The Alligator, or American Crocodile, has a vast mouth, furnished with sharp teeth; from the back to the end of the tail, it is serrated; its skin is tough and brown, and covered on the sides with tubercles. This dreadful species, which grows to the length of 17 or 18 feet, is found in the warmer parts of North America, and is most numerous, fierce, and ravenous, towards the south. Yet, in Carolina, it never devours the human species, but on the contrary, shuns mankind; it, however, kills dogs as they swim the rivers, and hogs which feed in the swamps. It is often seen floating like a log of wood on the surface of the water, and is mistaken for such by dogs and other animals, which it seizes, draws under water, and devours. Like the wolf, when pressed by long hunger, it will swallow mud, and even stones, and pieces of wood. They often get into the wears in pursuit of fish, and do much mischief by tearing them to pieces. They are torpid during winter, in Carolina, and retire into their dens, which they form by burrowing far under ground. They make the entrance under water, and work upwards. In spring they quit their retreats, and resort to the rivers, and chiefly seek their prey near the mouth, where the water is brackish. They roar and make a dreadful noise at first leaving their dens, and against bad weather. The female lays a vast number of eggs in the sand, near the banks of lakes and rivers, and leaves them to be hatched by the sun: multitudes are destroyed as soon as hatched, either by their own species, or by fish of prey. In South America, the carrion vulture is the instrument of Providence to destroy multitudes; and it thus prevents the country from being rendered uninhabitable.
The following account of Eastern Alligators is extracted from Forbes’s Oriental Memoirs.
The eastern districts of Travancore, intersected by lakes and rivers, abound with amphibious animals, especially alligators and seals. There seems to be no essential difference between the alligator of India, and the Egyptian crocodile; lacerta alligator, and lacertus crocodilus. Naturalists seem to confine the alligator to South America, the crocodile to Asia and Africa; but in India the lacerta crocodilus, generally called the alligator, is from five to twenty feet long, shaped like the genus to which he belongs; the back is covered with impenetrable scales; the legs short, with five spreading toes on the fore feet, and four in a straight line on the hinder, armed with claws: the alligator moves slowly, its whole formation being calculated for strength, the back bone firmly jointed, and the tail a most formidable weapon: in the river, he eagerly springs on the wretch unfortunately bathing within his reach, and either knocks him down with his tail, or opens his wide mouth for his destruction, armed with numerous sharp teeth of various lengths; by which, like the shark, he sometimes severs the human body at a single bite: the annals of the Nile and Ganges, although wonderful, are not fabulous. The upper jaw only of the alligator was thought to be moveable; but that is now completely disproved: the eyes are of a dull green, with a brilliant pupil, covered by a transparent pellicle, moveable as in birds: from the heads of those of large size, musk is frequently extracted.
It may not be improper in this place to introduce to the reader’s notice, one of the greatest curiosities of its kind, which late ages have produced; that is, a Fossil Crocodile.
This is the skeleton of a large crocodile, almost entire, found at a great depth under ground, bedded in stone. This was in the possession of Linkius, who wrote many pieces in natural history, and particularly an accurate description of this curious fossil. It was found in the side of a large mountain in the midland part of Germany, and in a stratum of black fossil stone, somewhat like our common slate, but of a coarser texture, the same with that in which the fossil fishes in many parts of the world are found. This skeleton had the back and ribs very plain, and was of a much deeper black than the rest of the stone; as is also the case with the fossil fishes, which are preserved in this manner. The part of the stone where the head lay was not found; this being broken off just at the shoulders, but that irregularly; so that in one place a part of the back of the head was visible in its natural form. The two shoulder-bones were very fair, and three of the feet were well preserved: the legs were of their natural shape and size; and the feet preserved even to the extremities of the five toes of each.
Our next subject is named The Ornithorhynchus Paradoxus, and is a very singular quadruped, remarkable for its structure. The head is similar to that of a duck, which would lead to the supposition that it belonged to an aquatic bird. Both jaws are as broad and low as those in a duck, and the calvaria has no traces of a suture, as is generally the case in full-grown birds. In the cavity of the skull there is a considerably bony falx, which is situated along the middle of the os frontis, and the ossa bregmatis. The mandible of this animal consists of a beak, the under part of which has its margin indented as in ducks, and of the proper instrument for chewing that is situated behind within the cheeks. Dr. Shaw says it has no teeth, though Mr. Home found, in a specimen examined by him, two small and flat molar teeth on each side of the jaws. The fore part of this mandible, or beak, is covered and bordered with a coriaceous skin, in which three parts are to be distinguished, within the proper integument of the beak. Into these three parts of that membrane numerous nerves are distributed, intended, probably, as the organs of feeling, a sense which, besides men, few mammalia enjoy; that is, few animals possess the faculty of distinguishing the form of external objects and their qualities, by organs destined for that purpose,—a property very different from the common feeling, by which every animal is able to perceive the temperature and presence of sensible objects, but without being informed, by the touch, of their peculiar qualities. Thus the skin in the wings of the bat, and its ear, are supposed the organs of common feeling, by means of which they are enabled to flutter, after being blinded, without flying against any thing. The whiskers of many animals appear likewise to serve the same purpose of informing them of the presence of sensible bodies, and hence they have been compared to the antennæ of insects.
But to return to the ornithorhynchus: It is an animal which from the similarity of its abode, and the manner of searching for food, agrees much with the duck, on which account it has been provided with an organ for touching, viz. with the integument of the beak, richly endowed with nerves. This instance of analogy in the structure of a singular organ of sense in two species of animals, from classes quite different, is a most curious circumstance in comparative physiology, and hence the ornithorhynchus is looked upon as one of the most remarkable phenomena in zoology.
We shall close this chapter with an account of The Marmot, or Mountain-Rat of Switzerland.—This rat is almost the size of a leveret, and resembles a common rat very much in appearance. These little creatures live together in societies, and have different dwellings for winter and summer; their fore paws are remarkably strong, which qualifies them for scooping out their burrows. The same form is always preserved in the construction of their dwellings, which consist of a long passage, just big enough to let the marmot enter, leading to two apartments; the largest of these serves the whole family for a chamber, where they lie close together, in a torpid state, rolled up like hedge-hogs, during the cold season, as dormice do in England. When they betake themselves to their winter quarters, after having lined their chamber with soft hay, they carefully stop up the entrance with a sort of cement, which they make of earth, mixed with stones and dry grass. Before they collect the grass, either for food, or for their winter habitations, they form themselves into a circle, sitting on their hind legs, looking with a cautious eye on every side. If the least thing stirs that alarms them, the first which perceives it makes a particular kind of cry, which its next neighbour repeats, and so on till it goes round, when they hastily make their escape. They are often seen upon the slopes of the Alps, where grass is in plenty; but they love a warm sheltered situation, and change their residence according to the season.