spots, at the close of summer, have been led into the popular belief of their having descended from the clouds in showers.

As soon as the frog has thus assumed its perfect form, it feeds no longer on vegetables, but on animal food; supporting itself on small snails, worms, &c. and insects. For the readier obtaining its prey, the structure of its tongue is extremely well calculated, being so situated that the root is attached to the fore rather than the bind part of the mouth; and when at rest, lies backwards, as if the animal was swallowing the tip. By this means the creature is enabled to throw it out to some distance from the mouth, which is done with great celerity, and the bifid and glutinous extremity secures the prey, which is swallowed with an instantaneous motion, so quick that the eye can scarely follow it.

The frog can hardly be said to arrive at its full size till the age of about five years, and is supposed to live at least twelve or fifteen years.

The frog is extremely tenacious of life, and, like other amphibia, will survive for a considerable space the loss of many of its organs. If confined entirely under water, it is still enabled to support its existence for several days, as appears by Sir Thomas Brown's experiment, who kept a frog under water six days. On the contrary, it cannot so well dispense with the want of water, and is unable to survive too long an exposure to a dry air and a hot sun. It is, therefore, particularly careful to secure a retreat where it may enjoy the benefit of shade and a sufficient supply of moisture. It delights, however, to bask occasionally in a moderate sunshine, and is unable to support severe cold.

Tree-Frog.

Rana arborea.-LINN.

In the beauty of its colours, as well as in the elegance of its form, and the agility of its movements, the tree-frog exceeds every other European species. It is a native of France, Germany, Italy, and many other European regions, but is not found in the British islands. Its principal residence, during the summer months, is on the upper parts of trees, where it wanders among the foliage in quest of insects, which it catches with extreme celerity, stealing

softly towards its prey in the manner of a cat towards a mouse, and when at the proper distance, seizing it with a sudden spring, frequently of more than a foot in height. It often suspends itself to the hinder parts of the leaves, thus continuing concealed beneath their shade. Its size is smaller than any other European frog, except the fire-frog. Its colour on the upper parts is green, more or less bright in different individuals; the abdomen is whitish, and marked by numerous granules: the under surface of the limbs is redish, and the body marked on each side by a longitudinal blackish or violet-coloured streak. The body is smooth above, and moderately short; the hind legs are very long and slender; the fore feet have four and the hind feet five toes, all of which terminate in rounded, flat, and dilated tips, the under surface of which, being soft and glutinous, enables the animal to hang with perfect security from the leaves of trees, &c. The skin of the abdomen is also admirably calculated by nature for this peculiar power of adhesion, being covered with small glandular granules, in such a manner as to fasten closely even to the most polished surface; and the animal can adhere at pleasure to that of glass, in whatever position or inclination it is placed, by merely pressing itself against it.

Though the tree-frog inhabits the woods, during the summer months, yet on the approach of winter it retires to the waters, and there submerging itself in the soft mud, or concealing itself beneath the banks, remains in a state of torpidity, and again emerges in the spring, at which period it deposits its spawn in the waters, like the rest of this genus. During their residence among the trees, they are observed to be particularly noisy on the approach of rain; so that they may be considered, in some measure, as a kind of living barometers; more especially the males, which, if kept in glasses, and supplied with proper food, will afford an infallible presage of the changes of the weather.

3. Toad.

Rana bufo.-LINN.

Of all the European toads, this seems to be the most universally known; at least, in its complete or perfect form. It is found in gardens, woods, and fields; and frequently makes its way into cellars, or any obscure recesses in which it may occasionally conceal itself, and where it may find a supply of food, or a security from

too great a degree of cold. In the early part of spring, like others of this genus, it retires to the waters, where it continues during the breeding-season, and deposits its ova or spawn in the form of double necklace-like chains or strings of beautifully transparent gluten, and of the length of three or four feet.

The toad is an animal too well known to require any very particular description of its form. It may be necessary to observe that it is always covered by tubercles, or elevations on the skin, of larger or smaller size, in different individuals; and that the general colour of the animal is an obscure brown above, much paler and irregularly spotted beneath.

The toad arrives at a considerable age; its general term of life being supposed to extend to fifteen or even twenty years: and Mr. Pennant, in his British Zoology, gives us a curious account, communicated by a Mr. Arscott, of Tehot, in Devonshire, of a toad's having lived, in a kind of domestic state, for the space of more than forty years, and of having been in a great degree tamed, or reclaimed from its natural shyness or desire of concealment; since it would always regularly come out of its hole at the approach of its master, &c. in order to be fed. It grew to a very large size, and was considered as so singular a curiosity, that even ladies, laying aside their usual aversion and prejudices, requested to see the favourite toad. It was, therefore, often brought to table, and fed with various insects, which it seized with great celerity, and without seeming to be embarrased by the presence of company. This extraordinary animal generally resided in a hole beneath the steps of the house-door, fronting the garden; and might, probably, have survived many years longer, had it not been severely wounded by a raven, which seized it before it could take refuge in its hole; and notwithstanding it was liberated from its captor, it never again enjoyed its usual health, though it continued to live above a year after the accident happened.

With respect to the supposed venomous qualities of the toad, from the experiments of Laurenti, it appears that small lizards, on biting the common toad, were for some time disordered and paralytic, and even appeared to be dead, but in a few hours were completely recovered.

It is also observed, that dogs, on seizing a toad, and carrying it for some little time in their mouth, will appear to be affected with a very slight swelling of the lips, accompanied by an increased eva

cuation of saliva; the mere effect of the slightly acrimonious fluid which the toad, on irritation, exudes from the skin, and which seems, in this country at least, to produce no dangerous symptoms in such animals as happen to taste or swallow it. The limpid fluid also, which this animal discharges when disturbed, is a mere watery liquor, perfectly free from any acrimonious or noxious qualities, and appearing to be no other than the contents of a peculiar reservoir, common to this tribe, destined for some purpose in the economy of the animals, which does not yet appear to be clearly understood. The common toad may therefore be pronounced innoxious, or perfectly free from any poisonous properties, at least with respect to any of the larger animals; and the innumerable tales recited by the older writers of its supposed venom, appear to be either gross exaggerations, or else to have related to the effects of some other species mistaken for the common toad; it being certain that some of this genus exude from their skin a highly acrimonious fluid.

It might seem unpardonable to conclude the history of this animal, without mentioning the very extraordinary circumstance of its having been occasionally discovered enclosed or imbedded, without any visible outlet, or even any passage for air, in the substance of wood, and even in that of stone or blocks of marble.

On this subject a curious experiment was made by Mons. Herrissant, of the French Academy, in consequence of an assertion, that in the year 1771, on pulling down a wall at a seat belonging to the Duke of Orleans, and which had been built forty years, a living toad had been found in it; its hind feet being confined or imbedded in the mortar. M. Herrissant therefore in the presence of the academy, inclosed three toads in as many boxes, which were immediately covered with a thick coat of plaster or mortar, and kept in the apartments of the academy. On opening these boxes eighteen months afterwards, two of the toads were found still living these were immediately re-inclosed; but on being again opened some months after, were found dead. These experiments are, perhaps, not very conclusive; and only appear to prove what was before well known, viz. that the toad, like many other amphibia, can support a long abstinence, and requires but a small quantity of air: but in the accounts generally given of toads discovered in stones, wood, &c. the animals are said to have been completely impacted or imbedded, and without any space for air.

[Herrissant. Mem. de l'Acad. Royal. Shaw.

SECTION VII.

Siren.

Siren lacertina.-LINN.

Mud-Inguana.-ELLIS.

THIS species stands eminently distinguished in the list of animals by the ambiguity of its characters, which are such as to have induced the great Linnæus to institute it for a new order of amphibia, under the title of meantes*; an order, however, which does not stand among the rest of the amphibia in the Systema Naturæ, but is mentioned in a note at the end of the second part of the first volume of that work.

The genus with which the siren has evidently the greatest possible affinity, is the lacerta, or lizard. It even very much resembles the larve, or first state of a lacerta; and it is still doubtful whether it may not really be such: yet it has never been observed in any other state, having two feet only, without any appearance of a hind pair: the feet are also furnished with claws, whereas the larves of all the lacertæ are observed to be without claws; or, in the Linnæan phrase digitis muticis: the mouth has several rows of smallish teeth: the body is eel-shaped, but slightly flattened beneath; marked on the sides by several wrinkles, and slightly compressed towards the extremity of the tail, which is edged with a kind of soft skin, or adipose fin, as it were on each side the neck are three ramified branchial processes, resembling, on a larger scale, those belonging to the larves of water-newts, and at the base are the openings into the gills; the eyes are very small, and blue. The general colour of the animal is a deep or blackish brown, scattered over, especially on the sides, with numerous minute whitish specks. Its size nearly equals that of an eel, being frequently found of the length of more than two feet. It is a native of North America, and more particularly of South Carolina, where it is not very uncommon in muddy and swampy places, living generally under water, but sometimes appearing on land. It has a kind of squeaking or singing voice, for which reason Linnæus distinguished it by the title of siren.

* The characters of this order are thus given by Linnæus, viz, branchiæ and pulmones simul. Pedes brachiati, unguiculati. The generic character stands thus, viz. corpus bipedum, caudatum, nudum. Pedes brachiati, unguiculati.