Dr. Mead supposes this rattle may serve to bring birds, &c., within the reach of the snakes, from the effect its sound produces. Major Gardner, who had lived long in East Florida, affirms, that the young Indians of that country, were accustomed to imitate the noise of the rattle-snake, for the purpose of taking squirrels, &c.

Blumenbach says, 66 we are assured, by credible eyewitnesses, that squirrels, small birds, &c. fall from the trees on which they stand, into the throat of the rattlesnake below; the circumstance is not, however, by any means confined to this genus, as it has been remarked in many other serpents of both the Old and the New World. Rattle-snakes are eaten by hogs and birds of prey. They may also be tamed, and rendered docile."

Why is the rattle-snake inaudible in the wet season? Because, as the cups of the rattle consist merely of dried matter, which, in the dry season, is brought into a condition to make a noise when the animal moves, so, in like manner, the rattle, in the wet season, is soft and mute.

THE SEA-SERPENT.

Why is the existence of the American sea-serpent no longer credited?

Because of the following exposure of its fraud, as related by Professor Silliman.

The first sea-serpent was a steam-boat, which, being established at Boston to coast along the shore, and from its powers and capabilities competent to injure the business of small boats, was described as a sea-serpent that had been seen off Nahant and Gloucester, and had probably come there to consume all the small fish in the place. This was received by many as a serious account, and believed accordingly.-Another sea-serpent history arose from the circumstance, that a small sloop, called the Sea-serpent, having been passed by

another vessel, the captain of the latter, when asked, upon his arrival at home, for news, said he had seen a sea-serpent, and then described its bunches on the back, the action of its tail, and other parts; all of which being understood literally, actually appeared in print, as evidence for the existence of the animal.

Then a piece of the skin of the bony scaled pike was taken for part of a sea-serpent's hide. And from such occurrences as these, perhaps, mingled with careless observation of the motions and appearances of porpuses, basking sharks, and balænopterous whales, appear to have originated every thing that has been said about American sea-serpents.

Dr. Fleming thinks it "probable, that many of those stories which have been propagated, regarding vast seasnakes, have originated in the appearance of some of the larger serpents at sea, where they have been driven by accident. Some of the Asiatic species reside almost constantly in the water, either fresh or salt."

In 1827, Dr. Harwood presented to the Royal Society an account of a new serpentiform sea animal, which he named the ophiognathus. The specimen is 4 feet 6 inches in length, and the jaws open wider than those of any other animal that the Doctor is acquainted with; not excepting even the rattle-snake. Its entire form indicates that it must possess great swiftness of motion in the waters.

FISHES.

GENERAL ECONOMY.

Why does swimming resemble flying?

Because the organs which are employed for both purposes, resemble the oars of a boat in their mode of action; and, in general, possess a considerable extent of surface and freedom of motion. The former condition enables them to strike the surrounding fluid with an oar of sufficient breadth, to give progressive motion to

the body; and the latter permits the same organ to be brought back to its former position for giving a second stroke, but in a different direction, and without offering so great a resistance. The centre of gravity is so placed, that the body, when in action, shall rest on the oars or swimmers, or be brought by certain means to be of the same specific gravity with the water.

Why do fish swim?

Because they have fins, which balance and keep them level; and tails, which act against the water, and direct them like rudders.

The form of the body in fishes, is infinitely more varied than in reptiles or serpents. In most, however the body has a vertical direction, i. e. flattened at both sides; in some, on the contrary, as the rays, it is hori zontal, and extended laterally; in others, as the eel, &c., it is more rounded; in some prismatic, or quadrangular. In all, the head and trunk are connected immediately, without being separated by a neck.-Blumenbach.

Why are the fisheries of Britain so important a portion of her resources?

Because her limited soil, contrasted with extensive sea-coasts, and numerous vers and lakes, intimate to her population, the expediency of obtaining a large portion of their sustenance from the waters. These are known to teem with life, and to furnish a supply of agreeable and nourishing food, which may be pronounced inexhaustible.

With

Savage nations, as the Kamschatkadales, Brazilians, &c. possess the art of preparing fish in a great variety of ways, even as a kind of flour, bread, &c. many, as the Islanders of the Pacific Ocean, fishing forms a principal occupation, and a serious kind of study with reference to the ingenious methods and instruments which they have invented. To a great part of the cultivated world, the taking of the herring, cod,

tunny, &c. is of still greater value. The oil of the shark, cod, and herring, is used for burning in lamps, &c. The inhabitants of the eastern coast of the middle of Asia, clothe themselves with the tanned skin of the salmon. Many parts of other fish are employed for the purposes of art, as the scales of the bleak, for making false pearls. Shagreen is made from the skins of sharks and rays.

Why do fishes die almost immediately in the air? Because asphyxia (or suspension of pulsation) is occasioned by the sinking of the branchiæ, or gills, no longer supported by the interposition of water between their laninæ (or layers); and this idea has been confirmed in prolonging the life of fishes, by artificially keeping the lamina in the state of separation which the water produces. On the other hand, by compressing the branchiæ under water, similarly to their condition in the air, death occurred as quickly as in the latter fluid.

Water may act on the respiration of fishes chemically, physically, or mechanically. The latter influence has, however, been but imperfectly attended to. In 1830, M. Fleurens, with the view that water exercises only a mechanical action on their respiration, put several fish into wine. They did not live as in water, but their death was much longer delayed than in air. He explained this action of the wine, by remarking that this liquid contains much less air than water.

Why do fishes, when dead, float on the surface of the zvater, with the belly uppermost?

Because the body being no longer balanced by the fins of the belly, the broad muscu ar back preponderates by its own gravity, and turns the belly uppermost, as lighter, from its being a cavity, and because it contains the swimming bladders, which continue to render it buoyant.-White's Natural History of Selborne.

Why have not fishes any voice?
Because they have not lungs.

Although fishes possess no voice by which they can communicate their sensations to others, some species utter sounds when raised above the water, by expelling the air through the gill-opening when the flap is nearly closed: while others, even under water, as the salmon, utter certain sounds while depositing their spawn; but for what purpose these sounds are uttered, or by what organs they are produced, we are still ignorant. -Fleming.

A writer in the Magazine of Natural History tells us, that some tench which he caught in ponds, made a croaking like a frog for full half an hour, whilst in the basket at his shoulder.

Why are fishes said to have "true" fins and gills? Because these organs may be distinguished from others to a certain degree analogous in young frogs, &c. The gills are filled with innumerable very delicate vessels, and are mostly divided on each side into four layers, which somewhat resemble the beard of a quill, and which are attached at their basis to a corresponding number of little bones.-Blumenbach.

Why are these fins essential to swimming?

Because they consist of jointed rays, covered by the common integuments: these rays serve to support the fishes, and approach or separate like the sticks of a fan, and move upon some more solid body as a fulcrum. Thus, in sharks, the rays of the fins behind the gill are connected by a cartilage to the spine.

The motions of fish are indeed performed by means of their fins. The caudal, or tail fin, is the principal organ of progressive motion; by means of its various flexures and extensions, it strikes the water in different directions, but all having a tendency to push the fish forward; the action resembling, in its manner and effects, the well known operation of the sailor termed