CHAPTER I.

_CROCODILES AND ALLIGATORS._

The Reptile Class, as defined by modern scientific limitations, includes among the living animals of the world the several groups of the Crocodiles, the Tortoises and Turtles, the Tuatera, the Lizards, and the Snakes. In the popular mind the Frogs and Toads, and the Newts and Salamanders, are often held to belong to the same main section; but these, as hereafter shown, claim, as Amphibians, an independent position of equivalent rank and value. In bygone geological ages the Reptile Class embraced a considerably larger number of groups; some of the members, such as the extinct Dinosaurs, comprised titanic monsters from 60 to 80 feet in length. The Crocodiles and Alligators of the present day are the only living reptiles which in any way approach the extinct Saurians in their dimensions, or assist us in some small measure to realise their unwieldy forms and bulk.

The members of the Crocodile Order, which, in addition to the Alligators, includes also the Caimans and so-called Gavials or Garials, agree with one another in the more or less ponderous lizard-like shape of their body, supported on well-developed but short and comparatively weak legs, in their special adaptation to an amphibious existence, carnivorous habits, and restriction to tropical and subtropical climates.

Among the salient characters of the CROCODILE, as the representative of its tribe, which specially adapt it for its aquatic habits, the long, powerful tail is strongly compressed and thus fitted for use as an organ of propulsion, and the feet are more or less webbed. The most striking of its structural adaptations is, however, associated with the formation of the creature's skull. The manner in which a crocodile or alligator contrives to breathe or to save itself from asphyxiation, when opening and shutting its mouth under water, as it may often be observed to do in the Regent's Park Menagerie, is a common source of wonderment to the onlooker. This seemingly difficult feat is compassed by virtue of the posterior nostrils, or breathing-passages, being set so far back in the skull, and being so completely cut off from the mouth-cavity by specially developed bones of the palate, that they have no intercommunication with the mouth. It is this mechanism which enables a crocodile to seize and hold an animal underneath the water between its open jaws until it is drowned. Special valves at the back of the mouth prevent any water running down the creature's throat, while it is able itself to breathe unrestrainedly by allowing just the tip of its elongated snout, with the anterior nostril-apertures, to remain above the water's surface. In many species a conspicuous knob-like bony excrescence is developed at the extremity of the snout, by which the nostril-openings are raised turret-wise above the surface of the water. The eyes also being usually elevated above the level of the creature's head, the crocodile is able to approach its floating or bank-side prey practically unperceived, its huge body, limbs, and even the head, with the exception of the nose and eyes, being totally submerged.

Although capable of moving with great activity in the water, crocodiles and their allies are usually accounted sluggish and slow movers on the land. Seen basking in the sun, as is their wont, by the hour together on some sand-bank, or creeping lazily thereon among their fellows, such a conclusion is natural. The celerity, however, with which even a huge 25-footer, as witnessed by the writer in the Norman River, North Queensland, will make tracks for and hurl itself into the water, if disturbed during its midday siesta by the near impact of a rifle-bullet, is a revelation. Crocodiles, moreover, as might be inferred from the slit-like contour of the eye-pupil, as shown by daylight, are to a large extent nocturnal, displaying their greatest activity, and being in the habit of travelling long distances along and away from the river-banks in search of food, or in connection with their migratory or mating instincts, under the cover of darkness.

Of all living animals the crocodile and its allies are probably equipped most efficiently for both defence and aggression. The thick, horny shields, quadrangular on the back, tail, and under-surface, and adapted in shape and size to cover the head, limbs, and sides, constitute an almost impenetrable cuirass. As weapons of offence the formidable array of trenchant teeth, with which the powerful jaws are armed, have not alone to be reckoned with by the victim assailed. The crocodile's limbs and claws are relatively weak, and incapable of aggressive mischief; but in the long, compressed, muscular tail the reptile possesses a terribly effective weapon, wherewith, with one swift, unexpected side-stroke, it will sweep a smaller animal into the water, or deal a blow of sufficient power to fell or disable a man or bullock. Thus well-nigh invulnerable, and cognisant of its marvellous power of jaw and tail, a full-grown crocodile will not hesitate to try conclusions with even such puissant adversaries as the bear, the tiger, and other large carnivora, when they approach the river's brink to drink. Not infrequently, too, the crocodile comes off the victor in these contests; while, as sometimes happens, both of the well-matched foes are found dead side by side at the water's edge. The dread in which crocodiles are held by the natives of tropical countries, and the heavy toll they levy upon the riverside population, and more especially the women-folk in their accustomed avocations of water-carrying or laundry work, are too familiar to need dissertation. Hence it is that in every country, excepting those particular locations where the creature is a subject of misguided veneration or fetish worship, it may be said that every man's hand is against them, and the enmity most cordially reciprocated.

All the members of the Crocodile Family propagate by egg-production. The eggs are relatively small in size, those of the largest species not exceeding that of a goose in dimensions. In shape they are more or less symmetrically ovate, and encased with a hard, white shell. In the case of the crocodile, the female selects a suitable dry sand-bank near the river's edge, in which it excavates a hole of about 2 feet deep, and, having deposited from twenty to sixty eggs therein, mounts guard over them, sleeping on top of the nest by day, until the young are hatched. With the alligator, the site chosen for the nest is more usually among bushes or reeds at some distance from the water, and the eggs, which may be laid to the number of over 100, are covered over with leaves and vegetable débris, whose decomposition engenders the heat required for their successful incubation. In both instances the parent jealously guards the nest and repels all intruders until the eggs are hatched, and ultimately conducts the young ones to the water, where they soon learn to shift for themselves. Numbers of them, nevertheless, in their young and weak state, fall victims to vultures, hawks, ichneumons, and all manner of birds and beasts of prey. From their birth the little saurians are most vicious and irascible in disposition, hissing and snapping at or laying hold with bull-dog tenacity of a finger or other seizable object that may be held towards them. From their earliest days also they are eminently aggressive and carnivorous. Contenting themselves at first with flies and other insects, they speedily extend their attentions to frogs, lizards, fish, or any small animals which frequent the marshes and river-banks; and finally, with their concurrently increased appetites and dimensions, requisition such larger prey as sheep, goats, deer, horses, and, as before mentioned, even the human species, if they can steal a march on them unawares. Crocodiles are provided with relatively small gullets, and are necessarily incapable of swallowing any prey whole which is of large dimensions. Accordingly any big quarry which is seized and dragged into the river is disposed of piecemeal, the reptile rending the carcase in fragments with the aid of its terrible teeth and side-wrenches of its ponderous body.

Of crocodiles proper, as distinguished from alligators, there are some dozen known species. From their last-named near allies they are distinguished by the entire absence of the supplementary bony armature which in most alligators underlies the outer horny cuirass on the under surface of the body. A more essential distinction is associated with the character of the teeth. The upper and lower teeth of the crocodile interlock, and the fourth lower canine-like tooth is received into a notch in the side of the upper jaw, and is consequently more or less visible when the mouth is closed. In the alligators, on the other hand, this bigger tusk-like tooth fits into a pit-like excavation in the upper jaw, and is invisible when the mouth is shut.

The TRUE CROCODILES are found in the tropical regions of Africa, Asia, Australasia, and Central America. The largest is undoubtedly the estuarine species, ranging from the eastern shores of India, through the Malay region, to North and East Australia, New Guinea, and the Fiji Islands. This wide range is a natural concomitant of their brackish- and salt-water proclivities. Individuals of the species are, in fact, not infrequently met with floating on the sea at some considerable distance from the land. An example of this estuarine species has been recorded which measured no less than 33 feet, while a length of 20 feet and over is by no means of uncommon occurrence.

The method adopted in Queensland and North Australia for capturing these destructive monsters is that of a running noose, so attached to a suitably flexible mangrove-tree growing in the vicinity of its nocturnal runs as to constitute a gigantic spring-trap. A dead carcase or other suitable bait is added to lure the animal to its doom. The crocodiles thus caught are alive and uninjured, and can be dispatched or reserved for menagerie exhibition. A somewhat amusing incident attended the transport of a "reprieved" captive by steamship from Cairns to Brisbane, Queensland, a few years since. In the dead of night, when all but the watch and engineer had retired to rest (they have to anchor and lay-to at night in the Great Barrier Reef channels), the saurian managed to free himself from his bonds, and started on a voyage of discovery around the decks. Arriving at the stoke-hold, he either incontinently stumbled into it, or descended of malice prepense, sniffing the chance of a supper or a good joke at the engineer's expense. Anyway, the engineer was aroused from his peaceful dozings with the impression that the last day of reckoning had arrived, and, rushing up the hatchway, awakened the whole ship's strength with his frantic outcries.

The NILE CROCODILE, the most familiar form in European menageries, and once abundant throughout Egypt to the Nile's delta, has now retired to the upper reaches of that great river. It never attains to the dimensions of the estuarine form. By the ancient Egyptians, as is well known, this species was pampered and worshipped with divine honours while living, and after death embalmed and preserved in the catacombs.

Other noteworthy crocodiles, of which space will allow only of the mention of their names, are the AMERICAN or ORINOCO CROCODILE, and the LONG-SNOUTED CROCODILE of West Africa, which distantly approach to the LONG-SNOUTED GAVIAL or GARIAL of India, in which the snout is elongated in a beak-like manner, and armed with close rows of long, recurved teeth, specially adapted for its exclusively fish-eating propensities. Full-grown examples of the gavial may attain to a length of 20 feet.

The TYPICAL or MISSISSIPPI ALLIGATOR is, as its name denotes, a North American form, having the modified dental and other structural details previously referred to, but otherwise in size and its aggressively destructive habits nearly corresponding with the Oriental crocodile. A second species of alligator is found in China.

In the tropical South American rivers the place of the alligator is occupied by the CAIMANS, some of which attain to huge proportions, and are distinguished from the former by the greater development of the bony armature of both their back and under-surface, and by certain essential, but to the lay reader obscure, modifications of the skull. An example of the GREAT CAIMAN once did duty as a riding-horse to the naturalist Waterton, as all those familiar with his book of travels will remember.

The habits of the caiman differ somewhat locally. From the main stream of the Lower Amazon they are in the habit of migrating in the dry season to the inland pools and flooded forests. In the middle districts of the same river, where the drought is excessive and protracted, the caimans are addicted to burying themselves in the mud till the rains return; while in the upper reaches of the Amazon, where the droughts are not prolonged, the caimans are perennially present. The eggs of these reptiles are much esteemed for food by the natives of Dutch Guiana.

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