Chapter III: The Order of Lizards.--Saurians (2)

Of the habits of a kindred species of Iguana, the _Cyclura lophura_, inhabiting Jamaica, Mr. Gosse has given an elaborate description; and he tells us that the gular pouch in the _Iguanidæ_ "is _extensible_, but not _inflatable_," as is the current opinion. Holbrook and others have remarked the same; and Professor Thomas Bell describes the fold of skin as being drawn down by a peculiar arrangement of the lingual bone, and a singular cartilage fixed to it and attached also to the skin. These parts are moved by delicate muscles, so that, when the cartilage is drawn down, the skin of course is distended, and follows it "in the same way that the silk is stretched over the whalebone of an umbrella." "In fact the skin," writes Professor Holbrook, "when distended in life by the animal, does not resemble the inflated vocal sacs of the Frogs and Toads, which are round, but looks like a fold of the skin, pinched and drawn down, the two portions of it being in contact, like a dew-lap." It appears that the _Cyclura_, also, is exclusively herbivorous; and Mr. Gosse remarks upon the severe wounds which it inflicts upon Dogs with its sharply-serrated tail. In general, the larger species of this family are solely vegetable-feeders, while the smaller kinds (such as the Anoles) are more or less insectivorous; and there are some, of intermediate size, which even prey occasionally upon the kindred Anoles and other small animals. The genera of these reptiles are exceedingly numerous, as we have seen, and amongst so many there must be considerable variety in the habits; but we can only notice a very few of them. Within the limited area of the small archipelago of the Galapagos, situated on the equator about ten degrees west of South America, there are two remarkable species of _Iguanidæ_, of which the habits have been described and commented upon by Mr. Darwin in his volume of the "Voyage of H.M.S. _Beagle_." One of them is particularly so, because, as that naturalist observes, it is the only existing Saurian which can properly be said to be a maritime animal. In the whole of that group of islands, as he tells us, there is only one rill of fresh water that reaches the coast; yet this reptile frequents the sea-beaches, and no other parts of the islands. He adds that it is the only known existing Lizard that feeds exclusively on aquatic productions. Although he refers both species to the genus _Amblyrhynchus_, the aquatic sort now constitutes the genus _Oreocephalus_ of Dr. Gray, and it bears the name of _O. cristatus_. This Lizard, according to Mr. Darwin, "is extremely common on all the islands throughout the archipelago of the Galapagos. It lives exclusively on the rocky sea-beaches, and is never found--at least, I never saw one--even ten yards inshore. It is a hideous-looking creature, of a dirty black colour, stupid and sluggish in its movements. The usual length of a full-grown one is about a yard, but there are some even four feet long. I have seen a large one which weighed twenty pounds. On the island of Albemarle they seem to grow to a greater size than on any other. These Lizards were occasionally seen some hundred yards from the shore swimming about; and Captain Colnett, in his 'Voyage,' says, 'they go out to sea in shoals to fish.' With respect to the object, I believe that he is mistaken; but the fact stated on so good an authority cannot be doubted. When in the water the animal swims with perfect ease and quickness, by a serpentine movement of its body and flattened tail--the legs, during this time, being motionless and closely collapsed on its sides. A seaman on board sank one, with a heavy weight attached to it, thinking thus to kill it directly; but when an hour afterwards he drew up the line, the Lizard was quite active. Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava which everywhere there form the coast. In such situations, a group of six or seven of these ugly reptiles may oftentimes be seen on the black rocks, a few feet above the surf, basking in the sun with outstretched legs. I opened the stomachs of several," continues Mr. Darwin, "and in each case found it largely distended with minced sea-weed of that kind which grows in thin foliaceous expansions of a bright green or dull red colour. I do not recollect having observed this sea-weed in any quantity on the tidal rocks; and I have reason to believe that it grows at the bottom of the sea, at some little distance from the coast. If such is the case, the object of these animals occasionally going out to sea is explained. The stomach contained nothing but the sea-weed. Mr. Bynoe, however, found a piece of a Crab in one; but this might have got in accidentally. The intestines were large, as in other herbivorous animals."

The food of this Lizard, equally with its compressed form of tail, and the certain fact of its having been seen voluntarily swimming out at sea, absolutely prove its aquatic habits; nevertheless, as we are told by Mr. Darwin, "there is in this respect one strange anomaly, namely, that when frightened it will not enter the water. From this cause, it is easy to drive these Lizards down to any little point overhanging the sea, where they will sooner allow a person to catch hold of their tail than jump into the water. They do not seem to have any notion of biting; but when much frightened they squirt a drop of fluid from each nostril. One day I carried one to a deep pool left by the retiring tide, and threw it in several times as far as I was able. It invariably returned in a direct line to the spot where I stood. It swam near the bottom, with a very graceful and rapid movement, and occasionally aided itself over the uneven ground with its feet. As soon as it arrived near the margin, but still being under water, it either tried to conceal itself in the tufts of sea-weed, or it entered some crevice. When it thought the danger was passed, it crawled out on the dry rocks, and shuffled away as quickly as it could. I several times caught this same Lizard by driving it down to a point, and though possessed of such perfect powers of diving and swimming, nothing would induce it to enter the water; and as often as I threw it in, it returned in the manner above described. Perhaps this singular piece of apparent stupidity may be accounted for by the circumstance that this reptile has no enemy whatever on shore, whereas at sea it must often fall a prey to the numerous Sharks. Hence, probably urged by a fixed and hereditary instinct that the shore is its place of safety, whatever the emergency may be, it there takes refuge. I asked several of the inhabitants if they knew where it laid its eggs: they said, that although well acquainted with the eggs of the other kind, they had not the least knowledge of the manner in which this species is propagated--a fact, considering how common an animal this Lizard is, not a little extraordinary. During our visit (in October) I saw extremely few small individuals of this species, and none I should think under a year old. From this circumstance it seems probable that the breeding season had not commenced."

The terrene species, _Amblycephalus subcristatus_, unlike the aquatic one, is confined to the central islands of the Galapagos archipelago, where they inhabit both the higher and damp, as well as the lower and sterile parts; but in the latter they are much more numerous. "I cannot give a more forcible proof of their numbers," relates Mr. Darwin, "than by stating that, when we were left at James Island, we could not for some time find a spot free from their burrows on which to pitch our tent. These Lizards, like their brothers of the sea-kind, are ugly animals; and, from their low facial angle, have a singularly stupid appearance. In size, perhaps, they are a little inferior to the latter, but several of them weighed between ten and fifteen pounds each. The colour of their belly, front legs, and head (excepting the crown, which is nearly white) is a dirty yellowish orange; the back is of a brownish red, which, in the younger specimens, is darker. In their movements they are lazy and half-torpid. When not frightened, they slowly crawl along, with their tails and bellies dragging on the ground. They often stop and doze for a moment, with closed eyes, and hind legs spread out on the parched soil. These Lizards inhabit burrows; which they sometimes excavate between fragments of lava, but more generally on level patches of soft volcanic sandstone. The holes do not appear to be very deep, and they enter the ground at a small angle; so that when walking over one of these Lizard _warrens_, the soil is constantly giving way, much to the annoyance of the tired pedestrian. This animal, when excavating its burrows, alternately works the opposite sides of its body. One front leg for a short times scratches up the soil, and throws it towards the hind foot, which is well placed so as to heave it beyond the mouth of the hole. This side of the body being tired, the other takes up the task, and so alternately. I watched one for a long time," continues Mr. Darwin, "till half of its body was buried; I then walked up and pulled it by the tail; at this it was greatly astonished, and soon shuffled up to see what was the matter; and then stared me in the face, as much as to say, 'What made you pull my tail?' They feed by day, and do not wander far from their burrows; and, if frightened, they rush to them with a most awkward gait. Except when running downhill, they cannot move very fast; which appears chiefly owing to the lateral position of their legs. They are not at all timorous; when attentively watching any one, they curl up their tails, and raising themselves on their front legs, nod their head vertically, with a quick movement, and try to look very fierce, but in reality they are not at all so; if one just stamps the ground, down go their tails, and off they shuffle as quickly as they can. I have several times observed small fly-eating Lizards, when watching anything, nod their heads in precisely the same manner; but I do not at all know for what purpose. If the _Amblyrhynchus_ is held, and plagued with a stick, it will bite it very severely; but I caught many by the tail, and they never tried to bite me. If two are placed on the ground, and held together, they will fight and bite each other till blood is drawn. Those individuals (and they are the greater number) which inhabit the lower country, can scarcely taste a drop of water throughout the year; but they consume much of the succulent cactus, the branches of which are occasionally broken off by the wind. I have sometimes thrown a piece to two or three when together; and it was amusing enough to see each trying to seize and carry it away in its mouth, like so many hungry Dogs with a bone. They eat very deliberately, but do not chew their food. The little birds are aware how harmless these creatures are: I have seen one of the thick-billed Finches (peculiar to the Galapagos) picking at one end of a piece of cactus--which is in request among all the animals of the lower region--whilst a Lizard was eating at the other; and afterwards the little bird, with the utmost indifference, hopped on the back of the reptile. The stomachs of several that I opened were full of vegetable fibres and leaves of different trees, especially of a species of _Acacia_. In the upper region they live chiefly on the acid and astringent berries of the guayavita, under which trees I have seen these Lizards and the huge Tortoises feeding together. To obtain the acacia leaves, they crawl up the low, stunted trees; and it is not uncommon to see one, or a pair, quietly browsing, whilst seated on a branch several feet from the ground.

"The meat of these animals, when cooked, is white; and by those whose stomachs rise above all prejudices, it is relished as very good food. Humboldt has remarked, that in intertropical South America, all Lizards which inhabit _dry_ regions are esteemed as delicacies for the table. The inhabitants of the Galapagos say, that those inhabiting the damp region drink water, but that the others do not travel up for it from the sterile country, like the gigantic Land Tortoises. At the time of our visit, the females had within their bodies numerous large elongated eggs. These they lay in their burrows, and the inhabitants seek them for food."

These two curious Lizards of the Galapagos agree nearly in general structure, and in many of their habits; and neither of them has that rapidity of movement which is characteristic of various other _Iguanidæ_. The form of the head resembles a good deal that of a land Tortoise, and we find the same form of head, and again the same disinclination to bite, in certain herbivorous Lizards, such as the _Uromastyx_ and kindred forms, which are referred by Dr. Gray to the corresponding Old World family of _Agamidæ_.]

In the family of Iguanas the Basilisk may be noted. According to ancient authors, reproduced by writers of the middle ages, the Basilisk, although such a small animal, could produce instant death by its sting. The man whose eyes met theirs was supposed to be at once devoured by an intense fire. Such are the fabulous ideas which tradition has transmitted to us about these animals. It is to be remarked, however, that the Basilisk of modern herpetology is not the +basiliskos+, or Royal Serpent, of the ancients, the Cockatrice of Scripture. The reptile which now bears the name is an inoffensive animal, living in the forests of Guiana, Martinique, and Mexico, and leaping from branch to branch, in order to gather the seeds or seize the insects on which it feeds.

The Basilisk is distinguished from the other Iguanian Lizards by the absence of the long and dilatable skin under the throat, and by the presence of an elevated crest which runs along the whole length of the back and tail.

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 a stream. 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 the _jalousies_, 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 it was 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, the _Dactylæ 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 me this 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]

[23] "A Naturalist's Sojourn in Jamaica," by P. H. Gosse.

Thus far we have treated of chiefly arboreal _Iguanidæ_; 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 terrene _Iguanidæ_, 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 of _Agancidæ_, and in neither instance are the majority of them ground-frequenting Lizards to any great extent. Thus, of Dr. Gray's first genus _Tropidolipis_ (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 (probably _Lecolænus 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 with great quickness in the loose sand. This Lizard, from its flattened body and short legs, cannot run quickly." With others these Lizards constitute the sub-family _Tropidolepinæ_ of Dr. Gray, which are followed by the sub-family _Phrynosominæ_, in which some very singular Lizards find their place. The most extraordinary of them constitute the genus _Phrynosoma_, four species of which inhabit Western North America. These have great spines to the occiput, in these respects resembling the African genus _Cordylus_ (p. 107), and very Toad-like proportions, looking somewhat like Toads with short tails; and again they decidedly approximate in appearance to the curious _Moloch horridus_ of Western Australia, which belongs to the corresponding Old World family of _Agancidæ_; 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.]

FLYING LIZARDS.

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 expand and 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 of _Pterodactyli_, 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 Timorensis_ of Schlegel; and the Fringed Flying Lizard, _D. fimbriatus_, keeled.

II. _Draconella_, of which there are two species, one _D. Dussumieri_, having the nape crested; and _D. 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; and _D. spilopterus_, having the wing reddish near the body.]

GECKOTIDÆ, OR THICK-TONGUED LIZARDS.

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.

[The _Geckotidæ_ are 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 in _Platydactylus_ the 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 the +Aakalabônme+ of Aristotle and the ancient Greeks; it clambered about their walls catching spiders, on which it fed. Schneider has shown it was the _Stellio_ of Pliny. Linnæus mentions three species, which he places with his great genus _Lacerta_. Modern herpetologists, following Cuvier and Duméril, class them according to the structure under the several genera _Ascalabotes_, _Platydactylus, Hemidactylus_, _Ptyodactylus_, _Thecadactylus_, _Stenodactylus_, and _Gymnodactylus_.]

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.

CHAMELEO. (LAURENTI.)

The genus _Chameleo_, 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, we still 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 which they 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, and even 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; including _C. 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, and _C. bifurcus_, having the muzzle in the male forked--both natives of Madagascar; _C. Tigris_, Seychille Islands; _C. ventralis_, from South Africa, and _C. pumilus_, from the Cape of Good Hope.

V. Having back and belly without crest; including _C. Parsonii_, a native of Madagascar; and _C. Owenii_, the Three-horned Chameleon, from Fernando Po, and _C. Brookesianus_, an adult species, from S. W. Brookes's collection.

EMYDOSAURIANS

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.]

CROCODILES.

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 and sharp 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 banks of 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).

[No specimens of the _Crocodilidæ_ have 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_, and _C. 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.

THE ALLIGATORIDÆ

Include the _Jacares_, _Alligators_, and _Caimans_.

The _Jacares_ have 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.

_Alligators_ have 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 as _Crocodilus Mississipensis_.

The _Caimans_ have 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_, and _C. 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. acutus_ is also found in Martinique and San Domingo; _C. rhombifor_, at Cuba; _A. palpebrosus_, _A. sclerops_, _A. punctulatus_, and _A. cynocephalus_ are natives of the southern part of the American Continent; and _A. lucius_ is 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.