preferve themfelves from injuries, does not always appear to them fufficient; they fortify the place they have chofen with a kind of entrenchment against attacks from without. The method

of fome is to fufpend themselves by the tail to threads which they draw from their own bodies, and thus they are fafe from the attacks of creeping infects, and they hold fo firmly by these threads that they are not easily detached. Others weave around them a web with large meshes, nearly refembling a fifher's net this keeps at a diftance from the centre fuch infects as might injure them, and prevents their being hurt by the fall of any body. Thefe two precautions are peculiar to thofe only which have fkins, fufficiently thick to refift the inclemencies of the weather. Thole which have not the fame advantage cover themselves with a particular fort of web. Some fpin cones of filk, others difcharge from the pores of their body a fort of long wool which covers them during all the time they remain in the nymph ftate. Many fortify thefe cones with their Lairs, which they diveft themselves of, (as the Phalana Caja ;) and thofe that have no hairs, and alfo want filk, gnaw pieces of wood, and employ the fmall bits in fortifying the infide and cutfide of their manfion, as is the practice of the Phalana aceris. Some of these cones are fo hard and fo well conftructed that they are with difficulty torn; they may be properly com pared to parchment. To connect the threads toge ther, they moiften them with a fort of gum which if fues from their bodies, and which gives their work the neceffary degree of hardnefs. The cones are not all of the fame figure. The greater part are oval or fpheroidal, but there are fome that reprefent an egg cut longitudinally. They are attached by the flat fide to fomething folid which may contribute to their fafe y. The precautions of fome are not confined folely to unis external one: in order the better to fhelter themselves against the inclemency of the weather, they cover it with a leaf, or many leaves gathered together; others enter into the earth and hide themselves there, but for fear of its falling, they either plafter the

walls

walls of their refidence with a fort of vifcid fubftance or line them with filk.

The period of their change into chryfalids or nymphs is fixed. Some change in May, fome in June; others in July, Auguft and September. The time of emerging from this ftate is alfo regulated. Some remain in it only twelve days, while others continue fifteen, fixteen or twenty. Some do not get free from their prifon fo foon, but are detained there three weeks or a month; others even two months, others fix, others nine, ten, and even fome a whole year; as the Phalana Abfynthii. It is eafy then to conceive that infects muft iffue from their cones

in different months of the year. We find them ap pearing in the months of February, March, April, May, June, July, and Auguft, and even in November and December. Some infects have this remark. able property, that they produce two broods that if fue from their prifon at two different feafons of the year, and prefent themfelves on the theatre of the world; for it deferves particular attention, that they never come forth, but at the time when there are plants and leaves fufficient to furnish them with food. Without this wife ordination of the providence of God, thefe little creatures would perish at their birth.

May I not now be allowed to afk if thefe transformations can be the effect of chance? If they were, is it poffible that there could be fo much regularity and order in the different particulars neceflary to operate fuch wonderful metamorphofes? Whatever is the effect of chance is fubject to no fixed, no determinate order. To day it operates in one way, to morrow in another, but here all is regular without the fhadow of variation. Who is it then who has taught these infects to accomplish what is neceffary,

each