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set with parallel or concentric rows of short, strong, sharp-pointed prickles. These prickles, though called teeth, are not for the purpose of mastication, like the teeth of quadrupeds: nor yet, as in fish, for the seizing and retaining of their prey, but for a quite different use. They form a filter. The duck, by means of them, discusses the mud, examining with great care the puddle. They break every mixture, which is likely to contain her food. If we had seen no other than the mouths of quadrupeds, we should have thought no other could have been formed. Little could we have supposed, that all the purposes of a mouth furnished with lips, and armed with teeth, could be answered by an instrument which had none of these-could be supplied, and that with many additional advantages, by the hardness, and sharpness, and figure of the bills of birds. Every thing about the animal mouth is mechanical. The teeth of fish have their points turned backward, like the teeth of a wool or cotton card. The teeth of lobsters work one against another, like the sides of a pair of shears. In many insects the mouth is converted into a pump or sucker, fitted at the end sometimes with a wimble, sometimes with a forceps; by which double provision, viz. of the tube and the penetrating form of the point, the insect first bores through the integument of its prey, and then extracts the juices. And, what is most extraordinary of all, one sort of mouth, as the occasion requires, shall be changed into another sort. The caterpillar could not live without teeth; in several species, the butterfly formed from it could not use them. The old teeth, therefore, are cast off with the exuviæ of the grub; a new and totally different apparatus assumes their place in the fly. Amid these novelties of form, we sometimes forget that it is, all the while, the animal's mouth; that, whether it be lips, or teeth, or bill, or beak, or shears, or pump, it is the same part diversified; and it is also remarkable that, under all the varieties of configuration with which we are acquainted, and which are very great, the organs of taste and smelling are situated near each other.
ON THE HUMAN TEETH AS INDICATIVE OF PROSPEC
I CAN hardly imagine to myself a more distinguishing mark, and consequently a more certain proof, of design, than preparation ; that is, the providing of things beforehand, which are not to be used until a considerable time afterwards: for this implies a contemplation of the future, which belongs only to intelligence. Of these prospective contrivances the bodies of animals furnish various examples. The human teeth afford an instance, not only of prospective contrivance, but of the completion of the contrivance being designedly suspended. They are formed within the gums, and there they stop; the fact being, that their farther advance to maturity would not only be useless to the new-born animal, but extremely in its way; as it is evident that the act of sucking, by which it is for some time to be nourished, will be performed with more ease, both to the nurse and to the infant, whilst the inside of the mouth and edges of the gums are smooth and soft, than if set with hard pointed bones. By the time they are wanted the teeth are ready. They have been lodged within the gums for some months past, but detained, as it were, in their socket, so long as their further protrusion would interfere with the office, to which the mouth is destined. Nature, namely that intelligence which was employed in creation, looked beyond the first year of the infant's life; yet, while she was providing for functions, which were after that term to become necessary, was careful not to incommode those which preceded them. What renders it more probable, that this is the effect of design, is, that the teeth are imperfect, whilst all the other parts of the mouth are perfect. The lips are perfect; the tongue is perfect; the cheeks, the jaws, the palate, are all perfect ;-—the teeth alone are not so. This is the fact with regard to the human mouth. The fact also is, that the parts above enumerated are called into use from the beginning, whereas the teeth would be only so many obstacles and annoyances, if they were there.
When a contrary order is necessary, a contrary order prevails. In the worin of the beetle, as hatched from the
egg, the teeth are the first things, which arrive at perfection. The insect begins to gnaw as soon as it escapes from the shell, though its other parts be only gradually advancing to their maturity. What has been observed of the teeth is true of the horns of animals, and for the same reason. The horn of a calf or a lamb does not bud, or at least does not sprout to any considerable length, until theanimal becapable of browsing upon its pasture; because such a substance, upon the forehead of the young animal, would very much incommode the dam in the office of giving suck. But, in the case of the teeth-of the human teeth at least the prospective contrivance looks still further. A succession of crops is provided, and provided from the beginning; a second tier being originally formed beneath the first, which do not come into use till several years afterwards. And this double or suppletory provision meets a difficulty in the mechanism of the mouth, which would have appeared almost insurmountable. The expansion of the jaw (the consequence of the proportional growth of the animal and of its skull), necessarily separates the teeth of the first set, however compactly disposed, to a distance from one another, which would be
inconvenient. In due time, therefore, that is, when the jaw has obtained a great part of its dimensions, a new set of teeth springs up, loosening and pushing out the old ones before them, more exactly fitted to the space which they are to occupy, and rising also in such close ranks, as to allow for any extension of line, which the subsequent enlargement of the head may occasion.
ON THE HAPPINESS OF ANIMAL LIFE.
It is a happy world after all. The air, the earth, the water, teem with delighted existence. In a spring noon or a summer evening, on whichever side I turn my eyes, myriads of happy beings crowd upon my view. “ The insect youth are on the wing. Swarms of newborn flies are trying their pinions in the air. Their sportive motions, their wanton mazes, their gratuitous activity, their continual change of place without use or purpose, testify their joy, and the exultation which they feel in their lately-discovered faculties. A bee, amongst the flowers in spring, is one of the most cheerful objects that can be looked upon. Its life appears to be all enjoyment; so busy and so pleased : yet it is only a specimen of insect life, with which, by reason of the animal being half domesticated, we are better acquainted, than with that of others. The whole winged insect tribe, it is probable, are equally intent upon their proper employments, and, under every variety of constitution, gratified, and perhaps equally gratified, by the offices, which the Author of their nature has assigned to them. But the atmosphere is not the only scene of enjoyment for the insect race.
Plants are covered with aphides, greedily sucking their juices, and constantly, as it should seem, in the act of sucking. It cannot be doubted but that this is a state of gratification. What else should fix them so close to the operation and so long ? Other species are running about with an alacrity in their motions, which carries with it every mark of pleasure. Large patches of ground are sometimes half covered with these brisk and sprightly creatures. If we look to what the waters produce, shoals of the fry of fish frequent the margins of rivers, of lakes, and of the sea itself. They are so happy, that they know not what to do with themselves. Their attitudes, their vivacity, their leaps out of the water, their frolics in it, which I have noticed a thousand times with equal attention and amusement, all conduce to show their excess of spirits, and are simply the effects of that excess. Walking by the seaside in a calm evening, upon a sandy shore, and with an ebbing tide, I have frequently remarked the appearance of a dark cloud, or rather very thick mist, hanging over the edge of the water, to the height perhaps of half a yard, and of the breadth of two or three yards, stretching along the coast as far as the eye could reach, and always retiring with the water. When this cloud came to be examined, it proved to be nothing else than so much space
filled with young shrimps, in the act of bounding into the air from the shallow margin of the water, or from the wet sand. If any motion of a mute animal could express delight, it was this: if they had meant to make signs of their happiness, they could not have done it more intelligibly. Suppose, then, what I have no doubt of, each individual of this number to be in a state of positive enjoyment, what a sum collectively of gratification and pleasure have we here before our view “The young of all animals appear to me to receive pleasure simply from the exercise of their limbs and bodily faculties, without reference to any end to be attained, or any use to be answered, by the exertions. A child, without knowing any thing of the use of language, is in a high degree delighted with being able to speak. Its incessant repetition of a few articulate sounds, or perhaps of the single word which it has learned to pronounce, proves the point clearly. Nor is it less pleased with its first successful endeavours to walk, or rather to run (which precedes walking), although entirely ignorant of the importance of the attainment to its future life, and even without applying it to any present purpose. A child is delighted with speaking, without having any thing to say, and with walking, without knowing where to go. And, prior to both these, I am disposed to believe that the waking hours of infancy are agreeably taken up with the exercise of vision, or perhaps more properly speaking, with learning to see.-—But it is not for youth alone, that the great Parent of creation hath provided. Happiness is found with the purring cat, no less than with the playful kitten; in the arm-chair of dozing age, as well as in either the sprightliness of the dance, or the animation of the chase. To novelty, to acuteness of sensation, to hope, to ardour of pursuit, succeeds, what is, in no inconsiderable degree, an equivalent for them all, “ perception of ease.” Herein is the exact difference between the young and the old. The young are not happy but when enjoying pleasure. The old are happy when free from pain. And this constitution suits with the degrees of animal power, which they respectively possess. The vigour of youth was to be stimulated to action by impatience of rest; whilst to the imbecility