HERPETOLOGY, from Erre7sc, .a reptile, and Aav65, a dis course, is that department of ZooLooy, in whicn is con sidered the natural history and economy of reptiles.
Under the term Reptiles, naturalists have generally comprehended all those tribes of oviparous animals com monly called AmrniniA, including both oviparous qua drupeds and serpents; and accordingly Linnxus has ar ranged both under this name in his third class of animals. See AMPHIBIA.
In the present article, we mean to confine ourselves en tirely to the first older of amphibia, according to the latest modification of Linnaeus's system, or the oviparous qua drupeds, to which the term Reptilia has, though improper ly, been restricted by the writers of the Linn2ean school. We shall reserve the history of the serpent tribes for the article OPIIIOLOGY.
The animals, of which we are now to consider the struc ture, economy, habits, and manners, belong to the second great division of vertebral animals, as characterized in our Comparative ANATOMY) namely, those with a single heart and cold blood. They have all articulated members, though, in a few instances, especially in one stage of their existence, these are only two in number, and very short. Many of them have tails, which, in some species, serve the purpose of hands, in others that of a fin or rudder. Most of them walk, or leap, or both ; many swim with facili ty ; and a few species are capable of supporting them selves in the air for a time, so as to imitate the action of flying. In these animals, the cavities of the chest and belly are not separated from each other, as in quadrupeds, by a fleshy partition or midriff.
In the reptile tribes we observe two remarkable circum stances, which will presently occupy a considerable share of our attention. These are, the great tenacity of life which they possess, and the extraordinary degree of repro ductive power that prevails in many of the species. Se veral of them support abstinence, and apparently total seclusion from atmospheric air, for a surprising length of time; and even their heads and hearts are capable of being excited to muscular action long after they have been sepa rated from the body. Again, when deprived of some less
important organ, as the tail, a limb, or an eye, this is in no long period reproduced.
Though called amphibia, they do not all live equally well on land and in the water. Some prefer the former, and some the latter element, and a few seem fitted indifferently for either.
The general appearance and habits of these animals are not very prepossessing. Few of them possess that ele gance of form and brilliance of colour, which we so much admire in most of the birds and in many of the quadru peds. Lurid in their aspect, clumsy in their mien, and awkward in their gait, they tend rather to excite our ab horrence and disgust ; and though few of them can pro perly be said to he poisonous, several are, from their bulk and ferocity, just objects of terror even to the human race.
Those who are fond of illustrating the idea of a regular scale or chain of being among the works of nature, may find several connecting links among the reptile tribes. Thus the crocodile may be said to connect the viviparous and oviparous quadrupeds, as resembling, in external ap pearance, the genus mania, or scaly lizards ; the turtles, especially those with soft coverings, may be regarded as connecting the cetacea and reptiles; the flying lizards, or dragons, may be said to form the link of connection be tween reptiles and birds; the sees and chalcis nearly re semble serpents ; and the siren is so very near the fishes, that some naturalists still enumerate it among the finny tribes.
It is scarcely possible to point out correctly how many species of reptiles are known to naturalists at the present day ; especially as many are considered species by one writer, and only varieties by another. According to the latest edition of Linnmus's 'System of Nature, only 170 species were then known; but in the systematic work of a late French writer, Daudin, the distinct species enumerated or described exceed three hundred.