venomous; nevertheless, it would seem that John's account of their being dreaded by the natives is not universal. In the "Zoological Society's Proceedings for 1838," p. 80, is the following:

"A paper was read by Dr. Cantor, entitled 'Obserservations on Marine Serpents.'

"This communication embodies the results of Dr. Cantor's observations upon the habits and general conformation of the marine Ophidians; a group to which but little attention has hitherto been given, from the danger attending their examination in the living state; and, also, from their geographical distribution, being entirely confined to the tropical seas. The author, being stationed in the East India Company's service, on the Delta of the Ganges, had, during a considerable period, most favourable opportunities for studying these Serpents; many of which were captured in the nets employed for fishing.

"His observations are principally directed to the anatomical characters, which distinguish the marine from the terrestrial Serpents, and to the modifications of structure, by which the former are adapted to the element in which they exist.

Dr.

"With respect to their physiology, the principal point of interest he establishes, is the circumstance of all the species, without exception, being highly venomous: a fact which has been denied by Schlegel, who states, that the marine Serpents are harmless; and the same erroneous idea is current with the natives. Cantor, in proof of the contrary, refers to the recent death of an officer in Her Majesty's service, within an hour or two after the bite of a Serpent caught at sea; and also to numerous experiments of his own, in which fowls, fish, and other animals invariably died within a few minutes after the bite had been inflicted." The observation by John, that sea Snakes are not found naturally inhabiting fresh-water rivers, or tanks, is correct; they are found, however, in salt-water creeks and ditches."

According to Mr. Gray, the family of Hydridæ consists of twenty-three genera, and forty-eight species; of which twenty are found in the Indian Ocean, and sixteen in the salt-water ditches of India, and the neighbouring islands, and six are found in similar situations in tropical America. Thirty distinct species are in the noble collection of the British Museum.

The genera into which the sea Serpents are divided, are reduced by Cuvier into three sections, or comprehensive genera, Hydrophis, Pelamys, and Chersydrus.

GENUS HYDROPHIS.

In Hydrophis, the under surface is covered with scuta, or shields, larger than the scales of the other parts; the head is small, not swollen, blunt, and covered above with plates. Some species inhabit the salt-water canals of Bengal, and others the Indian seas.

GENUS PELAMYS.

In Pelamys, the head is covered with plates; but the back of the head is swollen, in consequence of the length of the peduncles of the lower jaw-bone, which is extremely dilatable, as is also the throat. All the scales of the body are of equal size, small, and disposed hexagonally. Cuvier says, that one species, the P. bicolor, though very venomous, is eaten at Otaïti, (Tahiti,) in which assertion he is not correct. Sea Snakes, as already stated, are eaten at Savaii.

GENUS CHERSYDRUS.

In Chersydrus, both the head and the body are covered with small scales.

Of the habits and manners of the sea Snakes, little is known; many of them attain to considerable dimensions, and we may easily conceive of the ravages they commit among the fishes of the briny waters frequented by them.

A few observations on the poison of Snakes may not be here out of place.

Fontana, who made many experiments with Vipers, and the same observations apply to the Rattlesnakes and others, concludes from his researches :

1st. That the bite of the Viper is not poisonous to its own body, or that of its species. 2d. The venom is not equally destructive to all animals. 3d. The poison is neither acid, nor alkaline, nor saline. 4th. It has no positive taste, and taken into the mouth does not cause the tongue to swell. 5th. It is not inflammable. 6th. Mixed with water it sinks to the bottom; when shaken it renders the water turbid and whitish.

The assertion of Fontana, that the venom is neither acid, alkaline, nor saline, has been repeated by many writers: Schlegel asserts it; but Dr. Cantor has decidedly proved it to be acid. In five different genera of Indian Serpents, and in different species of marine Serpents, he invariably found the poison to possess the property of turning litmus paper red. Dr. Harlan notices the same fact, in the poison of the Rattlesnake.

Numerous experiments by Fontana, Mangili, Cloquet, and others, prove that, provided there be no abrasion of the skin of the lips, gums, or tongue, the poison of Snakes may be swallowed with impunity; and when a person is bitten by one of these Reptiles, where a cupping-glass is not at hand, or cannot be applied, the best way is instantly to suck the wound forcibly. Celsus was well acquainted with this fact: in the writings of that truly great man, we read, "Those persons who are called Psylli, have not, indeed, any special knowledge, but boldness, confirmed by habit; for the poison of a Serpent is not injurious when tasted, but when instilled into a wound. Therefore, whoever, following the example of the Psyllus, will suck the wound, will be both safe himself, and save the sufferer. But this point must be fairly settled, that no ulcer be either in the gums, the palate, or any other part of the mouth."

With respect to remedies, and especially those empirical medicines, commonly deemed efficacious, little can be said. Ammonia used externally and internally, after the poison is drained from the wound, seems to be the most efficacious. As for such herbs, as the lion's-foot, (Prenanthis serpentaria,) Witt's snake-root, (P. autumnalis,) Wildenow's snake-root, (P. rubicunda,) water plantain, (Alisma plantago,) the Ophiorrhiza mungo, and others, Dr. Harlan, after a series of experiments, concludes, that they are either destitute of active properties, or are altogether unworthy serious attention." The great aim must be to keep up the vital energies of the system; to extract the poison, or destroy its injurious properties.

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ORDER IV.—AMPHIBIA.

We have already stated, that the AMPHIBIA are divided into Caducibranchiate and Perennibranchiate sections, and explained the grounds of those divisions, which we need not again repeat.

All the Reptiles, which we have previously discussed, are covered with plates, shields, or scales. In the Amphibia, on the contrary, the skin is naked, smooth, and often moist, or lubricated with a fluid secretion, which, in some instances, as in the toad, is acrid, and apt to irritate the skin of persons handling it. In the common Salamander of Europe, the fluid poured out from the skin, when the creature is alarmed or injured, is very abundant, and white and glutinous.

The cuticle, as in snakes and lizards, is frequently shed; it is thrown off either in shreds, or altogether, according to the nature of the species. In some, as in the frog, and, perhaps, in all, the skin, as experiments satisfactorily prove, aids the lungs, and even supplies their place, as affording a surface for the aëration of the blood in the delicate cutaneous vessels. In these, as well as in the vessels of the lungs and gills, the blood, by the action of the air, undergoes those peculiar changes which are necessary for the maintenance of life. This cutaneous respiration, as it is called, is a curious and interesting circumstance in their economy. It is proved, however, that it can take place only while the skin is kept moist; and the same observation applies to the gills of fishes, of tadpoles, and of crabs, lobsters, and other crustacea. Hence are the Reptiles furnished with a skin capable of secreting a fluid for the purpose of preserving it in a humid condition; for the healthy action of this skin, as co-operating with the lungs, is essential to their existence.