feet long, and eight feet in circumference: the jaws open two feet wide, and the cutting-teeth, of which it has four in each jaw, are above a foot long, and four inches in circumference. This formidable creature, when full-grown, measures about 17 feet long from the extremity of the snout to the insertion of the tail, above 16 feet in circumference round the body, and stands above seven feet high. When excited, it puts forth its full strength, which is prodigious. "I have seen," says a mariner, as we find it in Dampier, "one of these animals open its jaws, and seizing a boat between its teeth, at once bite, and sink it to the bottom. I have seen it, on another occasion, place itself under one of our boats, and rising under it, overset it with six men who were in it, but who, however, happily received no other injury."

Why is a species of lizard called the monitor?

Because it is said to keep in company with the crocodile, and to warn, by its whistling noise, of the proximity of its formidable associate.

Why is another species of lizard called the flying dragon?

Because it flies or takes short leaps from tree to tree, by having, on each side of the body, a membranaceous wing, scarcely connected with the legs. It is supported by the first six false ribs, which instead of being bent round towards the belly, for the protection of the viscera, proceed laterally from the body.

CHAMELEON.

Why does the chameleon change colour?

Because of the circulation of the blood of the reptile, in increased temperature, either of the ambient air or of its own body, producing all the variations of the skin. As the passions of the human mind change the colour of the skin, as well as the form of the features, and according to the rapidity of the flow of blood; so the feelings of the chameleon may also, in some mea

sure, produce analogous changes in the reflecting surface of the skin.-J. Murray, F. L. S.

The reflection of coloured objects on the glittering scales of the chameleon, probably gave origin to the fable that its colour is regulated by that of the bodies near which it is placed.-Notes to Blumenbach.

Whatever may be the cause, the fact seems to be certain, that the chameleon has an antipathy to things of a black colour. One, which Forbes kept, uniformly avoided a black board which was hung up in the chamber; and, what is most remarkable, when it was forcibly brought before the black board, it trembled violently, and assumed a black colour.

It may be something of the same kind which makes bulls and turkeycocks dislike the colour of scarlet, a fact of which there can be no doubt.-J. Rennie.

Why was the chameleon formerly said to feed on air? Because its lungs are very large, and by expanding them, the animal can, at pleasure, make itself appear large or small.

Why do the eyes of the chameleon differ from those of other amphibia?

Because they can be directed in different ways; for instance, one upwards and the other backwards; and that with great rapidity.

Why may the mechanism of the tongue of the chameleon be compared with that of the woodpecker? *

Because the chameleon's tongue is contained in a sheath at the lower part of the mouth, and has its extremity covered with a glutinous secretion: it admits of being projected to the length of 6 inches, and is used in this manner by the animal in catching its food, which consists of flies, &c. It is darted from the mouth with wonderful celerity and precision, and the secretion on its extremity entangles the small animals which constitute the food of the chameleon.

*See the Woodpecker, page 102.

The form of the chameleon's tongue is, however, very different from that of the woodpecker.-Notes to Blumenbach.

GECKO.

Why is the gecko so dangerous a reptile in houses? Because it has a poisonous fluid between its scaly toes, which it communicates to the eatables over which it passes. It is common in Egypt, the East Indies, and the South Sea Islands, and even in some parts of Europe, as in the Kingdom of Naples.

Why do some lizards climb perpendicular walls, like the common house-fly?

Because they have suckers on the under side of the toes, the surfaces of which are broad. They consist of transverse pouches, with fringed margins.

THE PROTEUS.

Why has the classification of the proteus animal been so much controverted among naturalists?

Because its characteristics are equally those of a lizard and a fish.

66

Sir Humphry Davy, in his Consolations in Travel, (to which work we have already referred in Popular Chemistry), describes this extraordinary animal as far greater wonder of nature than any of those which the Baron Valvasa detailed to the Royal Society, a century and a half ago, as belonging to Carniola, with too romantic an air for a philosopher." Sir Humphry saw the proteus in a lake, in the beautiful grotto of Maddalena, at Adelsburg, in Illyria. “At first you might suppose it to be a lizard, but it has the motions of a fish. Its head, and the lower part of its body, and its tail, bear a strong resemblance to those of the eel; but it has no fins; and its curious bronchial (or lunglike) organs are not like the gills of fishes; they form a singular vascular (net-like) structure, almost like a crest round the throat, which may be removed without occasioning the death of the animal, who is likewise

furnished with lungs. With this double apparatus for supplying air to the blood, it can live either below or above the surface of the water. Its fore-feet resemble hands, but they have only three claws or fingers, and are too feeble to be of use in grasping or supporting the weight of the animal; the hinder feet have only two claws or toes, and in the larger specimens are found so imperfect as to be almost obliterated. It has small points in place of eyes, as if to preserve the analogy of nature. It is of a fleshy whiteness, and transparency in its natural state, but when exposed to light, its skin gradually becomes darker, and at last gains an olive tint. Its nasal organs appear large;" and it is abundantly furnished with teeth, from which it may be concluded, that it is an animal of prey; yet, in its confined state, it has never been known to eat, and it has been kept alive for many years, by occasionally changing the water in which it was placed."

Sir Humphry does not think the proteus is bred in the lake in the grotto: "in dry seasons they are seldom found here, but after great rains they are often abundant. I think it cannot be doubted, that their natural residence is an extensive, deep, subterranean lake, from which, in great floods, they sometimes are forced through the crevices of the rocks into this place." We have not space for this great philosopher's theory of the proteus; but we may state its conclusion: "the problem of the re-production of the proteus, like that of the common eel, is not yet solved; but ovaria have been discovered in animals of both species, and in this instance, as in all others belonging to the existing order of things, Harvey's maxim of 'omne vivum ab' ovo,' (every animal from an egg) will apply." The curious reader should turn to the "Consolations" for Sir Humphry's ingenious speculations on this and many other striking phenomena of nature: indeed, every page of that work is penned in a delightful strain of deep-souled philosophy.

SERPENTS.

Why may the ventral, or belly-plates, or scales of serpents, be considered as their feet?

Because these scales slide under each other by a kind of inclusion, so as to permit the ventral surface to shorten or lengthen at the will of the animal. When some of the foremost scales are pressed on the ground, those behind are brought forward, and in their turn supporting the body, enable the forepart to advance. To qualify the scales to do this with greater advantage, they are connected with one another, by means of muscular threads and a longitudinal band, and are likewise aided by the peculiar mechanism of the ribs, which last are connected with the ventral scales by a flexible cartilage. The body, in general, is of a rounded form, but, when preparing for progressive motion, the ribs are drawn so as to flatten the scales of the belly, and by moving anteriorly or posteriorly, give to the scales with which they are connected, a corresponding degree of motion. The ribs in this case act as limbs to the scales, which may be compared to feet. This singular use of the ribs of snakes, in assisting progressive motion, was detected by the acute Tyson, and has been still further illustrated by Sir Everard Home.-Fleming.

Sir Everard Home was led to this discovery of the aid afforded by the ribs, to the whole tribe of snakes, in the progressive motion of those animals, by the following circumstances. A snake of unusual size, brought to London to be exhibited, was shown to Sir Joseph Bankes; the animal was lively, and moved along the carpet briskly; while it was doing so, Sir Joseph thought he saw the ribs move forward in succession, like the ribs of a caterpillar. The fact was readily established, and Sir Everard felt the ribs with his fingers, as they were brought forward: when a hand was laid flat under the snake, the ends of the