Reptiles and Birds / A Popular Account of Their Various Orders, With a Description of the Habits and Economy of the Most Interesting

by Louis Figuier

The Viperine Snakes,

Which have a long, perforated, erectile fang on the maxillary bone, which is extremely short and bears no other teeth. This is described in greater detail subsequently (pp. 93, 94). They are arranged under the two families Crotalidæ and Viperidæ.

The Crotalidæ, or Pit Vipers, have the body robust, the tail of moderate length, or rather short, sometimes prehensile; head broad, sub-triangular, frequently scaly above or imperfectly shielded; a deep pit on the side of the snout, between the eye and nostril; the eye of moderate size, with vertical pupil. They are viviparous. The Pit Vipers are found only in Asia and America; those of the New World surpassing the Asiatic species in size, and therefore they are much more dangerous. Some live in bushes, others on the ground. A rudiment of the curious caudal appendage of the American Rattlesnakes is found as a simple spine-like scale in the Asiatic species, constituting the genus Halys.

Some have the head covered with scales, having small shields on the edge of the forehead and brows; the cheeks are scaly, and the tail ends in a spine. Of these, the American genus Craspedocephalus and the Asiatic genus Trimeresurus have the subcaudal plates two-rowed to the tip.

The genus Craspedocephalus comprises the terrible Fer-de-lance of certain islands in the West Indies, which occurs on the mainland of South America, where four other species are recognised—one of them being found as far north as Mexico.]

Fig. 19.—Fer-de-lance (Trigonocephala mycalæ).

The Fer-de-lance (C. lanceolatus) is met with in Martinique, Santa Lucia, and in the little island of Boquin, near St. Vincent. It attains to a length of nearly six feet; its colour is not always yellow, sometimes it is greyish, and even marbled with brown; the head, which is large, is remarkable for a triangular space, the three angles of which are occupied by the muzzle and the two eyes.

This space, raised at its front edge, represents the head of a lance, large at its base and slightly rounded at the summit. On each side of the upper jaw, one, sometimes two, and even three, fangs are visible; all of which the animal makes use of for the purpose of wounding and discharging his venom. Of the poison fangs of the Fer-de-lance, Professor Owen remarks, "that they (in common with the Rattlesnake and Viper) are coated with a thin layer of a sub-transparent and minutely cellular cement. This disposition of the dentinal tubes is obedient to the general law of verticality, and the external surface of the tooth can be exposed to no other pressure than that of the turgescent duct with which it is in contact." It feeds on Lizards and the smaller Mammals, especially Rats, but it is capable of killing large animals, such as Oxen. The Negroes working among the sugar-cane, and soldiers in the Martinique service, often become victims to the Fer-de-lance. This Snake is, unfortunately, very prolific, and its venom is so subtle, that animals stung by it die three hours, twelve hours, one day, or several after the accident; but their death is certain. The wound produces extreme pain, and is immediately followed by more or less livid swelling; the body becomes cold and insensible, the pulse and respiration become slower, the head becomes confused, coma appears, and the skin turns bluish; sometimes extreme thirst and spitting of blood are experienced, and paralysis attacks the whole system.

Another species is known in Brazil as the "Jararaca" (C. brasiliensis), and there is a third in the same country, the C. bilineatus; a fourth, C. elegans, is believed to be from the west coast of South America; and a fifth, C. atrox, inhabits from Demerara to Mexico. All of them are most highly formidable and dangerous Snakes, which are held in especial dread.

The ten or more species of Trimeresurus occupy their place in the woodland districts of tropical Asia and its islands. In them the hinder labial shields are the smallest. The head is triangular, covered above with small scales, except the foremost part of the snout and the superciliary region, which generally are shielded; body with more or less distinctly keeled scales, in from seventeen to twenty-five series. Body and tail of moderate length, prehensile. These reptiles are more or less arboreal, as is indicated by their prehensile tail, and by their green or varied coloration. "In general," remarks Dr. Günther, "they are sluggish, not attempting to move out of the way, and as they very closely resemble the branch on which they rest, they are frequently not perceived until they prepare to dart, vibrating the tail, and uttering a faint hissing sound, or until they have struck the disturber of their rest. Accidents caused by them, therefore, are not of uncommon occurrence, and it is a fortunate circumstance that comparatively few of them attain to a size of more than two feet, so that the consequences of their bite are less to be dreaded than that of various other poisonous Snakes. Indeed, numerous cases are on record which show that the symptoms indicating a general effect on the system were of short duration, extending only over from two to forty-eight hours, and confined to vomiting, retching, and fever. After the pain and swelling of the bitten member or spot have subsided, the vicinity round the wound becomes discoloured, mortifies, and is finally thrown off as a black, circular slough, after which health is speedily restored. The bite of larger specimens, from two to three feet long, is more dangerous, and has occasionally proved fatal; so that the greatest care should always be observed in the immediate treatment of the patient. When roused, these Snakes are extremely fierce, striking at everything within their reach; and Cantor states that in the extreme of fury they will fix their fangs in their own bodies. Frogs, small mammalia, and birds form their food, and I have never found a Lizard or Snake in their stomach."

Three or more of the species inhabiting India and Burmah are of a beautiful leaf-green colour, which changes to dull blue after long immersion in spirit. The commonest of them, T. carinatus, varies remarkably in colouring, however, in the Andaman and Nicobar Islands; if, indeed, the species be quite the same. These grow to over three feet in length, of which size they are sufficiently formidable. The kindred genus, Peltopelor, is founded on a single species inhabiting the mountains of Southern India, P. macrolepis, which is remarkable for the very large scales with which its head and body are covered. Lachesis, with two species, is another kindred genus in South America, in which the end of the tail has four rows of scales underneath. The Calloselasma rhodostoma is a very formidable reptile of this same series, which inhabits the Malay countries. It has a remarkably broad head, and grows to three feet or more in length. Dr. Günther states that "it is one of the most beautiful and most dangerous of venemous Snakes. Feeding on frogs, it frequents grassy plains, and approaches gardens and human dwellings. Kuhl was eye-witness to a case where two Men, bitten by one and the same Snake, expired five minutes after." Another Malayan species is known as the Atropos acouba. The genus Halomys is characteristic of the fauna of Central Asia, the species being found in Tartary, on the northern side of the Himalayas, in China, in Japan, and in Formosa. One of them occurs in the Western Himalaya, at an altitude of 9,000 feet, and another has been referred to this genus from the mountains of Southern India. The "carawalla" of Ceylon (Hypnale nepa) is likewise found on the mountains of Southern India. It is a small species, but a good deal dreaded, although, remarks Dr. Günther, "its bite is but exceptionally fatal to Man, and in such cases death does not occur before the lapse of some days. There is always every hope of restoring the patient by a timely application of the proper remedies." Its crown is more shielded than is usual with Snakes of this family, and it varies much in colouring.

The rest of the Crotalidæ are American, and consist of the famous Rattlesnakes and their immediate kindred. In the genus Cenchris the tail ends with a spine, and the tip of the tail has several rows of scales beneath. The well-known "Copperhead" (C. contortrix) belongs to this genus, and the black "Water Viper" (C. piscivorus). The last has bred repeatedly in the London Zoological Gardens, and is rather a large species, of very aquatic propensities. "The Copperhead," according to Dekay, "is a vicious reptile, and its venom is justly dreaded, being considered as deadly as that of the Rattlesnake; and an instance is recorded in which a Horse, struck by one of these reptiles, died in a few hours. Its motions are sluggish, and when approached it assumes a threatening aspect, raising its head and darting out its tongue. It chiefly occurs in pastures and low meadow grounds, feeding on Field-mice, Frogs, and the smaller disabled birds." The poison of the black Water Viper is equally to be dreaded.

The true Rattlesnakes have the tail furnished with the extraordinary appendages at its tip which will be described presently. According to differences in the shields and scales covering the head, Dr. Gray arranged them into three genera—Crotalophorus, with three species; Uropsophus, with one; and Crotalus also with one, C. horridus, which appears to be the only one known in South America. Of the common Northern Rattlesnake (Uropsophus durissus), Dekay remarks that, "although furnished with such deadly weapons, the Rattlesnake can scarcely be termed a vicious animal, for he rarely strikes unless almost trodden upon. When suddenly disturbed, he throws himself into a coil, and warns the aggressor by rapidly vibrating his rattles, which, however, can scarcely be heard beyond the distance of a few yards. This is most usually the case, but they occasionally strike without the slightest warning. At the moment the Snake strikes, he ejects the venom forcibly into the wound. In an instance of a very large Rattlesnake from Florida (C. horridus), which was irritated, he struck violently against the iron wire on the side of the cage, and spurted the venom to the distance of three feet."[16] The fibulæ, or rattles, seldom exceed fifteen in number, and are rarely so many.]

The common Northern Rattlesnake sometimes attains to six feet in length, the middle being about the size of a man's leg; the colour of the back is grey, mixed with yellow. Upon this foundation extends a longitudinal row of black spots, bordered with white; towards the muzzle the flat head is covered with six scales larger than the others, and disposed in three transverse rows, each formed of two scales. The males are smaller, much more brightly and less darkly coloured than the other sex. The very long and visible fangs are situated in front of the upper jaw. The scales on the back are oval, and raised in the middle by a bone which extends in the direction of their greatest diameter. The underpart of the body is furnished with a single row of large plates. The Rattlesnake owes its name to a remarkable peculiarity in its structure; the extremity of the tail is furnished with small horny cells, articulated one into the other. When the animal advances these little capsules resound slightly, like the dry husks of beans which still retain their seeds, thus giving notice of the approach of this terrible enemy. The sibilant rattle of these appendages is not very loud, but it may be heard about thirty paces off, and announces the approach of the reptile while it is still at that distance.

Fig. 20.—Northern Rattlesnake (Uropsophus durissus).

Rattlesnakes feed on small mammals and upon other reptiles, waiting patiently for their approach; when close to them, the Rattlesnake throws itself upon them. They are oviparous; and for some time after they are hatched, the young are said to seek a refuge in the mouth of their mother. During summer Rattlesnakes remain in the midst of stony mountains, uncultivated places, or places covered with wild wood; they generally choose those parts most exposed to the heat,—the sunny shores of a fountain or stream where small animals come to drink. They like also to place themselves under the shadow of an old fallen tree. Audubon, the celebrated ornithologist, says that he has often met with Rattlesnakes rolled up in a state of torpor when the temperature was low. Rattlesnakes are revered by some of the American natives, who know how to lure them from their houses without killing them; for it is a singular fact that this terrible animal is not insensible to the sound of music. Chateaubriand's remarks will be read with interest: "In the month of July, 1791," says this celebrated writer, "we were travelling in Upper Canada with some savage families of the Ounoutagnes. One day, when we had stopped in a plain on the banks of the river Genedie, a Rattlesnake entered our camp. We had a Canadian amongst us who played on the flute; wishing to amuse us, he approached the animal with this new kind of weapon. At the approach of his enemy, the splendid reptile at once coiled itself up spirally, flattened its head, puffed out its cheeks, contracted its ears, and showed its envenomed fangs, while its forked tongue moved rapidly, and its eyes burned like red-hot coals; its body became inflated with rage, rose and fell like a pair of bellows; its dilated skin bristled with scales; and its tail, which produced a sinister sound, oscillated with lightning rapidity. The Canadian now began to play upon his flute. The Snake made a movement expressive of surprise, gradually drew its head backwards, closed its inflamed mouth, and, as the musical sounds struck it, the eyes lost their sharpness, the vibration of its tail relaxed, and the noise which it made became weaker, and finally died away altogether; the coiled-up line became less perpendicular, the orbs of the changed Snake opened, and in their turn rested in wider concentric circles on the ground. The scales of the skin were also lowered, and immediately recovered their wonted brilliancy, and, turning its head slowly towards the musician, it remained immovable in an attitude of pleased attention. At this moment the Canadian walked away a few steps, drawing low and monotonous tones from his flute; the reptile lowered his neck, opened a way among the fine grass with its head, and crawled in the steps of the musician who thus fascinated him, stopping when he stopped and following him when he began to move away. The Snake was thus conducted from our camp in the midst of a throng of spectators—as many Red-skins as Europeans—who could hardly believe their eyes."

It is generally agreed that Rattlesnakes only attack Men in self-defence, but it is at all times a dangerous neighbour, and it is important to know how to keep them at a distance in countries where they abound. The Pig is an excellent auxiliary in obtaining this result. In the west and south of America, when a field or farm is infested by these ferocious reptiles, it is usual to put a Sow with its young brood there, and the Snakes, it is said, will soon be eaten up. It appears that owing to the fatty matter which envelopes the body of this animal, it is safe from the venemous bite. Besides, it likes the flesh of the Snakes, and eagerly pursues them. According to Dr. Franklin, when a Pig sees a Rattlesnake, it smacks its jaws, and its hairs bristle up; the Snake coils itself up to strike his enemy; the Pig approaches fearlessly, and receives the blow in the fold of fat which hangs upon the side of its jaw. Then he places a foot on the tail of the Snake, and with his teeth he begins to pull the flesh of his enemy to pieces, and eats it with evident enjoyment.[17] The Pig is not the only animal employed to destroy Rattlesnakes. Dr. Rufz de Lavison, who has long resided in the French Antilles, and who has since been manager of the Jardin d'Acclimatation, of Paris, has published a highly interesting work, in which he relates the very important services which certain birds, especially the Secretary-bird, or Serpent-eater (imported from South Africa), render by destroying Rattlesnakes in the West Indies. We have said that the Crotalidæ are some of the most dangerous of any Snakes; let us mention some facts which show the frightful power of their venom. A Crotalus, about three feet in length, killed a Dog in about fifteen minutes, a second in two hours, and a third in about four hours. Four days after he bit another Dog, which only survived thirty seconds; and another, which only struggled four minutes. Three days afterwards it bit a Frog, which died at the end of two seconds; and a Chicken, which perished at the end of eight minutes.

An American, named Drake, arrived at Rouen with three live Rattlesnakes. In spite of the care which he had taken to preserve them from cold, one of them died. He put the cage which contained the other two near to a stove, and excited them with a small stick, to assure himself that they were alive and in health. As one of the Snakes made no movement, Drake took it by the head and tail and approached a window to see if it was dead; the animal turned its head quickly, and bit the unfortunate man on the back of his left hand; as he replaced it in the cage he was bitten anew in the palm of the same hand. "A doctor! a doctor!" cried the unhappy man. He rubbed his hand upon some ice which was close by, and two minutes after, he bound the wrist tightly with a cord. Four hours later a doctor arrived, and cauterized the wound, but alarming symptoms soon appeared. Syncope, noisy respiration, scarcely any pulsation, and involuntary evacuations followed; the eyes closed, their pupils contracted; the limbs became paralyzed, and the body cold. Drake died at the end of nine hours.

Some experiments made by a friend of Dr. Bell seem to present different results. This gentleman had received a living Rattlesnake from America, intending to try the successive effects of its bite upon some Rats. He introduced one into the cage with the Snake: it immediately struck the Rat, and the latter died in two minutes. Another that was placed in the cage ran to the farthest corner, uttering cries of distress. The Snake did not attack it immediately; but after about half an hour, on being irritated, it struck the Rat, which, however, exhibited no signs of being poisoned for several minutes; nor did it die for about twenty minutes after the bite had been inflicted. A third Rat, remarkably large, was then introduced into the cage, and exhibited no signs of terror, nor did it seem to be noticed by its dangerous companion: after watching some time, the gentleman retired to bed, leaving the Rattlesnake and Rat in the cage together. In the morning the Snake lay dead, and the Rat had supped on the muscular part of its backbone. Unfortunately, Dr. Bell does not remember at what season this experiment took place, but thinks it was not in very warm weather.

The climate of France differing only slightly from that of the United States, it is consequently well adapted for the production of Rattlesnakes. If a living male and female of these dangerous Crotalidæ were to escape from a menagerie, they would soon infest the country with their terrible progeny. It is for this decisive reason that public exhibitions of Rattlesnakes are forbidden in France. Nevertheless, two or three may be seen in the collection of the Museum of Natural History at Paris, miserably installed in a chest, which is quite unworthy of this establishment. The Rattlesnakes are enclosed in a double cage, and every measure of precaution is taken which prudence demands.

It is a remarkable fact that the poison is secreted after death. Dr. Bell, in his "History of British Reptiles," adduces the following as evidence of the facts:—He was dissecting very carefully and minutely the poison apparatus of a large Rattlesnake, which had been dead some hours; the head had been taken off immediately after death; yet, as Dr. Bell continued his dissection, the poison continued to be secreted so fast as to require to be dried up occasionally with a sponge or rag: and his belief is, that there could not be less than six or eight drops of the poison. It is obvious that such experiments require the utmost caution, seeing that preparations are not without danger.

[The family of the Viperidæ, or true Vipers, are peculiar to the Old World, inclusive of Australia, with the sole known exception of one species in Peru. They have generally a robust body, with non-prehensile tail; the head broad or thick, generally scaly above or incompletely shielded; the eye of moderate size, with vertical pupil, and they are at once distinguished from the Crotalidæ by the absence of the pit below the eye. The scales are keeled except in one genus (Acanthopis). For the most part, these reptiles inhabit exposed and arid situations, though perhaps all of them will take to the water on occasions, as does the common British Adder.

They are divided, firstly, into those which have a depressed head, rounded on the sides, and covered with acutely-keeled scales. Some of these have large nostrils in the centre of a ring-like shield, edged with a large scale above. Such are the genera Daboia in the warmer parts of Asia, and Clotho, which is peculiar to Africa—both genera are terrifically venemous.

The famous Tic-polonga of Ceylon (Daboia elegans) is also widely diffused over India and Burmah. It is beautifully marked with three rows of white-edged, oblong, brown spots. Occasionally the spots forming the middle row are connected like the beads of a necklace, whence the name Cobra monil (literally Coluber moniliger), applied to the young of this Viper by the Indo-Portuguese, and now corrupted into "Cobra de Manilla," which bears the reputation of being a highly poisonous Snake of diminutive size; it attains, however, to a length of nearly five feet, the tail then measuring about eight inches, with considerable thickness of body. It is nocturnal, and preys chiefly on Mice. In Burmah this formidable Viper is dreaded almost as much as the Hamadryas. It has been obtained in the Himalayas at an elevation of 5,500 feet, at Almorah, and elsewhere. Mr. Theobald has known one to kill a Bull-terrier in twenty minutes. The D. xanthina is a second species of this form inhabiting Asia Minor.

Fig. 21.—The Horned Puff-adder (Clotho cornuta).

The genus Clotho consists of the terrible Puff-adders of Africa, of which there are at least four or five species. Among the best known of them are the ordinary Puff-adder (C. arietans), and the Berg-adder (C. atropos), of the Cape colonists. The Rhinoceros Puff-adder, C. nasicornis, of Guinea, has the scales over the nostrils of the male produced into a long recurved spine; and in the Horned Puff-adder, C. cornuta, of South Africa, there is a group of small horn-like scales over each eye. Examples of the Common and of the Rhinoceros Puff-adders may generally be seen in the reptile house of the London Zoological Gardens. The last mentioned is a huge Viper of wondrous beauty, both of colouring and in the complex pattern of its markings, especially as seen when it has newly shed its epidermis; but the aspect of its surprisingly broad, flat, and triangular-shaped head unmistakably betokens its terrific powers. Its head is remarkably massive. One peculiarity of the Puff-adders is that they sometimes hold on to their victim by their long fangs. Thus, of the common C. arietans Sir A. Smith remarks that "although generally inactive, it is by no means so when attacked—its movements are then bold and energetic, and when once it seizes the obnoxious object, it retains its hold with great determination, and some considerable exertion is often necessary to detach it."[18] The traveller Burchell remarks of this Snake that "its venom is said to be most fatal, taking effect so rapidly as to leave the person who has the misfortune to be bitten no chance of saving his life, but by instantly cutting out the flesh surrounding the wound. Although I have often met with this Snake," he adds, "yet, happily, no opportunity occurred of witnessing the effects of its poison; but, from the universal dread in which it is held, I have no doubt of its being one of the most venemous species of Southern Africa. There is a peculiarity which renders it more dangerous, and which ought to be known to every person liable to fall in with it. Unlike the generality of Snakes, which make a spring or dart forward when irritated, the Puff-adder, it is said, throws itself backwards, so that those who should be ignorant of this fact would place themselves in the very direction of death, while imagining that by so doing they were escaping the danger. The natives, by keeping always in front, are enabled to destroy it without much risk. The Snakes of South Africa, as of Europe, lie concealed in their holes in a torpid state during the colder part of the year. It is, therefore, only in the hottest summer months that the traveller is exposed to the danger of being bitten." Dr. Gray refers doubtfully to this genus both the Echidna inornata of Sir A. Smith, and the E. mauritanica of Duméril and Bibron, from Algeria; likewise a Peruvian species named Echidna ocellata by Tschudi, which is the only known instance of a member of this family inhabiting the New World. The appellation Echidna, however, belongs properly to the Porcupine Ant-eaters of the class Mammalia.

Fig. 22.—The Unadorned Puff-adder (Clotho inornata).

The species of Cerastes and of Echis have the nostrils much smaller than the preceding, and are Vipers of less formidable size. In the two species of Cerastes, or Horned Viper, the eyebrows of the male bear commonly a sort of horn. C. Hasselquistii is common in Egypt, and the other, C. Richii, inhabits Tripoli. Of Echis there is one species in Egypt and North Africa—E. arenicola, and another in India—E. carinata. The latter grows to about twenty inches long, of which the tail measures two inches and a third. These Vipers commonly lie half-buried in the sand, which they much resemble in colour. They feed upon Centipedes (Scolopendra), and no case is known of their bite having proved fatal.

The remaining Viperidæ have the head more or less shielded. They are divided by Dr. Gray into Vipera (with two European species, not found in Britain—V. aspis from the Alps, and V. ammodytes from the countries bordering on the Mediterranean);—Pelias, which contains only the Common British Adder, P. berus; Sepedon, with one species only, from South Africa, S. hæmachates; Causus, with also only one African species, C. rhombeatus; and finally, Acanthopis, founded on the Death-adder of the Australian colonists, A. antarctica, which is the only member of the family Viperidæ known to inhabit Australia, where the Poisonous Colubrine Snakes are so numerous. It is also the only known species the scales of which are smooth or not keeled. It seldom exceeds thirty inches in length, and varies a good deal in colour. Like other Viperidæ it is sluggish in its movements, but when irritated it flattens itself out generally in the form of the letter S, turning round to one side or the other with astonishing rapidity, but never jumping at its enemy or throwing itself backward, as the Puff-adders are described to do. The Death-adder is found in almost every part of Australia northward of the thirty-sixth parallel of south latitude.]

The Common Adder (Pelias berus), is not improbably the Εχις of Aristotle, and the Vipera of Virgil, as it is the Manasso of the Italians, the Adder of the country-people in England and Scotland, and the Vipère of France. It is found in all these countries, and in Europe generally.

Fig. 23.—The Common Adder (Pelias berus).

The Common Adder varies in length, from thirteen or fourteen inches to double that length; and from two to three or even four inches in girth.

Its general colour varies considerably: in some it is olive, in others reddish-brown, varying sometimes to an ashy-grey; at other times it is greyish-black. A waving brown or blackish line runs along the back. A row of unequal spots of the same colour is observable on the flanks; the belly is slate-coloured; the head nearly triangular, a little larger than the neck, obtuse and truncated in front, and covered with granulated scales. Six small plates cover the muzzle, two of which are perforated for the nostrils, which are lateral, forming a blackish spot. Above is a sort of V shape, formed by two black bands. The upper jaw is a white ground, spotted with black; the lower jaw is yellow. The eyes are small and sharp, edged with black. The tongue is long, grey, and forked.

Adders are met with in the wooded, stony, and mountainous regions of southern and temperate Europe—in France, Italy, England, Germany, Prussia, Sweden, Poland, and even Norway. They are met with in the heaths near London and in the neighbourhood of Paris; they are met with at Montmorency, and in the forest of Fontainebleau. They feed upon Lizards, Frogs, mollusks, worms, insects, and small mammalia, such as Field-mice, Shrews, and Moles. They pass the winter and early spring in a state of torpor in deep hollows, where they are sheltered from the cold. It is not unusual to find several Adders coiled up together in one heap, entwined and intimately interlaced together.

The movement of Adders is abrupt, slow, and irregular. They appear to be shy and timid creatures, shunning the day, and only seeking their food in the evening. The young come into the world naked and living: so long as they are maintained within the mother, they are enclosed in eggs with membranous shells. Soon after their birth the young Vipers, whose length does not exceed six or seven inches, are abandoned by the mother, and left to shift for themselves. They do not, however, acquire their full development till they are six or seven years old. Adders are justly considered objects of fear and horror both to Men and to other animals. They carry with them a formidable apparatus, of which it is important that both the structure and the mode of action should be known. This venemous apparatus is composed of three parts—the secreting glands, the canal, and the hooked fangs.

The gland is the organ which secretes the venom; it is situated upon the sides of the head, behind and a little beneath the globe of the eye; it is formed of a number of inflated bladders, composed of a granulous tissue, and disposed with great regularity along the excretory canal, not unlike the barbs of a pen-feather. This arrangement, however, is only visible through a microscope. The tube destined to conduct the secreted venom through the gland is straight and cylindrical; after being filled, in its short journey it ends in two peculiar hook-like teeth, called fangs, tapering to a point, and in shape horn-like. They are much longer than the others, and placed one to the right, the other to the left of the upper jaw. The Adder, then, is furnished with two of these poison-fangs; they are curved and sharp-pointed, convex anteriorly, and furnished with a straight duct which commences in one part by a slit placed at the anterior part of its base, terminating by a second and smaller cleft towards its point, and on the same side. This last cleft is like a little trench or fine furrow, which extends the whole length of the convexity. These hooked teeth are surrounded by a fold of the gums, which receives and partly hides them, like a sheath, when they are at rest or hidden. They are attached to the upper maxillary bones, which are small and very mobile, and are put in motion by two muscles. Behind them are dental germs, intended to replace them when they fall out. The other teeth in the roof of the mouth belong to the palate, where they form two rows.

Fig. 24.—Fangs and Tongue of a Poisonous Colubrine Snake.

Such are the terrible weapons of the Viper group. It is not, therefore, as many persons still believe, with the tongue that the Adder inflicts its wound; the forked, projecting tongue serves them as a feeler, and to drink with, but cannot inflict a wound. We have said that when in a state of repose the hooked teeth are hidden; when the animal wishes to use them, they issue from their fleshy sheath, somewhat in the same manner as a man draws his knife, when attacked, to defend himself, and in this case the knife is poisoned.

Adders use their fangs to seize the small animals which serve as their prey. They do not voluntarily attack a Man; on the contrary, they flee at his approach. But if he imprudently places his foot on or attempts to seize them, they defend themselves vigorously. Let us see how an Adder conducts itself when it hunts its prey and takes it. In this case it may be supposed to act without passion, merely seizing its prey for food; it simply bites, sinking its fangs into the body of its victim. In proportion as the fangs penetrate the body of the animal the poison flows into the canal, which again conducts it to the fangs under the influence of the contracting muscles, by which they are raised and made to press upon the gland; but this movement causes the Adder to close its mouth, and the venom is injected into the wound.

Adders bite in much the same manner when seized by the tail or middle of the body; but when they think themselves attacked and become irritated, they strike rather than bite. At first they coil themselves up into several superposed circles, then they will uncoil themselves to their whole length with excessive quickness, extending their bodies like a spring, drawing it out with the rapidity of lightning, and gliding over a space equal to their own length; for they never leave the ground. They will now open their jaws wide, erect their fangs, and strike, first throwing back their heads, by which means they contrive to strike as with a hammer.

Dr. Bell expresses doubts, in his "History of British Reptiles," of the existence of any well-authenticated case in this country of an Adder bite terminating fatally.[19] At the same time he cautions all persons against exposure to them in the heat of summer and autumn, when the poison is most virulent. The remedy applied to such a bite is to rub the part with olive oil, over a chafing dish of coals, and to take a strong dose of ammonia (spirit of hartshorn) internally.

Open copses, dry heaths, new woodland clearings, and sandy wastes are the usual haunts of the Adder; and in such places its hibernaculum is usually found in winter, where several of the same species lie intertwined in a torpid state.

It was long supposed that Adders, and Snakes generally, exercise a sort of magnetic action from a distance—a power which has been called fascination. This impression has been denied, and attributed, not without reason, to a less mysterious cause; namely, the sentiment of profound terror which these creatures inspire. This terror manifests itself in animals by tremblings, spasms, and convulsions. The sight of a venemous Snake sometimes renders its victims immovable, incapable of flight, and as it were paralyzed, and they allow themselves to be seized without opposing the slightest resistance. Others give themselves over to confused movements, which, far from saving them, only make their capture easier. M. Duméril, while pursuing experiments in the Museum of Natural History, demonstrative of the sudden and mortal action of the bite of a Viper on little birds, saw a Goldfinch, which he held in his hands, die suddenly, merely at the sight of the Viper.

In warm countries, wounds produced by the larger species of these terrible reptiles are extremely dangerous—they swell, become red and ecchymose, and sometimes livid; the wounded person is seized with syncope, fever, and a series of morbid symptoms, which often terminate in death. The remedy is to bind immediately a ligature above the wound with a band, such as a rolled handkerchief, a cord, or a string, so as to stop all communication of the blood with the rest of the body, and thus prevent the absorption of the venom into the system till more effectual means can be adopted. It is well to suck the wound and make it bleed; it is necessary also to make an incision, so as to expose the internal parts, and then to cauterize the wound immediately, either with a red-hot iron or by means of a caustic agent. For this purpose the following composition may be employed:—

Perchloride of iron	60	grains.
Citric acid	60	"
Hydrochloric acid	60	"
Water	144	"

A few drops of this is poured on the wounded part, which is then covered with a small piece of lint. Iodine or iodinet of potassium can also be employed. M. Viand-Marais has substituted the following composition for this compound with great success:—

Water	50	grains.
Iodinet of Potassium	50	"
Metallic iodine	50	"

To facilitate the introduction of caustic into the wound, the same naturalist has invented a little bottle closed with emery; the stopper, which is long, and conical at the lower end, plunges into the liquid. By means of this stopper the medicated substance can be made to penetrate by drops as far as the bottom of the wound, which has been previously enlarged by the bistoury. This little apparatus will replace with advantage the bottle of volatile alkali with which Viper-hunters are usually furnished. But all these means are only useful when applied immediately. The limbs and round about the wound must besides be rubbed with ammoniacal liniments. Afterwards emollient poultices should be used to lower the swelling and reduce the chances of congestion; while tonics, sudorifics, and sometimes ammoniacal potions should be given internally.

It is a remarkable fact that this venom, which is one of the most virulent poisons known, can yet be swallowed with impunity. It is neither acrid nor burning, and only produces a sensation on the tongue analogous to that caused by greasy matter. But if introduced into a wound in sufficient quantities, it enters into the blood, and causes death with frightful rapidity. This is a characteristic common to all morbid and venemous virus.

The strength of the venom varies according to the species of Snake, and likewise the condition of the animal. The same species is more dangerous in hot than in cold or temperate regions. The bite is serious, according as the poison is more or less abundant in the glands, and probably with the degree of rage experienced by the animal, as Professor Owen supposes.

[Of Snakes in general it has been remarked that "all strangers in countries where these reptiles abound are apt to exaggerate their danger; but in a year or two they think as little of them as we do in England. I never knew an instance of a Snake attacking a person unless it was trodden upon or molested, and even then they almost always give warning by hissing, or endeavour to effect their escape. During my residence in the Cape colony, I have at different times trodden on them or kicked them in the grass unintentionally, but was never bitten."[20] This writer, however, could hardly have accidentally placed his foot upon a Puff-adder.[21]]

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CHAPTER III.
The Order of Lizards.—Saurians.

This is the second order of the great section of Scaly Reptiles (Squamata), as distinguished from the Shielded Reptiles (Cataphracta). The name Saurian, Σαυρος, given by Aristotle to the genus of Lizards, has been more comprehensively applied to a group of Reptiles which have the body elongated, covered with scales, or having the skin rough like shagreen. They have, for the most part, four feet, the toes of which are furnished with hooked claws; their eyelids are movable, and their jaws armed with encased teeth; they have a distinct tympanum, a heart with two auricles and a single ventricle, sometimes partially valved, having sides and a sternum. They are not subject to metamorphosis, and, finally, they are furnished with a tail.

["By far the greater number of the Saurians," writes Dr. Günther, "are easily distinguished from the other orders of reptiles by their elongated form, by their movable thorax covered with skin, by the presence of legs, and by their general integuments, which are either folded into scales, or granular, or tubercular, or shielded; still, there are many Saurians which, at a superficial glance, might easily be taken for members of the preceding order—that of the Snakes; and it cannot be denied that there is a gradual transition from one of these orders to the other. On the part of the Saurians, we allude to those which have no externally visible limbs, and which combine with a greatly elongate, cylindrical body, the peculiar kind of locomotion we observe in Snakes. Yet the greater affinity of these reptiles to the ordinary Lizards is indicated by another character, which is in intimate connection with their mode of life. The Snakes, having movable maxillary bones, and mandibles not joined by a symphidis, are enabled to swallow other animals of apparently greater bulk than their own. In the Saurians the maxillæ are fixed and immovable, and the mandibles are joined by an osseous suture, so that the cleft of the mouth can be dilated only in the usual vertical direction. Moreover, in these limbless Saurians we always find bones of the shoulder hidden below the skin, whilst no trace of them can be discovered in the true Snakes. The motions of some Lizards are extremely slow, while those of others are executed, with very great, but not lasting, rapidity. Many of them have the power of changing their colours, which depends on the presence of several layers of cells loaded with different pigments; these layers the animal compresses by more or less inflating its lungs, whereby the changes in the coloration are effected."

Dr. Günther does not follow Dr. Gray in arranging all true reptiles into the two grand divisions of Shielded Reptiles (Cataphracta) and Scaly Reptiles (Squamata), but he includes the Crocodilidæ among the Saurians as a first grand division of them—Emydosauri, and the other Lizards constitute his second grand division of them—Lacertini. These latter are again primarily divisible according to the structure of the tongue. Thus, in the series of Leptoglossa, the tongue is elongate, forked, and exsertile, much as in the Ophidians; in that of Pachyglossa the tongue is short, thick, attached to the gullet, and is not exsertile; and in the Vermilingues it is Worm-like, club-shaped in front, and very exsertile.

The various genera of Saurians which have either not a trace of external limbs, or have them more or less diminutive and rudimentary—either the usual two pairs or one pair only, and in the latter case sometimes the fore and sometimes the hind pair being deficient—are included among the Leptoglossa, or the series which have a forked and protrusile tongue; and, so far as is practicable, we will commence by noticing the different serpentiform genera; only, in a classification which is not confessedly superficial, it will be found that the various Snake-like Saurians appertain to several distinct natural families, most of the other genera belonging to which have, in sundry cases, limbs that are well developed. Some of them, therefore, will have to be noticed as the different families to which they belong are successively treated of; and there will yet remain the curious serpentiform family of Amphisbænidæ, which Dr. Gray refers to his grand series of Shielded Reptiles (Cataphracta).

The same naturalist divides the Leptoglossa into two tribes, which he styles Geissosaura and Cyclosaura; and, as constituting particular division of the former, he includes under it the family Typhlopidæ, which Dr. Günther refers—as we have seen—to the order of Ophidians. In the series of Geissosaura, the scales of the belly and (almost always) of the back and sides are quincuncial, rounded, and imbricate; the tongue is narrow, short, flat, and but slightly forked; and the head is of a conical shape, and is covered with regular shields.

Of the families thus characterised, some only have distinct eyelids, as the families Acontiadæ, Ophiomoridæ, Sepsidæ, and Scincidæ; while others have the eyelids rudimentary and the eyes exposed, as the families Lialisidæ, Aprasiadæ, Pygopodidæ, and Gymnopthalmidæ. In the Acontiadæ the nostrils are placed in the enlarged rostral plate, with a longitudinal slit behind. The form of the body much resembles that of our common Orvet, or Blind-worm, and their limbs, when present, are so rudimentary that they can aid little in locomotion. One genus, Acontias, is without limbs, and the eyes are furnished with a lower lid, while the upper eyelid is rudimentary. Of this, one species, A. meleagris, inhabits South Africa; and another, A. Layardii, has been discovered in Ceylon. The genus Nessia has four rudimentary limbs, and the rostral shield is large, sub-conical, and depressed. In one species, N. monodactyla, the limbs are diminutive, the posterior placed far apart from the anterior, all being very short, weak, and undivided into toes. In another, N. Burtoni, each foot is divided into three minute toes. Both species are peculiar (so far as known) to Ceylon, and the habits of this family are much the same as those of our common Orvet (Anguis fragilis).

The family of Ophiomoridæ is founded on a single genus and species, Ophiomorus miliaris, which inhabits North Africa. As remarked by Dr. Gray, this reptile seems to be intermediate to the Acontiadæ and the Scincidæ, and makes it appear as if the large rostral shield of the former was formed of the united rostral, supra-nasal, and nasal shields of the present family, and of the Scincidæ. It has an elongate, cylindrical body, without external limbs, and the ears are hidden under the skin; the eyes are distinct, with valvular eyelid; and the scales of the body and somewhat elongate tail are hexagonal.

The Sepsidæ differ from the preceding, and also from the great family of the Scincidæ, by having the nostrils placed in the front edge of a small shield, in a notch at the hinder side of the rostral plate, which latter is rather large and square. The eyes are distinct, the lower eyelid scaly, or with a transparent disk. Body fusiform or sub-cylindrical, elongate. These reptiles burrow in dry sand, and are peculiar to the anciently-known continents and certain islands. Some have a wedge-shaped head, with prominent rostral plate. Of these the genus Sphenops has more developed limbs, each dividing into four toes; and the only species, S. sepsoides, inhabits Egypt and other parts of North Africa. Sphenocephalus has a more slender and elongate shape, and the limbs are placed more distantly apart; the anterior minute, and fitting into a groove, the posterior as large as in Sphenops, and each of them having but three toes, of which the innermost and next are sub-equal, and the outer much shorter. The only known species, S. tridactylus, is common in Afghanistan. In Scelotes the anterior limbs disappear altogether; and the only known species, S. bipes, inhabits South Africa. Other genera have a pyramidal head, with the rostral plate erect, and rounded in front. Such are the five following, each founded on a single species:—Gongylus ocellatus, from North Africa and the borders of the Mediterranean; Thyrus Bojeri, from the Mauritius; Amphiglossus astrolabi, from Madagascar; Seps tridactylus, from the south of Europe and north of Africa; and Heteromeles mauritanicus, from North Africa. The last has only two toes to the fore-feet, three to the hind; and Seps has three toes to each foot, while the other three genera have five to each foot. In general these animals are found in dry and elevated spots, where they hide themselves in the sand or under stones.

Fig. 25.—Seps tridactylus.

The Scincidæ have the head covered with shields, which are symmetrically arranged. Tongue slender, free, extersile, terminating in two pointed lobes. Scales on the back rounded, quincuncial, imbricate; those on the belly similar to those on the back and on the sides. No fold across the throat or along the side; no femoral or inguinal pores. Tail generally long, rounded, fragile. Eyes and eyelids well developed. Nostrils in a separate plate, between the frontal and labial shields. Generally four limbs, moderately developed, sometimes feeble or hidden below the skin. The species of this family are exceedingly numerous, and inhabit almost every part of the tropical regions, some extending into the temperate zones. They are thoroughly land Lizards, preferring dry ground, and hiding themselves in the sand, under stones, fallen leaves, &c., very few of them entering the water. They do not attain to any considerable size, only a few species of Australia and the West Indies growing to the thickness of a man's wrist, and exceeding a foot in length. Some of them are viviparous, others deposit from eight to twelve globular eggs. Dr. Gray divides them into the sub-families of Scincinæ, or those which have the scales thin, smooth, and neither striated nor keeled; the nostrils in a single smooth plate, without any lunate groove behind; and the tail round, tapering, unarmed; and Tropidophorinæ, or those which have the scales thick, bony, rugous, striated, and with one or more keels upon each of them; the rostral plate rounded in front, and the body fusiform, with well-developed limbs, which terminate always in the full complement of toes. A few species of the Scincinæ have no external limbs, thus approximating in their appearance to certain of the burrowing Ophidians.]

The Orvet, or Blind-worm, Anguis fragilis, is small, cylindrical in shape, about eleven or twelve inches in length, and having the exterior appearance of Snakes. The scales which cover the body are small, smooth and shining, being red in the middle, and edged with white, of a silvery yellow on the upper part, and dusky beneath; the sides somewhat dusky brown, and the throat slightly marbled with white, black, and yellow. Two larger spots appear, one above the muzzle, the other upon the back of the head; from this point two blackish longitudinal rays start, which extend to the tail, as well as two other nut-brown rays, which start from the eyes; the markings vary, however, in different countries, and probably with age and sex.

Fig. 26.—Orvet, or Blind-worm (Anguis fragilis).

The Orvet is found in woods and dry, sandy, and stony wastes. They are timid, harmless creatures, retiring into holes and concealing themselves in moss at the foot of trees to hide themselves from observation. They feed upon worms, insects, and the smaller mollusks. Although perfectly harmless, the country-people are strongly prejudiced against them, believing their bite to be a deadly poison. This animal is extremely brittle. Laurenti and others assert that when captured it throws itself into a position of such rigidity that it sometimes breaks in two, and that a smart blow of a switch will at any time divide it.

[There are little-known species of Anguis in India and South Africa, which are at least provisionally so considered, and certainly do not differ essentially; and next we come to forms in which the limbs are successively more developed. Such are the Ophiodes striatus of Brazil, which has two short, flattened, undivided, and one-pointed limbs, corresponding to the usual hind pair; the Brachymeles bonitæ of the Philippines, in which there are two pairs of short and rudimentary limbs, the fore bearing two minute claws, while the hind are undivided; Venira bicolor, of the same archipelago has very short limbs, the fore and hind being placed distantly apart, but in this genus all have five distinct toes; Chiamelea lineata, from some part of India, and Hagria Vosmaërii, from Bengal, are kindred forms which conduct to the genus Eumeces, the species of which are very numerous, and spread over nearly all the different countries between or near the tropics, and in certain of them (as the Burmese E. anguinus) the limbs are still remarkably diminutive, and (as in E. isodactylus of Cambodia) the fore and hind limbs are placed very far apart, the body and tail being long and anguiform. In various other species of Eumeces, however, the proportions are more those of an ordinary Scink, as again in the kindred genera Mabonia and Plestiodon, which are widely distributed.

In other series of Scinks, the distinctions of which are far from being conspicuous, we again have limbless genera, or nearly so, as the Australian Soridia lineata, which has one pair of small, posterior, undivided extremities; while in another Australian form, the Rhodona punctata, the anterior pair of limbs are simple and undivided, while the hinder divide into two unequal toes, and the two pairs of limbs are situate as distantly apart. And thus we may continue to trace the successive gradations, in sundry genera, until we arrive at the Scincus officinalis of North Africa, a well-known reptile, the geographical range of which extends eastward into Afghanistan, and which was formerly in considerable request for its supposed medicinal properties. Indeed, this notion still prevails in Hindustan, into which country dried specimens of both this reptile and of Sphenocephalus tridactylus (p. 101) are brought by Afghan traders, and are sold in the bazaars. Both of these are Sand Lizards, which burrow into the sand with great rapidity.

We now come to the Tropidophorinæ, or second sub-family of Scinks indicated by Dr. Gray (vide [p. 102]), which have always well-developed limbs, the body only moderately elongated, and the scales variously keeled. Several species of larger size appertain to this series, as the Cyclodus gigas of Australia, and the curious Stump-tail Lizards, Trachydosaurus rugosus and T. asper, of the same insular continent, which latter have most prominently rugous scales, and the tail literally appearing like the short and abrupt stump of one. Egernia Cunninghami and Tropidolesma (of different species) are other comparatively large Australian Lizards; and examples of most of those that have been mentioned may generally be seen alive in the London Zoological Gardens, where the Cyclodus gigas has bred and proves to be viviparous. Of the species of Euprepes, of which several inhabit the Indian region, some (as the very common E. rufescens) are viviparous, and others (as E. multicarinata) are oviparous. These have three more distinct, though not prominent, keels upon each scale; and the different species inhabit both the Old World and the New, as well as Australia. The Galliwasps (Celestus) of the West Indies, and sundry other genera, do not greatly differ. Of Tropidophorus, which has exceedingly rugged scales, the species inhabit the Indo-Chinese countries, and one (T. cocinsinensis) is found likewise in the Philippines; while of another (T. Berdmorei), in Burmah, Mr. Theobald remarks that "its scales are dull and lustreless, and the coloration peculiar for a Scink. It harbours under half-immersed stones, and enters the water and gravel freely." In several of this family of Lizards the scales are beautifully iridescent, and many of them show longitudinal pale or white lines, or are otherwise variegated.

Nearly akin to the extensive family of Scincidæ, there are three small families (as classed by Dr. Gray), the species of which are peculiar to Australia. They have small, undivided, posterior limbs only, or are quite limbless. These families are the Lialisidæ, founded on three or more species of a single genus, Lialis; the Aprasiadæ, founded upon one species only—Aprasia pulchella, which is limbless; and the Pygopodidæ, comprising the two genera Pygopus and Delma, the former containing two, the latter only one ascertained species. The Gymnopthalmidæ constitute still another small family, quadrupedal, but with the limbs small and weak. Of seven genera referred to it, five are Australian, one is European, and one belongs to South America. Ablepharus pannonicus is a small Lizard of this family, inhabiting Eastern Europe, with a congener, A. bivittatus, in the Caucasus; and Gymnopthalmus lineatus inhabits Brazil and the Island of Martinique.

In the second tribe of Leptoglossa, entitled Cyclosaura, the scales of the belly are square, in cross bands; those of the back and tail are rhombic and imbricate, or circular and subgranular; the tongue is lengthened, and more or less conspicuously furcate; and the eyes are diurnal, having two valvular lids. The limbs are generally well developed; but in several genera they still are more or less rudimentary, or even absent.

There are four small families in which the sides are rounded and covered with scales like the back. Of these, that of Chamæsauridae is founded upon the South African Lacerta anguina of Linnæus, now Chamæsaura anguina, which has the limbs quite rudimentary. In the American families of Cercosauridæ, Chirocolidæ, and Anadiadæ, the limbs are moderately developed, and have each five toes. The two last-mentioned families are founded each upon a single species, Chirocolus imbricatus and Anadia ocellata; and the other contains the two genera Circosaura and Lepisoma—of which the first comprises some two or three species only. All of these reptiles have exceedingly long tails, though not so inordinately long as in the Lacertidæ of the genus Tachydromus.

Certain other families have a distinct longitudinal fold, covered with small granular scales on each side. These are the families Chalcidæ, Holaspidæ, and the more extensive one of Zonuridæ. The Chalcidæ have the head covered with regular many-sided shields, and the lateral fold is indistinct; limbs small and rudimentary, and the hind feet are undivided in the genera Chalcis and Bachia, with three tubercles in place of toes in Microdactylus, and with four clawed toes in Brachypus. Each of these genera is founded on a single species, and all are doubtless peculiar to the New World. The Holaspidæ is also founded on one species only, the Holaspis Guentheri, which again is supposed to be South American. It has four well-developed limbs, a double row of plates along the back and upper surface of the tail, and the latter organ is curiously serrated laterally.

The Zonuridæ constitute a considerable family, to which some eighteen or twenty genera are assigned, and which present considerable modification of form. The ears are distinct, whereas in the Chalcidæ they are hidden under the skin. The head is pyramidal, or depressed, and covered with regular many-sided shields; eyes with two valvular lids. Limbs mostly well developed, but short in some, and rudimentary, or even wanting in the so-called "Glass-snakes" which constitute the sub-family Pseudopodinæ. There is no external trace of them in the North American Glass-snake, Ophisaurus ventralis; and in the Old World genus, Pseudopus, there is only one pair, posterior, rudimentary, and undivided. These reptiles are long, and serpentiform in shape: whilst in other Saurians the whole skin of the belly and of the sides is extensible, the extensibility is limited in the "Glass-snakes" to a separate part of the skin; and, as Dr. Günther remarks, "the scaly covering of the upper and lower parts is so tight that it does not admit of the same extension as in Snakes and other Lizards; and the Pseudopus, therefore, could not receive the same quantity of food in its stomach as those animals, were it not for the expansible fold of the skin running along each side of its trunk." One species of Pseudopus, the P. Pallasii, inhabits Asia Minor and the south-east of Europe; and there is another, P. gracilis, in the Indo-Chinese countries (or those lying eastward of the Bay of Bengal). A second sub-family, Gerrhonotinæ, is peculiar to America, and consists of more ordinarily-shaped Lizards, which are ranged in four genera. Together with the Ophisaurus, or American Glass-snake, they are the only known Zonuridæ that inhabit the New World. The great mass of this family and all of its most characteristic species are African, and these are arranged by Dr. Gray under the sub-families Cicigninæ and Zonurinæ. In the first of these sub-families the tail is smooth, or unarmed, and in the second it is spinous. The Cordules, Cordylus, Zonurus, &c., are very characteristic Lizards chiefly of Southern Africa, several species of which have been figured by Sir Andrew Smith. They are mostly of shortish form, and the neck is more or less spinous; the body-scales in some (as Zonurus cataphractus) being extraordinarily rugous. These Lizards squeeze themselves into crevices in the rocks, in which they hold on so firmly by their nuchal spines that it is next to impossible to dislodge them, the tail commonly giving way at once if it be attempted to pull them forth by means of it.

The family of Lacertidæ, comprising our ordinary European Lizards, have no longitudinal fold along the sides, but generally one across the throat; the tail is very long, rounded, with its scales arranged in rings, being also fragile; the head is covered with shields, which are symmetrically arranged; scales on the back granular or rhombic; on the sides granular; on the belly largely quadrangular or rounded, and arranged in cross-bands; eyes diurnal, with eyelids; the tympanum distinct; limbs always four, and well developed. This group of Lizards has no representative in America or (so far as known) in Australia.

The sub-family of Tachydrominæ is included by Dr. Gray in the family Zonuridæ. These are Asiatic Lizards, with a most inordinate length of tail, the fore and hind limbs being not placed distantly apart, as in the various anguiform Lizards already treated of—there is an indistinct collar, and the toes are not serrated or keeled. Two genera have been distinguished, Tachydromus and Tachysaurus, the latter founded on a Japanese Lizard, T. japonicus. At least three species are known of Tachydromus, two of which inhabit China, T. septentrionalis and T. meridionalis; the third belonging to the Indo-Chinese countries, T. sex-lineatus. In an example of the last, measuring fourteen inches long, the tail occupies eleven inches and a half. It is the longest-tailed creature that we have any knowledge of, in proportion to its other parts; indeed, something quite wonderful to behold and muse over.

The rest of the Lacertidæ are chiefly from Africa and the south of Europe; there are probably more of them to be discovered in Middle Asia, and only three or four species are known to inhabit the Indian region. Fifteen or more genera are recognised. In temperate Europe (inclusive of the British Islands) two species are common—the Zootica vivipara and the Lacerta agilis. The former, as its name imports, is viviparous, whereas the other genera belonging to the family are (so far as known) oviparous. Others occur in the south of Europe.]

The common Grey or Sand Lizard (L. agilis), sometimes attains the length of from eight to ten inches, of which the tail occupies more than half. These little inoffensive creatures, so common in Southern Europe, are slender and active; their movements are so rapid that they escape the eye as quickly as a bird. They require a mild temperature, and seek shelter among ruins. When the sun strikes with its meridian force upon a wall, they may be seen basking in its rays, enjoying themselves delightedly upon the heated surface. They seem to be pervaded with the blessed warmth, and mark their pleasure by soft undulations of the tail. It is commonly said that the Lizard is the friend of Man, since far from flying at his approach, they seem to regard his appearance with great complacency. They pass the winter at the bottom of small holes which they have hollowed out of the earth, where they become torpid. At the commencement of spring they issue from their hiding-place, and each seeks its mate; they go in pairs, male and female, it is said, living in faithful union for many years, sharing between them the domestic arrangements, which comprise hatching the young and nursing them in their helplessness, carrying them into warm and sunny places, and sheltering them from cold and damp.

Lizards feed chiefly upon insects, and especially flies. All who have watched the actions of the Grey Lizards must have observed that the caudal vertebræ are so extremely fragile that they separate on the slightest touch, the tail remaining in the hand of any one attempting to seize it. These tails sometimes grow again. When an attempt is made to seize a Grey Lizard on the wall it lets itself fall to the ground, and remains there a moment immovable before attempting to run, evidently simulating death.

Grey Lizards are easily tamed, and appear happy in captivity. From their extreme gentleness they soon become familiar with their keepers, and return caress for caress, approaching mouth to mouth, and suck the saliva from between their lips with a grace that few people would allow them to display.

In the Green Lizard, L. viridis, the scales of the temple are many-sided and unequal, with a central layer; back granular and oblong, with shelving sides; throat fold distinct. Nothing can be more brilliant than the variegated colouring with which it is ornamented. Its favourite locality is a slightly elevated woody place, where the sun's rays readily penetrate. It is also found in sunny meadows. It feeds upon small insects, and shows no alarm at the presence of Man, but stops to look at him. Snakes, on the contrary, they seem to fear much, but when they cannot avoid them they fight courageously. In length they are about eighteen inches.

Fig. 27.—Green Lizard and Ocellated Lizard.

Green Lizards are found in Jersey and Guernsey, and other warm countries of Europe, on the African coast of the Mediterranean, and they are not rare in France.

How often have we admired their magnificent colours in the neighbourhood of Montpelier, where they rival the green of the meadows, and glitter in the sun like so many living emeralds!

In the Ocellated Lizard, L. ocellata, the upper part of the body is green, variegated, spotted, and reticulated or ocellated with black, having large round blue spots upon the flanks; the underpart of the body is white, frosted with green; in size it is about twenty inches. They are found at Fontainebleau, in the south of France, and in Spain. They establish themselves in hard sand, often between two beds of calcareous rock, upon some steep declivity, more or less directly exposed to the south; they are also found between the roots of old stems, either in hedgerows or vineyards. They feed almost exclusively on insects; but are said to attack Mice, Shrews, Frogs, and even Snakes, and to destroy the eggs of the Partridge. They have sometimes been tamed by feeding them on milk.

[In the genus Ophiops, two species of which inhabit Asia Minor, and one of them the shores of the Mediterranean, the eyelid is rudimentary and the eye exposed, whence the name, signifying "snake eye." So far as known, the habits of the various Lizards which constitute the family of Lacertidæ are much the same.

The family of Teidæ is peculiar to the New World, and some of the species attain to the length of several feet. In these Lizards the head is pyramidal, and is covered with regular many-sided shields; supra-orbital plate horny; the teeth solid and well rooted; tongue elongate, flat, free (rarely slightly sheathed at its base); the scales of the back are regular and keeled, and of a rhombic shape; sides flat, and covered with small granular scales; the throat scaly, with a double collar, rarely indistinct.

In some the throat has two cross-folds, with large six-sided scales within; and of these some have the ventral shields small, long, and smooth, while others have them much broader. The former are known as the Teguexins (Teius and Callopistes), and the latter as the Ameivas (Ameiva, and three other genera). One species of Teguexin, Teius teguexin, may commonly be seen alive in the London Zoological Gardens. This is a large and powerful Lizard, exceeding five feet in length when full grown, and extremely active. It feeds on small living animals of any kind, and will even devour poultry, and especially their eggs, for which latter it manifests an especial liking, as observed in captivity. Sometimes it has been known to prey on other and kindred Lizards, as the Ameivas. The teeth of this species are strong, and the reptile can bite with great force. It is a bold and determined combatant when attacked, and if it succeeds in seizing its foe, retains its hold with pertinacity. Its flesh is eaten by some people, who consider it excellent. Together with a second species, T. nigropunctatus, it inhabits Brazil, and the two species of Callopistes are also South American, one at least of them occurring in Chili. The species of this family, although strong and agile, never ascend trees, but range at will the hot sandy plains or the dense and damp underwood on the margins of lakes and rivers, into which they plunge when alarmed, and remain below the surface until the danger has passed away, their capacious lungs and imperfect circulation permitting them to endure a very long immersion without inconvenience.

The Ameivas have a long whip-like tail, and peculiarly elongated toes on their hind feet. The species of Ameiva and Cnemidophorus are numerous, and the genera Dicrodon and Acrantus are founded each of them upon a single species. In general these are Lizards which correspond with the ordinary Lacertidæ of the Old World. One species only, Cnemidophorus sex-lineatus, inhabits the Southern States of North America; there are at least four others in Mexico, and the rest belong to South America and the Antilles. "The Ameiva dorsalis," writes Mr. Gosse, "is one of the most common of the reptiles of Jamaica, and is as beautiful as abundant. Its colours are striking, but not showy, and its countenance has a very meek expression. All its motions are elegant and sprightly; when it is proceeding deliberately, its body is thrown into latent curves the most graceful imaginable; but when alarmed its swiftness is so excessive that it appears as if it literally flew over the ground, and the observer can scarcely persuade himself that it is not a bird. It is very timid, and though its toes are not formed as in the Geckos and Anoles, for holding on against gravity, I have seen a large Ameiva run with facility on the side of a dry wall, along the perpendicular surfaces of the large stones."

A second series occurs in those Teidæ which have a collar of large shields on the throat. As many as five genera of them have been established, each upon a single species, and all are from intertropical America. In Crocodilurus lacertinus the two rows of crests along the tail recall to mind the Crocodiles, whence the name bestowed. Others have been styled Dragons, as the Great Dragon, Ada guianensis, and the Smaller Dragon, Custa bicarinata. All bear a certain amount of superficial resemblance to the Crocodiles, and the Great Dragon grows to six feet in length, and is found in many parts of South America. This large reptile runs up the trunks of trees with facility, is quick when on the ground, and it also swims, though not particularly well. It preys upon such small animals as it can manage to seize, and chiefly frequents the inundated savannahs and marshy localities, where it is seen basking in the sunshine; but there is considerable difficulty in taking this Lizard, as it makes generally for its burrow in some raised spot, and bites desperately in self-defence. Its flesh is eaten, and is considered a delicacy. Its eggs, also, are considerably esteemed at Cayenne and other places, and each female lays some dozens of them.

The family of Helodermidæ is founded on a very remarkable Lizard from Mexico, the H. horridum, which is of the same size as the Great Dragon, and in some respects approximates the following Old World family of Varanidæ. Its back and sides are covered with oblong, hexagonal, very convex and shield-like scales, and the belly with oblong, rather convex plates; tail cylindrical, with oblong, convex scales above, and flat, elongate, thin plates beneath. The head is somewhat flattened, and is covered with polygonal, convex shields; the muzzle is rounded; and the teeth are on the inner side of the jaws, incurved, with a groove on the front of their inner side. The bite of this reptile is said to be severe.

The family of Varanidæ inhabit South-eastern Asia and its islands, Africa, and Australia. In this family are comprised the largest of existing Lizards, with the exception of the Crocodilidæ. They are very commonly miscalled Iguanas by Europeans and their descendants, in the countries where they are found. These reptiles have a pyramid-shaped head, more or less elongated, and covered with small and scale-like, but not imbricate, shields. Their teeth are acute and compressed. The tongue is elongate, slender, terminating in a long fork, and is retractile into a sheath at its base. Their scales are small, equal on the sides and on the back, and arranged in cross rings; those on the belly and tail are square, in cross bands. Tail long, and generally more or less compressed. The feet are well developed, with five toes on each, which are armed with strong claws. Most of them live near water, and they are excellent swimmers, their long and compressed tail serving as a propeller. Their movements on land are not much less rapid than in the water. Several of the species climb trees, and they are more or less nocturnal in their time of action, though also about by day. They are exclusively carnivorous, feeding on the different water animals, and on the eggs of birds, and likewise on those of other large reptiles; some of them are also destructive to ducklings, and to various Snakes. Dr. Günther remarks that "their external nasal opening leads into a spacious cavity situated in the snout; when the animal dives, it closes the nasal aperture, and retaining a certain quantity of air in that pouch, or rather in the two pouches, it is enabled to remain under water for a prolonged period without the necessity of rising to the surface in order to breathe. It is the same plan of structure as that with which a large northern Seal (Cystophora borealis) is provided." In like manner, the air-bag connected with the one developed lung of the Ophidians retains the necessary supply of air during the tedious process of deglutition or swallowing. The nostrils are variously placed, either mid-way between the eye and muzzle, or nearer to one or to the other; and according to this and some other differences, Dr. Gray divides the Varanidæ into as many as seven genera, but Dr. Günther would seem to admit not more than two genera. When the tail of these Lizards is mutilated, the lost portion is never renewed; whereas in the preceding families of the Zonuridæ, Lacertidæ, and Teidæ a new tail or portion of one soon sprouts forth—but this renewed portion contains no bony vertebræ, and it remains smooth externally; when the fracture is cleft, as sometimes happens, two new tails are put forth. Another family of Lizards in which the tail is thus commonly renewed is that of the Geckos; but never in the Iguanidæ, the Agamidæ, and the Chameleonidæ, any more than in the Varanidæ. The species of this family defend themselves vigorously, when attacked, by lashing forth smart blows with the tail, as do also the Crocodiles and the larger Iguanidæ.

In the genus Varanus, the nasal apertures form an oblique slit, in, or nearly in, the middle, between the eye and the tip of the snout. The scales are elliptic and small; those on the back and on the sides are not imbricate, each of them being surrounded by a small, circular, granular fold. Tail with a low crest, formed by two or four series of strongly keeled scales. Throat with a transverse fold. One very common in India and Ceylon is the V. dracæna, which grows to a length of five feet, the tail being longer than the body. These reptiles live in holes, and in mid-day they steal out of their cells to seek their food, which consists chiefly of the smaller reptiles and of insects. In many parts of India, and in Ceylon, the flesh is much eaten by the natives. The late Dr. Kelaart states that he once tried some excellent soup made from it, which tasted not unlike hare-soup. At Trincomali, he tells us, they are hunted down by Dogs, and sold in the market for sixpence each. This species climbs walls, and holds on so firmly with its strong claws, wherever these can be inserted, that it is actually used by house-breakers in India to help in raising themselves up a wall or building, the man grasping the tail, while the reptile affords a lift by endeavouring to escape from him upwards. It lays twenty or thirty eggs, which in texture and appearance resemble those of many Snakes, being similarly agglutinated together by a viscid mucus. Sir J. E. Tennent remarks that "one of the earliest, if not the first, remarkable animal to startle a stranger on arriving in Ceylon, whilst wending his way from Point de Galle to Colombo, is this large Lizard, which may be seen at noonday searching for Ants and other insects in the midst of the highway and along the fences. When disturbed, but by no means alarmed, by the approach of Man, it moves off to a safe distance; and the intrusion being at an end, it returns again to the occupation in which it had been interrupted. It lives in any convenient hollow, such as a hole in the ground, or the deserted nests of the Termites; and some small ones, which frequented my garden at Colombo, made their retreat in the heart of a decayed tree."

Of another species, V. flavescens, which inhabits Lower Bengal, and to the eastward in Burmah, &c., Mr. Theobald remarks that "large specimens are not often procurable by Europeans, as they are much sought after by both Burmese and Karéns as choice articles of food. They are chiefly hunted with Dogs, whose scent enables them to discover the Varans in the hollow trees in which they habitually shelter themselves. A Burman, though ordinarily a lazy man, will think nothing of cutting down and breaking up a large tree in which one of these creatures has sought refuge. The Varanidæ deposit their eggs in the ground, usually selecting a deserted White-ant's nest. The eggs are cylindrical, with tapering ends, of a dirty white colour and leathery texture (those of V. dracæna are two inches long), and, being esteemed an uncommon luxury by the Burmese, sell dearer than fowls' eggs. They are oily and feculent-looking, though devoid of any nauseous odour, and some Europeans eat them with pleasure."

A well-known African species, the V. or Psammosaurus scincus, extends (without the slightest difference) to the extreme desert region of the north-west of India, and more habitually frequents dry localities than others. In this species the nasal apertures are placed very near the eyes.

In the genus Hydrosaurus, the nostrils are more or less rounded, and are situate near the extremity of the snout. These animals are more decidedly aquatic than the preceding, and some of the species grow to seven or even eight feet in length. Such is the H. giganteus of Australia, where three, if not four, species inhabit. In all south-eastern Asia and its islands, its range extending to Lower Bengal but not to India proper, although found in Ceylon, the H. salvator is a common species, which, according to the late Dr. Cantor, is "very numerous in hilly and marshy localities of the Malayan peninsula. It is commonly, during the day, observed in the branches of trees overhanging rivers, preying upon birds and their eggs and smaller Lizards, and when disturbed it throws itself from a considerable height into the water; it will courageously defend itself with teeth and claws, and by blows with its tail."

We have now to treat of the