if they did not fee it, how could Frisch clafs this infect with those which, after their transformation, have the legs under the belly? How could he even affirm that it is among the number of thofe that undergo transformation? I come now to his own infect, which is the fingle one we can begin with in establishing this new clafs. I have examined this infect which is one of the largest found in this country, and confequently fo much the cafier examined. (It is the Dytifeus piceus Lin.) I have fed it, and followed it in its transformations from the egg to its becoming the perfect infect, which Frifch could not do, as he did not know its proper food; and the fruit I have reaped from my attention is, not only the discovery of many remarkable properties, but the pri vilege of affirming pofitively, and with more confidence than Frisch does the contrary, that the infect in question has, in every ftage of its life, the legs placed in the under fide like all other infects. It would be fufficient to look at it fwiming to be convinced of this; but I have much more certain proofs; I have made the infects change into nymphs under my eye, and I have feen them very diftinctly in the act of withdrawing their feet from the cruftaceous cover under which they performed the office of feet, while the infects were ftill in a state of larva. This is not all; as I have brought up many, it has fometimes happened that when they were preparing themfelves to appear in the ftate of nymph, fome of them have not been able to extricate their head from the old cranium: and therefore their skin burst on different parts of their body, without their being able to difengage themselves from the fragments. I have then taken them, and have removed the skin from the place oppofite to that where the feet of the infect were placed; here according to Frisch, the limbs of the nymph ought neceffarily to have been found, but I never found there any thing refembling them; afterwards I difengaged the head from the old cranium, but when I attempted to remove the skin from the place where the feet were fituated in its larva state, I never could fucceed, the feet of the nymph being there entangled in the cruftaceous cover of those of the infect; that cover ferved them as a fheath, and to it they were attached fo ftrongly that I could not difengage them without their breaking. I had thus a nymph which had its fix feet broken off, and of which the part torn away, remained in the cruftaceous cover of the feet of the infect. Can there be a stronger proof that this animal in its creeping ftate, has its feet

precifely

precifely in the fame place they are fituated in, while in the nymph ftate, and confequently alfo in its state of perfect infect, that is, under the belly, and by no means on the back, as Frifch afferts?

The circumstance that may have led him into this error, is, that this animal has not its head inclined towards the belly, as is the cafe with almost all other infects, but that it carries it a little bending backwards. This fituation of the head feems to have been given it to enable it the more commodiously to eat those small fnails which are its common food. Thefe fnails are found among the Ducks-meat which fwims on the furface of the water. In order to seize these, the reverfed fituation of the head makes it eafy for them when they are below. After laying hold of them, the thell is to be broken in order to get at the animal; this cannot be done but by refting the inail upon fomething to keep it faft; the feet of the larva are not adapted to this purpose, they are too weak, too distant, and have neither claws nor nails; accordingly, in this cafe they are useless. It is to their back that they have recourfe; it ferves them for a fixed point, on which to break the fhell, and as a table on which to eat the fnail enclosed in it. When they have seized it with their teeth, they fold themfelves back, they raise the back a little, and on it, they lay down the fnail. In this attitude their head naturally a little inclined backwards, bears more perpendicularly on the fnail, and makes it more eafy for them to break the fhell, and to swallow the animal, than if their head were inclined downwards.

There is another circumftance that may have milled Frisch, which is, that the infect in queftion, when it prepares to change into a nymph, does not bend itself forwards, as do moft terrestrial infects, but backwards, like fome other aquatic infects, of which perhaps Frisch had never obferved the transformations; and in the opinion that all insects, when they difpofe themselves for their change, appear incurvated towards the belly, the contrary attitude in which he had feen the animal in queftion may have contributed to make him take for the belly of the infect, what was really its back.

PAGE 158, 1. 18.

Such are all caterpillars. Caterpillars properly fo called,

and

and which have this name in contra-diftinction to other larvæ, and to those called Geometræ, have generally fixteen feet; fix anterior, eight intermediate, and two posterior. The pofterior and the intermediate, properly fpeaking, have no articulation. They are capable of elongation, contraction and flexure in every direction, without having any apparent joint. Being purely membraneous, thofe fixed fulcra, and that stiffnefs of parts neceffary to; the existence of a true articulation are wanting. As to the anterior feet, they terminate, it is true, in a pointed hook: but that hook does not conftitute the foot, and when it is examined minutely, there are distinguishable three articulations at least, small indeed, but very diftinct. If there be infects whose feet have but one articulation, the fingular water-Tipula I have mentioned above, Page 315, may be ranked in the number.

PAGE 158, 1. 33.

The fore legs in fome being the longest. Plin. Lib. xi. CAP. 48. Infectorum pedes primi longiores duros habentibus oculos, ut fubinde pedibus eos tergeant, ceu notamus in mufcis.

If that obfervation be true, the flies in the country of Pliny, and the other infects with hard lenticular eyes must be made differently from thofe in this country; for here we hardly fee one which has not the anterior pair fhorter than the intermediate or pofterior.

PAGE. 159. 1. 19.

*Some have a fort of cup at the knee joint. The larger Dytifci have within this cup at the knee, a muscle which they can retract. When they have applied this cup against any thing, it connects itself therewith fo closely, that no air can enter within it, and then by contracting the muscle, the void which is then formed, renders the adhesion the strongIt is by this organ that the infect attaches itself closely to the female, to its prey, or to any other object it pleafes. The Author.

er.

The cup here mentioned, is fituated on the firft pair of feet. The males of many fpecies of Dytifci are furnished with it, but I have never obferved it on the feet of the females. This affords a prefumption that it is beftowed on the males to enable them to fasten themselves more fecurely

to the females at the time of coupling; and accordingly they do not fail to employ it for this purpose..

PAGE 160, 1. 3.

Thus Aristotle

* Some employ their feet in cleaning. fays:-De partib. Animal. L. IV. CAP. 6. Pedes priores nonnulla ex iis longiores ideo habent, ut quoniam propter oculorum duritiem non exquifite cernant, cruribus iis longi- oribus abftergeant incidentem moleftiam atque arceant &c. See too Pliny L. xi. Cap. 48.

I have already remarked above on the paffage of Pliny here refered to, that almost all the infects of this country have the anterior pair of feet thorter than the rest.

PAGE 160, 1. 6.

Thofe which dig in the earth. The ftrength which nature hath given to the feet of many forts of infects which use them for this purpose, is astonishing when we confider their minutenefs; in order to be convinced of this, we have only to close our hand upon fome of those beetles that dig in the earth, and we will be furprized at the efforts we mult make to keep them.

* The earth is the abode of the Gryllo-talpa, (Gryllus Gr) Its feet accordingly are formed for digging; they are not lefs hard than the claw of a crab, and the firft articulation is round at the extremity, and ferrated; with such feet he can dig on each fide, above and below him. A fpecies of baftard wafp (Sphex), of the largest fize, depofits its eggs in holes made in the earth or in fand. For this purpose it generally throws with its anterior pair of feet, the earth or fand below its belly, nearly as dogs do when they dig for moles. When the heap of earth or fand grows too large it gets above it, and works as before with so much dispatch that in a moment the whole is removed; thus it prevents the earth from falling back, and filling up the hole.

PAGE 160, 1. II.

*Some use them for feizing their prey. The anterior pair of feet, in the cimices aquatici, are of no ufe in walking. They are used as antennæ, and as claws for feizing and holding their prey. They have along their feet a groove in which the foot or the claw may be lodged from the articulation to the extremity. This groove refembles that which receives the blade.

of a pocket knife, and is given them, left the claw fhould be clogged or hurt by any accident.

PAGE 160. 1. 12,

* By the structure of the legs, the fpecies diflinguishable. Files that prey on one another, have at the laft articulation of the foot, long and ftrong nails. The end of the leg is forked, and each nail occupies an extremity. This is com mon to all the flies which are carnivorous, and is a mark by which they may be known, as we know hawks and vultures by their talons.

PAGE 161, 1. 18.

There is great diverfity in the figure of the farinaceous wings. Although the figure of the wings in lepidopterous infects varies exceedingly, yet that which their fuperior wings are most inclied to, is the fcalene triangle of which the long fide aufwers to the exterior margin of the wing and the thort fide to the interior nargin, The mxt or curved lines which form the margins are generally very irreguar, and the exterior margin feldom forms an arch as Jonfton has though fit to represent it The under wings

of moths, are often made in the form of a fan, and, are folded nearly in the fame manner.

PAGE 161, 1. 26.

The margin of the wings is often indented. When the wings of the lepidopterous infects are indented, the dents are found always at the apex of the wing, rarely on the interior margin. I know only one or two forts of butterflies which have any thing like it on the exterior margin of the upper wings.

PAGE 161, 1. 31.

Ornamented with fine fringes. This ornament nature has given almost to the whole tribe of Phalanas The apex and the interior margin of their wings are adorned with fringes, but their upper wings have none at the exterior mar gin.

PAGE 162, 1. first.

In the form of very delicate feathers. It has been already remarked above, that the name of fcales or plates would agree better with the coloured duft which adorns the wings

of