Fig. 29.—Hooded Basilisk.
Fig. 29.—Hooded Basilisk.
The Hooded Basilisk,B. americanus(Fig. 29), measures seven or eight inches from the nose to origin of the tail, which is itself nearly three times as long, being nineteen or twenty inches in length. Upon the occiput it has a sort of horn or bag, in shape like a hood, round at the summit, and slightly inclined towards the neck. This bag, when distended, is about the size of a pullet's egg. In the male the back and tail are surmounted by a raised crest, such as we have described above, sustained in its thickness by the knotty process of the vertebræ. The general colour is a mixture of sandy brown, slightly marbled on the back and sides, with shades of blue on the upper part, and a silvery white underneath. On the throat are larger bands of brown, and on each side of the eye is a white ray bordered with black, which is lost upon the back; and the tail is so remarkably attenuated towards its extremity as to show the articulations of the vertebræ beneath.
[According to Mr. O. Salvin, the Basilisk is very common about Lanquin, in the province of Guatemala, where it may frequently be seen on the low branches of a bush, and it is particularly fond of basking on the boughs of a felled tree in a clearing near astream. In some specimens of the males, we are informed, the tail is much more compressed than in others. In a series of the young the crest is shown in all stages of development. We also learn from this naturalist that, notwithstanding the compressed form of its tail, the Basilisk does not habitually enter the water, as most writers have supposed.
The sub-family of Anoles (Anoliinæ) have mostly the skin of their toes widened (under the ante-penultimate phalanx) into an oval disk, striated crosswise underneath, which enables them to attach themselves to various surfaces. They do not attain the large size of the Iguanas, and the habits and characteristics of the various species inhabiting Jamaica are thus vividly described by Mr. P. H. Gosse in his "Naturalist's Sojourn" in that beautiful island. "The stranger," he remarks, "walks into the dwelling-house. Lizards, still Lizards, meet his eyes. The little Anoles (A. iodurus,A. opalinus, &c.) are chasing each other in and out between thejalousies, now stopping to protrude from the throat a broad disk of brilliant colour, crimson or orange, like the petal of a flower, then withdrawing it, and again displaying it in coquettish sport. Then one leaps a yard or two through the air and alights on the back of his playfellow; and both struggle and twist about in unimaginable contortions. Another is running up and down on the plastered wall, catching the Ants as they roam in black lines over its whitened surface; and another leaps from the top of some piece of furniture upon the back of the visitor's chair, and scampers nimbly along the collar of his coat. It jumps on the table;—can it be the same? An instant ago it was of the most beautiful golden green, except the base of the tail, which was of a soft, light, purple hue; now, as if changed by an enchanter's wand, it is of a dull sooty brown all over, and becomes momentarily darker and darker, or mottled with dark and pale patches of a most unpleasing aspect. Presently, however, the mental emotion, whatever it was—anger, or fear, or dislike—has passed away, and the lovely green hue sparkles in the glancing sunlight as before."
The green colour of certain of these Anoles so closely resembles that of foliage, that they are apt to be overlooked. Thus Mr. Gosse was about to throw a net over a Butterfly, when, as he remarks, "on a slight rustle among the leaves, I observed that itwas fluttering as if unable to get away. My impression was that an invisible Spider's-web was holding it; but, looking closer, I found that a little green Anolis had the Butterfly in its mouth. Its colour was so exactly that of the verdant leaves of the bush, that I had not perceived it before, although my eyes were fixed on the spot. I have also observed the same species feeding on Ants. On a gateway a number of scattered Ants of a small kind were running to and fro, as they very frequently are seen to do. A beautiful male Anolis had stationed himself on the post perpendicularly, with the head downwards, and as the Ants one by one came near him he snapped them up. Each capture was the work of an instant; he touched the post with his muzzle, and the Ant was gone: they were evidently seized with the lips, not with the tongue. These little creatures are as playful as they are pretty. As they creep about they often catch sight of another of the same species; immediately one suddenly raises and depresses the head and fore-parts, flirts the tail from side to side, and extends the goitre by means of the elastic arched bone in front, till its tip reaches nearly as far as the muzzle. The brilliant goitre is thus alternately extended and relaxed several times. After being thus 'signalized' for a few seconds, one darts towards the other, who usually runs away, apparently as if wishing to be caught." Elsewhere Mr. Gosse describes the noosing of an example of a fine Lizard of this Anolis group, theDactylæ Edwardsii, which is also a native of Jamaica, "about a foot long, and of a lively green colour. He was very savage, biting at everything near: presently his colour began to change from green to blackish, till it was of an uniform bluish black, with darker bands on the body, and a brownish black on the tail; the only trace of green was just around the eyes." He was placed in a cage, and "at night," continues Mr. Gosse, "I observed him vividly green as at first—a token, as I presumed, that he had in some measure recovered his equanimity. The next day he continued very fierce. I hung the cage out in the sun; two or three times in the course of the day I observed him green, but for the most part he was black. The changes were rather quickly accomplished. The food of this Lizard appears to include both vegetable and animal substances. I was never able to induce one to eat in captivity; but the dissection of several has given methis result. Thus in one I have found seeds and farinaceous substance; in another the fragments of a brilliant beetle of the weevil group. I once observed one deliberately eat the ripe glass-berries, munching half of one at a mouthful."23
Thus far we have treated of chiefly arborealIguanidæ; and although a Marine Lizard (Trachycephalus cristatus) cannot well be so designated, it nevertheless belongs to the same particular series. We have next a long series of mainly terrene genera of the same great American family, in which the body is subtrigonal or depressed. As many as twenty-two genera, with sixty-one species of the terreneIguanidæ, were catalogued by Dr. Gray in 1845, and a good many have since been added. There is a corresponding series in the kindred Old World family ofAgancidæ, and in neither instance are the majority of them ground-frequenting Lizards to any great extent. Thus, of Dr. Gray's first genusTropidolipis(so named from its large keeled scales), and of which as many as nine species are given from Mexico, a tenth (T. undulatus, of the United States) is described by Professor Holbrook to inhabit chiefly the pine-forests, where it is often found under the bark of decaying trees; it also commonly chooses old fences for its basking-place. "It is exceedingly rapid in its motions, climbing with great facility to the tops of trees, and is hence not taken alive without great trouble. Its food consists of insects, especially such as are found under decaying wood." The colouring of this Lizard is remarkably brown, with narrow zigzag black bands above, and green below, with a white medium stripe bordered with black; throat and breast black, with a broad green band across. Various species of kindred genera were collected by Mr. Darwin, and are figured in the "Zoology of H.M.S.Beagle," and of one of these (probablyLecolænus Darwinii), which he observed at Bahia Blanca, in Northern Patagonia, he remarks that "it lives on the bare sand near the sea-coast, and from its mottled colour, the brownish scales being speckled with white, yellowish red, and dirty blue, can hardly be distinguished from the surrounding surface. When frightened it attempts to avoid discovery by feigning death, with outstretched legs, depressed body, and closed eyes: if further molested, it buries itself withgreat quickness in the loose sand. This Lizard, from its flattened body and short legs, cannot run quickly." With others these Lizards constitute the sub-familyTropidolepinæof Dr. Gray, which are followed by the sub-familyPhrynosominæ, in which some very singular Lizards find their place. The most extraordinary of them constitute the genusPhrynosoma, four species of which inhabit Western North America. These have great spines to the occiput, in these respects resembling the African genusCordylus(p. 107), and very Toad-like proportions, looking somewhat like Toads with short tails; and again they decidedly approximate in appearance to the curiousMoloch horridusof Western Australia, which belongs to the corresponding Old World family ofAgancidæ; and, like that strange reptile, they are slow of motion, and perfectly harmless, and they may be handled with impunity, as they never attempt to bite.]
Fig. 30.—Flying Lizard (Draco volans).
Fig. 30.—Flying Lizard (Draco volans).
Flying Lizards (Draco) have the head small, the nostrils in a scale, tubular, on the side ridge; tympanum white and opaque. They live on trees, walking with agility with their wings folded by their sides. These wings they expandand use as a parachute when they throw themselves upon their prey from the tops of trees or other elevated places. But they cannot move them as birds do their wings. These remarkable appendages also serve to drive away insects.
[The fabulous Dragons of the ancient Greeks were Serpents or Lizards with remarkably piercing sight, which guarded treasures and devoured men. The Dragons of mediæval artists were frightful and fantastic beings, one half Bat and the other half quadruped or Serpent. The little Saurians which now bear the once dreaded name are no less interesting, although they are no longer monsters; they are distinguished from all other reptiles by a kind of wing, which is a large fold of skin, or membrane, on each side of the body. These wings are entirely independent of the other members, being sustained by six false ribs, which do not surround the abdomen, but rather extend horizontally. They are the only existing examples of our day of that organic arrangement which distinguished the reptiles known under the name ofPterodactyli, and which belonged to the jurassique period of geology.
Dr. Gray divides the Draconina into three genera, namely:—
I.Dracos, having the ears naked, nostrils below the fore ridge, of which three species are described—viz.,D. volans, the Flying Lizard (Fig. 30), having the scales of the back broad, generally smooth, those of the throat granular; wings grey, fulvous, or brown, spotted and marbled with black, sometimes forming four or five oblique black bands near the outer edge; the sides with a series of large keeled scales: the Timor Flying Lizard,D. viridis Timorensisof Schlegel; and the Fringed Flying Lizard,D. fimbriatus, keeled.
II.Draconella, of which there are two species, oneD. Dussumieri, having the nape crested; andD. hæmatopogon, the Red-throated Dragon, without crest on the nape.
III.Dracunculus, of which five species are described—namely,D. quinquefasciatus, the Banded Flying Lizard, nape not crested, having a longitudinal fold;D. lineatus, having the nape crested, the ears slightly concave;D. ornatus, wings grey, reticulated with black, and having broad black bands at the edge; the Spotted Winged Dragon,D. maculatus, grey, and the wings black spotted; andD. spilopterus, having the wing reddish near the body.]
This singular family of Saurians have the head wide and flattened, the mouth wide, the nostrils distant and lateral, the eyes large, with short lids; the tongue short, fleshy, and capable of slight elongation. The body is thick and short, low on the legs, rather squat and depressed, with a belly trailing on the ground; back without crest. The skin is defended by granular scales, interlaced with others of a tubercular character; they are almost always of a sombre colour. Their feet are short, wide apart, and robust; they are furnished on the upper part with imbricated laminæ, which enable them to adhere firmly to the surface of even the smoothest bodies, and to run with rapidity in all directions on a plain surface, and even to remain stationary with the back downwards, like the common house Fly. More generally, however, their hooked and retractile claws, like those of cats, assist them in climbing, crawling up trees, rocks, and even perpendicular walls, and to remain there immovable for several hours. Their flexible bodies mould themselves into the depressions of the surface of the earth, in which they become scarcely visible, their natural colour blending, and being confounded with, the colour of the soil. Their eye-balls, which dilate and contract considerably, protect them from the action of the sun's rays, and enable them, it is thought, to see in the dark. They are nocturnal, avoid the sun's rays, and catch their food in the chinks of rocks. Their movements are rapid, silent, and sudden. They hibernate, and are provided with fatty masses in the groin which are supposed to be a provision for their nourishment during that period. Geckos emit sounds which resemble the noise an equestrian makes when he would encourage his horse—smacking their tongues on the palate to produce the sound. They seek habitations in which they can find food, and are timid, inoffensive, and quite incapable of inflicting injury either by their bite or claws; but their repulsive appearance makes them objects of general repugnance, and has caused evil properties to be attributed to them. Thus people try to destroy them by every possible means. There are about sixteen known species of Geckos distributed in all quarters of the globe, but chiefly in warm countries.
Fig. 31.—Platydactylus homalocephalus.
Fig. 31.—Platydactylus homalocephalus.
[TheGeckotidæare divided into many genera, according to the construction of the toes. Duméril refers to the comparative shortness and general structure of the feet and conformation of the toes, which he describes and figures in detail. The lower surface and the sole he states are very dilatable, and furnished with small plates or lamellæ, following or overlying each other in a mode which varies in the different species. The nails are sometimes wanting on all the toes, but more frequently hooked, and more or less retractile; the toes sometimes united at the base, and inPlatydactylusthe extremity of the toe expands into a fan shape, as in the Tree Frogs. The membranous and soft plates of the lower surface of the toes have various modifications in different genera, which have been made the basis of their arrangement. The Wall Gecko is supposed by Gesner to be the Lizard spoken of by Aristophanes and Theophrastus, and the Tarentula of the Italians: and there is little doubt that it was theΑακαλαβωνμεof Aristotle and the ancient Greeks; it clambered about their walls catching spiders, on which it fed. Schneider has shown it was theStellioof Pliny. Linnæus mentions three species, which he places with his great genusLacerta. Modern herpetologists, following Cuvier and Duméril, class them according to the structure under the several generaAscalabotes,Platydactylus, Hemidactylus,Ptyodactylus,Thecadactylus,Stenodactylus, andGymnodactylus.]
The Wall Gecko (P. homalocephalus),Fig. 31, is of an ashy grey colour, as if powdered on the upper part of the body. It is white underneath, and inhabits the islands of the Mediterranean, as well as the countries which form the basin of that sea, such as Italy, France, Spain, and Africa. They are generally found in old walls; they are, however, sometimes seen running on those of modern habitations. They feed on all sorts of insects, particularly on the dipterous insects and Arachnidans.
The genusChameleo, of which ten species are described in the British Museum Catalogue, are natives of Africa and Asia and naturalised in Southern Europe. They live on trees, clinging to the branches by their feet and prehensile tails; they move slowly and with great caution, feeding upon insects, which they catch with singular dexterity by the rapid elongation of their tongue, which is viscid at the tip.
Certain groundless metaphors, deeply rooted in the popular mind, have singularly distorted the truth in respect to these reptiles. It is commonly believed that the Chameleon often changes its shape, that it has no fixed colour belonging to itself, but takes that of all objects which it approaches. This singular idea has descended from very ancient times. According to the reports of Theophrastus and Plutarch, the Chameleon takes all colours in turn but white; according to Aristotle it changes colour all over the body; but Ælian seems to have had views more in accordance with those of modern observers, for he says when it takes other colours than grey and disguises itself, it covers only certain parts of the body with them. Altogether the ancients made the Chameleon a very fantastic animal; hence in the familiar comparisons of literature these fabulous beings serve as a type to designate uncertain principles; to paint fawning men, who have neither character nor individuality of their own, but who bend themselves to the will and adopt the opinions of others. Putting aside the imaginary attributes accorded to the Chameleon by the fancies of the ancients, and painting them such as they are, westill see in them animals most worthy of observation and highly interesting to the naturalist, as well for the singular formation of different parts of their bodies as for their remarkable habits, and even for peculiarities which have given some sanction to the errors and prejudices to which we have alluded.
Chameleons have compressed bodies; the back round and projecting, or rather pyramidal; the skin granulated; the head angular, with salient occiput resting on a short and thick neck; their legs are slender; the hind, as well as the fore toes are five; the tail prehensile and round. The eyes are very large and protruding, their globes covered by a single shagreen-like eyelid, which the animal can dilate or contract at will, but which leaves little liberty to a small hole pierced at the centre, through which a quick and rather brilliant eye-ball is perceived. The eyes, in the Chameleon, are thus completely enveloped, as if they were too delicate to sustain any glaring light; but this is not all—their eyes have a singular mobility. By certain special muscular arrangements they have the power to direct them on objects either together or separate. Sometimes they turn their eyes in such a manner that one eye looks back and the other forward. With one eye they can see objects above them, while with the other they can see those situated below. It is a common saying in France, applied to the Chameleon, "that it could look into Champagne and see Picardy in flames."
The vermiform and retractile tongue is also a most singular organ. It is cylindrical, about six inches long, terminating in a fleshy, dilatable, and somewhat tubular tip, which is covered with a glutinous secretion, by the aid of which it seizes its insect food, and draws it towards its mouth. The feet have five very long and almost equal strong and hooked claws, but the skin of the legs extends to the end of these toes, and unites them in a very peculiar manner. Not only is this skin attached to each of the toes, but it envelops them, and forms, as it were, two bundles,—the one of three fingers, and the other of two. From this structure one can anticipate the extreme difference which exists between the habits of Chameleons and those of Lizards. These two bundles of long toes are placed in such a manner as to enable them to seize the branches easily on whichthey love to perch; they can grasp these branches by holding on with one bundle of fingers before, and the other behind, in the same manner as Woodpeckers, Cuckoos, and Parrots. Chameleons are better able to preserve their equilibrium upon trees than upon the ground; consequently they are more often seen in those ærial domiciles. Besides, their long and strong prehensile tail serves them as a fifth limb. They swing themselves about like monkeys, grasping the small branches, and thus saving themselves from falling. Moreover, they are cautious, moving at all times very slowly when going from one branch to another. Walking becomes much more difficult for them when they rest upon a level surface—groping their way as they advance, placing their feet upon the earth, one after the other, with the greatest circumspection. They also steady themselves on the ground by the aid of their tail. In their walk they display a certain gravity which contrasts with their diminutive size and the agility which might be expected from them. Even when perched upon a tree their movements exhibit a slowness and deliberation that one would be inclined to say was affected. It is true that the arrangement of their eyes, and the rapid movements of their tongue, render personal activity superfluous in their search for food. They can see their prey and their enemies from a great distance, and in all directions. The latter they readily avoid. As to their prey, when about to seize it, the Chameleon rolls round its extraordinary eye-balls so as to bring them to bear on the devoted object. As soon as it arrives within range of the tongue, that organ is projected with unerring precision, returning into the mouth with the prey adhering to the viscous tip. This tongue they can extend to a length sometimes surpassing that of their body. The skin of the Chameleon does not adhere to the muscles everywhere; some spaces are left free, into which the air penetrates, causing the skin to heave and swell; this mechanism is voluntary, the animal having the power of inflating or relaxing it at pleasure. When this great living bladder is emptied, the animal may be said to resemble a bag of gold-beaters' skin filled with bones. Chameleons exhibit great variation in their colours; that is to say, they may be almost white, sometimes yellowish, at other times green, reddish, andeven black, either in portions, or all over their bodies. These changes of colour were for a long time attributed to the greater or less distention of the vast lungs they possess, and to the corresponding modifications in the quantity of blood sent to the skin; but this explanation is now abandoned. According to Mr. Milne Edwards, the cause of these variations of colour lie in the peculiar structure of their skin, in which there exists two layers of membranous pigment, placed the one above the other, but disposed in such a manner as to appear simultaneously under the cuticle, and at other times so that the one hides the other. Again, occasionally the cuticle is hidden under the superficial pigment.
[Sixteen or seventeen species of Chameleon are described in the British Museum Catalogue.
I. Having an erect fin on the back, the belly crested; which includes the Fringed Chameleon,C. cristatus, a native of Fernando Po.
II. Having the back high, and compressed belly and sides, with a toothed crest; including the Side-crested Chameleon,C. laterales, a native of Madagascar.
III. The back and belly having a toothed crest, the sides simple, the scales small and equal, muzzle simple; including the Common Chameleon,C. vulgaris, with many synonyms. It is a native of the East Indies, is the recognised type of the family (Fig. 32), and the one most commonly brought to England. There are probably two varieties,—one from North Africa, which is also found in Sicily and the South of Spain; the other, the East Indian variety—C. Senegalensis, the Senegal Chameleon, a native of West Africa;C. arpelis, from Ashantee and Gaboon;C. verrucosus, a native of Bourbon and Madagascar; the Rhinoceros Chameleon,C. rhinoceroceratus, also from Madagascar.
IV. Having a toothed crest on the back, with the belly and sides simple, the chin and muzzle simple; includingC. tuberculiferus, a native of South Africa;C. cucullatus, the Hooded Chameleon, a native of Madagascar;C. nasutus, having the chin simple, and the muzzle compressed, andC. bifurcus, having the muzzle in the male forked—both natives of Madagascar;C.Tigris, Seychille Islands;C. ventralis, from South Africa, andC. pumilus, from the Cape of Good Hope.
Fig. 32.—Chameleo vulgaris.
Fig. 32.—Chameleo vulgaris.
V. Having back and belly without crest; includingC. Parsonii, a native of Madagascar; andC. Owenii, the Three-horned Chameleon, from Fernando Po, andC. Brookesianus, an adult species, from S. W. Brookes's collection.
Have the head large, covered with a thick skin, ears closed with two valves, gape very wide, tongue short, jaws with a single series of cone-shaped teeth inserted in sockets; back with a hard disc formed of a longitudinal series of square keeled plates of hard bony consistence embedded in the skin; the under surface covered with smooth thin square plates; legs short, feet webbed, with four to five toes, the three inner toes of each foot only armed with claws.
They are divided into two groups:—
I.Crocodilidæ, having the lower canines fitting into a notch in the edge of the upper jaw.
II.Alligatoridæ, having the canines fitting into a pit in the upper jaw.]
The Shielded Saurians, as Duméril designates the largest of living species of that order of reptiles, have the body depressed, elongated, and protected on the back with a solid carinated shield or buckler; the tail longer than the trunk, compressed laterally, annulated and crested above; having four very short feet; the toes of the posterior feet united, or web-footed, each foot having three claws only; head depressed and elongated into a muzzle; the gape of the mouth extending back beyond the skull; tongue fleshy, adherent; teeth conical, simple, hollowed at the base or towards the root, unequal in length, and in a single row. Such is a brief summary of the family by Duméril and Bibron.
If the Eagle is the king of the air, the Tiger and the Lion the tyrants of the forests, and the Whale the monarch of the deep, the Crocodile has for the exercise of his undisputed control the maritime shores of tropical seas and the borders of tropical rivers. Living on the confines of land and water, this formidable reptile is at all times the scourge of those human beings who are compelled to reside near its haunts. Much larger than the Tiger, Lion, or Eagle, the Crocodile surpasses all terrestrial animals, with the exception of the Elephant, Hippopotamus, and some Serpents, in its power of destruction.
Crocodiles have the head depressed and elongated into a muzzle, in the front of which the nostrils are seen close to a fleshy tubercule, and furnished with movable valves. The mouth opens up to the ears; the jaws are of commensurate length, and are armed, as we have seen, with conical-pointed teeth, bent back, and disposed in such a manner that when the mouth is closed they pass one under the other. These teeth are implanted in a single row, and continually maintained in a good condition by an organic system which ensures their immediate reparation. In short, each tooth is hollowed at the base in such a manner as to form the cell or sheath of another tooth of a larger calibre. The new tooth, which presses on, exercises a sort of absorption upon the base of the old hollow tooth, so that the first is developed while the second is decaying. In some species the front teeth of the lower jaw are so long andsharp that they perforate the edge of the upper jaw and appear above the muzzle when the mouth is closed. The lower jaw alone is movable, and that only in a downward movement. The mouth is without lips, consequently, whether walking or swimming, the teeth of Crocodiles are always visible.
This formidable conformation gives to the Crocodile an aspect at once terrible and alarming, which is increased by two wicked-looking eyes placed obliquely and close together, surmounted by a kind of eyebrow. The tail of these animals is very long, as thick as the body at the junction, and in shape it is flat, like an oar; this enables them to steer through the water like a fish, and to swim with rapidity. They have four short legs, of which the hinder have toes, united by a natatory membrane, and only three claws to each foot. The skin is coriaceous, thick, and resistant; being also protected by very thick knots intermingled with plates of different size, according to the parts of the body they protect. On the skull and face the skin adheres closely to the bone, and there is no trace of scales.
Nature has provided for the safety of these animals by covering them with a cuirass, the resistance of which is proof against almost everything. Thus the scales which defend the back and the upper part of the tail are square, and form hard transversal bands possessed of great flexibility, which prevents them from breaking. Down the centre of the back there is a hard crest, which adds to the strength of their armour. This cuirass is in many points proof against a bullet from a gun. The plates which cover the belly, the upper part of the head, neck, tail, and legs are also arranged in transversal bands, but less hard, and without crests. It is at these weaker and consequently vulnerable parts that those inhabitants of the waters which are enemies to Crocodiles manage to attack them successfully.
The general colour of the Crocodile is a dullish brown, with sometimes a shade of green along the back; the head and the sides are marked with green, or at least they have a greenish tint, with blackish spots; the under part of the legs and belly are of a yellowish grey. All these shades, however, vary with age and sex, and the nature of the water in which the animals live.
Crocodiles are oviparous, and their eggs are provided with resistant shells. These eggs are deposited by the female in some secluded place in the sand on the banks of the river, and are hatched simply by the ambient heat, without any assistance from the mother. The female Crocodiles of the Nile deposit their eggs where the solar heat soon brings them to maturity. In certain countries, such as the neighbourhood of Cayenne and Surinam, the eggs are buried under a kind of mound which the Alligators raise in damp places by gathering together leaves and herbaceous stems. This vegetable debris undergoes a kind of fermentation, the result of which is an increase of temperature, which, joined to that of the atmosphere, produces the desired result.
Lacépède describes an egg in the Museum of Natural History in Paris, which was laid by a Crocodile fourteen feet in length, which was killed in Upper Egypt. This egg is only two inches and five lines in its greatest diameter; in its least diameter it is one inch and eleven lines. It is oval and whitish. Its shell is cretaceous in substance, like the eggs of birds, but not so hard. At the time of their birth the little Crocodiles are only about six inches in length, but their growth is very rapid. They abound in large rivers in the tropics, and in marshy places near their banks. They often come on shore, for they are amphibious. In the night they watch for their prey. They feed exclusively on flesh—that is to say on fish, small Mammalians, aquatic birds, and reptiles. When they have seized a large object they drag it under the water, where it soon dies by asphyxia; there they leave it to macerate, when they eat it by instalments. In this manner men are sometimes carried away by Crocodiles, but it is contrary to the habits of the animal to suppose that they are devoured immediately. When a Crocodile has succeeded in seizing a negro, it does not devour him till the body becomes decomposed, when it can tear it to pieces with greater facility.
From the general structure of their bony framework it is difficult for Crocodiles to turn round or move otherwise than forward. This circumstance renders it easy to escape their pursuit. When chased by a Crocodile, it can be avoided by describing a circle, or running in a succession of curves. Upon the banksof the Lake of Nicaragua, in America, an Englishman was once pursued by an Alligator which had surprised him when on its margin. The animal was gaining upon him rapidly, when some Spaniards who witnessed the scene cried out to him to run round it. Thus fortunately warned the pursued dodged the Alligator, and escaped from his dangerous enemy (Fig. 33).
Fig. 33.—The Englishman and the Caiman, or the Circular Flight.
Fig. 33.—The Englishman and the Caiman, or the Circular Flight.
[No specimens of theCrocodilidæhave been found in Europe, and until very recently none had been found in Australia, but they are very common in the new colony of Queensland, an Alligator twenty feet long having been shot on the banks of the Mackenzie river, which was afterwards exhibited at Rockhampton. Crocodiles, properly so called, are found in Africa, Asia, and America. The Gavials seem to be limited to the Ganges and other large rivers in India. Besides the Gavial, Asia produces three other species, namely,C. vulgaris,C. galeatus, andC. bifurcatus. Of the first, Siam is the chief locality; the others are found in the rivers which debouch into the Indian Ocean and the Ganges.
Include theJacares,Alligators, andCaimans.
TheJacareshave the head oblong and depressed, with a ridge across the face in front of the eyes; teeth unequal, canines of the lower jaw fitting into a pit in the upper jaw; toes only partially webbed, eyelids fleshy, nostrils separated by a cartilage. Five species are described—namely,J. fissipes, from Tropical America, six feet in length;J. sclerops, from the Brazils;J. Nigra, also from the Brazils;J. punctulatus, with triangular oblong head, muzzle elongated, thin and flat, with a rounded point in front, and a slight enlargement behind the nostrils;J. vallefrons, differing slightly from the above—both natives of the Brazils.
Alligatorshave the jaws oblong, much depressed, broad and nearly parallel; forehead with a small longitudinal ridge between the orbits; feet fringed, toes half webbed, the outer toes free; nostrils separated by a bony septum rising from the upper edge, muzzle lengthening with age. One species only is known, which is a native of North America; it attains a length of six to seven feet, and is known also asCrocodilus Mississipensis.
TheCaimanshave the jaws oblong, depressed, rounded, and swollen at the end, without frontal ridges or maxillary pits; teeth unequal, the lower canines fitting into pits in the upper jaw; toes webbed. There are three species described—C. trigonatus,C. palpebrosus, andC. goddeceps, all natives of Tropical America.
The Jacares, Alligators, and Caimans are natives of America, which country is fruitful in other species of the family.C. acutusis also found in Martinique and San Domingo;C. rhombifor, at Cuba;A. palpebrosus,A. sclerops,A. punctulatus, andA. cynocephalusare natives of the southern part of the American Continent; andA. luciusis found in the north.]
The principal characteristics of the American Crocodile are a head one-third its length, and a very short muzzle; teeth unequal in shape and size, the fourth lower tooth being buried in the upper jaw when the mouth is closed; the first teeth of the lower jaw piercing the upper at a certain age, so as to appear through the muzzle when closed. The hinder legs and feet rounded, having neither crest nor indentation on their edges; the intervals of the toes more than half covered with a short membrane, forming semi-palmated feet.
It is generally admitted, as we have stated above, that there are five species of this genera, all exclusively American, the type of which is the Alligator, orCaiman.A. Mississipensis(Gray) belongs properly to North America, through the whole southern extent of which it is found. They are gregarious, living together in large herds in the Mississippi and its southern tributaries; they are also found in the lakes and marshes of Louisiana, Carolina, and even as far north as thirty degrees of north latitude. Alligators do not appear to leave fresh water. During the winter season they bury themselves in the mud of the marshes, and await in a state of torpor the return of spring, which is the signal of their restoration to activity. In the neighbourhood of Bayou Sarah, on the Mississippi, flats of lakes and marshes stretch away to a vast extent on either bank; every year these reservoirs are flooded by the overflow of the river, when they are visited by myriads of fishes. The heat soon partly dries up these lakes, leaving only about two feet deep of water, thus displaying a vast amount of prey ready prepared forthe shore birds and Crocodiles. Millions of ibis, herons, cranes, and cormorants wade into the water in pursuit of these fish. In the deepest portions vast quantities of these imprisoned fish accumulate, and these parts are known in the country as the Alligators' holes. Thither these reptiles crowd, pressing one against the other, and they soon thoroughly clear it of the fish which lately were in such dense crowds. As evaporation proceeds and the marshes gradually dry up, the fish are more and more exposed to their voracious enemies. The Alligators pursue and devour them in the water, whilst the ibis destroys those which seek the banks for refuge. Alligators fish chiefly during the night. In the hours of darkness and obscurity they assemble in large herds, chase the fish before them, driving them into some retired creek, where they rejoice their hearts at the expense of the unfortunate finny tribes, which they force into their widely opened mouths by a lateral movement of their tails. On these occasions the clashing of their jaws may be heard at the distance of a mile. Alligators are found by thousands in Mexican waters, and nearly all North American rivers to the south of them. In the beautiful transparent waters of Lake Claro they abound, and are without difficulty seen by the naked human eye. Here they are so closely pressed one against the other that they resemble a raft of trees recently felled, and the resemblance is further increased by the colour of their backs and the bark of a newly-felled tree being identical. In this united and immovable condition, while waiting for their prey, the approach of a boat is disregarded; but they rush with avidity at everything animate which either falls or is thrown into the lake. Many children of poor negro women become a prey to the Caiman in this locality. They rarely, however, pursue men, yet they would not hesitate to devour them if their imprudence has placed them close to their terrible jaws.
The natives of Mexico hunt the Caiman. When they meet an isolated individual asleep, they throw a lasso round its body, and when secured, gag it. After this operation, the victim's career is terminated by hammering on his head. There is another means which the Indians use to capture the Caiman. They provide themselves with four pieces of hard wood about a foot long, and as thick as a man's finger, and pointed at each end; round these they tiea cord in such a manner that, supposing the cord to be an arrow, the four sticks would form the head of it. They then fasten the other end of the cord round a tree, and bait with meat. This device is thrown into the water. When the Caiman snaps at the prey the points of the hook, on straining on the line, penetrate into its flesh. Having waited till the Alligator is dead, it is drawn from the water, when the captors further gratify their dislike and spirit of revenge by breaking its skull with stones and sticks.
Another method of capturing Alligators is practised by the residents on the upper waters of the giant river Orinoco. A tree is bent (generally a bamboo is selected from its elasticity) till the top is brought down to the butt, a bait is then placed on a sharp hook, the line attached to it being fastened securely to the small end of the bent tree, which is caused to relax its position by an ingenious piece of mechanism which gives way the moment the least strain is felt upon the line; the tree-point becoming thus released, straightens itself with great velocity, and drags the victim from the water.
Frequently the Alligator, from constant pursuit and interruption, becomes excessively wary and difficult to destroy; when such is the case, a live bait is sometimes successfully employed. For instance, a Dog with a hook tied to his back is taken in a canoe and dropped in the water; it is seldom the unfortunate cur is permitted to swim far before being seized.
It is currently believed that the Alligator prefers dog-flesh to all others. The negroes on the plantations in the South-Western States of America, by imitating the barking of a dog, frequently lure these reptiles from their hiding-places, when a well-directed bullet terminates their career.
Alligators are very voracious, but, like Serpents and Turtles, they can live a long time without nourishment. In Brown's "Natural History of Jamaica," he asserts that he has known the Caiman to live several months without food. The following experiments have been tried in that island:—The mouth of an Alligator was muzzled by a strong cord, it was then thrown into a reservoir of water. Thus these animals lived a considerable time. They were seen to rise occasionally to the surface of the water, until death came to their rescue. Let us add tothis, that Crocodiles bred in captivity in the menagerie of the Museum of Natural History, at Paris, sometimes live for several months without eating.
Fig. 34.—Alligator (Crocodilus lucius).
Fig. 34.—Alligator (Crocodilus lucius).
The female Alligator takes more care of her young than the female Crocodile, properly so called. She conducts them to the water, and in the slimy mud she disgorges her half-digested food for their nourishment.
Thetrue Crocodilesare indigenous to Africa, but they are found also in Manilla and India. Their length of head is almost double its breadth. The fourth tooth of the lower jaw is the longest and largest of all, and passes into an indentation hollowed out in the edge of the upper jaw, becoming visible on the outside. The hind feet have on their external edge a dentated crest, and the interstices of their toes, externally, are palmated.
The principal type is the Common Crocodile,C. vulgaris, which sometimes attains the length of nine or ten feet. The upper part of the body of these reptiles is of an olive green colour spotted withblack, and marbled upon the head and neck with the same colour, also the back and tail; two or three broad, oblique black bands are visible upon the flanks of the under part of the body, which is of a yellowish green. Crocodiles abound in Africa. Formerly they were found in all parts of the Nile, but lately it is said thatC. vulgarisis no longer to be met with in the Delta, but that it exists in great numbers in the Thebaid and in the Upper Nile. They are also found in the rivers Senegal and Niger, in Caffraria, and in Madagascar. Most authors give them the name of Crocodiles of the Nile. This species are found also in India.
The Crocodile was considered a sacred animal by the ancient Egyptians. In ruins of temples mummies of Crocodiles are still found in a perfect state of preservation. The Romans introduced living Crocodiles at the national games in the Colosseum. At first only five were imported under the ædileship of Scaurus. Under the Emperor Augustus thirty-six were killed in the Circus of Flaminius. Several ancient medals represent this reptile, the body of which perfectly resembles that which now lives in the waters and on the banks of the Nile. There is a truly wonderful fact in the natural history of the Crocodile. Listen to what Herodotus, the father of history, tells us with regard to it:—"When the Crocodile takes his food in the Nile, the interior of its mouth is always covered withbdella(flies). All birds, with one single exception, flee from the Crocodile; but this one, the Nile Bird,Trochylus, far from avoiding it, flies towards the reptile with the greatest eagerness, and renders it a very essential service. Every time the Crocodile goes on shore to sleep, and at the moment when it lies extended with open jaws, the Nile Bird enters the mouth of the terrible animal and delivers it from thebdellawhich it finds there; the Crocodile shows its recognition of the service, and never harms the bird."
This fact, reported by Herodotus, was long considered to be a fable, but the naturalist, Etienne Geoffroy Saint-Hilaire, who formed part of the commission that General Bonaparte took with him in his expedition into Egypt, had on several occasions opportunities of proving the truth of the historian's narrative.
In a memoir read to the Academy of Science on the 28th of January, 1828, he says, "It is perfectly true that thereexists a little bird which flies about, perpetually seeking, even in the mouth of the Crocodile, the insects which form the principal part of its nourishment." This bird, which Geoffroy Saint-Hilaire recognised as theCharadrius Ægyptiusof ornithologists, is like a Plover. Thebdella, which thus torment the Crocodiles, and even excite them to madness, are no other than our European gnats. Myriads of these insects haunt the banks of the Nile, and when these giants of its waters repose on its margin, warming themselves in the sun, they become the prey of these insignificant pigmies. It is like the war between the Lion and the Mouse, described by La Fontaine. Thebdellafly into the Crocodiles' mouths in such numbers that they cover the entire surface of the palate, and form a brownish crust. These little pests pierce the tongues of the reptiles with their stings. It is then that this bird comes into the mouth of the monster to catch them, and deliver it from such innumerable enemies. The Crocodile with one bite could easily destroy the bird, but he knows too well what he owes to this friend to do it an injury. Crocodiles of the Nile are more voracious than the American Alligators. Hasselquist asserts that in Upper Egypt they often devour women who come to draw water from the Nile, as well as children playing upon its banks. Geoffroy Saint-Hilaire says, that in the Thebaid they often met with Arabs wanting an arm or leg, who accused Crocodiles of this mutilation. Sir Samuel Baker also mentions, in his late work on the Nile and its tributaries, the desire of these amphibia for human flesh, and the dread they are held in by the natives. Livingstone, the celebrated traveller, gives the following account of an encounter he had with one of these ferocious animals:—
"The Crocodile," says the celebrated traveller, "makes many victims every year among the children who are so imprudent as to play on the banks of the Liambia when their mothers go to fetch water. The Crocodile stupefies its victim with a blow from its tail, then drags it into the river, where it is soon drowned. In general, when the Crocodile perceives a Man it dives, and furtively glides away from the side which he occupies. Sometimes, on the other hand, it precipitates itself with surprising agility towards the person it has discovered, which may be noticed from the disturbancecaused on the surface of the water. An Antelope which is being hunted and takes to the water, in the lagunes of the Barotsé valley, a Man or a Dog who goes there to seek for game, will scarcely fail to be seized by a Crocodile, of whose presence he has not the slightest suspicion. It often happens that, after having danced in the moonlight, the young natives of the river's bank will often plunge into the water in order to refresh themselves, when, being seized by an Alligator, they perish."
[This mode of attack (striking with the tail) is also one of the methods adopted by the Alligator of America for disabling its prey. A friend, on whose veracity I have much dependence, while shooting wild fowl on one of the tributaries of the Lower Mississippi, had the fortune to witness a fight between a Bear and an Alligator. He was called to the scene of the struggle by the noise made by the combatants, in the dry cane, that yielded to their pressure as they fought in each other's embrace. Several times both ceased only to recover breath and fresh energy; at length the Alligator missed striking the foe with its tail, Bruin seized the opportunity, and with all his efforts succeeded in turning the amphibian on its back, where he held him for some minutes, at the same time gnawing one of the fore-shoulders. A final struggle of the now worsted Alligator hurled both into the water, where they disappeared, the disturbed surface telling of the dreadful contest that was being prolonged beneath; after the lapse of over a minute the Bear came up, evidently much fatigued, and swam ashore, my friend forbearing to wound, or possibly kill, the gallant conqueror.]
Crocodiles, it is said, which have never eaten human flesh, are much less dangerous than those that have acquired a taste for it. Mr. Combes states that he was assured by an inhabitant of Khartoum, who had reached the town with the Egyptian troops—that is to say, before the horrors committed by the Desterdar, acting with Mehemet Bey, who had been Governor of the Soudan some time before Mr. Combes's voyage—that the Crocodiles appeared to be quite indifferent to human flesh; but after the many executions by drowning ordered by Mehemet Bey, as he was told by a native whom he interrogated—"since the Nile has been loaded with the carcasses of my brethren"—the monsters which inhabit it havebecome habituated to substantial food, which they scarcely knew before: so that afterwards those swimming in the river, or even bathing on its banks, were exposed to imminent danger.
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.
TheGavials, 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 indentationsin 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 theGavial of the Ganges, orGavial 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.
["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 (TrionyxandSphargis), 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, andtail 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 acarapace, or back-piece, andplastron, 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, fromχελωνη, a Tortoise, are also calledTestudinata, fromtestudo, 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 thelateral 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.
The plastron, or ventral plate, is made up of nine pieces, of which eight are arranged in pairs; but the ninth, which is always placed between the four pieces composing the two anterior pairs, is single, and occupies the mesial line. The bones of the shoulder and hip are placed within the thorax, and articulated to the sides of the vertebral column.
Of this vertebral column in these extraordinary animals, Professor Owen remarks that the manifold modifications of the framework which render it a portable abode, appear to have been given as a compensation for inferior powers of locomotion, and the absence of offensive weapons. But with all its modifications, the same number of pieces are found in the bony skeleton as in other ordinary vertebratæ, the form and volume of many of these pieces being alone changed.
The skin which covers the body of these animals sometimes preserves its softness, being altogether devoid of scales; but in nearly all the species it is covered with horny scales of great consistency. Upon the plastron and carapace these scales form large plates, the arrangements and appearances of which vary in different species, some of them being often remarkably beautiful. The material which bears the name of Tortoise-shell forms an important article of commerce.
Aristotle mentions three groups of Tortoises; namely,χελωη χερσαια, or Land Tortoises;θαλαττια, or Sea Tortoises; andΕωhυς, or Fresh-water Tortoises. Cuvier divides them into five sub-genera:—1, Land Tortoises,Testudo(Brogniart); 2, Fresh-water Tortoises,Emydes(Brogniart); 3, Marine Tortoises,Chelque(Cuvier); 4, Chelydes,Testudo fimbriata; 5, Soft Tortoises,Trionyx(Geoffrey)—in which he is followed by Dr. Gray in the BritishMuseum Catalogue, who makes them the third order of Reptiles in his arrangement as follows:—
In the valuable "Erpétologie" of Messrs. Duméril and Bibron, the Chelonians are divided into—1, Land Tortoises,Chersites; 2, Marsh Tortoises,Elodites; 3, River Tortoises,Potamites; 4, Sea Tortoises, or Turtles,Thalassites.
This arrangement being the most simple, is adopted as best adapted to our purpose.]
Terrestrial Tortoises are distinguished by their short, oval, and convex bodies, covered by carapace and plastron; four feet, and the absence of teeth; short, stumpy, unshapely legs; nearly equal toes, armed with claws, united by a thick skin, so as to form a clumsy foot, the periphery of which forms a sort of hoof, which seems adapted for the land.
In this group the carapace is very convex, its height sometimes exceeding its breadth; it forms a solid, generally an immovable, arch, under which the animal can completely conceal its feet and tail. Thisbuckleris covered with large horny plates or scales.
Land Tortoises have been known from the earliest times, representations of them being found on numerous monuments of antiquity, the product of ancient art. Moreover, ancient writers tellus that the carapace of the Tortoise contributed its substance to the formation of the first lyre; it was consequently sacred to Mercury as the deity of music and inventor of that instrument.
The Land Tortoises are divided into four genera, which Duméril and Bibron again divide into three sub-genera and thirty species. The most interesting species, however, to which we must limit our remarks are—the Marginate Tortoise,Testudo marginato; the Moorish Tortoise,Testudo Mauritianica; the Greek Tortoise,Testudo Græca; and the Elephantine Tortoise,Testudo elephantina.