As to the rest, this animal is found in greatest numbers at Ancona, in Italy; it is found along the shores of Normandy and Poitou in France; it is found also upon some of the coasts of Scotland; and in general is considered as a very great delicacy at the tables of the luxurious.

OF FROGS, LIZARDS, AND SERPENTS.

CHAPTER I.

OF FROGS AND TOADS IN GENERAL.

IF we emerge from the deep, the first and most obvious class of amphibious animals that occur upon land are frogs and toads. These, wherever they reside, seem equally adapted for living upon land and in the water, having their hearts formed in such a manner as to dispense with the assistance of the lungs in carrying on the circulation. The frog and the toad therefore can live several days under water, ..without any danger of suffocation: they want but little air at the bottom, and what is wanting is supplied by lungs, like bladders, which are generally distended with wind, and answer all the purposes of a reservoir from whence to breathe.

To describe the form of animals so well known would be superfluous; to mark those 'differences that distinguish them from each other, may be necessary. The frog moves by leaping, the toad crawls along the ground. The frog is in general less than the toad, its colour is brighter, and with a more polished surface; the toad is brown, rough, and dusky. The frog

is light and active, and its belly comparatively small; the toad is slow, swoln, and incapable of escaping. The frog when taken contracts itself so as to have a lump on its back; the toad's back is straight and even. Their internal parts are nearly the same, except that the lungs of the toad are more compact than those of the frog: they have air-bladders, and of consequence the animal is less fitted for living under water. Such are the differences with respect to figure and conformation; their habitudes and manners exhibit a greater variety, and require a separate description.

CHAPTER II.

OF THE FROG, AND ITS VARIETIES.

THE external figure of the frog is too well known to need a description. Its power of taking large leaps is remarkably great, compared to the bulk of its body. It is the best swimmer of all four-footed animals; and nature hath finely adapted its parts for those ends, the arms being light and active, the legs. and thighs long, and furnished with very strong mus

cles.

If we examine this animal internally, we shall find that it has a very little brain for its size, a very wide swallow, a stomach seemingly small, but capable of great distension. The heart in the frog, as in all other animals that are truly amphibious, has but one ventricle; so that the blood can circulate without the assistance of the lungs while it keeps under water. The lungs resemble a number of small bladders joined together, like the cells of a honey

comb; they are connected to the back by muscles, and can be distended or exhausted at the animal's pleasure. The inale has two testiculi lying near the kidneys, and the female has two ovaries lying near the same place; but neither male nor female have any of the external instruments of generation, the anus serving for that purpose in both. Such are the most striking peculiarities in the anatomy of the frog; and in these it agrees with the toad, the lizard, and the serpent. They are all formed internally pretty much in the same manner, with spongy lungs, a simple heart, and are destitute of the external instruments that serve to continue the kind.

Of all those who have given histories of the frog, M. Ræsel of Nuremberg seems the most accurate and entertaining. His plates of this animal are well known; his assiduity and skilfulness in observing its manners are still more deserving our esteem. Instead, therefore, of following any other, I will take him for my guide; and though it be out of my power to amuse the reader with his beautiful designs, yet there will be some merit in transcribing his history.

The common brown frog begins to couple early in the season, and as soon as the ice is thawed from the stagnating waters. In some places the cold protracts their genial appetite till April, but it generally begins about the middle of March. The male is usually of a grayish-brown colour; the female is more inclining to yellow, speckled with brown. When they couple, the colours of both are nearly alike on the back; but as they change their skins almost every eighth day, the old one falling off in the form of mucus, the male grows yellower, and the female more brown. In the males, the arms and legs are much stronger than in the females; and at the time of coupling they have upon their thumbs a kind of fleshy excrescence, which they fix firmly to the breast of

VOL. IV.-Y