CHAPTER II.

_TORTOISES AND TURTLES._

The order of the Chelonians, including the Tortoises, Turtles, and Terrapins, with their allies, constitutes one of the most distinct and readily defined groups of the Reptile Class. The more or less complete bony shell, or carapace, which encases the body, and into which both head and limbs can in many cases be completely retracted, separates these reptiles very widely from the other orders. In some respects certain details of the skull-structure assimilate them to the Crocodiles; but here again there is an entire absence of the rows of formidable teeth, the upper and lower jaws being sharply pointed, covered with horn, and thus converted into a trenchant beak. The two leading groups of the Tortoises and the Turtles are distinctly separated, by the respective conformation of their limbs, for a terrestrial or aquatic existence. The Tortoises have normal walking-legs, with toes and, in most instances, claws, fitting them for walking on the land or burrowing into the earth. In the True Turtles these limbs take the form of flattened paddles, and in no instance are more than two of the toes provided with claws.

The TORTOISES are sub-divided by zoologists into some six or eight subordinate groups or families, for the most part distinguished by the respective modifications of their protective shells. This shell in all tortoises and turtles consists of two essential elements--the upper or back casing, known as the "carapace," and the under one, or so-called "plastron," which covers the ventral surface. In some forms these two elements are completely welded into one another, forming a continuous box-like shell; in others they are more or less separate; while in yet another series the lower shell is rudimentary. These distinctions have been found to constitute a convenient basis for classification.

In the TRUE LAND-TORTOISES, which invite first attention, the upper and lower shells are completely united in a box-like form, and the neck, bent in the form of the letter S, can be completely retracted within it. The limbs are club-shaped, covered with horny scales or tubercles, and adapted for walking, the toes being unwebbed, and provided with strong claw-like nails.

Pre-eminent among this typical terrestrial series come the huge GIANT or ELEPHANT-TORTOISES, formerly abundant, as their fossil remains indicate, in Southern Europe, India, and North and South America, and now represented only in the isolated oceanic islands of Aldabra, off Madagascar, the Seychelles, and the Galapagos groups. Even within historic times they were very abundant in the islands of Mauritius and Rodrigues; but their huge size and lethargic habits, combined with their esculent qualities, have brought about their extermination. Those remaining in the islands mentioned are now so reduced in numbers that there is a possibility of their becoming extinct at an early date, and this notwithstanding the strenuous endeavours that are being made to save them. A large percentage of the small residue of these giant Chelonians have been transported from their island homes and presented to the London Zoological Gardens, where they are now comfortably housed.

An instructive idea of the aspect and relative dimensions of these giant tortoises may be obtained by a reference to page vii of the First Volume, in which one of these Chelonians is shown to be equal in size and strength to carrying a human rider. It is recorded that these reptiles were so abundant in the island of Rodrigues in 1691 that one might count as many as 3,000 of them in a single flock, and walk for over 100 paces upon their backs. All of these giant tortoises, as obtained from separate island groups, or islets of the groups, exhibit characteristic differences, indicating the length of time they have been separated from one another. The age to which these giant tortoises attain is altogether phenomenal. One example at Port Louis, Mauritius, originally brought from the Seychelles, is definitely known to have lived for over 130 years from the date of its transportation. It is stated to have been of large size when imported; and as these animals are notoriously slow growers, another couple of centuries may be safely added to its life-span. The Galapagos Islands down to recent times have produced the greater number of species of these tortoises, the carapace of the largest of these not infrequently measuring as much as 4 feet in direct length, and the weight of such an animal being over 400 lbs.

Highly interesting details concerning the Galapagos giant tortoises and their habits are contained in Darwin's "Voyage of the Beagle." At the time of that illustrious naturalist's visit they were still very abundant in the islands. He remarked that they abounded in both the higher and damper and the lower and arid districts, but gave preference to the former. The old males were invariably the largest, growing to such a size that they required six or eight men to lift them, and yielded as much as 200 lbs. of good, highly nutritious meat. On some of the islands there was no water; and in these cases, as also when they occurred in the dry and arid lowlands, they were observed to feed chiefly on the succulent cactuses. When water was plentiful, the tortoises exhibited a great fondness for it, drinking large quantities and wallowing in the mud. In the larger islands, where wells and springs existed in the higher and damper portions, regular well-beaten paths radiated in every direction, indicating the routes, like sheep-tracks, regularly followed by the tortoises to and from the water-holes. It was these tracks which betrayed their presence and led to their first discovery by the older Spanish navigators. When travelling long distances to the watering-places, it is recorded that they march night and day, pursuing the "even tenor of their way" at the rate of sixty yards an hour--one yard per minute, or four miles per day! During the breeding-season the larger males indulge in hoarse roarings or bellowings that can be heard for a considerable distance. The female deposits her eggs either in the sand, where this is plentiful, covering them up again, or, where the ground is rocky, drops them indiscriminately in any crevice or depression encountered. The eggs are white, spherical, and hard-shelled, as in all tortoises, and somewhat exceed those of a hen in bulk.

The very antithesis of the giant land-tortoises of the Galapagos Islands is the small and familiar GRECIAN TORTOISE, frequently exposed for sale on hand-barrows in the London streets, and acquired by the unsophisticated suburban resident as a quaint but not altogether estimable garden pet. Like the majority of tortoises, this is a vegetarian, and with epicurean tastes that will guide it instinctively to select your choicest lettuces and the gems of your horticultural triumphs for the delectation of its fastidious appetite. The Grecian tortoise rarely exceeds 5½ inches in length, and is abundant throughout South-eastern Europe, Sicily, Italy, and the Grecian Archipelago, extending thence to Syria. In Algeria an almost identical tortoise occurs which grows to the greater length of 9 inches; while Greece produces yet a third form, the so-called MARGINED TORTOISE, which attains the greater length of 11 inches, and is distinguished by the colour of the carapace usually being black, with a small spot of yellow on each shield-like plate. All three of the foregoing species are collectively imported by shiploads for sale in England, and it would be interesting to know what fate befalls them. In Greece and Sicily they are regularly placed on the market as an article of food. When acclimatised in England, and even in their warmer native country, these Grecian tortoises bury themselves in the earth and hibernate during the cold winter months.

Next to the typical Land-tortoises the so-called HINGED TORTOISES demand brief notice. The several members of this little group are denizens of tropical Africa, and notable for the circumstance that the hinder portion of their carapace is united with the anterior one by a movable ligamentous hinge. As a result of this peculiarity the animal, when retracted within its shell, can entirely close up the hinder aperture. None of these forms exceed a length of 9 inches.

In another group, distinguished by the title of BOX-TORTOISES, a ligamentous hinge is developed across the centre of the lower shell, or plastron, which, being freely movable with relation to the upper shell, enables the animal, when retracted, to completely close up both the anterior and posterior carapace apertures. The box-tortoises are natives of the South-eastern United States and Mexico, and, in addition to the foregoing structural peculiarity, are distinguished by the high or vaulted contour of their carapace. In some the toes are slightly webbed, and their habits are mainly carnivorous, indicating affinity with the flesh-eating and essentially aquatic Terrapins.

Between the two, however, have been intercalated a little group, known as the POND-TORTOISES, one species of which is found in Southern Europe, and a nearly allied one in North America. These pond-tortoises are distinguished by the smooth and depressed form of the carapace; the toes are fully webbed, fitting them for an aquatic life; while a ligamentous hinge, separating the anterior and posterior moieties of the plastron, enables them to cover in and protect their retracted head and limbs, after the manner of the Box-tortoises. The carapace of the European pond-tortoise does not exceed 7½ inches in length, and is usually dark brown or black, ornamented with yellow dots or radiating streaks. This species inhabits both ponds and running water, and during the daytime creeps out on the banks, like the Crocodiles, to bask in the sun. As with the Crocodiles, however, the daytime does not represent the period of its greatest activity, this being during the night. The pond-tortoises are highly esteemed for the table in the countries where they are indigenous.

The TRUE TERRAPINS are all tortoises of essentially aquatic habits, differing, however, from the water-frequenting Pond-tortoises, last referred to, in that they have no ligamentous hinge providing for the hermetical closure of the carapace apertures. The carapace and plastron, moreover, are firmly united by bone, so that the two form conjointly a rigid, continuous shell, as in that of the typical Land-tortoises. The terrapins are widely distributed, being found in North America, Japan, China, the Persian Gulf, Spain, and North-west Africa. Terrapin ranks highly as a table delicacy in the United States. The real DIAMOND-BACKED species, however, is now becoming very scarce, the supply not being equal to the demand, and many inferior varieties being substituted in its place. The "fishing" for these terrapins is mainly prosecuted during the autumn months, when the reptiles become dormant, and are easily discovered and secured by probing the mud with sticks. The female terrapin, or "cow," as it is designated, is considered the greater delicacy, the eggs, to the number of twenty or thirty, usually found inside its body, being the _de rigueur_ garnishing of the dainty dish. The diamond-terrapin rarely exceeds a length of 7 inches; but some of the inferior varieties, or "Sliders," as they are termed, are of much larger dimensions, and may weigh as much as 4 lbs.

From an æsthetic standpoint the PAINTED TERRAPIN undoubtedly bears the palm. Its smooth, depressed carapace is not more than 6 inches long, and its ground-colour is usually a dark olive-green, yellow lines bordering its component central shields; the small marginal shields are sometimes almost crimson with black markings, and the "bridge" uniting the carapace and plastron exhibits the same brilliant coloration. The soft skin of the head, neck, and other exposed parts have yellow and red bands on a brown or blackish ground-colour. This beautiful little terrapin, which is a special favourite for aquariums, is a native of Eastern North America.

Passing the small and not peculiarly conspicuous group of the AMERICAN MUD-TERRAPINS, we arrive at the very distinctly differentiated family of the SNAPPERS, SNAPPING-TURTLES, or ALLIGATOR-TERRAPINS, as they are variously called. These likewise are exclusively confined in their present-day distribution to the New World, though in former ages allied species inhabited Europe. The alligator-terrapins are characterised by the relatively small size of the carapace, within which the animal is unable to completely retract its head and limbs, as in the preceding types. The head is relatively large, and armed with a formidable hooked beak; while the tail greatly exceeds in relative length that of any of the ordinary tortoises or terrapins, and is scaly and crested somewhat like that of a crocodile along its upper ridge, and has horny plates on the under-surface. Their popular name has, in fact, been conferred upon these Chelonians on the strength of their presenting the aspect to no inconsiderable extent of an alligator's body, to which the carapace of an ordinary terrapin has been united. The common alligator-terrapin, or snapping-turtle, is among aquatic Chelonians an animal of considerable size. The carapace alone may be as much or more than 20 inches long, and to this have to be added the thick head and neck and elongated tail, which, taken together, are of almost similar dimensions.

A second closely related member of this family, known by the name of TEMMINCK'S SNAPPER, attains to yet longer proportions, and is the largest known river-tortoise. The carapace in this species may measure over 2 feet in length, and has three strongly marked longitudinal ridges. The head is relatively larger and the tail somewhat shorter than in the preceding species. It is a denizen of the southern districts of the United States, being met with in Texas, Florida, and as far north as the Missouri.

The habits of the two species are stated to be identical. Both of them frequent the rivers and swamps of the areas indicated, preferring the waters that have a muddy bottom, and in some localities occurring in vast numbers. As a rule they prefer lying in deep water near the centre of the river or swamp they inhabit, but they also occasionally ascend to the surface and float in midstream with outstretched necks. Like other water-tortoises, they come on land to find suitable locations for depositing their eggs. The name of Snappers, commonly applied to these tortoises, bears reference to their inveterate habit of snapping and biting viciously at everything placed within their reach. Even from the egg the young of Temminck's species is wont to display this trait. The animals are somewhat esteemed for food, and are consequently caught for the market. They will take almost any bait, but manifest a predilection for fish. Considerable caution has necessarily to be exercised in dealing with them in the boats, and it is a common custom to decapitate them immediately they are hauled on board, otherwise they are capable of inflicting the most terrible wounds with their powerful cutting beaks on the persons of all or any who may remain within their reach. Bathing in waters tenanted by the pugnacious and distinctly aggressive snappers is a risky proceeding, and many cases of serious injuries that have happened to incautious adventurers in this direction have been recorded.

The food of both the alligator and Temminck's snapper consists mainly of fish, and where common these tortoises must be ranked among the most potent agencies in denuding the rivers and lakes of their finny denizens. Not content with fish, the larger examples have been known to drag under water and devour such large water-fowl as ducks, and even geese. It is stated that the snappers exhibit a surprising amount of agility in the water, and swim after and capture the fish on which they feed. Such a feat seems scarcely credible of a bulky adult individual, while, moreover, it is provided with a remarkable and effective adaptation for taking its prey by stratagem. A very fine example of Temminck's snapper was for many years confined in a tank in the Reptile-house in the Regent's Park Zoological Gardens. It usually lay prone at the bottom of its tank, giving little or no signs of life throughout the day, but was wont to display more activity and to move about its tank at night. At times, when ready for a fresh food-supply, it was observed that it would lie motionless as a stone, as usual, but with its mouth open to its widest gape. This attitude it would maintain for several hours together. The singularity of this action was that the gaping jaws displayed to view two elongate worm-like structures, which sprang close to one another from the floor of the mouth just within its entrance. These worm-like appendages were continually writhing to and fro, and presented in both aspect and movements a most remarkable resemblance to actual living worms. With this naturally provided decoy for fish there can be no need for the snapper to exhaust its energies in the strenuous pursuit of its quarry. To make the delusion complete, the head, neck, and chin of Temminck's snapper are decorated with small lobular or leaf-like membranous appendages resembling sponges or aquatic vegetation. The solid grey-brown triangular head of the animal itself might easily be mistaken for a piece of rock, and thus decorated with seemingly natural growths the unwary fish come browsing along it, rush upon the wriggling worms at the entrance of the cavernous chamber, and are lost. A photograph of this interesting Chelonian is reproduced on page 560, which depicts it with its mouth open, and indicates both the position and the presence of the worm-like decoy-appendages.

There are several water-tortoises presenting a considerable external resemblance to the forms already noticed which belong to distinct family groups. Thus the MATAMATA TORTOISE of Northern Brazil has at first sight, except for its short tail and nose-like proboscis, much in common with Temminck's snapper. Fimbriated and foliaceous membranous outgrowths are developed on the head and neck to a much more luxuriant degree, and it would be interesting to ascertain if it possesses similar decoy-appendages inside the mouth.

The so-called SNAKE-NECKED WATER-TORTOISES of South America, and the LONG-NECKED aquatic ones of Australasia, possess modifications of skull-structure and other details that indicate family distinctness. A broad external character that serves to separate this group from the Terrapins and all preceding forms is that the neck, when drawn within the cavity of the carapace, is not flexed in the form of the letter S, but simply bent sideways along the anterior margin of the body. The species belonging to this group, which includes the Matamata, Snake-necked, and Soft-shelled Water-tortoises, and also a few essentially terrestrial species, are distinguished collectively by the appellation of the "SIDE-NECKED" Tortoises.

TURTLES.

Certain of the Terrapins, or Water-tortoises, belonging to the groups above described frequent saline river-estuaries and salt marshes, but none are strictly marine. With the Turtle Family, however, we arrive at an exclusively pelagic section, in which the animals are specially adapted for life in the high seas, the walking-limbs of the terrestrial and fresh-water species being replaced by long and powerful swimming-flippers. The shell in these marine Chelonians is more or less heart-shaped and flattened, and the carapace and plastron are always separate, and never united in a rigid box-like form, as with the Land-tortoises. In common with those fresh-water tortoises which pass the greater portion of their existence in lakes or rivers, the MARINE TURTLES resort to the land to deposit their eggs. The locations chosen are the sand-beaches or isolated sandy islets in tropical oceans, wherein, after excavating hollows to receive them, the eggs are covered up and left to hatch with the heat of the sun. The eggs of turtles differ from those of the Land-tortoises and Terrapins in that their external covering is soft or leathery. So soon as the young turtles are hatched, they emerge from the sand, and instinctively make their way to the water. Many, however, are the perils that beset their course, and few there be out of perhaps 80 or 100 turtlets which gain the shore and get through into deep water. Fish-hawks and sea-birds of every description are waiting ready to pounce down upon them immediately they make their appearance, or to thin their ranks as they run the gauntlet of perhaps 100 yards or so to reach the sea in safety. Even at the waters edge the ordeal is by no means passed. Shoals of the smaller sharks and other predatory fish are continually cruising round in the shallow water, and have as high an appreciation of the toothsomeness of tender turtle as the proverbial London alderman. The writer was fortunate on one occasion, among the coral islands on the Australian coasts, to light upon a young turtle brood just emerging from their sandy nest. The majority were assisted to the sea, and a few, reserved in the interests of science, were liberated in a bath of sea-water to have their first swim. Snapshot photographs were taken, one of which, reproduced on page 561, serves to illustrate the great relative length of the paddle-like limbs at this early stage and the variety of postures assumed during natation.

Of the typical Marine Turtles three distinctly characterised species are recognised by zoologists. These are the GREEN TURTLE, indispensable for soup at aldermanic banquets; the HAWKSBILL, or tortoiseshell-producing turtle; and the LOGGERHEAD. Of these three, the green turtle and the loggerhead more nearly resemble one another, and are apt to be confounded by the uninitiated. Such an error is very readily detected when the Chelonian comes to the table, the flesh of the loggerhead being rank and utterly unfit for food. In order, however, to be wise before the event, and to avoid a grievous misdirection of culinary energy--turtle being a standard dish in the coral seas--it is only necessary to count the number of large shield-like plates that flank each side of the central series in the creature's carapace. In the true green or edible turtle there are only four pairs of these large lateral shields, while in the loggerhead there are never less than five, and sometimes more. The loggerhead-turtle also, as its name implies, has a conspicuously larger and coarser head than the esculent species. The fact that while the green turtle is a strict vegetarian, feeding entirely on seaweeds, the loggerhead is altogether carnivorous, readily accounts for the diametrically diverse gastronomic properties of these two Chelonians. Both species attain to a considerable size, over 3 feet in length (the loggerhead being the larger), and are found inhabiting the same waters throughout the tropics.

The HAWKSBILL, or true tortoiseshell-producing turtle, never attains to quite as large dimensions as the two preceding species, though its carapace may measure as much as 2 feet 6 or 8 inches long. The structural feature that at once distinguishes the hawksbill from either the green or loggerhead species is the character of the horny shields developed on the surface of the carapace. Instead of the edges meeting in juxtaposition, as in those two forms, they overlap one another, like the scales of a fish, and are notable for their thickness and their exceedingly beautiful but variably marbled patterns. It is these marbled horny plates which constitute the tortoise-shell of commerce. In young individuals the substance is thin and very transparent, but thickens with advancing age, until in old individuals the plates may vary from 1/8 to ¼ inch in thickness. Like the two preceding species, the hawksbill, within tropical seas, enjoys a cosmopolitan distribution. Its habits, like the loggerhead's, are essentially carnivorous; but while the flesh is coarse and rank, the eggs are valued for the table.

A remaining member of the Marine Turtle series is the so-called LUTH or LEATHERY TURTLE. This Chelonian differs so materially in structure from the foregoing species as to be referred to a distinct family. The horny plates, so conspicuous in all the other types, are entirely absent, the bony carapace, which is distinctly seven-ridged longitudinally, being covered with a homogeneous leather-like skin. Both jaws are formidably hooked and cutting throughout their edges, and the paddles are destitute of the two rudimentary claws found in the preceding species. The leathery turtle grows to an immense size; specimens have been recorded measuring as much as 8 feet in total length and weighing over 1,600 lbs. Its flesh is not only unfit for food, but is reported to be of a poisonous character. The coasts of Florida and Brazil are among the areas where the leathery turtle is met with in the greatest abundance.

The more ordinary method of capturing turtle for the market or to supply the deficiencies of the larder aboard ship in tropical climates is to land at night, preferably when the moon is full, on the islands to which the females are in the habit of repairing to deposit their eggs. This function is invariably discharged during the night hours, and unless the moon is up the presence of the reptiles is not easily determined. Time is generally given for the turtle to excavate its sand-burrow and lay its eggs, usually over a hundred in number, the proper moment for the capture being that when, the task accomplished, it sets forth to regain its more accustomed element. The creature is then seized and turned suddenly upon its back, where it is left to struggle and flounder helplessly, being perfectly incapable of righting itself, while other captures are made. On outlying coral islands, such as those of the Lacepedes, off the Western Australian coast, several dozen of the Chelonians may represent one good night's haul, the choice of the fittest examples being left until the return of daylight.

In many places turtles are pursued in the water and speared; while in some locations, notably at Keeling Island, as recorded by Darwin, the animals are chased by the natives in sailing-craft. One man steers the boat, the other one standing in the bows on the look-out for turtle. A Chelonian being sighted, an exciting stern chase ensues, and on coming abreast with the quarry the look-out man plunges into the water straight upon the turtle's back, and clings pertinaciously with both hands to the shell of the neck until the creature is exhausted, when it is dragged into the boat.

The most remarkable method of taking turtle, however, is that practised in Torres Straits, as also at Mozambique and formerly in the West Indies. The sucking-fish, or remora, is in this case impressed into the service of the human fishers. Taking advantage of the fish's natural propensity to swim towards and adhere pertinaciously to any larger floating object, fishermen go out with specimens kept alive in a small well in the bottom of their boats. When in pursuit of turtle, a long light line is attached to the fish's tail; and coming within sight of a Chelonian, the fish, with an abundance of slack or pay-out line, is thrown in the direction of the turtle. The remora immediately swims towards and adheres firmly to the under surface of the shell of the turtle, when it will suffer its body to be torn asunder rather than let go its hold of its newly gained sanctuary. Should the turtle be a small one, both fish and turtle are dragged with the line back to the boat. If, on the other hand, it is of large size, one of the natives plunges into the water, and, following the line down, secures the turtle.

In the island of Ascension the cultivation and breeding of turtles for exportation in artificially constructed enclosures have for a considerable time been the subject of an important industry. There are doubtless many other locations on both the Australian coast-line and in the British West Indies where this highly profitable trade could be established. In addition to the green turtle, attention might also be profitably directed at the same locations to the culture of the tortoiseshell-bearing species. Tortoiseshell possesses the singular and useful property of being susceptible of perfect amalgamation. Consequently a number of small-sized pieces can be welded so indistinguishably with one another as to serve the same use as the larger plates for commercial purposes. This amalgamation is effected by bevelling the edges of the two pieces that it is desired to unite along the proposed line of junction, and then, while they are held in juxtaposition in a metallic press, submitting them to the action of boiling water.

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