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 nobody 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 attitude 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.