but in the mouth. Behind the root of the tongue is the slit-like opening of the trachea and at the front of the upper part of the head are two nostrils, through which the animal always draws the air, never opening its mouth for this purpose. Indeed the jaws during this action are kept closely locked into each other by grooves; for if the mouth is kept open it cannot respire at all, and the animal will presently be seen struggling for breath. When we observe it carefully, we perceive a frequent dilatation and contraction in the skinny bag-like part of the mouth which covers the under jaw. From this it would appear, at first sight, as if the creature lived all the while on one mouthful of air, which it seems to be playing backwards and forwards betwixt its mouth and lungs. But for each movement in the jaw, a corresponding twirling movement may be observed in the nostrils. The mouth seems therefore to form a sort of bellows, of which the nostrils are the air-holes, and the muscles of the jaws by their contraction and dilatation make the draught. The nostrils are so situated that the least motion on them enables them to perform the office of a valve. By the twirl of the nostril the air is let into the mouth, when a dilatation of the bag takes place: it is then emptied from the mouth, through the slit behind the tongue, into the lungs, when there is a slight motion in the sides of the animal, and the muscles of the abdomen again expel it; and soon

afterwards a second twirl in the

nostrils takes place, Thus it appears that

and the like motions follow. Thus it

the lungs are filled by the working of the jaws, or, in other words, that Frogs swallow air much in the same manner that we swallow food.

Frogs cast their skins at certain periods. They arrive at full age in about five years, and are supposed to live to twelve or fifteen. Their voice is hoarse and unpleasant. They are so tenacious of life as to survive even the loss of their head for several hours.

This species is not so much in request for food as the following, not being so white, nor altogether so palatable. The hind-legs, however, are eaten, and the fore legs and livers often form an ingredient in the continental soups.

THE EDIBLE FROG*,

The Edible Frog is considerably larger than the common species; and though somewhat rare in England, is found in plenty in Italy, France, and Germany.

Its colour is an olive green, distinctly marked with black patches on the back, and on its limbs with transverse bars of the same. From the tip of the nose, three distinct stripes of pale yellow extend to the extremity of the body, the middle one slightly depressed, and the lateral ones consider

* SYNONYMS Rana esculenta. Linn. La Grenouille commune, ou mangeable. La Cepede. Esculent Frog, Green Frog. Shar Edible Frog. Penn. -Shaw's Gen, Zool. vol. 3. tab. 31.

ably elevated. The under parts are of a pale whitish colour tinged with green, and marked with irregular brown spots.

The spawn of the present species is not often deposited before the month of June. During this sea son the male is said to croak so loud as to be heard to a great distance. In some particular places, where these animals are numerous, their croaking is very oppressive to persons unaccustomed to it.-The globules of spawn are smaller than those of the Common Frog, and the young are considerably longer in attaining their complete state, this seldom taking place till November. They arrive at their full growth in about four years, and live to the age of sixteen or seventeen. They are excessively voracious, frequently seizing young birds, and even mice, which, like the rest of their prey of snails, worms, &c. they swallow whole*.

These creatures are brought from the country, thirty or forty thousand at a time, to Vienna, and sold to the great dealers, who have conservatories for them, which are large holes, four or five feet deep, dug in the ground, the mouth covered with a board, and in severe weather with straw. In these conservatories even during a hard frost, the frogs never become quite torpid. When taken out and placed on their backs, they are always sensible of the change, and have strength enough to turn themselves. They get together in heaps, one upon

* Shaw's Gen. Zool. iii. 103.

another, instinctively, and thereby prevent the evaporation of their humidity; for no water is ever put to them. In Vienna, in the year 1793, there were only three great dealers, by whom most of those persons were supplied who brought them to the market ready for the cook*.

From their spawning-time being very late in the year, it is supposed that those animals that are brought to market before the month of June for the Edible Frog, are either Common Frogs, or sometimes they are even Toads.

THE BULL FROG†.

This is an animal that frequently measures from the nose to the hind-feet a foot and a half, or upwards. The colour of its body is a dusky olive or brown, marked with numerous dark spots, lighter beneath than above. The external membranes of the ears are large, round, and of a brownish red, surrounded by a yellowish margin.

The interior parts of America are the principal residence of this species, where, at the springs. or small rills, they are said to sit in pairs. In Virginia they are in such abundance that there is scarcely a

*Townson's Travels, 14.

SYNONYMS. Rana Catesbeiana. Shaw. Rana ocellata. Linn? La mugissante, ou Grenouille Taureau. La Cepede. Bull Frog Catesby.Shaw's Gen. Zool. vol. 3. tab. 33.

Dr. Shaw is of opinion that Linnæus has described the Argus Frog of General Zoology under the name of Rana ocellata.

When

single spring that has not a pair of them. suddenly surprised, by a long leap or two they enter the hole, at the bottom of which they lie perfectly secure. The inhabitants fancy that they purify the water, and respect them as genii of the fountains*. -Kaim informs us that they frequent only ponds and marshes.

Their croaking is said somewhat to resemble the hoarse lowing of a bull; and when, in a calm night, many of them are making a noise together, they may be heard to the distance of a mile and a half. The night is the time when they croak, and they are said to do it at intervals. In this act they are either hidden among the grass or rushes, or they are in the water, with their heads above the surfacet. Kalm informs us that, as he was one day riding out, he heard one of them roaring before him, and supposed it to be a bull hidden in the bushes at a little distance. The voice was indeed more hoarse than that of a bull, yet it was much too loud for him to conceive that it could be emitted by so small an animal as a Frog, and he was in considerable alarm for his safety. He was undeceived a few hours afterwards by a party of Swedes, to whom he had communicated his fears.

When alarmed, they leap to a most surprising distance at each exertion. A full-grown Bull-Frog will sometimes leap three yards. The following

* Catesby, ii. 72. + La Hontan.

Kalm, ii. 170.