taken up.

Many years ago we remember the then small village of Keyport suffering a loss in one season of $50,000. Even a severe storm continued unusually long has smothered the beds by agitation of the mud, for the oyster must keep its nib out of the bottom. But two seasons ago, in one of the branches of Shrewsbury River, a crop was almost entirely lost, the supposition being that it was poisoned by the washing from a new turnpike, in the construction of which a peculiar ferruginous earth had been used. Formerly the oyster throve as a native as high up the North River as Peekskill, and probably its limit was not below fifty miles from the mouth of the river. They are now, however, exceedingly scarce, even as high as Croton. The belief exists that the railroad has destroyed them by the washing from the necessary working of the road, which is constantly finding its way to the river-bed. So long ago as 1851, Colonel John P. Cruger, of Cruger's Landing, a very intelligent observer, called our attention to the fact of the mischief thus done.

And there are meteoric causes which affect the oyster. We have known an unusually severe winter to kill the bivalves in great numbers. And even the seed in its transport from Virginia has been destroyed-whole valuable cargoes-by foggy weather, and adverse winds. Moreover, as will be seen, the oyster has its deadly enemies in the animate ranks.

THE PHYSIOLOGY OF THE OYSTER.-By persons engaged in the business, we have been asked, "Are there hes and shes among the oysters?" The answer of the naturalist would be, "There are not." Low down in the scale of life many animals on their sexual side are singularly suggestive of plants. Take, for example, that splendid grass, Zea mays-Indian-corn. On the top of this graceful plant is a

large, brush-like panicle. This contains the staminate or male flowers. Embedded in the green cob of the ear are the pistillate or female flowers. Their pistils make the tassel, which is called "the silk." Upon these falls the fertilizing pollen of the stamens from the raceme above. Without this contact there would be no kernels on the cob. In some plants this bisexuality occurs in the same flower. A notable instance is that of the prolific strawberry known as Wilson's Albany Seedling. A similar fact, certainly an analogous one, is true of the oyster. It is bisexual. It is not masculine alone, nor feminine alone, but both; and perhaps might be defined by that innovation in modern grammar, as of "the common gender." It is hermaphroditic.

The question of the parental relation of the young oyster on its paternal side is most certainly a very perplexing one; for, albeit no matrimonial dereliction was ever known among these Ostreæ, yet the fact remains that no oyster was ever begotten that knew its own father.

If, now, the reader will take a little pains to compare our description of the organism of the oyster with Fig. 7, he will see that, however lowly the oyster may be regarded, it has a compact and even a complex anatomical structure, manifestly a beautiful adaptation to the creature's necessities; and even exhibiting, in a very instructive manner, a wonderful likeness to our own organization. If this seems a startling position, let the reader follow the discussion, and see if it be not made good. If we take an oyster in the hand, it will be observed that, of the two valves or shells, one is much deeper and heavier than the other. This is the bottom or lower valve, because, when lying undisturbed on the bed of the water, it is the under side. The upper valve is often a mere thin plate of shell. It is observable, too, that generally the lower valve is, on the outside, quite convex, while the upper one is usually either flat or a little concave. Let it now be remembered that, anatomically, an oyster has also two sides, and that while living its normal position is to lie on its left side. The valve, then, represented by the cut, is the lower or deep valve, in popular speech, but in scientific phrase it is the left valve. The oyster itself is shown as representing what is popularly known as its upper side, the side seen when eaten on "the half-shell;" correctly speaking, it is the right side of the animal.

Let us now follow the index-words of the figure. We find a thin sheet of flesh lying on the shell. It is the left mantle, for there are two, one to cover the right side also, so that both together are continuous as one, and with it the animal inwraps itself.

The figure shows a portion of the right or upper lobe of the mantle. It is sometimes called the pallium, and really is the oyster's cloak, though it is always and only worn in the house. This is not true, however, of all the mollusca. The beautiful cowries, so high colored and bright, are exceptions. If you examine a common tiger

cowry or Cypræa, if an adult shell, you will find that, while the entire shell is covered with a shining enamel, there is along the whole length of the back of the shell "a line of pale color." The animal extends both folds of the mantle outside of itself and over the shell, and that line is where the lips of the folds meet. This mantle has much to do with obtaining food. The oyster opens its shells about a quarter of an inch apart. These membranes, that make the mantles from both sides of the animal, meet just at the opening of the shell. They are fringed at their edges with rows of tiny cilia, or soft fleshy hairs of extreme delicacy. This pallial fringe in an eminent degree serves the oyster as organs of touch. Probably this sense, though distributed. somewhat over the entire surface of the body, is along this fringe exquisitely acute. The English call this fringe the oyster's beard. It is protruded just a little out of the shell; and these cilia, almost numberless, keeping up their rapid movements in the water, make as it were two parallel vibrating curves, which beget a sort of aquatic vacuum inside the shell, into which the water flows, as in a diminutive whirlpool. The stream thus affected brings with it the alga spores and animalcules which constitute the oyster's food. But where is the oyster's mouth? Speaking popularly, it is away back near the hinge of the shell, as shown in the cut. To this point the current flows. Now, it must not be supposed that all is fish that comes to the oyster's Far from it. Hence this mollusk has eclectic functions. Doubtless a sharp spicule of a sponge may occasionally get into the mouth, even as a bone splinter can get by accident into a human throat. The word "tentacles," in the cut, refers to certain organs, that might be called labial or lip fingers. These, it will be noticed, have immediate relation to the mouth. They are the organs for discriminating foodfunctionally they are manipulating lips. The stomach is not shown in the cut, being overlaid by the other organs. The intestine, at least a part of it, is exposed, and its extremity is really the anus or vent. So much, then, is apparent, that the oyster possesses an alimentary system of some complexity.

net.

A series of plates or plaited frills, lies on the mantle, if indeed it is not a specialized portion of that organ. These plaits are the branchiæ or gills. In the respiratory system of an oyster these branchia or gills are precisely the same to it as are the gills to a fish, or our lungs to us. Through these gills the water is passed. After imparting to the blood the oxygen taken from the air which the water contained, that water, now laden with carbonic-acid gas, is expelled at the respiratory aperture, or ex-current orifice, the dark spot in the figure immediately under the end of the intestine, which we have already said is the anus or vent, whence this refuse water, like a cleansing stream, passes directly out of the shell. This contrivance is certainly very beautiful. It is in fact a miniature sewer carrying off promptly and quickly the excrements as fast as they are made.

The heart, constricted at the middle like the former silk purses of the ladies, is shown in place. The constriction separates the auricle and the ventricle. And so even an oyster has three sets of circulating organs, the heart with its double set of functions, and the arteries and veins. And this little organ beats with regular pulsations. That little auricle receives the blood from the gills, and that tiny ventricle is the vital force-pump that propels it into the arteries. "From the capillary extremities of the arteries it collects again into the veins, circulates a second time through the respiratory organ, and returns to the heart as arterial blood." The color of the oyster's blood is a pale bluish white-in fact it may be called opaline. Our oyster, then, is not a heartless thing. If you open it with care and skill, as would the naturalist, you may see and count the throbbings of its tiny heart.

In its proper place is seen the liver, which is always a large organ in the mollusca, or so-called shell-fish. It is true that this organ in the oyster secretes bile, and doubtless in large quantities. It is not probable, however, that this organ, though large, ever performs a metaphorical function, for it is very doubtful whether the oyster ever gets up the amount of emotion necessary to stir one's bile." To the fast liver this oyster-liver is every thing. The secret is just here: this secretion of the liver is the real appetizer of the feast. This oysterbile is both gustatory and digestive. It excites the glands of the palate and the secretions of the stomach.

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The part indicated by the word muscle is the portion through which the knife is passed when opening an oyster. In popular parlance it is sometimes called the "eye," and by some the "heart; terms which, thus applied, are without meaning. It is the adductor muscle, and is the organ with which the oyster pulls-to its doors.

To sum up these considerations of the oyster's physiology, we see that, to the full extent of its necessities, it has distinctive sets of organs for the performance of the three classes of functions carried on in our own organization, namely, ingestion, respiration, and circulation.

THE OYSTER'S SHELL.-The toughest part of the oyster is the adductor muscle (Fig. 7). The office of this large, strong muscle is to pull-to and keep shut the great doors of the house. And a very curious bit of mechanism is subsidiary to this action. At the upper part of the cut is seen the hinge, a white spot with a dark curve below it. This dark curve is the hinge-ligament. It is a dark substance which fills up the pit or depression near the hinge. In the living animal it is wonderfully like gutta-percha-black, tough, and elastic. Let us attempt to explain its use to the oyster. Although this mollusk has a strong muscle with which to close its valves, it has not any with which to open them. Now, supposing we should take a lady's writing-desk, and, between the hinges at the back of the lids, should insert a piece of India-rubber, then should press down the lid, and turn the key; it is plain that the bolt of the lock now keeps the lid down, which could