Portuguese men-of-war, Guinea- | few minutes had elapsed, a violent ships, frigates, sea-bladders, &c., from their fancied resemblance, when floating on the surface, to vessels in full sail. When first taken out of the water, the Physalia excites the admiration of the spectators, by the elegant and vivid colours with which it is adorned. These tints, however, are as evanescent as they are brilliant; and soon after this animal is taken from its native element, the crest sinks; the bright crimson, green, and purple tints, lose their brilliancy; and the beauty which had previously excited so much admiration, fades; and at last totally vanishes. The upper part of the animal, when floating, is surmounted with a kind of crest or ridge, formed by a membranous bag, which, it is said, the animal has the power of inflating at pleasure; but this is disputed by a recent observer. This bag or crest is fringed round the edges, and is of a beautiful light-blue colour, with occasional streaks of a delicate seagreen, tinged with crimson. The power it possesses of benumbing, when touched, appears to reside in its tentacula, or feelers, a large bunch of which are attached to the undermost part of its body, some short and thick, others long and threadlike, and extending to several yards in length; these seem to consist of a chain of globules, filled with an extremely acrid fluid; in colour, a beautiful purple, with an admixture of crimson. Mr Bennet, in his Polynesian Wanderings, relates the effects of its sting. "I was desirous of trying its effects on myself, for the purpose of ascertaining from personal experience, the constitutional irritative effects resulting from it. On taking hold of the animal, it raised its tentacula, and stung me on the second and ring fingers: the sensa tion was similar at first to that produced by the nettle, and before a aching pain succeeded, affecting more severely the joints of the fingers; on cold water being applied, it was found rather to increase than diminish the effects. In a quarter of an hour, the fore-arm and elbow were severely affected; till at length it became almost unbearable, and gradually extended itself to the shoulder and chest, and impeded the breathing. These symptoms continued for about half an hour, when they gradually abated; but the arm was benumbed for the remainder of the day.” ON THE PERIODICAL CASTING OF THE SHELL OF THE LOBSTER. THE process by which the periodical casting and renewal of the shell of lobsters are effected, has been very satisfactorily investigated by Réaumur. The tendency in the body and in the limbs, to expand during growth, is restrained by the limited dimensions of the shell, which resists the efforts to enlarge its diameter. But this force of expansion goes on increasing, till at length it is productive of much uneasiness to the animal, which is, in consequence, prompted to make a violent effort to relieve itself; by this means it generally succeeds in bursting the shell; and then, by dint of repeated struggles, extricates its body and its limbs. The lobster first withdraws its claws, and then its feet, as if it were pulling them out of a pair of boots: the head next throws off its case, together with its antennæ; and the two eyes are disengaged from their horny pendicles. In this operation, not only the complex apparatus of the jaws, but even the horny cuticle and teeth of the stomach, are all cast off along with the shell: and, last of all, the tail is extricated. But the whole process is not ac complished without long-continued efforts. Sometimes the legs are lacerated or torn off, in the attempt to withdraw them from the shell; I and in the younger crustacea, the operation is not unfrequently fatal. Even when successfully accomplished, it leaves the animal in a most languid state: the limbs, being soft and pliant, are scarcely able to drag the body along. They are not, however, left altogether without defence. For some time before the old shell was cast off, preparations had been making for forming a new one. The membrane which lined the shell had been acquiring greater density, and had already collected a quantity of liquid materials proper for the consolidation of the new shell. These materials are mixed with a large proportion of colouring matter, of a bright scarlet hue, giving it the appearance of red blood, though it differs totally from blood in all its other properties. As soon as the shell is cast off, this membrane, by the pressure from within, is suddenly expanded, and by the rapid growth of the soft parts, soon acquires a much larger size than the former shell. Then the process of hardening the calcareous ingredient commences, and is rapidly completed; while an abundant supply of fresh matter is added, to increase the strength of the solid walls which are thus constructing for the support of the animal. Réaumur estimates that the lobster gains, during each change of its covering, an increase of onefifth of its former dimensions. When the animal has attained its full size, no operation of this kind is required, and the same shell is permanently retained. A provision appears to be made, in the interior of the animal, for the supply of the large quantity of calcareous matter required for the construction of the shell at the proper time. A magazine of carbonate of lime is collected, previous to each change of shell, in the form of two round masses, one on each side of the stomach. In the crab these balls have received the absurd name of crabs' eyes; and during the formation of the shell they disappear. 1 It is well known that when an animal of this class has been deprived of one of its claws, that part is, in a short time, replaced by a new claw, which grows from the stump of the one which had been lost. It appears from the investigations of Réaumur, that this new growth takes place more readily at particular parts of the limb, and especially at the joints; and the animal seems to be aware of the greater facility with which a renewal of the claw can be effected at these parts; for if it chances to receive an injury at the extremity of the limb, it often, by a spontaneous effort, breaks off the whole limb at its junction with the trunk, which is the point where the growth more speedily commences. The wound soon becomes covered with a delicate white membrane, which presents, at first, a convex surface: this gradually rises to a point, and is found, on examination, to conceal the rudiment of a new claw. At first this new claw enlarges but slowly, as if collecting strength for the more vigorous effort of expansion, which afterwards takes place. As it grows, the membrane is pushed forwards, becoming thinner in proportion as it is stretched, till, at length, it gives way, and the soft claw is exposed to view. The claw now enlarges rapidly, and in a few days more acquires a shell as hard as that which had preceded it. Usually, however, it does not attain the same size; a circumstance which accounts for our frequently meeting with lobsters and crabs, which have one claw much smaller than the other. In the course of the subsequent | Sir Kenelm Digby, famous for his castings, this disparity gradually conversational powers, and for his disappears. The same power of talent of romancing. restoration is found to reside in the legs, the antennæ, and the jaws.Dr ROGET's Bridgewater Treatise. THE SMOOTH BARNACLE. THE curious popular error, that the Barnacle contained the young of a species of goose, which was thence called the Barnacle Goose, has lasted for many ages, and still prevails among the uneducated, on the shores of all the European seas. One reason of the continuance of this error in several Roman Catholic countries, is the permission granted by the priest to its members, to eat this goose on fish-days, because it is considered, on account of its supposed watery origin, to partake more of the character of a fish than a fowl. To show the extent to which an erroneous belief may be carried, we may quote the following notice sent by Sir Robert Moray to the Royal Society, and printed by them in their Transactions. He says, "The pedicle seems to draw and convey the matter which serves for the growth and vegetation of the shell and the little bird within it." "In every shell that I opened, I found a perfect sea-fowl; the little bill like that of a goose, the eyes marked; the head, neck, breast, wings, tail, and feet formed; the feathers everywhere perfectly shaped, and blackish coloured; and the feet like those of other water-fowl, to my best remembrance." "Nor did I ever see any of the little birds alive, nor met with anybody that did; only some credible persons have assured me that they have seen some as big as their fist!!" A curious anecdote respecting Barnacles occurs in the Memoirs of Lady Fanshawe, who, when in France, in 1649, met the learned When we came to Calais, (says her ladyship,) we met the Earl of Strafford and Sir Kenelm Digby, with some others of our countrymen. We were all feasted at the governor's of the castle, and much excellent discourse passed; but, as was reason, most share was Sir Kenelm Digby's, who had enlarged somewhat more in extraordinary stories, than might be averred, and all of them passed with great applause and wonder of the French then at table; but the concluding one was, that Barnacles, a bird in Jersey, was first a shell-fish to appearance, and from that, sticking upon old wood, became in time a bird. After some consideration, they unanimously burst out into laughter, believing it altogether false; and, to say the truth, it was the only thing true he had discoursed with them. That was his infirmity, though otherwise a person of most excellent parts, and a very fine-bred gentleman. THE PIKE. GESNER says, that a famished pike, in the Rhone, fixed on the lips of a mule that was drinking, and was drawn out by the beast before it could disengage itself. In December 1765, a pike was caught in the river Ouse, weighing upwards of twenty-eight pounds, and was bought by a gentleman in the neighbourhood for a guinea. When opened, the cook found a watch with two seals attached to it by a black riband, in the body of the fish. These, it was afterwards discovered, had belonged to a gentleman's servant, who had been drowned about six weeks before. Pikes are necessarily great destroyers of fish in ponds, but there are two descriptions of fishes, name ly, the perch and the stickleback, which they are unwilling to attack; the sharp spines of their back-fins sticking in the throat of the pike, more particularly that of the stickleback. An instance lately occurred at Edmonton of a pike capturing a sparrow, that was perched on the edge of a water-lily in a pond. The fish surprised the unsuspecting bird, by springing out of the water and seizing it by a sudden snap. A singular encounter, which took place at Waldstein, between a pike and a fox, is commemorated in a German print. Some country-people had taken a large pike, but in conveying it home during the night, it escaped. As it was a large fish, they returned with torches in search of their prize, and after some time found it on the grass, having fast hold of a fox by the nose. The fox, caught in this novel trap, endeavoured in vain to escape, and it was not until the pike was killed, that it was possible to separate them. Pikes are in the habit of basking in the sun, when they float upon the surface of the water; at this time they are sometimes shot, or taken by a noose of wire, fixed to a strong pole about four yards long, by which the wire, with great slowness, is conducted over the pike's head, gills, and fins, and then hoisted with a jerk to land. THE GYMNOTUS, OR ELEC TRICAL EEL. THE Gymnoti, or Electrical Eels, which resemble large water serpents, inhabit several streams of South America, and abound also in the Oroonoko, the Amazon, and the Meta, but the strength of the current, and the depth of the water in these large rivers, prevent their being caught by the Indians. They see these fish less frequently than they feel electrical shocks from them, when swimming or bathing in the river. To catch the Gymnoti with nets is very difficult, on account of the extreme agility of the fish, which bury themselves in the mud like serpents. Roots are sometimes thrown into the water to intoxicate or benumb these animals, but we would not employ these means, as they would have enfeebled the gymnoti: the Indians, therefore, told us that they would "fish with horses." We found it difficult to form an idea of this extraordinary manner of fishing; but we soon saw our guides return from the savannah, which they had been scouring for wild horses and mules. They brought about thirty with them, which they forced to enter the pool. The extraordinary noise caused by the horses' hoofs, makes the fish issue from the mud, and excites them to combat; they swim on the surface of the water, and crowd under the bellies of the horses and mules. A contest between animals of so different an organization, furnishes a very striking spectacle. The Indians, provided with harpoons and long slender reeds, surround the pool closely; and some climb upon the trees, the branches of which extend horizontally over the surface of the water. By their wild cries, and the length of their reeds, they prevent the horses from running away, and reaching the bank of the pool. The eels, stunned by the noise, defend themselves by the repeated discharge of their electric power, and during a long time they seem to prove victorious. Several horses sink beneath the violence of the invisible strokes, which they receive from all sides, and stunned by the force and frequency of the shocks, disappear under the water. Others, panting, with mane erect, and haggard eyes, expressing anguish, raise them selves, and endeavour to flee from the storm by which they are overtaken. They are driven back by the Indians into the middle of the water; but a small number succeed in eluding the active vigilance of the fishermen. These regain the shore, stumbling at every step, and stretch themselves on the sand, exhausted with fatigue, and their limbs benumbed by the electric shocks of the gymnoti. In less than five minutes two horses were drowned. The eel being five feet long, and pressing itself against the belly of the horses, makes a discharge along the whole extent of its electric organ. The horses are probably only stunned, not killed, but they are drowned from the impossibility of rising, amid the prolonged struggles between the other horses and the eels. We had little doubt, that the fishing would terminate by killing, successively, all the animals engaged, but, by degrees, the impetuosity of this unequal contest diminished, and the wearied gymnoti dispersed. The mules and horses appeared less frightened; their manes no longer bristled, and their eyes expressed less dread. The Gymnoti, which require a long rest and abundant nourishment to repair what they have lost of galvanic force, approach timidly the edge of the marsh, where they are taken by means of small harpoons, fastened to long cords. The Gymnotus is the largest of electrical fishes; I measured some that were from five to five feet three inches long, and the Indians assert that they have seen still longer. We found that a fish of three feet ten inches long weighed twelve pounds; the transverse diameter of the body was three inches five lines. The Gymnoti of Cano de Bera are of a fine olive-green; the under part of the head is yellow, mingled with red. Along the back are two rows of small yellow spots, from which exudes a slimy matter that spreads over the skin of the animal, and which, as Volta has proved, conducts electricity twenty or thirty times better than pure water. It is, in general, somewhat remarkable, that no electrical fish yet discovered in the different parts of the world, is covered with scales. The Gymnoti, which are objects of the most lively interest to the philosopher of Europe, are dreaded and detested by the natives. Their flesh furnishes pretty good food, but the electric organ fills the greater part of the body, and this being slimy and disagreeable to the taste, is carefully separated from the rest. The presence of the Gymnoti is also considered as the principal cause of the want of fish in the ponds and pools of the Llanos, where they kill many more fishi than they devour. The Indians told us, that when they take young alligators and gymnoti at the same time in very strong nets, the latter never display the slightest trace of a wound, because they disable the young alligators before they are attacked by them. All the inhabitants of the waters dread the Gymnoti; lizards, tortoises, and frogs, seek the pools, where they are secure from their action. It became necessary to change the direction of a road near Uritucu, because these electrical ecls were so numerous in one river, that they every year killed a great number of mules of burden as they forded the river. It would be temerity to expose ourselves to the first shocks of a very large and strongly irritated Gymnotus. If by chance you receive a stroke before the fish is wounded, or wearied by a long pursuit, the pain and numbness are so violent, that it is impossible to describe the nature of the feeling they excite. I do not remember having ever received from the dis |