construction shows to be its intended dwelling-place. The rabbit was intended to run, as well as to dig and burrow, the mole only to dig and burrow; let the construction of each be examined with reference to this difference of design, and the wisdom will be manifest. The mouse and rat can walk without difficulty on surfaces not horizontal, by means of the sharpness of their claws, united to their great strength, and the lightness of their bodies; for the walrus, however, whose destination was also to climb, another provision was necessary, and this was found, not in mechanics, like the other provisions, but in an abstruse philosophical principle. This amphibious animal, equally ponderous and inactive, is compelled to clamber over inclined and smooth rocks, in quitting the sea; and this object is attained by enabling it to produce a vacuum in the sole of its foot, like that by which children amuse themselves in lifting great stones, with a piece of moistened leather attached to a string. This remarkable contrivance is not confined to the walrus; it is not only found in numerous insects, as has already been mentioned, but in the gekko of India, where it is interesting to remark the different construction adopted in relation to its necessities. Each toe has transverse cavities, opening by slits below, which can be rendered vacuums by muscular action. By this means, it is enabled to run, with considerable speed, up the smooth walls of chunam, with which the houses of that country are usually covered.

Were we to examine the legs of quadrupeds, we should not be less struck with their admirable adaptations; some being formed for speed, others for climbing, others for leaping on their prey, or seizing it; and others again for strength to sustain an enormous body, such as those of the elephant; but the field which this opens up is much too extensive to be at present entered upon; and I shall conclude this branch of inquiry, by a short reference to the hair of this order of animals.

It has already been stated, how admirably the feathers

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of the winged tribes suit their peculiar functions as tenants of the air. The hair of quadrupeds is a covering of a different kind, adapted to their peculiar situation in the plan of existence. In hair, the great variations consist in quality, length, and density; while different lities, such as hair and fur, are sometimes united. general purpose is warmth; and the chief proof of intention in the variations, lies in the modifications to adapt this covering to different climates. I have already noticed this subject with reference to winter;* and I shall merely desire the reader here, to attend to the non-conducting and non-radiating properties of this covering, its annual renewals, its variations in quantity, or density, or quality, according to the variations of temperature, and its occasional power of changing colour, so as to adapt itself to that of the ground, or to some alteration of climate.

In all these particulars, and a hundred others which might be named, the structure and condition of quadrupeds, clearly exhibit such benevolent design, such a minuteness of attention to their circumstances and wants, as to furnish new and most interesting proofs of an unceasing and universal exercise of the Divine perfections in the works of creation.

TENTH WEEK-TUESDAY.

QUADRUPEDS. THE BAT.

In ascending from birds to quadrupeds, we meet with a family of animals which seems intended to form the connecting link between the two orders, thus completing the chain of animated nature, in this, as we have seen to be the case in other transitions. This family is that of the bat.

* "Winter," pp 285,289; 2d edit.

It is not one of the least remarkable proofs of the wisdom of the Creator, that each object or being in nature has been so perfectly fitted for its end, and the station it occupies, that those which, on the first view, are thought mis-shapen or disgusting, become, on closer investigation, the sources of pleasurable and instructive contemplation. Each part is found so well adapted to its use, that the changes which might appear to the superficial observer conducive to elegance or beauty, would but hinder the design, and produce confusion, where all is order and harmony. Of this the apparently ungainly form of the bat is an exemplification. Daubenton thus describes its structure:-"The elbow is found near the knee; the fore-arm is very long, and obliquely extended from above downwards, and from behind forwards, as far as the nose of the animal. The wrist is placed against the ground, and there is but one finger on the anterior extremity, which is the thumb. The knee is raised as high as the lower part of the rump, and the five toes of the hind feet are of equal length, and turned outwards. The arm is extended horizontally, from the front to the back part, and the thigh vertically, from above downwards; the arm is concealed behind the fore-arm, and the thigh behind the leg; they are, moreover, enveloped in the membranes which conceal the tail, and all the hinder parts of the body. Besides the thumb seen on the anterior extremities, there are four other very long fingers, extending from the fore-arm, enveloped in the membrane, and folded, near the elbow, by their extremity."

While on the ground, these long extremities are of little use to it, and it stands propped on the breast, appearing one of the most helpless and awkward quadrupeds in existence. To move along, many different and very fatiguing actions are required. Its pace is heavy and dragging, and it runs in a grotesque and ungraceful manner. The ears are often very large, and, together with the whole membranous surface, are quite naked;

the eyes are small, and too weak to endure the light of the sun; and the wide mouth, reaching from ear to ear, completes the uninviting picture. Were we to look no further, we might deem that the skill which lives through all creation, had been withheld from this feeble and imperfect animal. But when, gaining the aid of some slight eminence, it raises its fore-legs, unwraps from about them the numerous folds of its velvet wings, and darts away with tremulous but rapid flight, we see that it is not dependant for change of place, on the motion that has excited our pity; and, on pursuing the investigation, we find that every part of its structure has been so contrived, by a wisdom far above ours, as to make its existence easy and pleasant. Though the arms of the bat are much elongated, the bones of the fingers exceed their whole length. Over these is stretched the leather-like membrane, which constitutes the wing; it is only a prolongation of the skin, the back and belly each furnishing a layer, and yet it appears but a delicate and transparent net-work. Were the membranes, or bones which support it, compact and thick, their weight would disable the bat from using them; but, becoming thinner as they recede from the centre of motion, they are the instruments of its high and unimpeded flight. The pectoral muscles, which move the wings, are strong, and the breast-bone projects, that these may have an ample space for fixing upon. By means of this construction, the bat is enabled to fly very swiftly. It is gradually aroused from the torpor of winter, at the approach of a milder season, and, slowly recovering the power of motion in the dark recesses of its cave, at length goes forth in search of the insects which have been called into life and activity by the returning power of the sun. It readily discerns its prey, even at some distance, and darts at it, ascending at times, in the chase, to a considerable height, though, in general, it finds a more abundant supply while hovering near the ground, or skimming the surface of water. Here the softness of its wings is of essential ser

vice, as they swiftly cut the air, without making any sound to warn the insect into flight or concealment. Though in damp weather the bat can remain for days without food, and even sink again into torpor, his appetite is voracious, and he clears the air of swarms of insects, which, if not exposed to that and similar destructive agents, would multiply so fast as to encumber it, and render it unwholesome. The small eyes of the bat are less liable to injury than they would be if larger or more protuberant; and they are not made to bear the glare of day, as its season of activity is during the obscurity of twilight, when alone it can obtain food. Asif conscious of this, its exertions are, during that period, unremitted, and often continue till night has established her sable domain. Notwithstanding its faint power of vision, and even when totally deprived of it, the bat pilots himself through the air, with the greatest skill, avoiding every impediment, though no larger than a twig, and accurately seizing its minutest prey. This is imputed by some naturalists to its acute perception of sounds, and by others to the delicacy of the nerves; but Cuvier, more philosophically, refers it to the sense of touch resident in the membranous skin of the wings, affected by the reaction of the air in a near approach to any object. Here again we must admire the wisdom that launched this little being on its airy way; for, had this skin been covered by the reddish fur which clothes the rest of the body, that keen sensibility would have been destroyed, and the bat must have darted recklessly along, always in danger of being stunned or wounded by striking against objects which it could not discern, and snatching at random, and in vain, for food, till, spent

*

* Various experiments have, at different times, been tried, in order to ascertain how far, and under what circumstances, the peculiar faculty or sense, which supplies the place of sight, is called into operation; and it has been found that, though the eyes be sealed up, or even removed entirely, and the animal let loose in a room, with a thousand intricacies and objects, it will pursue its abruptly wheeling flight as usual, threading every labyrinth, avoiding every obstacle, and all this with the same ease, quickness, and precision, as would have been the case had the sight been ever so perfect.