Natural History, Reptiles/Loricata
ORDER II. LORICATA.
(Crocodiles.)
The appellation by which this Order is distinguished, derived from the word lorica, signifying a coat of mail, expresses the most obvious peculiarity by which its members may be known, the ridged and bony armour in which they are invested. "The Crocodiles and Alligators of both worlds, and the Gavials of India, which constitute this order, are distinguished," observes Mr. Bell, "from the true Saurians or Lizard tribe, by several important characters. Of these the most tangible and obvious is that upon which the name of the Order is founded; the covering of the whole of the back part of the neck, body, and tail, with distinct series of bones, of modederate size, imbedded, as it were, in the substance of the skin, and covered externally with a thick cuticle. These dermal bones are usually furnished with a crest, which renders them exceedingly strong, and they altogether form a panoply of defence which can resist the attacks of the most powerful enemies of whatever kind."[1]
The general form of the Loricata agrees with that of the Lizards; but besides the important difference already mentioned, the bony plates run down the body in longitudinal lines, the structure of the skull is much more solid, and the posterior orifice of the body is longitudinal. The tail is flattened at the sides; there are five toes before and four behind, of which the innermost three on each foot are armed with claws; the toes are connected by intervening membranes, varying in extent. There is a single row of pointed teeth in each jaw; the tongue is fleshy, flat, and free only at the extreme edge; whence the Crocodile was vulgarly reputed to be without a tongue. The back and tail, as already intimated, are covered by large and strong scales of square form, elevated into a ridge in the middle; the tail is surmounted by a deeply notched or saw-like crest, which is double at the base; the scales of the belly are delicate and smooth. The nostrils are situated at the end of the muzzle, and open by small crescent-form slits, closed by valves; they lead through a long and straight canal pierced in the bones of the palate, to the back of the mouth. The lower jaw is prolonged behind the skull, and this structure causes the upper jaw to seem moveable; but this is simply an illusion. The external ear is closed at pleasure by means of two fleshy lips; the eye is furnished with three lids: two small glandular orifices are placed beneath the throat, whence exudes a musky secretion, the odour of which strongly marks these animals even for years after their dried skins have been preserved in a museum.
The Reptiles of this Order are of large size and great strength; and as they are exclusively carnivorous and predaceous, and very ferocious, they are dreaded, not without reason, in the tropical countries which they chiefly inhabit. Yet these creatures, feared and hated as they are, were not created in vain. "In the grand policy of Nature," observes Prof. Jones, "the scavengers are by no means the least important agents. In hot climates, especially, where putrefaction advances with so much rapidity, were there not efficient and active officers continually employed in speedily removing all dead carcases and carrion, the air would be perpetually contaminated with pestilential effluvia, and entire regions rendered uninhabitable by the accumulation of putrefying flesh. Perhaps, however, no localities could be pointed out more obnoxious to such a frightful cause of pestilence, than the banks of tropical rivers—those gigantic streams, which, pouring their waters from realm to realm, daily roll down towards the sea the bloated remains of thousands of creatures which taint the atmosphere by their decomposition."[2]
Here, then, is the appointed dwelling-place of the Loricata. Lurking in the dense reeds, or tangled herbage that grows rank and teeming at the edges of rivers in hot climates, or under the mangroves that interweave their myriad roots in arches above the water, or concealed among the bleaching trunks and branches of trees that have fallen into the stream, these huge reptiles watch for the approach of a living prey, or feed at leisure on the putrid carcases with which the waters daily supply them. It is even affirmed that they prefer a condition of putrescence in their prey, and that their practice, when not pressed by immediate hunger, is, on seizing a living prey, to plunge into the stream in order to drown it, after which, it is dragged away to some hole, and stored until decomposition has commenced.
The subjects which compose this Order are few in number, and are all comprised in a single Family, which we shall presently describe more in detail. They are natives of both hemispheres, but are confined to the warmer regions of both, neither Europe nor Australia possessing any known species: they all inhabit fresh waters.
Family I. Crocodilidæ.
(Crocodiles.)
Messrs, Duméril and Bibron enumerate the following characters as proper to this family. The body is depressed, lengthened, protected on the back with solid and keeled scutcheons, or shields;
TOOTH OF CROCODILE.
the tail is longer than the trunk, compressed, the plates here set in rings, and rising into a ridge of pointed crests; the limbs are four in number, short; the toes of the hind feet united by a swimming membrane; three claws only on each foot; the head is flattened, lengthened into a muzzle, in the front of which are the nostrils, not far apart, upon a fleshy tubercle, furnished with moveable suckers; the gape opens beyond the base of the skull; the tongue is fleshy, entire, adherent, not protractile; the teeth are conical, simple, hollowed towards the root, unequal in length, but placed in a single row. The cavity at the root of each tooth serves as a case or sheath for the germ of the tooth destined to replace it, which is to be of greater bulk; and each being thus gradually pushed out from below by a successor ready to supply its place, the jaws of the Crocodiles present, at all ages, their formidable array of pointed teeth in undiminished number.
The Crocodiles, as we have said, are fierce and voracious, and prove destructive, not only to quadrupeds, (and those of large size), but also to man himself. Cuvier states that they are unable to swallow in the water, but this seems to be unconfirmed. They do, however, commonly resort to the shore for the purpose of devouring those animals which they have seized and drowned, dragging them out again after they have begun to decay. On land their motions are stiff, ungainly, and embarrassed, and a peculiar structure of the vertebræ precludes them from being able to turn themselves with facility. Yet they are able to bound forward with considerable agility, springing to a distance which would scarcely be expected from creatures so unwieldy.
In the water they swim with swiftness both upon and beneath the surface; here they know themselves to be at home, and usually leap into the water with precipitation if surprised on land by even the distant appearance of a man.
These are not only the largest of all reptiles, but are among the most gigantic of animals. Some are reported to have attained a length of twenty-five feet, and it seems probable that they are long-lived, and that their bulk continues to increase with years. The mouth is enormous; and the numerous pointed teeth, thirty or more on each side of each jaw, are so disposed as to fit into the interstices of each other. As the lips are altogether wanting, the teeth are visible when the mouth is closed; hence the animal, even when tranquil, seems grinning with rage. A similar expression is communicated to the visage from the eyes, which are placed obliquely near each other, and have a peculiarly fiery glare.
The compressed and dentelated tail, though from its length and weight it impedes the motions of these animals on the land, is yet an organ of the utmost importance to them in the water, where it is a most powerful instrument of progression, and influences their aquatic habits much more than their webbed hind feet. The latter are indeed used, when the animal is paddling with a slow and gentle action; but in sudden and swift motion, as in escaping from an object of alarm, or in energetic pursuit of prey, alternate strokes with the tail upon the element give the powerful impulse. On land, also, the Crocodile is said to use this organ as an efficient weapon of offence, dashing it from side to side with swift contortions, when its weight, its hard rough surface, and especially its saw-like crests, render its strokes eminently formidable. Like the Turtles, the Crocodiles lay their eggs in the sand, and leave them to be hatched by the heat of the sun. The general number is from eighty to a hundred: their size is about that of a goose's egg, but their form is more oblong.
When we consider the vast bulk of the adult animal, we may affirm that no creature exhibits so great a disproportion between its youth and age. The eggs are covered with a hard calcareous shell, like that of birds' eggs, but more shining, harder, and more brittle.
Genus Alligator. (Cuv.)
A broad obtuse muzzle, with uneven teeth, marks the genus before us; the fourth tooth on each side of the lower jaw enters into a cavity of the upper jaw, and not into an interspace of the opposite teeth; the webs of the hind feet are small, and extended only between the bases of the toes; the feet are not fringed or pectinated at the sides; and finally there are no holes, or very minute ones, in the skull, behind the orbits.
The five species which constitute this genus are peculiar to America, one being an inhabitant of the southern United States, and the four others of the tropical part of South America. It is worthy of remark, that while the islands of the West Indies possess species of the genus Crocodilus, which is common to both hemispheres, the Alligators are exclusively continental. The former are frequently seen in the brackish waters at the mouths of rivers, the latter never.
The term Alligator is commonly considered as a corruption of the Portuguese word lagarto, signifying a lizard; and it has been applied by the British colonists, not only to the species which inhabits the United States, but also to those inhabiting the West Indian Isles, though, as we have already intimated, the latter are genuine species of the restricted genus Crocodilus. Those of the South American continent bear the appellation of Caiman, which is probably a word of Indian origin.
In temperate climates, at least, the Alligators appear to hybernate; as winter draws near, they bury themselves in the mud, at the bottom of some stagnant pond, and there they remain hidden in a state of inactivity, till the return of milder weather. It is asserted by travellers, that they always avoid swiftly running streams and resort in preference to the creeks of large rivers or to stagnant ponds. In such localities they may be seen in immense numbers, and in the remote parts of South America which are unfrequented, they abound in incredible multitudes, protruding their great flat heads through the leaves of the aquatic plants, such as the nymphæa and pontederia, which cover the surface of the water, and there watch for their prey: at other times they may be seen sleeping or basking on the sunny banks. It is only during the hottest part of the day that they ever venture on shore: before evening they return to the water, as night is their time for seeking their prey, in which they manifest much activity. Fishes constitute their chief food, and some physiologists have supposed that the musky fluid secreted by the glands under the throat, as noticed above, forms a sort of bait by which their prey is attracted towards them. It is very rare that the Alligators attack man, unless their eggs or their young are in danger; but it is said that the female of these reptiles manifests a much more tender care for her offspring than is exhibited by this class in general. She generally lays from fifty to sixty eggs in one place, which are about as large as those of the goose; these she covers over with sand, leaving them to be hatched by the heat of the sun; but she never removes to any great distance from them. The young ones when they come forth from the shell are about five or six inches in length, and the female Alligator at once leads them to the water. In general at least half the brood perish before they reach the water; many while yet in the egg; some through the depredations of vultures, who watch the female Alligator when she repairs to the shore to lay; others are devoured by the adult males of their own species, and yet more by the
ravenous fishes and turtles that inhabit the same waters. Both the egg's and the flesh of these reptiles are eaten, though they diffuse a strong musky odour; some Europeans, however, have so far overcome their prejudices as to pronounce them savoury and agreeable.
The Alligator is believed to be very long-lived, as its growth is very slow, and its ultimate bulk gigantic.
The species with whose economy we are best acquainted is that of which we have already spoken as inhabiting the rivers that flow through the Southern United States, and the dismal swamps that border them. In Louisiana and Florida, this Alligator (Alligator lucius, Cuv.) is particularly abundant, from the low and swampy character of those regions conjoined with their hot climate. The snout of this species is flattened above, and slightly turned upwards; the sides of the head are nearly parallel, and the nose forms a regular curve. The rim of the eye-orbits is large and protuberant, but not united by a transverse crest. The colour is a deep greenish-brown above, and pale yellow beneath; the sides are marked with these colours in alternate bands.
Some interesting details of the history of the Alligator are given with much graphic power by the eminent American ornithologist, Mr. Audubon.
"In Louisiana," says this accurate observer, "all our lagoons, bayous, creeks, ponds, lakes, and rivers, are well stocked with them; they are found wherever there is a sufficient quantity of water to hide them, or to furnish them with food; and they continue thus, in great numbers, as high as the mouth of the Arkansas river, extending east to North Carolina, and as far west as I have penetrated. On the Red river, before it was navigated by steam-vessels, they were so extremely abundant, that to see hundreds at a time along the shores, or on the immense rafts of floating or stranded timber, was quite a common occurrence, the smaller on the backs of the larger, groaning and uttering their bellowing noise, like thousands of irritated bulls about to meet in fight; but all so careless of man, that, unless shot at, or positively disturbed, they remained motionless, suffering boats and canoes to pass within a few yards of them, without noticing them in the least. The shores are yet trampled by them in such a manner, that their large tracks are seen as plentiful as those of sheep in a fold. It was on that river particularly, that thousands of large ones were killed, while the mania of having shoes, boots, or saddle-seats, made of their hides lasted. It had become an article of trade, and many of the squatters and strolling Indians followed for a time no other business. The discovery that their skins are not sufficiently firm and close-grained to resist water and dampness long, put a stop to their general destruction, which had already become very apparent. The leather prepared from these skins was handsome and very pliant, exhibiting all the regular lozenges of the scales, and susceptible of the highest degree of polish and finishing. When Alligators are fishing, the flapping of their tails about the water may be heard at the distance of half a mile; but to describe this in a more graphic way, suffer me to take you along with me, in one of my hunting excursions, accompanied by friends and negroes.
"In the immediate neighbourhood of Bayou-Sarah, on the Mississippi, are extensive shallow lakes and morasses; they are yearly overflowed by the dreadful floods of that river, and supplied with myriads of fishes of many kinds, amongst which trout are most abundant, white-perch, catfish, and alligator-gars, or devil-fish. Thither in the early part of autumn, when the heat of a southern sun has evaporated much of the water, the squatter, the planter, the hunter, all go in search of sport. The lakes then are about two feet deep, having a fine sandy bottom. Frequently much grass grows in them, bearing crops of seed, for which multitudes of water-fowl resort to those places. The edges of these lakes are deep swamps, muddy for some distance, overgrown with heavy large timber, principally cypress, hung with Spanish-beard, and tangled with different vines, creeping plants, and cane, so as to render them almost dark during the day. Here and there in the lakes are small islands, with clusters of the same trees, on which flocks of snake-birds, wood-ducks, and different species of herons, build their nests. Fishing-lines, guns, and rifles, some salt and some water, are all the hunters take. Two negroes precede them, the woods are crossed—the scampering deer is seen—the racoon and the opossum cross before you—the black, the grey, and the fox-squirrel are heard barking. As you proceed further on, the hunk, hunk, of the lesser ibis is heard from different parts, as they rise from the puddles that supply them with cray-fishes. At last the opening of the lake is seen. It has now become necessary to draw oneself along the deep mud, making the best of the way, with the head bent, through the small bushy growth, caring about nought but the lock of your gun. The long, narrow, Indian canoe, kept to hunt these lakes, and taken into them during the fresh, is soon launched, and the party, seated in the bottom, is paddled, or poled, in search of water-game. There, on a sudden, hundreds of Alligators are seen dispersed all over the lake, their head and all the upper part of their body floating like a log, and in many instances so resembling one, that it requires to be accustomed to see them, to know the distinction. Millions of the large wood-ibis are seen wading through the water, muddling it up, and striking deadly blows with their bills on the fish within. Here are a horde of blue herons; the sand-hill crane rises with hoarse note; the snake-birds are perched here and there on the dead timber of the trees; the cormorants are fishing; buzzards and carrion-crows exhibit a mourning train, patiently waiting for the water to dry, and leave food for them; and far in the horizon the eagle overtakes a devoted wood-duck, singled from the clouded flocks that have been bred there. It is then that you see and hear the Alligator, at his work; each lake has a spot deeper than the rest, rendered so by those animals, who work at it; and always situated at the lower end of the lake, near the connecting bayous, which, as drainers, pass through all these lakes, and discharge sometimes many miles below where the water had made its entrance above; thereby ensuring themselves water, as long as any will remain. This is called by the hunters the Alligator's hole. You see them there lying close together. The fish, that are already dying by thousands, through the insufferable heat and stench of the water, and the wounds of the different winged enemies constantly in pursuit of them, resort to the Alligator's hole to receive refreshment, with a hope of finding security also, and follow down the little current, flowing through the connecting sluices: but no! for, as the water recedes in the lake, they are here confined. The Alligators thrash them, and devour them whenever they feel hungry, while the ibis destroys all that make towards the shore.
"By looking attentively on this spot, you plainly see the tails of the Alligators moving to and fro, splashing, and now and then, when missing a fish, throwing it up in the air. The hunter anxious to prove the value of his rifle, marks one of the eyes of the largest Alligators, and as the hair-trigger is touched, the Alligator dies. Should the ball strike one inch astray from the eye, the animal flounces, rolls over and over, beating furiously about him with his tail, frightening all his companions, who sink immediately, whilst the fishes, like blades of burnished metal, leap in all directions out of the water, so terrified are they at this uproar. Another and another receives the shot in the eye and expires; yet those that do not feel the fatal bullet, pay no attention to the death of their companions, till the hunter approaches very close, when they hide themselves for a few moments, by sinking backwards."
The Alligator, like most other reptiles, is endowed with great powers of abstinence; and as stones and pieces of wood are frequently found in its stomach, it is supposed that these are swallowed to relieve the pangs of hunger, by the mechanical distension of that organ. Catesby, Dr. Brickell, and many other persons of veracity, have testified to the fact from personal observation. In some of these cases the lumps, from the wearing down of their angles, seemed to have lain in the stomach for several months.
The female Alligator lays her eggs in hollows in the sand near the margin of the water, amassing for their reception a quantity of decaying leaves and other vegetable matters, and separating the different layers of eggs by layers of the same materials. The fermentation of the heap, when the whole is covered again with sand, is supposed to aid the heat of the sun, in the production of the young. Fifty or sixty eggs are laid in a season, in two or three batches. The mother keeps watch over the place, and after the young are excluded, tends them for months afterwards with much affection and care.
Though most abundant in the southern rivers, the Alligator extends far enough north to be within the influence of severe winters. Buried beneath the mud, however, at the bottom of his river or pool, he sleeps unconscious of the frost. If exposed at such times, sensation is found to be completely suspended, so that the body of the animal may be cut up without arousing him from his torpidity. It is not, however, frozen, and a few hours' warm weather, or the beams of the sun, are sufficient to restore his suspended animation.
Mr. Swainson's opinion of the comparative in-offensiveness of these huge reptiles seems to be contradicted by well-authenticated instances, in which their ferocity has been fatal to man.
Mr. Waterton thus records the fatal ferocity of an allied species, the Cayman of Surinam (Alligator palpebrosus, Cuv.), which is commonly reputed to be less bold than the former. "One Sunday evening, some years ago, as I was walking with Don Felipe de Ynciarte, governor of Angustura, on the bank of the Oroonoque, 'Stop here a minute or two, Don Carlos,' said he to me, 'while I recount a sad accident. One fine evening last year, as the people of Angustura were sauntering up and down here, in the Alameda, I was within twenty yards of this place, when I saw a large Cayman rush out of the river, seize a man, and carry him down, before any one had power to assist him. The screams of the poor fellow were terrible as the Cayman was running off with him. He plunged into the river with his prey; we instantly lost sight of him, and never saw or heard him more.'"[3]
