found to be much more rare. And even at Massafuero, and the islands in its vicinity, they are no longer found in that abundance which prevailed when these voyages were first undertaken. Nevertheless, during the last ten or twelve years there have been many vessels of the United States engaged in this business. In 1800 and 1801, as many as ten vessels, principally from New-York, Connecticut and Massachusetts, were thus employed. Some of the ships are said to have been very successful in their voyages, insomuch that a single one has carried 60,000, and in some instances 100,000, sealskins to the Canton market. Though the seal affords oil, it has not been customary to save it. They say that, though it is equal to whale oil, it will not sell profitably in China. If brought home, it would probably command as great a price as whale oil. Few of the skins are brought to the United States, except when a ship fails in her voyage, and is thereby induced to return home. They are generally carried to Canton, and bartered away for teas, silks, nankeens, and other Chinese produce or manufactures. The time necessary to complete such a voyage, and get back, is from twentyfour to thirty months.

1

The sea-elephant belongs to the same family with the seal. He is found on many of the uninhabited islands of the great Southern Ocean, particularly at Kerguelan's Land, which they frequent in great herds. They make little resistance, and, of course, are easily killed. Several of our vessels are said to have been engaged in their destruction. Their oil is found to be of an excellent quality; and not only answers for home consumption, but makes a valuable article of exportation,

The fish whose figure is here presented, was found on the south side of Long-Island in the autumn of 1803, by James Fairlie, Esq. He made a drawing and description of the animal,

and communicated them to Dr. Mitchill shortly after. It is evidently a different species from that figured and noticed by Pennant in his British Zoology. The creature being rare in these parts, we have thought proper to insert as particular an account of him as we could. The whole length of body and tail was thirteen feet and one inch. The skin, though thick as that of the common shark, was not at all rough, except a very little on the back. The colour was dusky or brown; and the shades darker on the upper side than on the belly. The tail was stout and elastic. Its superior edge was about three or four inches broad, and tapered away to nothing below. In this respect it had some resemblance to the fin of a sea-tortoise. The teeth were very sharp, of about three-fourths of an inch long, and formed but one row. The body was very cylindri cally round, and possessed the great general features of the shark family.

AN OVO-VIVIPAROUS ANIMAL.

Peculiarities in the Anatomy and Physiology of the Shark, particularly as respects the Production of its Young. By Dr. Mitchill.

It has been known a long time, that the young of the shark had something in their structure considerably different from any other creatures, and figures of them have been given by Edwards, in his Natural History, and probably copied from thence into the Encyclopædia; but there has been, as yet, no dissection of these animals in this period of their existence, nor any explanation of their physiology, that I ⚫ know of. This defect may be supplied by the explanation herein attempted of the structure and functions of the foetus of a species of shark found frequently along the coast of New-York, in the waters of the Atlantic, during the summer months. About seven years ago, as I was engaged in a fishing party in one of the bays on the south side of Long-Island, a shark, between four and five feet in length, was taken in the seine, and secured in our boat, without receiving any material injury. Upon examination, this animal was found to be a female, whose uterus contained eleven young ones, of the size and figure represented in the plate. It forms the connecting link between oviparous and viviparous animals.

Besides these young ones that had advanced thus far in their growth, there were contained a large number of ova within the body of this fish, in different degrees of evolution and size, some of them resembling the full grown eggs of

the tortoise, and others similar to the smaller rudiments of eggs found in the ovaria of laying hens. On opening the uterus with a knife, the young fishes, as represented in the figure, were found each connected with an egg, dependent from that part of the belly which may be considered as the umbilicus, and appearing in the form of a very large hernia. This hernia, on examination, proved to be a true ovum, filled with yolky substance, evidently intended for its nourishment; and what was very remarkable, the young animal, though grown to a considerable size, and connected in this manner with its egg, had no connection whatever by means of an umbilical cord, a placenta, or by vessels of any kind, to the uterus of its dam; but it was so completely organized as to derive no sustenance to its body, nor to receive any renovation of its blood from its parent.

The membrane covering the egg contained most beautiful ramifications of blood-vessels. The arteries descending from the little fish could be seen sending off their branches over its : whole exterior surface; and terminating in veins, to unite their trunks, and carry back their contents.

The singularity of all these appearances was considerably heightened by the capability of the little sharks, when cut out of the uterus, to live for a considerable time in the open air. The larger part of the brood had been left on the grass of the shore where the dam had been dissected; but the three which I reserved for examination lived, and exhibited, during the greater part of the time, brisk motion for almost two hours, although exposed to the temperature of a common atmosphere. During this time, while they lay before me on a plate, nothing of the kind appeared more beautiful or distinct than the branches of blood-vessels shooting through and running over the transparent membrane of the egg; the blood evidently appearing to acquire à brighter scarlet colour, whilst the fish was thus exposed to the air, than it had possessed during the immersion of the young animal in the fluid of the uterus. It seemed to have acquired more rapidly, and to a greater quantity than before exclusion from its maternal membrane, the oxygen of the air to which it was exposed; the union of which with the blood seemed to have brightened its colour, and imparted to it, at the same time, so much of a stimulant quality as to have shortened the duration of its life by excessiveexcitement.

The internal structure of the fœtus of this shark may be seen in the plate. The dissection was made by my colleague,

Mr. Post, Professor of Anatomy in Columbia College; and the drawing was executed, immediately after, by Dr. Alexander Anderson, of New-York, in the presence of the late Dr. Elihu H. Smith, Mr. William Dunlap, and Mr. Thorne.

In this drawing,

A represents the ovum, with its exterior membrane dissected off.

B the internal tube or duct extending from the egg to a sac or reservoir of nutriment within the body of the fish. C the sac alluded to in B, of considerable size, and occupying a good deal of room in the abdomen: it was filled with a pulpy or soft matter, evidently derived from the ovum, and apparently a little more elaborated, and prepared for nutrition by some concoctive operation in the sac itself. D the stomach, as yet not distended; of course exceedingly small; having never, as yet, been filled with food derived from the mouth. In the plate will be seen a small passage or opening,

E, through which the alimentary matter in the sac, C, passes into the stomach, to be absorbed afterward by the lacteals of the intestines.

F the oesophagus, of nearly the same size with the stomach. GG the two lobes of the liver.

H the cloaca, or gut stretching towards the anus, and filled with the refuse matter of the alimentary mass.

I the external membrane connecting the egg with the fish, cut through and turned back.

A species of shark, called catulus major vulgaris, is delineated by Edwards, but appears to be different from this. He has taken two views of the parent animal, and two more of the young. From the figures there given, it would seem that the same law of generation obtained as in this species. All the species probably breed in the same way.

There is a great variety in the multiplicative process of living beings. The female RANA PIPA, or, Surinam frog, nourishes its young in certain cells or cavities in her back, and not in the womb. The OPPOSSUM of this country supports her young appendant to the teats, within the paunch or sac, called a false belly. The KANGAROO of New-Holland has somewhat of a similar structure and economy. More extensive and penetrating inquiries show the exceptions to the common mode of generation to be almost indescribably curious and diversified. We see no end to the variety of ways in which the perpetuation of the species is carried on. Even Spallanzani (5 Viaggi alle due Sicilie, &c. p. 46), though he went to the Lake of Orbitello on purpose to examine the anatomy of the large eels which live there, could discover in them no appear

ance of sex.

DISCLOSURES IN MINERALOGY: FROM SPECIMENS BROUGHT TO DR. MITCHILL.

1. Gypsum from Upper-Louisiana.

Among the productions of this newly-acquired country is to be reckoned plaster of Paris. Specimens of a very pure gypsum have been brought from about 150 leagues up the Missouri. It is said to exist there in abundance. This, in process of time, will amply supply that inland country with the sulphate of lime for all the purposes of agriculture, architecture, and the other arts. It is remarkable how scantily gypsum is scattered through Fredonia. Except some small parcels which have been brought from St. Mary's, between the Patuxent and Potowmac, in Maryland, some other samples from the town of Marcellus, in Onondaga county, NewYork, and some other pieces obtained from the bed of the river below the Falls of Niagara, we have hitherto seen but few traces of this valuable stone in the United States. It is owing to the scarcity of plaster of Paris within our territories, that we are obliged to import the greater part of what we VOL. II.

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