The Animal World, A Book of Natural History Part 41

Two or three small kinds are to be found in the south of England, one of which is curious as representing a tribe, largely represented in other parts of the world, of legless burrowing lizards, which look much like little snakes, for none of them are more than ten or twelve inches long, while they are of the thickness of a lead-pencil. They look so s.h.i.+ny and serpent-like that many people are afraid of them.

But the blindworm, or slowworm, as this creature is called, is perfectly harmless. It cannot bite you, for its teeth are far too tiny to pierce the skin; and it cannot sting you, because it has no sting. There is its odd little forked tongue, of course, which is always darting in and out of its mouth, just like that of a snake. But this tongue is only a feeler. Whenever a blindworm comes to an object it does not quite understand, it touches it gently all over with the tip of its tongue, just as we might touch it with the tips of our fingers.

Notwithstanding its name, the blindworm has a pair of very good, though rather small, beady black eyes; and, of course, it is not a worm.

During the daytime the blindworm mostly lies hidden under a large stone; and on turning such a stone over, one may sometimes find two or three of these lizards all coiled up together. But in the evening they leave their hiding-places, and go out to search for the tiny white slugs on which they feed.

When it is suddenly startled the blindworm sometimes behaves in a very odd way. It stiffens its body, gives a kind of shudder and a twist, and actually snaps off its own tail! Then the tail begins to writhe about on the ground, wriggling and curling and even leaping up into the air in the most curious manner; and while you are watching its antics, the blindworm creeps away into some place of safety. You would think that it must suffer a great deal of pain from this extraordinary injury, wouldn't you, and that the blindworm would feel it quite as much as a man would feel if his leg were cut off? But it does not seem to suffer at all; and stranger still, a new tail very soon begins to grow in the place of the old one, so that in the course of a very few weeks the lizard is just as perfect as it was before!

SKINKS

These are queer little lizards with four short legs and very stumpy tails, which are found in many parts of Africa and Asia. They live in sandy deserts, and are rather slow in their movements as a rule. But if a fly should settle anywhere near them they will dart upon it with the most surprising quickness, and will hardly ever fail to capture it. And if they are alarmed they will burrow into the sand so rapidly that they really seem to sink into it just as if it were water. In a very few seconds, indeed, they will bury themselves to a depth of at least two or three feet.

In olden days skinks were very much used in medicine, and the powder obtained from their dried bodies was thought to be a certain cure for many diseases! It does not seem a very nice idea, yet even to this day skinks are used for the same purpose in Eastern countries.

There are several different kinds of these curious lizards, of which the common skink, found in Northern Africa, is the best known. It is about three inches and a half in length, and is yellowish brown in color, with a number of darker bands on the sides of the body.

GECKOS

Odder still are the geckos, which have their toes swollen out at the tips into round sucker-like pads, by means of which they can climb a wall or a pane of gla.s.s with the greatest ease, or even walk about like flies on the ceiling. They are very fond of getting into houses, generally remaining hidden in some dark corner during the day, but coming out toward evening to search for insects, and continually uttering their curious little cry of "geck-geck-geck-o."

People used to be very much afraid of geckos, some thinking that they could squirt out poison from the pads of their toes which would act like the sting of a nettle, and others declaring that their teeth were so sharp and strong that they could pierce even a sheet of steel! But the real fact is that these lizards are perfectly harmless, and cannot injure any living creature except the insects upon which they feed. When they take up their quarters in a house they soon become extremely tame, and will even climb up on the dinner-table to be fed.

Geckos are found in almost all hot countries of the Old World, and nearly three hundred different kinds have been found altogether.

IGUANAS

American lizards are almost wholly members of the numerous iguana family, which takes its name from the big examples found from Mexico down into Brazil. The commonly known one when fully grown will measure four feet from the tip of its blunt, top-shaped head to the end of its long tapering tail. It looks rather forbidding, for a row of sharp spikes runs right along its back, while under its chin is a great dewlap. Yet it is not quite so terrible as it seems, for though it will bite fiercely if it is driven to bay, and use its long tail like the lash of a whip, it will always run away if it can, and will either climb into the topmost boughs of a tree, or plunge into a stream and swim away.

This reptile is a very good swimmer, driving itself rapidly through the water by waving its long tail from side to side, just like a crocodile or an alligator. And it can dive beneath the surface and remain at the bottom for a very long time without coming up to breathe.

Iguanas live chiefly among the branches of trees which overhang the water. Their flesh is very good to eat, for it is as tender as the breast of a young chicken. Their eggs, too, which they bury in the sand on the river-bank, are often used as food, and it is said that, no matter how long they may be boiled, they never become hard.

VARIOUS AMERICAN LIZARDS

The hot open plains which stretch from central Texas westward to the Pacific Ocean, and northward in Utah and Nevada, abound in a great variety of small lizards, none more than eighteen inches or so in length. Some are fat and short-tailed, some slender and swift, with tails like whiplashes. Some have gay colors and the power of changing them more or less, while others are dull of hue and uninteresting or repulsive to look at. Mostly they are insect-eaters, but some subsist upon plants; and one of the latter is the big fat one known in southern California as the "alderman."

Another strange one is the broad, flat creature so frequently seen all over the Southwest, and called horned toad, on account of its shape and habit of sitting on its squat legs, with its tail tucked sideways out of sight. It is covered almost all over with long and sharp spikes. Those on its head, which are directed backward, are the longest; and from these it gets its name of horned toad. But those on the back are very nearly as long, while there are several rows upon the tail as well. Yet it is perfectly harmless, for even when it is caught for the first time it never seems to use either its spikes or its teeth.

But it has another peculiarity which it sometimes uses as a means of defence, and that is a very strange one indeed. It actually squirts out little jets of blood from its eyes! That seems impossible, doesn't it?

Yet there is no doubt at all about it, for when these lizards have been kept in captivity, and have been rather roughly handled, they have been known to squirt several drops of blood at a time to a distance of twelve or fifteen inches! Yet n.o.body seems to know how they do it.

THE GILA MONSTER

This same region, however, contains a poisonous lizard--the only kind of lizard in the world known to have sacs of venom in the mouth. This venom enters any wound made by the animal's biting with certain teeth, and acts upon the animal bitten like snake-poison. This is a sluggish, round-headed, short-tailed creature which dwells in the sandy plains along the Mexican boundary, and is called the Gila monster, or, scientifically, the _Heloderma_. Its scales are rounded, so that this lizard looks as if dressed in pebbled goatskin; and its colors are black and yellow, in irregular blotches. The hunters and sheep-herders are more afraid of it than need be, for it is sleepy and will never use its poisonous teeth without great provocation, so that it is only necessary to leave it alone in order to escape any harm.

THE FRILLED LIZARD

This lizard is a native of Australia, and has round its neck a kind of frill, or ruff, from six to eight inches in diameter! As a rule this frill is folded round the throat, so that from a little distance one would scarcely notice it. But as soon as the reptile is excited or alarmed it spreads it out, sits on its hinder legs and its tail, raises its head and body, and shows its teeth, just as if it were going to fly at its enemy. This is only pretence, however, for though the lizard grows to a length of nearly three feet, it is quite harmless.

Another very curious habit which this lizard has is that of walking upright on its hind legs, in the att.i.tude of a dog when "begging." It will even run in this position, and most odd it then looks. It is a capital climber, and spends most of its life in the trees, to which it always tries to escape when it thinks itself in danger. In color the frilled lizard is yellowish brown mottled with black.

THE CHAMELEON

Strangest of all strange lizards, however, is the chameleon. In the first place, this lizard has a very long tongue, which it can dart out to a really wonderful distance from its mouth. This tongue looks very much like a worm, and is exceedingly sticky, so that all that a chameleon has to do when it sees a fly settling near it is to dart out its tongue and touch it with the tip. Then the fly adheres to it, and is carried back into the mouth so quickly that it is almost impossible to see what becomes of it. In this way it can catch a fly at a distance of fully six inches.

Then the chameleon has most extraordinary eyes. They are about as big as peas; but instead of having lids which move up and down, as ours do, they are entirely covered by the lids with the exception of just a tiny round s.p.a.ce in the middle. The lizard sees, in fact, through a hole in the middle of its eyelid. That is strange enough; but what is stranger still is that the animal can move its eyes in different directions at the same time. They are hardly ever still for a single moment. But instead of moving together, like those of all other animals, one may be looking upward toward the sky and the other downward toward the ground; or the right eye may be peering forward in front of the nose while the left one is glancing backward toward the tail! Indeed, it would be very difficult to find an odder sight than that of a chameleon when it is moving its eyes about. They really look just as if they belonged to two different animals.

But the most wonderful fact of all about the chameleon is that it can change its color whenever it chooses.

How it does so no one quite knows. But the very same animal which is brown all over as it sits upon a branch will become green all over if you put it among leaves. The last thing at night, probably, you will find that it is gray. Next day, perhaps, brown spots will appear upon its body, and pinkish stripes upon its sides. And occasionally it may be violet, and sometimes yellow, and sometimes nearly black. So that if you were to go and look at a chameleon, and then go and look at it again half an hour afterward, you might very likely take it for a wholly different animal!

Then the chameleon has very odd habits. If it is annoyed, for example, it puffs out its body in the most extraordinary way till it is nearly double its ordinary size and its skin is stretched almost as tight as the parchment of a drum. When it is caught it hisses like a snake. And really it must be the very laziest creature on earth. If it lifts a foot into the air it will often wait for quite a minute before it puts it down again, and for two or even three minutes more before it takes a second step. Then it always has to rest for some little time after uncoiling its tail from a branch, while when it coils it round another it stops and rests again. It will hardly travel two yards, in fact, in a day.

Chameleons are found in many parts of Africa and Asia, and also in Southeastern Europe.

CHAPTER XXVIII

SNAKES

There are a great many different kinds of snakes; but before we read about some of them, we must tell you some thing about the wonderful way in which their bodies are made.

In the first place, then, remember that snakes have a very large number of those sections or pieces forming the spine which we call vertebrae. We ourselves have only thirty-three of these little parts when we begin life, and twenty-six afterward; this difference in number being caused by the fact that five of the joints very soon unite into a bony ma.s.s at the lower end, which we call sacrum, while four more unite into another, which we call the coccyx. But some snakes have hundreds of these vertebrae. The boas, for example, have no less than three hundred and four!

In the next place, remember that all these vertebrae are fastened together by what we call ball-and-socket joints. That is, there is a round k.n.o.b at the back of each vertebra which fits into a socket in front of the vertebra behind it. This gives to the spine of a snake great strength, for a vertebra cannot be forced out of its place without breaking the vertebra behind it. And it also allows the spine to be curled and twisted about in almost any direction; so that a snake can easily coil up its body like a spring, or even tie it into a knot.

Then, remember that a snake has a great many ribs. We have twelve pairs of these important bones, most of which are jointed to the breast-bone in front. But a snake may have as many as two hundred and fifty-two pairs of ribs, while it has no breast-bone at all; so that the tips of all the ribs are free. And every rib is fastened to a vertebra of the spine by a ball-and-socket joint, just like those which fasten the vertebrae themselves together. Besides this, there are no less than five separate sets of muscles connected with the ribs, so that the snake can move those bones about quite easily.

It is really by means of its ribs that a snake is able to glide over the ground. If you were to look at the under side of a snake's body, you would see that the scales are quite different from those on the upper part. On the back and sides the scales are quite small, and are almost oval, or oblong; but on the abdomen they are very long and very narrow, and are set crosswise like the laths of a Venetian blind.

[Ill.u.s.tration: CHARACTERISTIC FORMS AND MARKINGS OF AMERICAN BIRDS' EGGS

SEA-FOWL:--13. Guillemot. 14. Tern. 21. Skimmer.

WATER-FOWL:--9, 16. Ducks, WADERS. 7. Heron. 11. Gallinule.

12. Snowy Plover. 23. Stilt Sandpiper. 24. Ring Plover.

GAME-BIRDS:--6. Partridge. 19. Ptarmigan.

BIRDS OF PREY:--3. Owl. 17. Buzzard-hawk. 20. Falcon CUCKOOS:--8. Cuckoo. 10. Roadrunner.