By means of the beard or mantle described (m), the oyster secures his food, bringing it gradually, by means of little hooks bent inwards, to its mouth (b), wherein it is crushed and slowly consumed.

The stomach (i) is situated near the mouth, and all the organs are very simple. The mantle (m and m') above-named replaces the lungs. The liver (f) is small; the gall, comparatively speaking, large; the larger blood vessels little rarefied. The heart (h) consists of two cameras at a tolerable distance from one another, resembling small round bladders. The pulse beats rather slowly (caused by, perhaps, the want of food and sea water). From the stomach the rectum (a) leads directly to the anus. How digestion is effected in this short and simple way, I can scarce venture to assert. But it is a fact well known, that, after the spawning season, the oyster becomes thin, but a very short time enables it to recover its fat and succulence.

On examining the oyster the mantle (m), divided into two lobes (m and m'), the edges of which are fringed, will be perceived filling the greater part of the shell; also four membranous leaves crossed with stripes, which at their hinder extremities have as many capillary tubes. These leaves, or veins, unequally divided around the edges of the body perform the functions of the lungs, and separate from the water the necessary air for the maintenance of the animal.

The mouth (b) is a kind of trunk, or long aperture surrounded by four lips nearly resembling those of a gill, but far shorter.

Behind the muscles is to be seen a large fleshy white and cylindrical substance moving on a central muscle, and containing the stomach and intestines (i). This part resembles the trunk of other conchæ, but it has no power of opening or contracting. The canal of the intestines is situated on the top of the muscle (a).

The oyster has circular vessels, on the bottom of which are to be seen deep muscular cavities, occupying the place of the heart (h), and sending their moisture to the small skin through which they come in contact with the water or the air.

In his "Outline of the Animal Kingdom," Professor Rymer Jones most happily describes all these peculiarities. "Wonderful indeed is the elaborate mechanism," are his words, "employed to effect the double purpose of renewing the respired fluid and feeding the helpless inhabitants of these shells! Every filament of the branchial fringe, examined under a powerful microscope, is found to be covered with countless cilia in constant vibration, causing, by their united efforts, powerful and rapid currents, which, sweeping over the surface of the gills, hurry towards the mouth whatever floating animalcules, or nutritious particles, may be brought within the limits of their action, and thus bring streams of nutritive molecules to the very aperture through which they are conveyed to the stomach, the lips and labial fringes acting as sentinels to admit or refuse entrance, as the matter may be of a wholesome or pernicious character."

Nature, too, has given the oyster a sensitive perception of the changes of light as the means of its protection from the many enemies it has to contend with; for if the shadow of an approaching boat is thrown forward so as to cover it, it closes the valves of its shell before any undulation of the water can have reached it. This sensitiveness is easily studied in the marine vivary, where the oyster, with its beautiful cilia, more beautiful by far than the richest lace of a bride’s wedding dress, is always an object of great interest.

The oyster is an hermaphrodite animal, and hence its propagation is effected by self-produced eggs, which it bears within in the form of a greenish milky juice which it casts as spat in May, and which, as has already been stated, in this country is protected by wise and prudent acts of the Legislature. "The liquor in the lower shell of the oyster," says a writer in No. 587 of the "Family Herald," "if viewed through a microscope, will be found to contain multitudes of small oysters, covered with shells and swimming nimbly about—120 of which extend about an inch! Besides these young oysters, the liquor contains a variety of animalcules." Indeed, with the aid of a microscope one million of young have been discovered in a single oyster. Guarded by their two tender shells, these swim freely in the sea when ejected by the parent oyster, until, by means of a glutinous substance, they fix themselves so fast to some object that they can be separated only by force. These young are very soon able to produce others, many say at four months after their birth. When the oyster attains the size of a crown the shell is still very tender and thin; it is only after the second, third, or fourth year that it becomes fit for human food.

If we cannot answer the Fool’s question in Lear, and "tell how an oyster makes his shell," we can, nevertheless, tell by his shell what is his age.

"A London oysterman," says a correspondent of No. 623 of the "Family Herald," "can tell the ages of his flock to a nicety. The age of an oyster is not to be found out by looking into its mouth. It bears its years upon its back. Everybody who has handled an oyster-shell must have observed that it seemed as if composed of successive layers or plates overlapping each other. These are technically termed 'shoots' and each of them marks a year’s growth; so that, by counting them, we can determine at a glance the year when the creature came into the world. Up to the time of its maturity, the shoots are regular and successive; but after that time they become irregular, and are piled one over the other, so that the shell becomes more and more thickened and bulky. Judging from the great thickness to which some oyster-shells have attained, this mollusk is capable, if left to its natural changes unmolested, of attaining a great age." Indeed, fossil oysters have been seen, of which each shell was nine inches thick, whence they may be concluded to have been more than 100 years old.

For the most part the offspring remains near the mother, which accounts for the large oyster banks or beds which are found in almost all the seas of the temperate and torrid zones, and which in some places have been known to attain such magnitude as to cause ships to be wrecked upon them. The lower stratum is necessarily lifeless, being pressed upon by the upper one, so that the oysters beneath are unable to open themselves, and are consequently deprived of food.

The immense propagation of the oyster may be understood from the fossil oyster bed near Reading, in Berkshire. These fossils have the entire shape, figure, and are of the same substance as our recent oyster-shells, and yet must have lain there from time immemorial. This bed occupies about six acres, forming a stratum of about two feet in thickness. But the largest fossil oyster banks are those raised by earth-quakes along the western shores of South America, which measure from sixty to eighty feet in depth, are often forty miles in length, and in many places stretch above two miles into the interior.

The Abbé Dicquemare, fond of trying experiments in the spread of gastronomy, even to the stewing a mess of Gemmaceæ, the Gems of our water-vivaries, till they had something of the flavour of oysters, asserts that, when in a state of liberty, oysters can move from one place to another by suddenly admitting sea water into the shell, which they are able to open and shut with extraordinary power and rapidity, whereby they produce a strange sound; and this observation has been confirmed by other naturalists, and is recorded as an ascertained fact in several books of natural science. In like manner they defend themselves against smaller animals, especially against the spider crab, which constantly tries to penetrate into their half open shells. Much natural instinct or foresight is also attributed to the oyster; in proof of which I may name that, when in a position which is exposed to the variations of the tide, oysters seem to be aware that they remain for some hours without water, and consequently provide it within their shells.

This makes such oysters far more fit to be conveyed to a distance, than those taken nearer to the shore, which evacuate the water, thus exposing themselves to the heat of the sun, the cold, or an attack from their enemies; and this, too, is the reason why Colchester or Pyfleet oysters, packed at the beds, are in such request.

CHAPTER V.

THE OYSTER IN ITS NEW SETTLEMENT.

Dredging for Oysters; Oyster-beds and their formation; Sergius Orata; Pliny the Elder; Baia and the Lucrine Sea; Roman Epicurism and Gluttony; Martial and Horace, Cicero and Seneca; Masticate Oysters, and do not bolt them whole; Mediterranean and Atlantic Oysters; Agricola and the Rutupians; Apicius Cœlius, Trajan, Pliny, and the Vivarium.

The Oyster does not leave his home like the duckling, upon the call of "come here and be killed." If he is wanted, like Mrs. Glasse’s hare, we must "first catch him." This is done by dredging, and this dredging for oysters is performed by means of rakes and scrapers, on which is fastened a bag of sail-cloth, leather, or net-work. These are lowered into the sea by means of ropes and chains, and are dragged along its bottom by boats in full sail, or by rowing-boats. When the net or scraper is drawn to the surface, the oysters are immediately separated from all else which may be swept up. These oysters are then stowed away and sent up to market in due course. But it is not of these that are formed the new settlements or oyster-beds, which I am about to describe.

These oyster-beds are cavities or reservoirs which communicate with the sea by means of canals, and are placed in such manner that the level beds remain dry when the tide is high. These beds are made with sand-stones or other hewn stones; and the water is kept in or let out at low tide by means of locks, or traps, as may be most readily effected.

At some periods, however, the water is kept in for many days, or even weeks together. In the latter case the oyster becomes, for the most part, very tender, and green and fat, because the stagnant water promotes the germination of those microscopical spores of marine plants, which always abound in natural sea-water, and upon which it delights to feed. These reservoirs, therefore, are not only the means of preserving them for sale, but of purifying them from the muddy odour which they have imbibed at sea, and which indicates them to be hard and devoid of that luscious and somewhat gastronomic quality so much prized by the world at large.

The bottom and sides of these caves or reservoirs are paved with stones and thick layers of sand, to keep them free from all mud, which is not only very injurious to the animal, but sure to harbour its enemies; and great care is also observed not to admit too great a flow of water at one time, as that might drive particles of sand into the shells. When the reservoir is properly prepared, the oysters are placed in their natural position—the flat side being upwards, in a sloping or horizontal direction. The more care that is taken in keeping their beds clean and free from mud, by washing the sides of the reservoirs, pouring water over the oysters, especially those which are dry, and removing the dead ones, which can be recognised by their shells being open, the better; for the more valuable will they be as human food, both as to profit and condition, and the more appreciated by the gastronomic million, who hail the oyster season as does a sportsman the advent of grouse and partridges, hares and pheasants.

The oysters, which are thus preserved, cleaned, nursed, and fattened are taken from their beds at the low tide when the water is out.

There are doubts, various and conflicting, as to whether oysters contained in reservoirs, where the water is changed each successive tide, are not on that account preferable to those which exist in the same water for two weeks at a time. I give a decided preference to the latter, though the water must be kept very clean by constant care and attention to the removal of the dead, the decomposition of which would otherwise, but for the frequent change of water, seriously affect the health of the whole settlement, by an accumulation of sulphuretted hydrogen, with a smell like that emitted by the Thames and other drainage rivers in the dog-days. These oysters slip down the human throat divine with a tenderness and sublime relish which no words can describe.

Let me pass over, for the nonce, the mode of packing and sending them to the interior. Thanks to the railways, the gastronomical delight of oyster eating is now secured to many who for years scarcely knew what an oyster meant in its entire freshness and best qualities.