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VII. The Memoirs for the Natural History of Animals, published by the French Academy, A. D. 1687, furnish us with some curious particulars in the eye of a camelion. Instead of two eyelids, it is covered by an eyelid with a hole in it. This singular structure appears to be compensatory, and to answer to some other singularities in the shape of the animal. The neck of the camelion is inflexible. To make up for this, the eye is so prominent, as that more than half of the ball stands out of the head. By meansof which extraordinary projection, the pupil of the eye can be carried by the muscles in every direction, and is capable of being pointed towards every object. But then so unusual an exposure of the globe of the eye, requires for its lubricity and desence, a more than ordinary protection of eyelid, as well as more than ordinary supply of moisture; yet the motion of an eyelid, formed according to the common construction, would be impeded, as it should seem, by the convexity of the organ. The aperture in the lid meets this difficulty. It enables the animal to keep the principal part of the surface of the eye under cover, and to
preserve preserve it in a due state of humidity, without shutting out the light; or without performing every moment a nictitation, which, it is probable, would be more laborious to this animal than to others.
VIII. In another animal, and in another part of the animal economy, the same Me- moirs describe a most remarkable substitution. The reader will remember what we have already observed concerning the intestinal canal; that its length, so many times exceeding that of the body, promotes the extraction of the chyle from the aliment, by giving room for the lacteal vessels to act upon it through a greater space. This long intestine, whereever it occurs, is, in other animals, disposed in the abdomen from side to side in returning folds. But, in the animal now under our notice, the matter is managed otherwise. The fame intention is mechanically effectuated 5 but by a mechanism of a different kind. The animal of which I speak, is an amphibious quadruped, which our authors call the alopecias, or sea fox. The intestine is straight from one end to the other: but in this straight, and consequently short intestine, is a winding, corkscrew, spiral passage, through which, the
X. food, food, not without several circumvolutions, and in fact by a long route, is conducted to its exit. Here the shortness of the gut is compensated by the obliquity of the perforation.
IX. But the works of the Deity are known by expedients. Where we should look for absolute destitution; where we can reckon up nothing but wants; some contrivance always comes in to supply the privation. A snail, without wings, feet, or thread, climbs up the stalks of plants, by the sole aid of a viscid humour discharged from her skin. She adheres to the stems, leaves, and fruits of plants, by means of a sticking plaster. A muscle, which might seem, by its helplessness, to lie at the mercy of every wave that went over it, has the singular power of spinning strong, tendinous threads, by which she moors her shell to rocks and timbers. A cockle, on the contrary, by means of its stiff tongue, works for itself a shelter in the fand. The provisions of nature extend to cases the most desperate. A lobster has a difficulty in its constitution so great, that one could hardly conjecture before hand how nature would dispose of it. In most animals, the skin grows with their growth. If, instead of a soft skin, there be a shell, still it admits of a gradual enlargement. If the shell, as in the tortoise, consist of several pieces, the accession of substance is made at the sutures. Bivalve shells grow bigger by receiving an accretion at their edge: it is the fame with spiral shells at their mouth. The simplicity of their form admits of this. But the lobster's shell being applied to the limbs of the body, as well as to the body itself, allows not of either of the modes of growth which are observed to take place in other shells. Its hardness resists expansion ; and its complexity renders it incapable of increasing its size by addition of substance to its edge. How then was the growth of the lobster to be provided for? Was room to be made for it in the old shell, or was it to be successively fitted with new ones? If a change of mell became necessary, how was the lobster to extricate himself from his present confinement? How was he to uncase his buckler, or draw his legs out of his boots? The process, which fishermen have observed to take place, is as follows. At certain seasons, the shell of the lobster grows soft; the animal swells its body; the seams open, and the claws burst at the joints. When the shell is thus become loose upon the
x 2 - body, body, the animal makes a second effort, and by a tremulous, spasmodic motion, casts it off. In this state the liberated, but defenceless, fish, retires into holes in the rock. The released body now suddenly pushes its growth. In about eight-and-forty hours, a fresh concretion of humour upon the surface, i. e. a new shell, is formed, adapted in every part to the increased dimensions of the animal. This wonderful mutation is repeated every year.
If there be imputed defects without compenfation, I should suspect that they were desects only in appearance. Thus, the body of the oath has often been reproached for the slowness of its motions, which has been attributed to an impersection in the formation of its limbs. But it ought to be observed, that it is this slowness, which alone suspends the voracity of the animal. He fasts during his migration from one tree to another; and this fast may be necessary for the relief of his overcharged vessels, as well as to allow time for the concoction of the mass of coarse and hard food which he has taken into his stomach. The tardiness of his pace seems to have reserence to the capacity of his organs, and to his propensities with respect to food; h» e. is 6 calculated