Natives of Africa shoot the Crocodile with a gun, or attack it with a barbed javelin, which is thrown by hand, and aimed at the fore-shoulder. Some Egyptians are reported to be daring enough to swim under the Crocodile, and pierce him in the belly with a dagger. The negroes of Senegal are said to be equally expert. If they surprise the animals in parts of the river where there is not sufficient water for them to swim, they attack the monster with a lance; and with their left arm wrapped in a sheet of leather, they commence by aiming with their weapon at the eyes and throat; then they thrust the arm, encased in leather, into its mouth, and, holding it open, their enemy is either suffocated or expires under the wounds received. Traps are also employed successfully for their destruction. In Egypt the natives dig a deep hole in the ordinary route of the Crocodiles, which is easily discovered by the trail they leave in the sand. This hole is covered with branches and strewed with earth. The Crocodile is now alarmed with loud cries, which disturb and drive him back to the river, by the same way that it has left it. As it passes over the treacherous hole it falls in, when it is killed, often with the most brutal cruelty. At other times a thick cord is attached to a large tree, and to the other end of the cord a lamb is bound, held by a protruding hook. The cries of the lamb attract the Crocodile, which, in its attempt to carry off the bait, is taken by the hook.
Still another method for the destruction of these repulsive-looking creatures has been adopted on one or two occasions by our countrymen in India. A dead animal is procured, in its abdomen is placed a loaded shell, to which is attached a wire made fast to an electric battery; when the bait has been seized and carried to the bottom, the shell is exploded, which invariably maims or kills the Crocodile.
The Gavials, or Indian Crocodiles, have long narrow cylindrical muzzles, slightly inflated at the extremity; the teeth are almost the same, both in number and shape, on each jaw, the two first and the fourth of the lower jaw pass into notches or indentations in the upper jaw, and not into holes, as in Crocodiles; the hind legs are dentated and palmated, like those of African Crocodiles. The Gavials are chiefly remarkable for their long head, its type being the Gavial of the Ganges, or Gavial longirostre. It is of a deep watery green colour, having on the upper part numerous irregular brown spots; in the young, the back and limbs are transversely banded with black; the lower part is of a pale whitish yellow; the jaws are marked with brown, the claws are of a clear horn colour. This species is not so carnivorous as the others, and is consequently less dreaded.
The Gavial of the Ganges, G. Gangeticus, is supposed to be the largest of the existing Saurians; its length, as given by Duméril, is seventeen feet four inches.
CHAPTER IV.
CHELONIANS, OR SHIELDED REPTILES.
["The body," as described by Dr. Gray, "is covered with square imbedded plates, generally forming a dorsal and ventral shield united by their margins, leaving only the head, neck, limbs, and tail free, and (in some species, as the Box-Tortoises, Cinasternon, shut up by movable closely-fitting doors) only covered with a scaly skin; the upper shield formed of the ribs united together and adherent to the dorsal vertebræ by a toothed suture, and surrounded by a series of bones forming the edge of the shields; the lower shield, or sternum, formed of four pairs and a central anterior bone; the jaws toothless, covered with a horny bill, rarely hid by fleshy lips; eyelids distinct; drum of the ear visible; legs short and thick; tail conical." "The natural dwelling chamber of the Chelonia consists chiefly," says Professor Owen, "and in the marine species (Chelone) and Mud Turtles (Trionyx) solely, of the floor and the roof; side-walls of variable extent are added to the fresh-water species (Emydians) and Land Tortoises (Testudinians). The whole consists of 'osseous plates,' with superincumbent horny plates, or 'scutes,' except in the Soft or Mud Turtles (Trionyx and Sphargis), in both of which these are wanting."—("Circle of the Sciences.")
These animals, to which a portable stronghold is thus given in compensation for inferior powers of locomotion and defence, are recognisable at a glance from the singular armour with which Nature has provided them. A double shield envelopes all parts of their bodies, only permitting the head, neck, legs, and tail to pass through it: moreover, all these organs can be hidden within this double cuirass by means of a retractile power possessed by the animal. This double armour consists of a carapace, or back-piece, and plastron, or breast-plate, composed of a series of small bones or plates closely united together; the first resulting from the union of the sides and dorsal vertebræ, the plastron, or lower buckler, being only a highly-developed sternum. These organs are merely portions of the skeleton, which, in place of being lodged in the depths of the soft parts, has become the superficies, which is only covered by a thin, dry skin.
This numerous and highly-interesting order of Reptiles, called Chelonia, from χελωνη, a Tortoise, are also called Testudinata, from testudo, the Latin name for a Tortoise, from the double shield in which the bodies of all, whether terrestrial, fresh-water, or marine Tortoises, are enclosed.
The skeleton of the Tortoise is, perhaps, the most extraordinary structure with which we are acquainted. This oddly-organised animal when first seen strikes the beholder with astonishment. The carapace and plastron, with their connecting plates, form a sort of protecting box, in which the animal lives, its head and tail excepted. In the land Turtles the head and feet, which are comparatively senseless, can be withdrawn within the protecting armour. The ribs and sternum are both placed quite on the exterior of the body, so as to form a broad dorsal shield on the upper surface, and an equally strong ventral plate; between these, the limbs and the head can be more or less completely retracted. Nevertheless, the modifications in the arrangement of the elements by which these changes are accomplished are of the simplest nature. In the common Tortoise, Emys Europæus, the vertebræ of the neck and tail being connected together in the ordinary manner, the neck and caudal region of the spine present their usual flexibility, but the dorsal vertebræ are strangely distorted, the upper arch being disproportionately developed, while the bodies remain almost in a rudimentary state; the spinous processes of these vertebræ are flattened and converted into broad osseous plates, which form a longitudinal series along the centre of the back, and connected together by means of sutures. The ribs are changed into broad flat bones firmly united by sutures to each other, and also to the lateral margins of the spinous processes of the vertebræ, so that they form together a single broad plate; the heads of the ribs are feebly developed, and the intervals between them and the bodies of the vertebræ filled up with ligament. The margin of the shield thus formed by the dorsal ribs is further enlarged by a third set of flat bones fixed by sutures around the whole circumference of the carapace.