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النشر الإلكتروني

TENTH WEEK-MONDAY.

QUADRUPEDS. THEIR CHARACTERISTICS.

THE division of lower animals, which, in this, and the papers immediately following, is to engage the reader's attention, is generally placed by naturalists highest in the scale of importance. The frame-work of the various species of quadrupeds, though this differs widely in different classes, makes the nearest approach to the perfection of the human body, and, in many of them, there are points in which that perfection is rivalled, and even exceeded.

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It is not difficult, indeed, to trace, through every class of this extensive order, a similarity, more or less striking, to man; and-while in the limbs are stronger, in another, better adapted for agility, and in a third, for swiftness-to point out, in every species, the bones, muscles, and organs, which correspond to those of the human family. The ape, in all its varieties, presents, even to the eye of child, a ludicrous caricature of the human form and features. But even in the dog, when at his master's command he erects himself upon his hinder legs, it is at once observed that there exists a striking resemblance in his general structure to his nobler fellow-creature. If we examine the parts of his body, with minuteness, we shall find, that the forelegs, which require no great stretch of fancy to convert them into arms, are formed like our own, of several bones closely jointed together at their extremities, and each clothed with muscles adapted to its own purposes, capable of bending out or in, though less perfectly, still in a similar manner, and only differing in this, that while the hand and arm of man are fitted to enable him to perform the functions of a rational being, the foreleg and paw of the dog are calculated for the humbler services of tearing his prey, and aiding his locomotion. If we turn our attention to his posterior extremities, we shall find the haunch, the thigh, the shank, the heel, and the

foot of man, distinctly represented in those of the brute, though suited to the structure of the rest of the body to which they belong.

This resemblance, though it is visible even in the birds and fishes, is, in these classes, comparatively faint and imperfect; and the nearer approach to perfection, on the part of quadrupeds, which this similitude to the human family seems to indicate, is confirmed by other observations. It is true, that birds possessing the advantage of wings, are more rapid in their journeys, and more discursive in their habits. They can leave the swiftest quadruped far behind, and need no ship to waft them beyond the sea; but their bodies are necessarily lighter, and their limbs less muscular, while the brain is smaller, and they are in general much inferior in sagacity. The eagle, the noblest of the birds, will not abide a comparison with the lion or the elephant.

In casting our eyes over the various species of quadrupeds, we see them placed in all latitudes, and intended. for every conceivable mode of existence. One, subsists on roots; another, on leaves and herbage; a third, on grain; and a fourth, by preying on its weaker neighbors; --and, as we might have expected, the structure and organs of each are beautifully adapted to the situations they occupy, and the mode of life they are intended to pursue. The more narrowly we inspect the faculties of these creatures, with reference to their circumstances, the more clearly shall we perceive the truth of this assertion.

Compare, for example, if it can be done without a smile, the structure of the mole, with that of the cat,the former, dwelling in a subterranean apartment, habitually forcing its way through earth, and stones, and gravel; -the latter, subsisting on birds and mice, which it seizes, by means of its teeth and claws, with an agility the most surprising. The mole, to facilitate the means of its existence, possesses a round body, clothed in a smooth coat of hair, soft as velvet, and so close, that the soil cannot penetrate it. Its snout is hard and cartilaginous, like that of the hog. Its anterior extremities consist chiefly of feet,

resembling the human hand, fixed to the sides, without the intervention of legs, and admirably suited to the purpose of removing the earth as it pushes its way. Its eyes are made so small, as hardly to be perceptible, in order that it may not be incommoded by the dust or the sand through which it passes; while the ears, which are peculiarly sensitive, are securely defended from every ordinary annoyance. The first appearance of the mole, at once proclaims its entire unfitness for existing on the surface of the soil, and demonstrates that the Creator intended it to burrow under ground. The cat, on the other hand, gives direct and unquestionable proof of its superior destiny. The eye, active and suspicious, turns with rapidity from one point to another, in search of a victim, or in preparation for escape. The ear, pricked up as in the act of listening, gives instant notice of all that occurs immediately around it, and keeps the animal in readiness to spring upon its prey, or to fly from its pursuers, as circumstances may direct. The limbs, both posterior and anterior, are admirably suited to its natural disposition, being formed more for agility and sudden impulses, than for sustaining lengthened and persevering exertion. The hinder legs, composed of the usual number of bones and joints, every division of which is long in proportion, much inclined, and moved by muscles of great activity, afford all the advantage of a lengthened and rapid spring, without imposing the awkwardness of limbs stretching to an immoderate length from the body. The forelegs, clothed with flesh, which is more tendinous than muscular, and armed with claws of great sharpness and power, give the little animal a manifest superiority in striking its victim, and defending itself against oppression.

The difference in structure, which is so easily perceived between the mole and the cat, is not less remarkable, though it may be less striking, between the latter and its neighbors of the canine race. The cat is formed for very rapid, but not for long-sustained, movements. It leaps upon its prey. It climbs the nearest tree when flying from its enemy, or it skips about in graceful gyrations, when indulging in a mirthful mood; but its motions

are all sudden, and soon over; and we have seen how its structure answers to its habits. The dog, on the other hand, depends mainly upon his perseverance. Having once perceived the scent of his prey, he seeks to overtake it, more by the constancy and ardor of a sustained pursuit, than by extreme speed of foot. Accordingly, his limbs are formed rather for continued running, than for making a sudden spring. The hinder leg is less bent, because its parts are shorter in proportion to its height. The paws and forelegs are not so formidably armed; nor does he require that they should be so, for his prey is generally exhausted by its efforts to escape, before it is secured. His eye is less keen, but his sense of smell, on which he chiefly relies, is more acute. The hare and

the rabbit escape from him by superior swiftness, and, when taken, it is because their powers of endurance, or their steadiness and perseverance, are inferior to his. Their structure is not less adapted to their necessities than his, and the struggle between the constancy of the one, and the speed of the other, is not more interesting to the sportsman, than instructive to others. There is no department of this wide field, in which there do not exist proofs, as beautiful as they are ample, of the adaptation. of the animal creation to the posts appointed for them, respectively, in the economy of the world.

G. J. C. D.

TENTH WEEK-TUESDAY.

QUADRUPEDS.-THEIR BODILY ORGANS.

In this highest order of the inferior animal creation, the bodily organs are more fully developed than in the orders below them. This paper shall be devoted to a brief consideration of one of these organs, as modified in different species, so as to answer the peculiar ends to which the animals are respectively destined. With regard to birds, I have already noticed such variations in the different forms of their bills, and I shall therefore

begin by examining the corresponding organ in quadrupeds.

The mouth, in this order, is formed on a different principle from that of birds. It is not intended to cut the air like that member in the winged tribes, nor, like it, to act as a hand, for the capture of prey; and therefore the peculiar conformation, which constitutes a bill, was not required. There were other specific ends, which the habits and functions of beasts required, in reference to their food; and the adaptations by which these ends have been effected, form of themselves a delightful and improving study. If we regard the teeth, the mechanical contrivances are so ingenious, and the variations so admirably adapted to the different kinds of food, and the habits and powers of each animal, that in these, alone, we might find a demonstration of a wise and benevolent Contriver. So true is this, that not only from the form and arrangement of the teeth in the jaw, but even from the construction of a single tooth, a skilful comparative anatomist can with certainty assign the food and mode of life of the animal, and various other particulars of its physiological character. In ruminating animals, for example, there is one kind of teeth; in beasts of prey, another in gnawers, a third; in animals who live on both flesh and vegetables, a fourth. These varieties are constantly found combined with a difference of function. But not only so, every peculiarity of food and habit is consulted; and there are, under each of these general heads, numerous subdivisions, the object of which, can, in most instances, be distinctly traced.

If, from the teeth, we pass to the mouth itself, we discover the clearest evidence of premeditated intention. There is system within system, and variety within variety, all bearing a studied reference to the nature and instincts of the animal. Compare, for example, the mouth of the cow or the horse, with that of the wolf or fox; you see, at once, that the breadth in front of the one was constructed for grazing, and the narrowness of the other, and its length of jaw, was intended to afford a powerful forceps for the detention or killing of its living prey. In

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