viating the effects of cold in winter, is to be discovered in the change of colour, which takes place in the clothing of some species, both of quadrupeds and birds. It is remarkable, that the tendency of this change is from dark to pure white. Thus the ermine, which is so much prized for the snow-like whiteness of its fur in winter, is, in other seasons of the year, of a pale brown colour, inclining to red; and the Alpine hare of the Grampian range undergoes a similar change, throwing off its summer dress of tawny grey, and appearing in a coat of the colour of milk. Among the feathered tribes, we find the ptarmigan, which takes up its habitation on the summits of our most lofty Highland mountains, and the guillemot, which frequents our coasts, endowed with an analogous property. In the former, the change is complete ; in the case of the latter, its summer covering of black, is, in this climate, converted into a plumage clouded with ash-coloured spots, on a white ground; but, what distinctly marks the intention of the Creator, is, that this latter bird, when exposed, as in Greenland, to a more intense cold, throws off its spotted mantle, and appears in feathers of a beautiful and uniform white.

The object of this remarkable change in the appearance of these animals, is not merely, as some writers have supposed, to protect them from the prying eyes of their enemies, by assimilating their colour to that of the surface of the ground, though this intention is not to be overlooked; but chiefly, as I believe, to provide more effectually for their protection from the alteration in the temperature of the seasons. It might, perhaps, on a superficial view, appear, that white, which consists in the reflection of all the rays of light, was less favourable than any other colour to the heat of the body, and that, were the intention to protect the animals from cold, the process would just be reversed. It is true, indeed, that a dark surface imbibes the heat to which it is exposed in greater quantities than that which is of a light hue, and

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if this were all that was required, the objection might be held to be well founded. But it must be remembered, that the temperature of a living body depends chiefly on the power of retaining the animal heat; and it is on this principle that we are to look for the ultimate design in the change of colour to which we have alluded. It would appear, from chemical experiment, that the radiating power of bodies is inversely as their reflecting power; and, upon this principle, the white colour of animals, possessing less radiating power than any other, must be best calculated to retain the heat generated in their bodies by the vital principle. Thus, while there is less warmth absorbed from the external atmosphere than if their darker colour had remained, this disadvantage is far more than compensated by the power which their white clothing confers, of resisting the effects of the external cold in reducing the temperature. This is one of the cases which we so commonly meet with in investigations of a similar kind, where an imperfect knowledge of the laws of nature affords room for plausible objections against the arrangements of Providence, which a more profound acquaintance with these laws entirely overturns, and even converts into an argument on the opposite side. Had we only known, that a white colour rejects the influence of external heat more obstinately than all the other colours, we might well be puzzled to account for the fact, that during the winter months a change should take place, which was to render the bodies of the animals subject to it, less susceptible of atmospherical warmth, in proportion as they seemed most to require this blessing; but, when the more recent discoveries, which prove that the principle of radiation follows an opposite law, set the matter in its true light, it is impossible not to feel that peculiar satisfaction which arises from perceiving the consistency of benevolent design; and the lesson which we are thus taught goes even further, leading us, as it does, confidently to conclude, that wherever facts ap

parently contradictory of Divine wisdom or goodness are to be found, the difficulty lies, not in the nature of the thing, but in the darkness of human ignorance.

SEVENTH WEEK-SATURDAY.

HYBERNATION.-OF STORING ANIMALS.

As birds have the power, and are endowed, when necessary, with the instinct of migration, they scarcely stand in need of any other means of avoiding the inconveniences of winter; and, accordingly, we find, that except the change already mentioned, of a summer for a winter dress, which takes place in some species, and the autumnal repairing of their feathers, there is no other provision of great importance and extent made for their hybernation. But with quadrupeds, reptiles, and insects, the case is different. As they were destined to be confined to a limited locality, it was necessary to make sufficient arrangements for their accommodation within their native haunts. The warm clothing, which, as we have seen, quadrupeds acquire, is calculated to preserve them from the effects of cold; but something more is necessary. Not only is the breath of winter chilling, but its hand is niggardly of food; and there is danger of starvation, not less from the cravings of hunger than from the rigour of the weather. To this want the beneficent Creator has not been inattentive; and the means he employs to remedy the evil are not less remarkable than they are efficacious.

There are two ways in which a deficiency in the supply of the necessaries of life may be compensated for, namely, either by the accumulation of a store of provisions during the period of plenty, or by placing the body in such a state as to supersede the use of such accumulation, by rendering it insensible to the demands of hunger,

and yet preserving its vital existence. The Creator employs both of these means. This paper shall be devoted to the consideration of the former.

The class of quadrupeds, among which various species are to be found, that lay up a winter store, is exclusively. what is known to naturalists by the appellation of glires, or gnawing animals. Of this class are the mouse, the squirrel, and the beaver. Of the first species, the fieldmouse is the most remarkable for this propensity. This little animal is exceedingly active about the end of autumn in preserving fallen acorns, by burying them under ground; being thus made subservient to the double purpose of hoarding a store for future use, and of planting such part of the seed as it either forgets or does not require, in such a manner that it may germinate and spring up into a future tree,* destined to provide the means of subsistence to distant generations of the species. Such is the wonderful economy of Providence; and this, let it be remarked, in passing, is only one instance of a kind of contrivance extensively employed, which we shall afterward have occasion to notice.

We have mentioned the common squirrel as another example of the storing tribe. This agile and interesting creature takes up its residence in our woods and forests, and, during the last month of autumn, is exceedingly industrious in collecting for itself a hoard of nuts, acorns, and other kinds of food, which it carefully deposits in a storehouse, scooped out with some labour, in a wellchosen place of concealment, among the large and embowering branches of a shaggy old tree. Here it takes up its winter abode, prudently abstaining from the violation of its little magazine, as long as it can find the means of subsistence in its neighbourhood.

But of all the quadrupeds which provide for their pre

"In the time of acorns falling," says Derham, " I have, by means of the hogs, discovered that the mice had, all over the neighbouring fields, treasured up single acorns in little holes they had scratched, and in which they had carefully covered up the acorn. These the hogs would, day after day, hunt out by the smell."-Derham's Physico Theology.

servation during winter, by laying up a stock of food, there are none so wonderful as the beavers. A branch of this amphibious family was at one time to be found in Britain; and beavers are still natives of some northern countries in Europe, though their chief residence is in the wilds of America. They have long attracted the admiration of mankind by their extraordinary habits. Some of our most celebrated naturalists, indeed, fired by the exaggerated accounts of travellers, have launched out into encomiums on their wonderful faculties, which a more accurate knowledge of their operations has of late considerably modified. After every allowance, however, for the natural propensity of men to add astonishment to the wonderful, we find enough in the most sober and authentic accounts given of this quadruped, to excite our surprise.

The form of the beaver does not appear to be peculiarly well fitted for performing works of skill and labour. It is described as not exceeding three feet in length; its paws are said to be about the size of a crown piece; and its tail, though, by its breadth and flatness, answering some important purposes, seems to be limited in power as an instrument of labour, by having naturally such an inclination downwards, that it can with difficulty be brought on a line with its back. Yet this apparently weak and ill-furnished creature, is represented as supplying, by its ingenuity, the seeming defects in its. bodily form, and constructing works for the comfort and convenience of its winter residence, which, in reference to its more contracted wants, rival the skill and science of a human architect! The following notice of the manner in which these animals provide against the inclemency of the winter season, is abridged from a judicious article in the Edinburgh Encyclopedia.

"Toward autumn they quit their roving way of life, form themselves into communities, and, instructed by that admirable instinct of which we have so many examples in the history of the animal creation, begin to