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Few animals have been more celebrated by natural historians than the Chamaleon, which has been sometimes said to possess the power of changing its colour at pleasure, and of assimilating it to that of any particular object or situation. This, however, must be received with great limitations; the change of colours which this animal exhibits varying in degree, according to circumstances of health, temperature of the weather, and many other causes, and consisting chiefly in a sort of alteration of shades, from the natural greenish or bluish grey of the skin into pale yellowish, with irregular spots or patches of dull red. The chamæleon is a creature of a harmless nature, and supports itself by feeding on insects, for which purpose the structure of the tongue is finely adapted, consisting of a long missile body, furnished with a dilated and somewhat tubular tip, by means of which the animal seizes insects with great ease, darting out its tongue in the manner of a woodpecker, and retracting it instantaneously with the prey secured on its tip. It can also support a long abstinence, and hence arose the idea of its being nourished by air alone. It is found in many parts of the world, and particularly in India and Africa, and also in Spain and Portugal. One that was kept alive in Liverpool, was regularly fed with sugar and bread, and appeared to have an affection for the person who had the care of it. Its change of form was as remarkable as that of colour.-(Companion to Mr. Bullock's Museum, p. 93.)
On his rear,
Circular base of rising folds, that towered
Floated redundant; pleasing was his shape
The SERPENTES, or serpents, are generally distinguishable from the rest of the amphibia by their total want of feet. One of the most singular properties of the serpent tribe, is that of casting their skin from time to time. When this takes place, so complete is the spoil or coat-skin, that even the external' coat of the eyes themselves makes a part of it. Among the poisonous serpents, the fangs or poisonous teeth are always of a tubular structure, and furnished with a small hole or slit, near the tip,-they are rooted into a particular bone, so jointed to the remainder of the jaw on each side, as to permit the fangs or poisoning teeth to be raised or depressed at the pleasure of the animal. Above the root of each is a glandular: reservoir of poison, which, in the act of biting, is pressed into the tube of the tooth, and discharged into: the wound through the hole near the tip. The genera are: 1. Crotalus, rattlesnake. 2. Boa, immense serpents of India and Africa. 3. Coluber, viper. 4. Anguis, blind-worm. 5. Amphisbæna. 6. Cæcilia. 7. Acrochordus. 8. Hydrus. 9. Langaya. 10. Siren.
DE LILLE, in his Trois Règnes de la Nature,' has admirably described the various motions of the serpent:
Il court, nage, bondit, gravit, vole, ou serpente;
The eagle and the stork
Their downy breast: the swan with arched neck
Walked firm; the crested cock whose clarion sounds
THE skeleton or bony frame of birds is, in general, of a lighter nature than in quadrupeds, and is calculated for the power of flight the spine is immoveable, but the neck lengthened and flexible: the breast-bone very large, with a prominent keel down the middle, and formed for the attachment of very strong muscles. The bones of the wings are similar to those of the fore legs in quadrupeds, but the termination is in three joints or fingers only, of which the exterior one is very short. What are commonly called the legs, are analogous to the hind legs in quadrupeds, and they terminate in general in four toes, three of which are commonly directed forwards, and one backwards; but in some birds there are only two toes, in some, only three. All the bones in birds are much lighter, or with a larger cavity, than in quadrupeds.
The feathers with which birds are covered, resemble in their nature the hair of quadrupeds, being composed of a similar substance appearing in a different form. Every single feather (says Dr. Paley) is a mechanical wonder. If we look at the quill, we find properties not easily brought together, strength and lightness. I know few things more remarkable than the strength and lightness of the very pen with which I am now writing. If we cast our eye toward the upper part of the stem, we see a material made for the purpose, used in no other class of animals, and in no other part of birds; tough, light, pliant, elastic. The pith, also, which feeds the feathers, is neither bone, flesh, membrane, nor tendon.
But the most artificial part of a feather is the beard, or, as it is sometimes called, the vane; which we usually strip off from one side, or both, when we make a pen. The separate pieces of which this is composed are called threads, filaments, or rays. Now the first thing which an attentive observer will remark is, how much stronger the beard of the feather shows itself to be when pressed in a direction perpendicular to its plane, than when rubbed either up or down in the line of the stem; and he will soon discover, that the threads of which these beards are composed are flat, and placed with their flat sides towards each other by which means, while they easily bend for the approaching of each other, as any one may perceive by drawing his finger ever so lightly upwards, they are much harder to bend out of their plane, which is the direction in which they have to encounter the impulse and pressure of the air, and in which their strength is wanted. It is also to be observed, that when two threads, separated by accident or force, are brought together again, they immediately reclasp. Draw your finger down the feather which is against the grain, and you break, probably, the junction of some of the contiguous threads; draw your finger up the feather, and you restore all things to their former state.
It is no common mechanism by which this contrivance is effected. The threads or laminæ above mentioned are interlaced with one another; and the interlacing is performed by means of a vast number of fibres or teeth which the threads shoot forth on each side, and which hook and grapple together.
Fifty of these fibres have been counted in one twentieth of an inch. They are crooked, but curved after a different manner; for those which proceed from the thread on the side toward the extremity of the feather are longer, more flexible, and bent downward; whereas those which proceed from the side to❤ ward the beginning or quill-end of the feather, aré shorter, firmer, and turned upward. When two laminæ, therefore, are pressed together, the crooked parts of the lung fibres fall into the cavity made by the crooked parts of the others; just as the latch which is fastened to a door enters into the cavity of the catch fixed to the door-post, and there hooking itself, fastens the door!'
Beneath, or under the common feathers or genera plumage, the skin in birds is immediately covered with a much finer or softer feathery substance, called down. The throat, after passing down to a certain distance, dilates itself into a large membranaceous bag, answering to the stomach in quadrupeds: it is called the crop, and its great use is to soften the food taken into it, in order to prepare it for passing into another strong receptacle, called the gizzard. This, which may be considered as a more powerful stomach, consists of two very strong muscles, lined and covered with a strong tendinous coat, and furrowed on the inside *. In this receptacle the food is completely ground and reduced to a pulp. The lungs of birds differ from those of quadrupeds in not being loose or free in the breast, but fixed to the bones all the way down-they consist of a pair of large spongy bodies,
In the birds of prey or accipitres this is wanting, the stomach being allied to that of quadrupeds.