While commending the mussel as an important article of food, we must not conceal the fact, that it has produced in certain persons very grave effects, showing that for them its flesh has the effects of poison. The symptoms, commonly observed two or three hours after the repast, are weakness or torpor, constriction of the throat and swelling of the head, accompanied by great thirst, nausea, frequent vomitings, and eruption of the skin and severe itching.

The cause of these attacks is not very well ascertained; they have in turn been ascribed to the presence of copper pyrites in the neighbourhood of the mussel; to certain small crabs which lodge themselves as parasites in the shell of the mussel; to the spawn of star-fishes or medusæ that the mussel may have swallowed. But, probably, the true cause of this kind of poisoning resides in the predisposition of individuals. The remedy is very simple: an emetic, accompanied by drinking plentifully of slightly acidulated beverages.

We have now come to the twentieth family, the Aviculidæ, which contains Avicula, Malleus, Maleagrina, Perna, and Pinna. The shells of the Hammerheads (Malleus) have a rough resemblance to the implement from which they derive their name. The valves are nearly equal, blackish, and somewhat wrinkled on the exterior, often brilliantly nacred in the interior. They are enlarged to the right and left of the hinge, forming prolongations on each side, which give them the fancied resemblance to the Hammerhead (Fig. 163). At the same time they grow in a direction opposite to the hinge, which gives something approaching the handle of the implement.

This is the first feature which a glance at Malleus alba (Fig. 162) conveys. The hinge is without teeth, having instead a deep conical fossette or dimple, for the reception of a very strong ligament which acts upon the valves. The animal is contained in the interior of the shell, its mantle fringed by very small tentacular appendages. Only six actually living species of the genera are known, which are inhabitants of the Indian Ocean, of the Australian seas, and the Pacific Ocean.

The beautiful diaphanous nacre which embellishes the interior of so many ornamental cabinets are principally produced by the animal inhabiting the Meleagrina, a bivalve, sometimes designated the pintadine, or mother-of-pearl shell. This bivalve moors itself to the bottom of the sea by a strong byssus of a brownish colour. The door-posts of the shells are irregularly rounded in their young days; they are externally lightly foliated, and ornamented with bands of green and white, which spring from the summit in rays, and afterwards break off into two or three slightly scattered branches. In old age they become rugged and blackish. The shell is in its perfection when about eight or ten years old, their size being then about six inches in diameter, with a thickness of about an inch and a quarter.

Nacre is the hard and brilliant substance with which the valves of certain shells are lined in the interior. This substance is white, silky, slightly azure, and more or less iridescent. Most of the bivalves are supplied with nacre; some of them even yield a blue, or blue and violet pigment. The iridescent Haliotis iris, for instance, is an emerald-greenish blue of changing colour, with reflections of a purple violet. Turbo argyrostomus (Linnæus) presents a mouth of bright silvery hue, while Turbo chrysostomus appears in all the glory of gold; but the Pintadine yields the purest white nacre, as well as the most uniform, and especially the thickest. This product owes its brilliant and delicate appearance to the play of light on it in its highly-polished state. For practical purposes the nacre is separated from the shell with an instrument; sometimes all the exterior part of the shell being dissolved away from the precious substance, leaving only the naked bed of nacre.

But the most interesting of all the nacre-bearing shells is the pearl oyster (Meleagrina margaritifera), the exterior, as well as the interior, of which is represented in Fig. 164. The interior of the shell affords the most exquisite pearls; the Esterhazy collection of jewels afforded many such specimens. This shell is nearly round, and greenish in colour on the outside; it furnishes at once the finest pearls, under favourable circumstances, and the nacre so useful in many industrial arts. Fine pearls and nacre have, in short, the same origin. The nacre invests the whole interior of the shell of Meleagrina margaritifera; being the same secretion which in the pearl has assumed the globular form: in one state it is deposited as nacre on the walls of the bivalve, in the other as a pearl in the fleshy interior of the animal. This nacre is therefore at once a calcareous and horny matter, which the animal secretes, and which it attaches to the interior walls of the shell during the several periods of its development. Pearls are formed of the same substance, only in place of being deposited upon the valves in beds, the material is condensed and agglomerated in small spheroids, which develop themselves either on the surface of the valves or in the fleshy part of the mollusc. Between nacre and pearls, therefore, there is only the difference of the form of deposition. Fig. 165 represents the pearl oyster with calcareous concretions in various states of progress.

The finest pearls—solidified drops of dew, as the Orientals term them in the language of poetry—are secretions supposed to be the result of disease in the animal. The matter, in place of being spread over the surface of the valves in their beds, is condensed either on the centre of the valves or in the interior of the organ, and forms a more or less rounded body. The pearls, when deposited on the valves, are generally adherent; those which originate in the body of the animal are always free. Generally we find some small foreign body in their centre which has served as a nucleus to the concretion, the body being perhaps a sterile egg of the mollusc, the egg of a fish, a rounded animalcule, a grain of sand even, round which has been deposited in concentric layers the beautiful and much-prized gem.

The Chinese, and other Eastern nations, are said to turn this fact in the natural history of bivalves to practical use in making pearls and cameos. By introducing into the mantle of the mollusc, or into the interior of a living valve, a round grain of sand, glass, or metal, they induce a deposit which in time yields a pearl, in the one case free, and in the other adhering to the shell. In some cases they are said to be produced in whole chaplets by the insertion of grains of quartz connected by a string into the mantle of a species of Symphynota; in other cases, a dozen enamelled figures of Buddha seated have been produced by inserting small plates of embossed metal in the valves of the same species.

The pearls are very small at first; they increase by annual layers deposited on the original nucleus, their brilliancy and shade of colour varying with that of the nacre from which they are produced. Sometimes they are diaphanous, silky, lustrous, and more or less iridescent; occasionally they turn out dull, obscure, and even smoky.

The pearl oyster is met with in very different latitudes; they are found in the Persian Gulf, on the Arabian coast, and in Japan, in the American seas, and on the shores of California, and in the islands of the South Sea; but the most important fisheries are found in the Bay of Bengal, Ceylon, and other parts of the Indian Ocean. The Ceylon fisheries are under Government inspection, and each year, before the fisheries commence, an official inspection of the coast takes place. Sometimes the fishing is undertaken on account of the State, at other times it is let to parties of speculators. In 1804 the pearl fishery was granted to a capitalist for £120,000; but, to avoid impoverishing all the beds at once, the same part of the gulf is not fished every year.

The great fishery for mother-of-pearl Pintadines (Meleagrina margaritifera) takes place in the Gulf of Manaar, a large bay to the north-east of the island; it commences in the month of February or March, and continues thirty days, taken collectively, and occupies two hundred and fifty boats, which come from different parts of the coast; they reach the ground at daybreak, the time being indicated by a signal gun. Each boat's crew consists of twenty hands, and a negro. The rowers are ten in number. The divers divide themselves into two groups of five men each, who labour and rest alternately; they descend from forty to fifty feet, seventy being the very utmost they can accomplish, and eighty seconds the longest period the best divers can remain under water, the ordinary period being only thirty seconds. In order to accelerate their descent, a large stone is attached to a rope. According to travellers the oars are used to rig out a stage, across which planks are laid over both sides of the boat; to this stage the diving-stone is suspended. This stone is in the form of a pyramid, weighing about half-a-hundredweight; the cord which sustains it sometimes carries in its lower parts a sort of stirrup to receive the foot of the diver. At the moment of his descent he places his right foot in this stirrup, or, where there is no such provision, he rests it on the stone with the cord between his toes. In his left foot he holds the net which is to receive the bivalves; then, seizing with his right hand a signal-cord conveniently arranged for his purpose, and pressing his nostrils with the left hand, he dives, holding himself vertically, and balancing himself over his foot.

Each diver is naked, except the band of calico which surrounds the loins. Having reached the bottom, he withdraws his foot from the stone, which ascends immediately to the stage. The diver throws himself on his face, and begins to gather all the pintadines within his reach, placing them in his net. When he wishes to ascend he pulls the signal cord, and is drawn up with all possible expedition.

A good diver, we have said, seldom remains more than thirty seconds under water at one time; but he repeats the operation three or four, and, in favourable circumstances, even fifteen or twenty times. The labour is extremely severe. On returning to the boat they sometimes discharge water tinged with blood by the mouth, nose, and ears. They are also exposed to great danger from sharks, which lie in wait for and frequently devour the unhappy divers.

They continue to fish till mid-day, when a second gun gives the signal to cease. The proprietors wait on shore for their boats, in order to superintend their discharge, which must take place before night sets in, in order to prevent concealment and robbery.

In past times the Ceylon fisheries were very valuable. In 1797 they are said to have produced £144,000, and in 1798 as much as £192,000. In 1802 the fisheries were farmed for £120,000; but for many years the banks have been less productive, and are now said to yield only the sum of £20,000 per annum.

The natives of the Bay of Bengal, those of the Chinese coast, of Japan, and the Indian Archipelago, all abandon themselves to the pearl fishery, the produce being estimated to realize at least £800,000. Fisheries analogous to those of Ceylon take place on the Persian coast, on the Arabian Gulf, along the coast of Muscat, and in the Red Sea.

In these countries the pearl fishing does not commence till the months of July and August, the sea being at that time calmer than in other months of the year. Arrived on their fishing-ground, the fishermen range their barques at a proper distance from each other, and cast anchor in water from eight to nine fathoms deep. The process is pursued here in a very simple manner. When about to descend the divers pass a cord, the extremity of which communicates with a bell placed in the barque, under the armpits; they put cotton in their ears, and press the nostrils together with a piece of wood or horn; they close their mouths hermetically, attach a heavy stone to their feet, and at once sink to the bottom of the sea, where they gather indiscriminately all shells within their reach, which they throw into a bag suspended round the haunches. When they require to breathe they sound the bell, and immediately they are assisted in their ascent.

On the oyster-banks off the Isle of Bahrein the pearl fishery produces about £240,000; and if we add to this the addition furnished by the other fisheries of the neighbourhood, the sum total yielded by the Arabian coast would probably not fall short of £350,000.

In South America similar fisheries exist. Before the Mexican conquest the pearl fisheries were located between Acapulco and the Gulf of Tehuantepec; subsequently they were established round the Islands of Cubagua, Margarita, and Panama. The results became so full of promise that populous cities were not slow to raise themselves round these several places.

Under the reign of Charles V., America sent to Spain pearls valued at £160,000; in the present day they are estimated to be worth £60,000. In the places mentioned, the divers descend into the sea quite naked; they remain there from twenty-five to thirty seconds, during which space they can only secure two or three pintadines. They dive in this way a dozen times in succession, which gives an average of between thirty and forty bivalves to each diver.

The bivalve is carried on shore, and piled up on mats of Espartero grass. The mollusc dies, and soon becomes decomposed; it requires ten days to be thoroughly disorganized. When in a thoroughly corrupt state, they are thrown into reservoirs of sea-water, when they are opened, washed, and handed over to the dealers. The valves furnish nacre, and the parenchyma the pearls.

The valves are cleansed, and piled up in tuns or casks; by raising their external surface plates of nacre are obtained more or less thick, according to the age of the mollusc.

Nacre of three kinds are distinguishable in commerce: silver-faced, bastard white, and bastard black. The first are sold in cases of two hundred and fifty to two hundred and eighty pounds; they are brought from the Indies, from China, and Peru. The ships of various nations import these shells as ballast. The second is delivered in casks of two hundred and fifty pounds weight; it is a yellowish white, and sometimes greenish; sometimes red, blue, and green.

Pearls form by far the most important product of the animal. When they are adherent to the valves they are detached with pincers; but, habitually, they are found in the parenchyma of the animal. In this case the substance is boiled, and afterwards sifted, in order to obtain the most minute of the pearls; for those of considerable size are sometimes overlooked in the first operation. Months after the mollusc is putrified, miserable Indians may be observed busying themselves with the corrupt mass, in search of small pearls which may have been overlooked by the workmen.

The pearls adherent to the valve are more or less irregular in their shape; they are sold by weight. Those found in the body of the animal, and isolated, are called virgin pearls, or paragons. They are globular, ovoid, or pyriform, and are sold by the individual pearl. In cleaning them, they are gathered together in a heap in a bag and worked with powdered nacre, in order to render them perfectly pure in colour and round in shape, and give them a polish; finally, they are passed through a series of copper sieves, in order to size them. These sieves, to the number of twelve, are made so as to be inserted one within the other, each being pierced with holes, which determine the size of the pearl and the commercial number which is to distinguish it. Thus, the sieve No. 20 is pierced with twenty holes, No. 50 with fifty holes, and so on up to No. 1000, which is pierced with that number of holes. The pearls which are retained in Nos. 20 to 80, said to be mill, are pearls of the first order. Those which pass and are retained between Nos. 100 to 800 are vivadoe, or pearls of the second order; and those which pass through all the others and are retained in No. 1000 belong to the class tool, or seed pearls, and are of the third order.

They are afterwards threaded; the small and medium-sized pearls on white or blue silk, arranged in rows, and tied with ribbon into a top-knot of blue or red silk, in which condition they are exposed for sale in rows, assorted according to their colours and quality. The small or seed pearls are sold by measure or weight.

In America the bivalve is opened with a knife, like the common edible oyster, and the pearl is obtained by breaking up the mollusc between the finger and thumb without waiting for its decomposition; nor is it boiled. This is a much longer and less certain process than that pursued in the East; but the pearls are preserved in greater freshness by the process—for the nacre of the dead shells is less brilliant than that of those which have been suddenly killed, and at once separated from the soft parts.

Some few pearls have become historical, from their size and beauty. A pearl from Panama, in the form of a pear, and about the size of a pigeon's egg, was presented in 1579 to Philip II., King of Spain: it was valued at £4000. A Lady of Madrid possessed an American pearl in 1605 valued at 31,000 ducats.

The Pope Leo X. purchased a pearl of a Venetian jeweller for £14,000. Another was presented to the Sultan Soliman the Great by the Venetian Republic valued at £16,000. Julius Cæsar, who was a great admirer of pearls, presented one to Servilia which was valued at a million of sesterces, about £48,000 of our money.

There is no data for the volume or value of the two famous pearls of Cleopatra; one of these which the queen is said to have capriciously dissolved in vinegar and drank—Heavens preserve us from such a draught!—is said by some authors to have been worth £60,000; the other was divided into two parts, and suspended one half from each ear of the Capitoline Venus. Another pearl was purchased at Califa by the traveller Tavernier, and is said to have been sold by him to the Shah of Persia for the enormous price of £180,000.

A prince of Muscat possessed a pearl so extremely valuable—not on account of its size, for it was only twelve carats, but because it was so clear and transparent that daylight was seen through it—he refused £4000 for it.

In the Zozema Museum at Moscow there is a pearl, called the "Pilgrim," which is quite diaphanous; it is globular in form, and weighs nearly twenty-four carats. It is said that the pearl in the crown of Rudolph II. weighed thirty carats, and was as large as a pear. This size, besides being indefinite, is more than doubtful.

The shahs of Persia actually possess a string of pearls, each individual of which is nearly the size of a hazel nut. The value of this string of jewels is inestimable.

At the Paris Exposition of 1855, Her Majesty the Queen exhibited some magnificent pearls; and on the same occasion the Emperor of the French exhibited a collection of 408 pearls, each weighing over nine pennyweights, all of perfect form and of the finest water. The Romans were passionately fond of pearls, and they have transmitted their taste to the Eastern nations, who attach notions of great grandeur and wealth to the possessor of large and brilliant pearls.

The genus Pinna, so called by Linnæus, from one of the species which was so designated from the resemblance of its byssus to the aigrette or plumelet which the Roman soldiers attached to the helmet. French naturalists name them jambonneau, from their singular resemblance to a dried ham (Figs. 166 and 167), their brown, smoky colour not a little aiding the resemblance. This shell is fibrous, horny, very thin and fragile, compressed, regular, and equivalve, triangularly pointed in front, round or truncated behind. The hinge is linear, straight, and without teeth; the ligament, in great part internal, occupies more than half the anterior half of the dorsal edge of the shell, forming a straight elongated fossette.

The animal is thick, elongated, with mantle open behind, presenting a conical furrowed foot, hearing a considerable byssus.

The Pinnæ are found in almost every sea, and at various depths; they are constantly attached by their byssus, and in a vertical position, the larger side of their shell being uppermost. They assemble on sandy bottoms in considerable numbers. The byssus has in all ages fixed the attention of the Mediterranean fishermen upon these curious shells. With its tuft of fine silky hairs, six or seven inches in length, of a fine reddish-brown hue, articles of luxury are formed, which are often mentioned by the Latin writers. The threads of the byssus, which are remarkable for their unalterable colour, were formed by both Greeks and Romans into a fabric to which there is nothing analogous in the world. The Maltese and Neapolitans still fashion soft tissues from it, but the stuffs so manufactured are pure objects of curiosity.

Twelve species are described as living in the several seas. Pinna nobilis (Fig. 169), the byssus of which was employed in the ancient Neapolitan industry, inhabits the shores of the Mediterranean. Pinna bullata, Swainson (Fig. 168), is also a well-known species.

Ostreidæ.

Our twenty-first family, Ostreidæ, contains Lima, Spondylus, Pecten, Anomia, and the all-important oyster. The common oyster, Ostrea edulis, is found in all seas. It is unequally valved, modified in shape by the form of the submarine body to which it happens to be attached. The lower or adherent valve is concave, always the largest; the upper one thin, usually flat; the shell is lamellar, rough externally, and seems to be composed of broken layers, adhering slightly to each other, as if the successive layers had been built up from within, and each succeeding layer was an enlargement upon its predecessor. The hinge which unites the valves is an elastic toothless ligament placed behind the centre, which opens the valves.

The interior surface of the valves is smooth and white, diaphanous or pearly towards the centre, but near the back an oval or rounded impression may be observed, to which a thick and whitish fleshy body is attached. This is the central muscle which draws the valves together, hermetically closing them upon the animal. This muscle is cut through in the process of opening the oyster.

The animal has no power of locomotion; its foot is very small and often wanting, no syphon, but lies with its mouth open, and slightly attached to the shell. The shell itself is always adherent, as if soldered to the rock or other submarine body, the point of adherence being near the summit of the lower valve, at the part called the heel.

Let us suppose the oyster opened by the double dissection of the ligament of the central muscle and of the abductor valves. When displayed before our eyes, we see in the bottom of the shell a flattened, shapeless animal, semi-transparent, greyish, and somewhat oval-shaped. The gastronomist, who seldom sees beyond his nose, thinks that in spite of its culinary merits the oyster belongs to the lowest rank of animal existence; but he deceives himself, and does not know how complex and delicate is the organization of the humble bivalve. The animal is enveloped in a sort of smooth, thin, contractile tissue called the mantle, which folds round it, presenting two lobes, separated on the greatest part of its circumference, and forming a sort of hood, the summit of which abuts upon the hinge of the bivalve. The edges of this mantle are fringed with very small cilia, which the creature can extend and draw back at pleasure, and which seem to be gifted with a certain amount of sensibility. It is this mantle which secretes and deposits the calcareous matter which forms the shell, each plate of which is an enlargement on the preceding one, until it constitutes a pyramid of thin convex lamellæ.

At the point where the lobes of the mantle meet, near the summit of the valve, is the mouth of the animal, with its thin membranous lips. This organ is large and dilatable, and is accompanied by four flat triangular pieces, by means of which the animal introduces its food into the stomachal cavity.

A very short gullet is attached to the mouth, which leads to a pear-shaped stomach. After this stomach comes a slender sinuous intestine, which, leading obliquely towards the interior, descends a little, then reascends, passes behind the stomachal cavity, nearly on a level with the mouth, crossing its first path in order to reach the posterior face of the adductor muscle, in the centre of which it terminates with a free opening. The stomach and intestines are surrounded on all sides by the liver, which alone constitutes a notable portion of the mass of organs. This liver is of a blackish colour, pervaded with a deep yellow liquid, which is the bile. Thus the stomach and intestines of the oyster are surrounded by the liver; the mouth is connected with the stomach, and the intestines open in the back.

The heart of the oyster is placed under the liver, and is surrounded closely by the terminal part of the intestines. It is composed, like the same organ in the superior animal, of two distinct cavities, an auricle and ventricle. From the ventricle issues a vessel, which is divided into three distinct canals. One of these carries the blood towards the mouth and tentacles; another carries it towards the liver; the last distributes the nourishing fluid to the rest of the body. The blood of the oyster is limpid and colourless; it passes successively from the auricle of the heart, where it is vivified, into the ventricle, and from this last cavity into the great vessel of which we spoke, which distributes it into the interior of the animal.

The oyster thus possesses a true circulation; not that double system which characterises the mammals, and which includes arterial and pulmonary action, but a simple circulation, as it exists in fishes and many other animals. It breathes also in the bottom of the water, after the manner of fishes, being, like the fish, provided with organs called gills or branchiæ, whose function is to separate the oxygen dissolved in the water from its other ingredients; these branchiæ, which are placed under the mantle, consist of a double series of very delicate canals, placed close together, not unlike the teeth of a fine comb.

Having no head, the oyster can have no brain; the nerves originate near the mouth, where a great ganglion is visible, whence issues a pair of nerves which distribute themselves in the regions of the stomach and liver, terminating in a second ganglion, situated behind the liver. The first nervous branch distributes its sensibility to the mouth and tentacles; the second, to the respiratory branchiæ.

With organs of the senses oysters are unprovided. Condemned to a sedentary life, riveted to a rock where they have been rooted, as it were, in their infancy, they neither see nor hear; touch appears to be their only sense, and that is placed in the tentacles of the mouth.

The mode of reproduction in these creatures is very peculiar. The oyster unites in itself the functions of both sexes. In the same organ are found the eggs—called spat—and the mobile corpuscles intended to fertilize them.

The eggs are yellowish in colour, and exist in prodigious numbers in each individual. We are assured that an oyster may carry as many as two millions of eggs! Nature always makes ample provision for the preservation of species; but in spite of the most ample provision here displayed, man, in his reckless and wasteful gluttony, has all but defeated Nature. A tyro can compute how many individuals a bank of oysters reckoned at twenty thousand would produce, at the rate of two millions, or eight hundred thousand, as other authorities assert, from each one annually, and it will amount to an incredible number—in fact, each would multiply itself by millions in three years; and yet, thanks to our improvident management, they get scarcer every year.

The spawning season is usually from the month of June to the end of September: during this season the oysters deposit their eggs in the folds of the mantle. During the period of incubation the eggs remain surrounded by mucous matter, which is necessary to their development, the whole having the appearance of a thick cream—this milky appearance being due to the accumulated mass of ova surrounded by the mucus: this mass undergoes various changes of colour while losing its fluidity, becoming successively yellowish, greyish, brown, and violet, a condition which indicates the near termination of the embryo state, for the oysters do not, like many other inhabitants of the sea, leave their ova; they incubate them in the folds of their mantle, and only discharge them when they can live without the maternal protection. Nothing is more curious to witness than a bank of oysters at the spawning season. Every adult individual of which it is composed throws out its phalanx of progeny. A living dust is seen to exhale from the oyster bank, troubling the water and giving it a thick cloudy appearance, which disseminates itself little by little in the liquid, until it dissipates and loses itself far from its focus of production. The spat is soon scattered far and wide by the waves; and unless the young oyster finds some solid body to which it can attach itself, it falls an inevitable victim to the larger animals which prey upon it. In this its infant state, when it has just left the protection of the parent shell, the microscope reveals the young bivalve, with its shell perfect, having an apparatus which is also a swimming pad, ready to adhere to the first solid body which the current drives it against. This pad or cushion (which is represented in Fig. 170) is furnished with vibratile cilia, disposed round the young shell. Aided by the powerful adductor muscles, with which it is also provided, this cushion is projected through the water at the will of the young inhabitant, which has every facility for the purpose: it is even said to swim about near the mother, before final dismissal from the maternal protection, seeking shelter at the least alarm between the valves of the parent shell. The pad disappears after the young oyster has finally attached itself to a permanent bed of its own.

Before this period of its life arrives, however, many are the dangers to which it is exposed: its enemies are numerous; they lie in ambush for it in every cranny! It has to guard itself against eddies and currents, which would drive it out to sea, and mud banks, in which it would be smothered. Crustaceans, worms, and polyps, with other equally voracious marine inhabitants, prey upon it. Last, but not least, come the terrible and multiplied engines of the eager fisherman—and we readily comprehend why the oyster is provided with such accumulated masses of ova.

If the young bivalve is fortunate enough to escape all the snares and dangers we have enumerated, it grows rapidly. It is quite microscopic at the period of its discharge from the parent shell; at one month it is of the size of a large pea, at the end of six months it is about three-quarters of an inch, a year after its birth an inch and a half to two inches, and finally, at the end of three years it has become merchandise; that is to say, it is in a state to be sent to the parks for preservation and feeding. In Fig. 171 we see a group of oysters,[9] of various ages, attached to a piece of wood: a being oysters of twelve to fifteen months, b five or six months, c three to four months, d one to two months, and e oysters twenty days after birth.

The species of oysters usually eaten are the common oyster (Ostrea edulis, Linn.) of our own coasts and the opposite shore, and the horsefoot oyster (O. hippopus, Linn.). On the Mediterranean coast are the rose-coloured oyster (O. rosacea, Favanue), and the milky oyster (O. lacteola, Moquin-Tandon), besides the small and little-known crested oyster (O. cristata, Born), and the folded oyster (O. plicata, Chemnitz). On the Corsican coast is the oyster called foliate (O. lamellosa, Brocchi).

There are two principal varieties of the common oyster dredged on the French coast, which differ in size and delicacy of flavour. These are the Cancale and Ostend oyster. When the first has been fed for some time in the oyster park, and has assumed its greenish hue, it is designated the Marenna oyster, from "the park" so named in the Bay of Seudre. Of this green colour we shall speak elsewhere.

Who believed Uncle Jack when he told us in our youth of oysters growing on trees, and oysters so large that they required to be carved like a round of beef—of oysters on the Coromandel coast as large as soup-plates? Nevertheless Uncle Jack's stories were true: there are oysters which require carving, and oysters have been plucked off trees. In some parts of America they grow very large. Virginia possesses nearly two million acres of oyster-beds. The sea-board of Georgia is famed for its immense supplies; the whole coast of Long Island, extending to a hundred and fifteen miles, is occupied with them, and all over the States evidence is to be seen of the estimate in which the favoured bivalve is held by the American people.

Natural oyster-beds are found in bays, estuaries, and other sheltered sinuosities of the coast, with shelving and not too rocky bottoms, such places being, according to the natural law of production, favourable for the increase of the colony. Such banks abound in every sea. In France the oyster-beds of Rochelle, of Rochefort, the Isles of Ré and Oleron, the Bay of St. Brieuc, of Cancale, and Granville, are famous for the quality of their produce.

On the Danish coast there are from forty to fifty oyster-banks, situated on the west coast of Schleswig; the best bed lying between the small isles of Sylt, Amron, Fohr, Pelworm, and Nordstrand. At the point of Jutland, and opposite Shagen, beds less productive are found.

The great oyster-beds of England extend from Gravesend, in the estuary of the Thames and Medway, along the Kentish coast on the one hand, and the estuary of the Colne and other rivers on the Essex coast. The Frith of Forth is also famous for its oyster-beds, extending from Preston Pans far up the estuary of the river; but, curiously enough, all these great banks, without exception, have been impoverished, and all but exhausted, by improvident dredging, in spite of the "close season" which has always existed.[10]

"He was a bold man who first ate an oyster," has been said before. The name of the courageous individual has not been recorded, but Mr. Bertram, in his "Harvest of the Sea," tells us a legend concerning him: "Once upon a time,"—it must have been a long time ago,—"a man of melancholy mood was walking by the shores of a picturesque estuary, listening to the monotonous murmur of the sad sea-waves, when he espied a very old and ugly oyster-shell all coated over with parasites and sea-weeds. It was so unprepossessing that he kicked it with his foot, and the animal, astonished at receiving such rude treatment on its own domain, gaped wide with indignation, preparatory to closing its bivalve still more tightly. Seeing the beautiful cream-coloured layers that shone within the shelly covering, and fancying that the interior of the shell itself must be beautiful, he lifted up the aged 'native' for further examination, inserting his finger and thumb within the valves. The irate mollusc, thinking, no doubt, that this was meant as a further insult, snapped its pearly door down upon his finger, causing him considerable pain. After releasing his wounded digit, our inquisitive gentleman very naturally put it in his mouth. 'Delightful!' exclaimed he, opening wide his eyes; 'what is this?' and again he sucked his finger. Then the great truth flashed upon him that he had found out a new delight—had, in fact, achieved the most important discovery ever made. He proceeded at once to realize the thought. With a stone he opened the oyster's stronghold, and gingerly tried a piece of the mollusc itself. 'Delicious!' he exclaimed; and there and then, with no other condiment than its own juice, with no accompaniment of foaming brown stout or pale Chablis to wash it down, no newly-cut, well-buttered brown bread, did that solitary anonymous man inaugurate the first oyster banquet."

Another story makes the act of eating the first oyster a punishment. The poetaster also had his views on the subject:

And ever since men have gone on eating oysters. Emperors and poets, princes and priests, pontiffs and statesmen, orators and painters, have feasted on the favoured bivalve.

Man has made use of the oyster from the most remote antiquity. Among the débris of festivals which precede by ages the epoch of written history, oyster-shells are found. On the "midden heaps" of northern Europe they are often discovered, mingling with other rubbish and with stone implements, evidently the refuse of very ancient feasts. We have all read of the classic feasts of the Romans, which began with oysters brought from fabulous distances. Vitellius ate oysters all day long, and the idea prevailed that he could eat a thousand. Calisthenes, the philosopher, was a passionate oyster eater; so was Caligula; Seneca the wise could eat his hundred, and the great Cicero did not despise the savoury bivalve. Lucullus had sea-water brought to his villa from the shores of the Campania, in which he bred them in great abundance for the use of his guests. To another Roman, Sergius Orata, we owe the original idea of the oyster-park. He invented the oyster-pond, in which he bred oysters, not for his own table, but for profit.

Among modern celebrities whose love of oysters is recorded, we may mention Louis XI., who feasted the learned doctors of the Sorbonne once a year on oysters. Another Louis invested his cook with an order of nobility, in reward for his skill in cooking them. Cervantes loved oysters, although he satirized oyster dealers. Marshal Turgot used to eat a hundred or two just to whet his appetite. Rousseau, Helvetius, Diderot, the Abbé Raynal, and Voltaire, are recorded lovers of oysters. Danton, Robespierre, and other of the revolutionists, frequented the oyster salons of Paris. Cambaceres was famous for his oyster feasts, and it is recorded of the great Napoleon that he always partook of the bivalve on the eve of his great battles, when they could be procured.

In short, it has been demonstrated as a gastronomic truth that there is no feast worthy of a connoisseur where oysters do not come to the front. It is their office to open the way by that gentle excitement which prepares the stomach for its sublime function, digestion; in a word, the oyster is the key of that paradise called appetite. "There is no alimentary substance, not even excepting bread, which does not produce indigestion under given circumstances," says Reveille-Parise, "but oysters never." This is an homage which is due to them: "We may eat them to-day, to-morrow, eat them always, and in profusion, without fear of indigestion." Dr. Gastaldi could swallow, we are assured, his forty dozen with impunity—quite a bank must he have eaten. He was unfortunately struck with apoplexy at table before a paté de foie gras.

Montaigne quaintly says, to be subject to colic, or deny oneself oysters, presents two evils to choose from, since one must choose between the two, and hazard something for his pleasure.

England has always been famous for its oysters, and its pearls are said to have been the chief incentive to Cæsar's invasion. It is not, therefore, to be supposed that British magnates could be indifferent to the "native." But the bivalve has perhaps been more celebrated, in prose and verse, north of the Tweed than south, where silent enjoyment is more relished than noisy demonstration. Dugald Stewart, Hume, Cullen, and other Scotch philosophers of the last centuries, had their "oyster ploys" as an accompaniment to their "high jinks," in the quaint and dingy taverns of the old town of Edinburgh; and what the bivalve has been to modern celebrities let the Noctes Ambrosianæ tell.

The oyster may thus be said to be the palm and glory of the table. It is considered the very perfection of digestive aliment. From Stockholm to Naples, from London to St. Petersburg, it is always in request. At St. Petersburg they cost a paper rouble (nearly one shilling), and at Stockholm fivepence each. For the last year or two the English amphitryon must pay from two shillings to half a crown a dozen for choice natives.

For his daily nourishment a man of middle size requires a quantity of food equal to twelve ounces of dry nitrogenized substance. According to this calculation, it would be necessary to swallow sixteen dozen of oysters to make up the necessary quantity. The small proportion of nutritive matter explains the extreme digestibility of the oyster. It also explains the immense consumption of them attributed to the Emperor Vitellius. The oyster is nothing more than water slightly gelatinized. Without this Vitellius, all emperor and master of the world as he was, never could have absorbed twelve hundred oysters by way of whetting his appetite.

The gourmets were long of opinion that the quadrangular pad or cushion in the bivalve was the most savoury and exciting part. Certain distinguished amateur performers adopted and proclaimed the principle of dividing transversely the body of the mollusc, and eating the cushion only. Natural history explains this gastronomical discovery. It recognizes the fact that the bile secreted by the liver is contained in this substance, that it accelerates while it exhausts the qualitative surface of the tongue and palate, aiding also the functions of the stomach.

We have described the organization of the oyster, and we have said something of the enjoyment it confers. Did it ever occur to the various Societies for the Prevention of Cruelty to Animals to consider whether the oyster might not be a very proper object of their care? Let us see if we can bridge over the gulf.

We commence operations upon them by dragging them violently from their own element. We place them out afterwards in water-parks, more or less briny and unsuitable, filled with villainous green matter, which presently pervades their breathing apparatus, impregnating, obstructing, and colouring it; the oyster swells, fattens, and soon attains that state of obesity which verges on sickness.

When the poor creature has attained its livid green colour, it is fished up a second time. Alas! it is now doomed neither to return to the sea, to the park, nor to its native rock. It has water at its disposal only in the very small quantity which it can retain between its two valves, a quantity scarcely sufficient to keep away asphyxia. It is shut up in an obscure narrow basket—an ignoble prison-house, without door or window. It seems to be forgotten that they are animals: they are piled upon the pavement like inert merchandise. The basket is carried by railway; the animal, shaken out of existence almost, is at last landed at the door of some oyster-shop; and this is the critical moment for the poor bivalve! It is thrown into a tub with clean water enough to remind it of its former luxurious life, when it is again seized by the pitiless master of its fate. With a great knife he brutally opens the shell, cuts through the muscle by which it adheres to the valve, and violently detaches it, after breaking the hinges. It is now laid out on a plate, exposed to every current of air, and in this state of suffering it is carried to the table. There the pitiless gourmet powders it over with the most pungent pepper, squeezes over the wounded and still bleeding body the abomination of its race in the shape of citric acid or vinegar, and then, alas! with a silver knife which cannot cut, he wounds and bruises it a second time; or, worse still, he saws and tears and rends it from its remaining shell; he seizes it with a three-pronged fork, which is driven through liver and stomach, and throws it into his mouth, where the teeth cut, crush, and grind it, and, while still living and palpitating, reduced to an inanimate mass, these organs first triturate it, while our gourmet is drinking its blood, its fat, and its bile.

We have said that oysters have no head, no arms—that they are without eyes (although that is disputed), without ears, and without nose; that they do not stir—that they never cry!

Agreed, perfectly agreed; but all these negatives do not prevent its being sensible to pain. Two eminent Germans, Herren Brandt and Ratzeburg, have proved that they possess a well-developed nervous system, and if they possess sensation they must suffer. "Can an animal with nerves be impassible?" asks Voltaire. "Can we suppose any such impossible contradiction in Nature?"

There is consolation, however, for all concerned. Let the humanitarian fishermen, oyster-dredgers, merchants, and consumers, console themselves with the vast difference between the helpless imperfect mollusc and the higher classes of animals. In the case of the former we swallow the animal, scarcely thinking of its animal nature. It is the denizen of another element, lives in a medium in which we cannot exist, presents itself in a form, so to speak, degraded—an obscure vitality, motions undecided, and habits scarcely discernible. We may therefore see the oyster mutilated, mutilate them oneself, grind them, and swallow them, without emotion or remorse.

A learned naturalist dwelling on the sea-shore possessed himself one day of a dozen oysters. He wished to study their organization; he turned them, and turned them again, examined their several parts inside and out. He made drawings of and described them, and, having satisfied himself that he had exhausted Science in observing, he swallowed them; the interesting bivalves had lost nothing of their excellence, and the examination did not prejudice the consummation.

Oyster fishing is pursued in a very different manner in different countries. Round Minorca, divers, with hammers attached to the right hand, descend to the depth of a dozen fathoms, and bring up in their left hand as many of the bivalves as they can carry, two fishermen, usually associating for the purpose, diving alternately until the boat is filled. On the English and French coasts the dredge is employed, as represented in Pl. XII. This operation is necessary to keep down vegetation, which would stifle the oysters; the engine is of iron, and is very heavy. It is thrown overboard, and descends to the bottom of the sea, which it ploughs and scrapes up, detaching the oysters, and throwing them into a net attached to the dredge. In this process oysters, large and small, are torn from their native bed, some going into the net, but a larger number, old and young, are torn from their native bed, and buried in the mud. It would be difficult to imagine a more destructive process; and when the habits of the oyster are considered, it is evidently one admirably contrived to destroy the race.