Amphibious Animals are so called, on account of their living partly on land, and partly in water. We cannot, consistently with our plan, enter into a disquisition re-ting their nature and functions; and shall therefore. content ourselves with observing, that in their structure, they are principally distinguished from land-animals, by having red cold blood.
of lungs, either tills or •ally observed in snakes, fish, which chiefly inhabit the water. Sometimes however, drey have the open between the right and left heart; and, in many; the arterial canal is also tree. '. is a distinguishing character of the phocae, or such animals as enjoy their chief functions on land, for instance, otters, beavers, frogs, crocodiles, some kind of rats, birds, etc. While these remain ter, where they may. continue for several hours, their respiration is interrupted; and the blood, not-finding a free passage through the pulmonary artery, rushes through the hole from the right to the left auricle, and partly through the arterial canal; having but a short course to the aorta, the largest of all the blood vessels, and thence circulating- to every part of the on rising to come blood makes i lungs, as soon as the animal begins to respire.
As in all hind animals a large on of the mass of blood conti, nually' dates through the 1ungs; would be stopped, if the free access of air were excluded ; so we find in fish a great number of blood.- through the which must be perpetually wet, lest the blood should, in like manner, be checked, and consein its progress Hence, when the latter are removed from their natural element, the branchinee very soon grow crisp and dry, the vessels become corrugated r.nd the blood finds no outlet: likewise, when land-animals are immersed under water, or in any other manner deprived of respiration, the circulation ceases, and the animal inevitably dies.
Inquisitive physiologists have advanced, that wan may, by art, be rendered amphibious and enabled to live under water, as well as the beaver, or turtle ; because the tus in utero lives is continued by of the oval hole : if, there. . this important opening could the birth of the useful remain. This we do not hesitate to declare, that country, such atmeans for the advan-from a succcessful the theory, would calculable. In its support, and an instance of the v. underfill power we ; ove respiration, it may be urged, that expert divers feel no inconvenience from remaining for several minutes under water, at a considerable depth; that individuals affected with asthma (among whom the writer of this article is a living evidence) have by by mere force of habit obtained effectual and permanent relief in that distressing complaint, by accustoming them, from the commencement of it, to respire principally through the nostrils, whether in a waking or sleeping state; and lastly, that none of the interior organs possess a flexibility and power of expansion (unattended with loco-motion) equal to those of respiration.
After this short digression, we shall proceed to state the meanns by which that desirable faculty of respiring under water, may- be acquired by the human subject.
It should previously be remarked, that the lungs of the embryo are compressed during its confine: ment, so that the pulmonary bloodvessels are impervious, and consequently the circulation must place through the oval hole, and the arterial canal before - mention hence the amphibious animal and the foetus in utero are so far an gous in their nature; and thou closes at an early-period of infancy, yet there are by anato-in occasionally found not quite closed in human subjects, who have died at an vanced age. There is, however, one material difference between. them: the foetus never haying respired, is sufficiently nourished by the maternal blood circulating through its whole body, which progressively grows, till its birth, without feeling the want of respiration during the whole period of pregnancy ; on the contrary, terraqueous animals having respired moment of' port life for any length of out it: because both the canal above d to would be closed, or a.
them, as is the case in land animals, if they did not instinctively, soon after the birth of the cub, instruct it in the exercise of that vital function. This is effected, by frequently. Carrying it into the water—a p tice by which those kept open during life, and the creatures enabled to procure that kind of food which is designed for them by the ; providential care of Nature. Thus we may easily conceive that, in , the oval hole, by proper expedients and persevering exertions, might, without much difficulty, be preserved in an open state ; for graduallyaccustoming young children, soon after their birth, to suspend their breathi once, or oftener creasing the duration of the ex: ment with eve- attempt, so that
Mood may at length be directed to circulate through its passage, which, by several trials cautiously repeated, would no doubt remain sufficiently lubricated, and never again be closed in the generally find it in the deceased body.
That these are rational, and, we may venture to add, well founded conjectures, few will dispute; especially if it be considered that ordinary divers, without having been trained to dais practice from infancy, are capable of re-taining their breath, and continuing much longer underwater, than persons in whom that primitive organ pf respiration, having never been exercised, I) as an useful substitute for the lungs, while instances of persons who the full possession of the uncom-0 faculty of others, we
Sicilian, named the Fish Colas who possessed . it in so eminent at he lived rather the of a fish than a man in consequence of J from his youth, and by an tice. successfully acquired the habit of living in and thus e fete change of his
We shall conclude this interject with a short account of the alimentary uses, and properties, of amphibious animals.
In some Countries, especially in old France and Italy, the legs of esteemed a deli dish; but, in Britain, we regale our friends with the more delicious the. Yet these as well as 3 - m ral, and the West -c Indian guana . hi particular, c to be eaten not • ---with , but also additionn of salt, and acid : the i former, for the pur of neutralizing into a sap; st easily latter, wid) a view to counteract: their -scent tendency, in —both* in order facilitate their digestion in the human stomach