There is another- very curious circumstance attending the reviviscence of quadrupeds from their torpid state, which deserves to be mentioned. As soon as they have re covered from their slumbers, they prepare for the great business of propagation. This is a proof, that torpidity, instead of exhausting the energies of nature, increases their vigour. It also indicates a peculiarity of constitution, to the preservation and health of which a brumal lethargy is indispcnsibly requisite.
It appears to be the general practice of modern natu ralists, to treat with ridicule those accounts which have been left us of Binns having been found in a torpid state during winter. These accounts, it is true; have in many instances been accompanied with the most absurd stories, and have compelled us to pity the credulity of our ances tors, and withhold our assent to the truth of many of their statements. But are there no authenticated instances of torpidity among birds ? In treating of the torpidity of quadrupeds, we were un able to detect the cause of torpidity, as existing in any cir cumstances connected with structure or with circulation, respiration, or animal temperature ; nor in the places which they frequent, nor the food by which they are supported. Hence we cannot expect much help from a knowledge of the anatomy, physiology, or' even habits of birds, in the re solution of the present question. It has indeed been said, that as birds can readily transport themselves from one country to another, and in this manner shun the extremes of temperature, and reach a supply of food, the power of becoming torpid would be useless if bestowed on them, although highly beneficial to quadrupeds, that ate impatient of cold, and cannot migrate to places where there is a sup ply of food. This mode of reasoning, however, is faulty, since we employ our pretended knowledge of final causes, to ascertain the limits of the operations of nature, and can not be tolerated in a science depending entirely on fact and obseHations. Besides, there are many animals, as we have seen in the class illainnzalia, which become torpid, and a similar state obtains among the reptiles. As birds, in the scale of being, hold a middle rank between these two classes, being superior to the reptiles, and inferior to the mamma lia, we have some reason to expect instances of torpidity to occur among the feathered tribes.
These remarks have for their object, to prepare the mind for discussing the merits of the question, by the removal of presumptions and prejudices, as we fear preconceived opinions have already exercised too much influence.
In treating of the migrations of the swallow, we endea voured to point out their winter residence, and even traced them into Africa. We are not however prepared to assert,
that in every season all these birds leave this country. If they remain, in what condition are they found ? Many naturalists, such as Klein, ',litmus, and others, have believed in the submersion of swallows during winter in lakes and rivers. They have supposed, that they de scend to the bottom, and continue there until the following pring. Many of the proofs produced in support of this opinion may be found by consulting the article BIRDS. On this subject we willingly quote the judicious note in the introduction to Bewick's Land Birds. " There are various instances on record, which bear the strongest marks of veracity, of swallows having been taken out of water, and of their having been so far recovered by warmth as to exhibit evident signs of life, so as evil to fly about for a short space of time. But, whilst we admit the fact, we are not inclined to allow the conclusion generally drawn from it, viz. that swallows, at the time of their disappearance, fre quently immerse themselves in seas, lakes, and rivers, and, at the proper season, emerge and reassume the ordinary Functions of life and animation ; for it should be observed, that in those instances which have been the best authenti cated, it appear's, that the swallows so taken up were ge nerally found entangled amongst reeds and rushes, by the sides, or in the shallowest parts of the lakes or rivers where they happened to be discovered, and that having been brought to life so far as to fly about, they all of them died in a few hours after. From the facts thus stated we would infer, that, at the time of the disappearance of swal lows, the reedy grounds by the sides of rivers and stand ing waters are generally dry, and that these birds, especially the later hatchings, which frequent such places for the sake of food, retire to them at the proper season, and lodge themselves among the roots, or in the thickest parts of the rank grass which grows there ; that during their state of torpidity they are liable to be covered with water from the rains which follow, and are sometimes washed into the deeper parts of the lake or river, where they have acci dentally been taken up; and that probably the transient signs of life which they have discovered on such occasions, have given rise to a variety of vague and improbable ac counts of their immersion."—We may add, that whoever denies that swallows have been found in such situations, let his reasonings be what they may, tramples under his feet the laws of evidence, and cherishes a scepticism as un philosophical as the most unthinking credulity.