found, on the edge of a lake or pond. In selecting the exact spot where they may form their houses, they appear to be guided by two considerations, viz-a sufficient depth of water, to prevent its being completely frozen; and the exist ence of a current, by means of which they can readily convey wood and bark to their habitations. To prevent the water from being drained off, when the frost has stopped the current towards its source, the beavers construct a dam across the stream; and, in this work, they certainly display wonderful sagacity, skill, and perseverance. The dam is constructed of drift-wood, branches of willows, birch, poplar, stones, and mud, brought by the beavers in their mouths, or between their paws, and not, as many have asserted, on their tails. If the current be slow, the dam runs straight across; but if the stream be rapid, the dam is formed with a regular curve, having the convexity towards the current, so as effectually to resist the force of the water and ice, that rush down during the storms of winter, or the thaws that take place in spring. These dams are several feet in thickness, and of such strength, when completely formed, that a man can walk along them with perfect safety.

'Having completed their dam, they proceed to construct their cabins. These are partly excavations in the ground, though their roofs form a sort of vaulted dome that rises a little above the surface. The houses have seldom more than one apartment, and never more than one floor, which is raised in the middle, to allow of the inhabitants eating and sleeping in a dry situation. The principal entrance and outlet to these houses, is next the water, on the very edge of which they are constructed; and the opening always slopes towards the water, till it terminates so far below its surface, as to pre serve a free communication in the most severe frosts. There appears to be another, though smaller, opening next the land. The houses are of various sizes, in proportion to the number of inhabitants, which seldom exceeds ten or twelve, though sometimes double that number has been found in the same dwelling. Many of these houses stand together along the

margin of the water, forming a village of from ten to thirty

tenements.

( During the latter end of summer, the beavers cut down their wood and collect their roots. The latter are kept in the water, whence they fetch them as occasion may require. In eating, they sit on their rump like a squirrel, with their tail doubled in between their hind legs, and holding their food between their paws. When disturbed, they utter a peculiar cry, and plunge into the water, flapping the ground and the water with their tail.'

The faculty of storing is also to be found, as we have previously stated, among insects, of which the example of the honey-bee is the most striking. The habits of this wonderful insect, the large and orderly community in which it lives, yielding undeviating fealty to a female sovereign; the mathematical precision with which it builds its cell; its unwearying industry; its wise foresight; its colonizing propensity,have already been described in speaking of the hybernating instincts of the insect creation. In studying its operations, as well as that of the beaver, and indeed of the other storing animals, we seem to get still deeper insight into the nature of that mysterious faculty which, resembling reason in so many particulars, yet differs from it in this, that its impulses are uniform and unchangeable, belonging nearly in equal perfection in all ages, and under all circumstances, to every individual of the species; scarcely capable of improvement by education, but regulated by propensities directed by a wisdom of which the species is not conscious, to the attainment of a future object, which they have not forethought to contemplate.* What is this but the impress of the finger of God?

* Mr. Broderip gives a curious and interesting account of the habits of a tame beaver, brought to this country in 1825, which seems to illustrate the distinctive difference subsisting between reason and instinct, even where they appear to make the nearest approach. This little creature was still very young when let out of his cage, but immediately showed his building instinct. He began by selecting the longest materials within

TENTH WEEK-WEDNESDAY.

HYBERNATION.-TORPIDITY OF ANIMALS.

AMONG the contrivances by which the Author of Nature enables the lower animals to sustain the privations of winter, that by which they are endowed with the faculty of becom ing insensible to external objects, and of approaching a state of temporary death, is very worthy of attention. The ordinary phenomena of sleep have long been a subject of deep curiosity to the philosophical inquirer. The torpidity of animals during the cold season, in some respects resembles this state; but there is a marked difference not only in the period

his reach, such as sticks, sweeping-brushes, &c., which he piled up in such a way that one end touched the wall, and the other projected into the room. 'As the work grew high, he supported himself upon his tail, which propped him up admirably; and he would often, after laying on one of his building materials sit up over against it, apparently to consider his work, or, as the country people say, "judge it." This pause was sometimes followed by changing the position of the material "judged," and sometimes it was left in its place. After he had piled up his materials in one part of the room (for he generally chose the same place,) he proceeded to wall up the space between the feet of a chest of drawers which stood at a little distance from it, high enough on its legs to make the bottom a roof for him, using, for this purpose, dried turf and sticks, which he laid very even, and filling up the interstices with bits of coal, hay, cloth, or any thing he could pick up. This last place he seemed to appropriate for his dwelling; the former work seemed to be intended for a dam. When he had walled up the space between the feet of a chest of drawers, he proceeded to carry in sticks, cloth, hay, cotton, and to make a nest; and, when he had done, he would sit up under the drawers, and comb himself with the nails of his hind feet.'

It is scarcely necessary to say, that there was, in the case of this tame beaver, a propensity evinced to construct, where the object of the propensity no longer existed. The Author of its being had bestowed on it this instinct, for the use of the species in its wild state; and being destitute of the reasoning power which would have taught it the needlessness of the trouble it was taking, it still continued not only to build its house, and line its nest, where it was already sheltered and comfortable, but to construct a dam where there was no water.

of insensibility, and in the wise intentions of Providence which it fulfils, but also in the nature of this provision, as it affects the bodily frame, as well as in other particulars.

The subject of torpidity has given rise to several ingenious experiments, by which some curious facts have been elicited. It is not our object to record these, but merely to give a succinct view of their results, in so far as they throw light on the operations of that Divine Being, from whose wisdom and goodness they derive their origin.

The classes of animals, among whom this kind of hybernating principle is found, are very various, viz. quadrupeds, reptiles, insects, perhaps fishes, and, according to some, even birds. Among quadrupeds, the species which are known to become torpid, belong exclusively to the digitated order. A few of these species are of the class primates, such as the bat; and of the class fere, such as the hedgehog; but the most numerous instances occur among the glires, of which the dormouse and the marmot are familiar examples.

Attempts have been made, but without much success, to ascertain the causes on which torpidity depends. It is not extreme cold, as many have maintained, for some animals collect in deep caves, where the temperature is never low, or congregate and burrow in the earth, where the heat of their bodies preserves a temperature not much inferior to that of the average state of the external atmosphere; and others become lethargic even in warm climates. It is not the position which the body assumes, when about to become torpid, though this has also been alleged; for the different species seem to assume no other position than that to which they are accustomed in ordinary rest. It is not, so far as has been ascertained, any distinct and uniform state of the anatomical conformation, for anatomists have, in vain, attempted to establish any peculiarity in the bodily structure of such animals, which can account for the phenomenon. It is not, in fine, an immediate destitution of food, for a remarkable fact connected with this state is, that when animals become torpid, they are generally speaking, unusually plump and fat. Some of these

circumstances, indeed, commonly occur at the period when these animals fall into the dormant state, and seem, in a certain degree, to influence the result. Thus, the exact time of the change may be hastened or retarded, by the temperature of the atmosphere, or the plenty or scarcity of food; but there seems to be no reason to conclude, that these circumstances, considered merely as physical causes, are sufficient to account for the phenomenon; and we are rather inclined to believe, that the animals themselves have some power in their own volition, of either inducing or resisting the lethargic condition. Spallanzani has seen bats in a torpid state, even during summer. A migratory hamster (cricetus glis), was placed by Mangili in a state of confinement, in spring when it was naturally in its waking period; and, as soon as it found that it could not escape, it refused to eat, and, throwing itself on its back, became torpid, in which state it remained till the 17th July. The land testacea certainly have the power of becoming torpid, independent of the severity of the weather. If specimens of the helix hortensis, for example, be placed, even at midsummer, in a box without food, they soon attach themselves to the side of the place of their confinement, and become dormant; in which state they may be kept for several years.

Torpidity, in short, is an instinct, and exhibits many of the interesting but mysterious characteristics of this faculty. When the season of storms and scarcity is about to arrive, the animals to whom this habit belongs, carefully select a proper place of retreat, respectively corresponding to their several natures, where they may spend, in a happy oblivion, the dreary winter months. The bat,' to borrow the words of the article Hybernation,' in the Edinburgh Encyclopædia, ' retires to the roof of gloomy caves, or to the old chimneys of uninhabited castles; the hedgehog wraps itself up in those leaves of which it composes its nest, and remains at the bottom of the hedge, or under covert of the furze which screened it during summer, from the scorching sun or the passing storm; the marmot and the hamster retire to their subterra

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