The employment of shells as a medium of exchange was exceedingly common amongst uncivilised tribes in all parts of the world, and has by no means yet become obsolete. One of the commonest species thus employed is the ‘money cowry’ (Cypraea moneta, L.), which stands almost alone in being used entire, while nearly all the other forms of shell money are made out of portions of shells, thus requiring a certain amount of labour in the process of formation.

One of the earliest mentions of the cowry as money occurs in an ancient Hindoo treatise on mathematics, written in the seventh century A.D. A question is propounded thus: ‘the ¼ of ¹/₁₆ of ⅕ of ¾ of ⅔ of ½ a dramma was given to a beggar by one from whom he asked an alms; tell me how many cowry shells the miser gave.’ In British India about 4000 are said to have passed for a shilling, but the value appears to differ according to their condition, poor specimens being comparatively worthless. According to Reeve[204] a gentleman residing at Cuttack is said to have paid for the erection of his bungalow entirely in cowries. The building cost him 4000 Rs. sicca (about £400), and as 64 cowries = 1 pice, and 64 pice = 1 rupee sicca, he paid over 16,000,000 cowries in all.

Cowries are imported to England from India and other places for the purposes of exportation to West Africa, to be exchanged for native products. The trade, however, appears to be greatly on the decrease. At the port of Lagos, in 1870, 50,000 cwts. of cowries were imported.[205]

A banded form of Nerita polita was used as money in certain parts of the South Pacific. The sandal-wood imported into the China market is largely obtained from the New Hebrides, being purchased of the natives in exchange for Ovulum angulosum, which they especially esteem as an ornament. Sometimes, as in the Duke of York group, the use of shell money is specially restricted to certain kinds of purchase, being employed there only in the buying of swine.

Among the tribes of the North-West coasts of America the common Dentalium indianorum used to form the standard of value, until it was superseded, under the auspices of the Hudson’s Bay Company, by blankets. A slave was valued at a fathom of from 25 to 40 of these shells, strung lengthwise. Inferior or broken specimens were strung together in a similar way, but were less highly esteemed; they corresponded more to our silver and copper coins, while the strings of the best shells represented gold.

The wampum of the eastern coast of North America differed from all these forms of shell money, in that it required a laborious process for its manufacture. Wampum consisted of strings of cylindrical beads, each about a quarter of an inch in length and half that breadth. The beads were of two colours, white and purple, the latter being the more valuable. Both were formed from the common clam, Venus mercenaria, the valves of which are often stained with purple at the lower margins, while the rest of the shell is white. Cut small, ground down, and pierced, these shells were converted into money, which appears to have been current along the whole sea-board of North America from Maine to Florida, and on the Gulf Coast as far as Central America, as well as among the inland tribes east of the Mississippi. Another kind of wampum was made from the shells of Busycon carica and B. perversum. By staining the wampum with various colours, and disposing these colours in belts in various forms of arrangement, the Indians were able to preserve records, send messages, and keep account of any kind of event, treaty, or transaction.

Another common form of money in California was Olivella biplicata, strung together by rubbing down the apex. Button-shaped disks cut from Saxidomus arata and Pachydesma crassatelloides, as well as oblong pieces of Haliotis, were employed for the same purpose, when strung together in lengths of several yards.

“There is a curious old custom,” writes Mr. W. Anderson Smith,[206] “that used formerly to be in use in this locality [the western coast of Scotland], and no doubt was generally employed along the sea-board, as the most simple and ready means of arrangement of bargains by a non-writing population. That was, when a bargain was made, each party to the transaction got one half of a bivalve shell—such as mussel, cockle, or oyster—and when the bargain was implemented, the half that fitted exactly was delivered up as a receipt! Thus a man who had a box full of unfitted shells might be either a creditor or a debtor; but the box filled with fitted shells represented receipted accounts. Those who know the difficulty of fitting the valves of some classes of bivalves will readily acknowledge the value of this arrangement.”

Shells are employed for use and for ornament by savage—and even by civilised—tribes in all parts of the world. The natives of Fiji thread the large Turbo argyrostoma and crenulatus as weights at the edge of their nets, and also employ them as sinkers. A Cypraea tigris cut into two halves and placed round a stone, with two or three showy Oliva at the sides, is used as a bait for cuttles. Avicula margaritifera is cut into scrapers and knives by this and several other tribes. Breast ornaments of Chama, grouped with Solarium perspectivum and Terebra duplicata are common among the Fijians, who also mount the Avicula on a backing of whales’ teeth sawn in two, for the same purpose. The great Orange Cowry (Cypraea aurantiaca) is used as a badge of high rank among the chieftains. One of the most remarkable Fijian industries is the working of whales’ teeth to represent this cowry, as well as the commoner C. talpa, which is more easily imitated.

Among the Solomon islanders, cowries are used to ornament their shields on great field days, and split cowries are worn as a necklace, to represent human teeth. Small bunches of Terebellum subulatum are worn as earrings, and a large valve of Avicula is employed as a head ornament in the centre of a fillet. The same islanders ornament the raised prows of their canoes, as well as the inside of the stern-post, with a long row of single Natica.

The native Papuans employ shells for an immense variety of purposes. Circlets for the head are formed of rows of Nassa gibbosula, rubbed down till little but the mouth remains. Necklaces are worn which consist of strings of Oliva, young Avicula, Natica melanostoma, opercula of Turbo, and valves of a rich brown species of Cardium, pendent at the end of strings of the seeds known as Job’s tears. Struthiolaria is rubbed down until nothing but the mouth is left, and worn in strings round the neck. This is remarkable, since Struthiolaria is not a native Papuan shell, and indeed occurs no nearer than New Zealand. Sections of Melo are also worn as a breast ornament, dependent from a necklace of cornelian stones. Cypraea erosa is used to ornament drinking bowls, and Ovulum ovum is attached to the native drums, at the base of a bunch of cassowary feathers, as well as being fastened to the handle of a sago-beater.

In the same island, the great Turbo and Conus millepunctatus are ground down to form bracelets, which are worn on the biceps. The crimson lip of Strombus luhuanus is cut into beads and perforated for necklaces. Village elders are distinguished by a single Ovulum verrucosum, worn in the centre of the forehead. The thick lip of Cassis cornuta is ground down to form nose pieces, 4½ inches long. Fragments of a shell called Kaïma (probably valves of a large Spondylus) are worn suspended from the ears, with little wisps of hair twisted up and thrust through a hole in the centre. For trumpets, Cassis cornuta, Triton tritonis, and Ranella lampas are used, with a hole drilled as a mouthpiece in one of the upper whorls. Valves of Batissa, Unio, and Mytilus are used as knives for peeling yams. Spoons for scooping the white from the cocoa-nut are made from Avicula margaritifera. Melo diadema is used as a baler in the canoes.[207]

In the Sandwich Islands Melampus luteus is worn as a necklace, as well as in the Navigator Islands. A very striking necklace, in the latter group, is formed of the apices of a Nautilus, rubbed down to show the nacre. The New Zealanders use the green opercula of a Turbo, a small species of Venus, and Cypraea asellus to form the eyes of their idols. Fish-hooks are made throughout the Pacific of the shells of Avicula and Haliotis, and are sometimes strengthened by a backing made of the columella of Cypraea arabica. Small axe-heads are made from Terebra crenulata ground down (Woodlark I.), and larger forms are fashioned from the giant Tridacna (Fiji).

Shells are used to ornament the elaborate cloaks worn by the women of rank in the Indian tribes of South America. Specimens of Ampullaria, Orthalicus, Labyrinthus, and Bulimulus depend from the bottom and back of these garments, while great Bulimi, 6 inches long, are worn as a breast ornament, and at the end of a string of beads and teeth.[208]

The chank-shell (Turbinella rapa) is of especial interest from its connexion with the religion of the Hindoos. The god Vishnu is represented as holding this shell in his hand, and the sinistral form of it, which is excessively rare, is regarded with extraordinary veneration. The chank appears as a symbol on the coins of some of the ancient Indian Empires, and is still retained on the coinage of the Rajah of Travancore.

The chief fishery of the chank-shell is at Tuticorin, on the Gulf of Manaar, and is conducted during the N. E. monsoon, October-May. In 1885–86 as many as 332,000 specimens were obtained, the net amount realised being nearly Rs.24,000. In former days the trade was much more lucrative, 4 or 5 millions of specimens being frequently shipped. The government of Ceylon used to receive £4000 a year for licenses to fish, but now the trade is free. The shells are brought up by divers from 2 or 3 fathoms of water. In 1887 a sinistral specimen was found at Jaffna, which sold for Rs.700.[209] Nearly all the shells are sent to Dacca, where they are sliced into bangles and anklets to be worn by the Hindoo women.

Perhaps the most important industry which deals only with the shells of Mollusca is that connected with the ‘pearl-oyster.’ The history of the trade forms a small literature in itself. It must be sufficient here to note that the species in question is not an ‘oyster,’ properly so called, but an Avicula (margaritifera Lam.). The ‘mother-of-pearl,’ which is extensively employed for the manufacture of buttons, studs, knife-handles, fans, card-cases, brooches, boxes, and every kind of inlaid work, is the internal nacreous laminae of the shell of this species. The most important fisheries are those of the Am Islands, the Soo-loo Archipelago, the Persian Gulf, the Red Sea, Queensland, and the Pearl Islands in the Bay of Panama. The shell also occurs in several of the groups of the South Pacific—the Paumotu, Gambier and Navigator Islands, Tahiti being the centre of the trade—and also on the coasts of Lower California.[210]

Pearls are the result of a disease in the animal of this species of Avicula and probably in all other species within which they occur. When the Avicula is large, well formed, and with ample space for individual development, pearls scarcely occur at all, but when the shells are crowded together, and become humped and distorted, as well as affording cover for all kinds of marine worms and parasitic creatures, then pearls are sure to be found. Pearls of inferior value and size are also produced by Placuna placenta, many species of Pinna, the great Tridacna, the common Ostrea edulis, and several other marine bivalves. They are not uncommon in Unio and Anodonta, and the common Margaritana margaritifera of our rapid streams is still said to be collected, in some parts of Wales, for the purpose of extracting its small ‘seed-pearls.’ Pink pearls are obtained from the giant conch-shell of the West Indies (Strombus gigas), as well as from certain Turbinella.

In Canton, many houses are illuminated almost entirely by skylights and windows made of shells, probably the semitransparent valves of Placuna placenta. In China lime is commonly made of ground cockle-shells, and, when mixed with oil, forms an excellent putty, used for cementing coffins, and in forming a surface for the frescoes with which the gables of temples and private houses are adorned. Those who suffer from cutaneous diseases, and convalescents from small-pox, are washed in Canton with the water in which cockles have been boiled.[211]

A recent issue of the Peking Gazette contains a report from the outgoing Viceroy of Fukhien, stating that he had handed over the insignia of office to his successor, including inter alia the conch-shell bestowed by the Throne. A conch-shell with a whorl turning to the right, i.e. a sinistral specimen, is supposed when blown to have the effect of stilling the waves, and hence is bestowed by the Emperor upon high officers whose duties oblige them to take voyages by sea. The Viceroy of Fukhien probably possesses one of these shells in virtue of his jurisdiction over Formosa, to which island periodical visits are supposed to be made.[212]

Shells appear to be used occasionally by other species besides man. Oyster-catchers at breeding time prepare a number of imitation nests in the gravel on the spit of land where they build, putting bits of white shell in them to represent eggs.[213] This looks like a trick in order to conceal the position of the true nest. According to Nordenskjöld, when the eider duck of Spitzbergen has only one or two eggs in its nest, it places a shell of Buccinum glaciale beside them. The appropriation of old shells by hermit-crabs is a familiar sight all over the world. Perhaps it is most striking in the tropics, where it is really startling, at first experience, to meet—as I have done—a large Cassis or Turbo, walking about in a wood or on a hill side at considerable distances from the sea. A Gephyrean (Phascolion strombi) habitually establishes itself in the discarded shells of marine Mollusca. Certain Hymenoptera make use of dead shells of Helix hortensis in which they build their cells.[214] Magnus believes that in times when heavy rains prevail, and the usual insects do not venture out, certain flowers are fertilised by snails and slugs crawling over them, e.g. Leucanthemum vulgare by Limax laevis.[215]

Mollusca as Food for Man.—Probably there are few countries in the world in which less use is made of the Mollusca as a form of food than in our own. There are scarcely ten native species which can be said to be at all commonly employed for this purpose. Neighbouring countries show us an example in this respect. The French, Italians, and Spanish eat Natica, Turbo, Triton, and Murex, and, among bivalves, Donax, Venus, Lithodomus, Pholas, Tapes, and Cardita, as well as the smaller Cephalopoda. Under the general designation of clam the Americans eat Venus mercenaria, Mya arenaria, and Mactra solidissima. In the Suez markets are exposed for sale Strombus and Melongena, Avicula and Cytherea. At Panama Donax and Solen are delicacies, while the natives also eat the great Murex and Pyrula, and even the huge Arca grandis, which lives embedded in the liquid river mud.

The common littoral bivalves seem to be eaten in nearly all countries except our own, and it is therefore needless to enumerate them. The Gasteropoda, whose habits are scarcely so cleanly, seem to require a bolder spirit and less delicate palate to venture on their consumption.

The Malays of the East Indian islands eat Telescopium fuscum and Pyrazus palustris, which abound in the mangrove swamps. They throw them on their wood fires, and when they are sufficiently cooked, break off the top of the spire and suck the animal out through the opening. Haliotis they take out of the shell, string together, and dry in the sun. The lower classes in the Philippines eat Arca inaequivalvis, boiling them as we do mussels.[216] In the Corean islands a species of Monodonta and another of Mytilus are quite peppery, and bite the tongue; our own Helix revelata, as I can vouch from personal experience, has a similar flavour. Fusus colosseus, Rapana bezoar, and Purpura luteostoma are eaten on the southern coasts of China; Strombus luhuanus, Turbo chrysostomus, Trochus niloticus, and Patella testudinaria, by the natives of New Caledonia; Strombus gigas and Livona pica in the West Indies; Turbo niger and Concholepas peruvianus on the Chilian coasts; four species of Strombus and Nerita, one each of Purpura and Turbo, besides two Tridacna and one Hippopus, by the natives of British New Guinea. West Indian negroes eat the large Chitons which are abundant on their rocky coasts, cutting off and swallowing raw the fleshy foot, which they call ‘beef,’ and rejecting the viscera. Dried cephalopods are a favourite Chinese dish, and are regularly exported to San Francisco, where the Chinamen make them into soup. The ‘Challenger’ obtained two species of Sepia and two of Loligo from the market at Yokohama.

The insipidity of fresh-water Mollusca renders them much less desirable as a form of food. Some species of Unionidae, however, are said to be eaten in France. Anodonta edulis is specially cultivated for food in certain districts of China, and the African Aetheriae are eaten by negroes. Navicella and Neritina are eaten in Mauritius, Ampullaria and Neritina in Guadeloupe, and Paludina in Cambodia.

The vast heaps of empty shells known as ‘kitchen-middens,’ occur in almost every part of the world. They are found in Scotland, Denmark, the east and west coasts of North America, Brazil, Tierra del Fuego, Australia and New Zealand, and are sometimes several hundred yards in length. They are invariably composed of the edible shells of the adjacent coast, mixed with bones of Mammals, birds, and fish. From their great size, it is believed that many of them must have taken centuries to form.

Pre-eminent among existing shell-fish industries stands the cultivation of the oyster and the mussel, a more detailed account of which may prove interesting.

The cultivation of the oyster[217] as a luxury of food dates at least from the gastronomic age of Rome. Every one has heard of the epicure whose taste was so educated that

The first artificial oyster-cultivator on a large scale appears to have been a certain Roman named Sergius Orata, who lived about a century B.C. His object, according to Pliny the elder,[219] was not to please his own appetite so much as to make money by ministering to the appetites of others. His vivaria were situated on the Lucrine Lake, near Baiae, and the Lucrine oysters obtained under his cultivation a notoriety which they never entirely lost, although British oysters eventually came to be more highly esteemed. He must have been a great enthusiast in his trade, for on one occasion when he became involved in a law-suit with one of the riparian proprietors, his counsel declared that Orata’s opponent made a great mistake if he expected to damp his ardour by expelling him from the lake, for, sooner than not grow oysters at all, he would grow them upon the roof of his house.[220] Orata’s successors in the business seem to have understood the secret of planting young oysters in new beds, for we are told that specimens brought from Brundisium and even from Britain were placed for a while in the Lucrine Lake, to fatten after their long journey, and also to acquire the esteemed “Lucrine flavour.”

Oysters are ‘in season’ whenever there is an ‘r’ in the month, in other words, from September to April. ‘Mensibus erratis,’ as the poet has it, ‘vos ostrea manducatis!’ It has been computed that the quantity annually produced in Great Britain amounts to no less than sixteen hundred million, while in America the number is estimated at five thousand five hundred million, the value being over thirteen million dollars, and the number of persons employed fifty thousand. Arcachon, one of the principal French oyster-parks, has nearly 10,000 acres of oyster beds, the annual value being from eight to ten million francs; in 1884–85, 178,359,000 oysters were exported from this place alone. In the season 1889–90, 50,000 tons of oysters were consumed in London.

Few will now be found to echo the poet Gay’s opinion:

There were halcyon days in England once, when oysters were to be procured at 8d. the bushel. Now it costs exactly that amount before a bushel, brought up the Thames, can even be exposed for sale at Billingsgate (4d. porterage, 4d. market toll), and prime Whitstable natives average from 3½d. to 4d. each. The principal causes of this rise in prices, apart from the increased demand, are (1) over-dredging; (2) ignorant cultivation, and to these may be added (3) the effect of bad seasons in destroying young oysters, or preventing the spat from maturing. Our own principal beds are those at Whitstable, Rochester, Colchester, Milton (famous for its ‘melting’ natives), Faversham, Queenborough, Burnham, Poole, and Carlingford in Co. Down, and Newhaven, near Edinburgh.

The oyster-farms at Whitstable, public and private, extend over an area of more than 27 square miles. The principal of these is a kind of joint-stock company, with no other privilege of entrance except birth as a free dredgeman of the town. When a holder dies, his interest dies with him. Twelve directors, known as “the Jury,” manage the affairs of the company, which finds employment for several thousand people, and sometimes turns over as much as £200,000 a year. The term ‘Natives,’ as applied to these Whitstable or to other English oysters, requires a word of explanation. A ‘Native’ oyster is simply an oyster which has been bred on or near the Thames estuary, but very probably it may be developed from a brood which came from Scotland or some other place at a distance. For some unexplained reason, oysters bred on the London clay acquire a greater delicacy of flavour than elsewhere. The company pay large sums for brood to stock their own grounds, since there can be no certainty that the spat from their own oysters will fall favourably, or even within their own domains at all. Besides purchases from other beds, the parks are largely stocked with small oysters picked up along the coast or dredged from grounds public to all, sometimes as much as 50s. a bushel being paid for the best brood. It is probably this system of transplanting, combined with systematic working of the beds, which has made the Whitstable oyster so excellent both as to quality and quantity of flesh. The whole surface of the ‘layings’ is explored every year by the dredge, successive portions of the ground being gone over in regular rotation, and every provision being made for the well-being of the crop, and the destruction of their enemies. For three days of every week the men dredge for ‘planting,’ i.e. for the transference of suitable specimens from one place to another, the separation of adhering shells, the removal of odd valves and of every kind of refuse, and the killing off of dangerous foes. On the other three days they dredge for the market, taking care only to lift such a number as will match the demand.

The Colne beds are natural beds, as opposed to the majority of the great working beds, which are artificial. They are the property of the town of Colchester, which appoints a water-bailiff to manage the concern. Under his direction is a jury of twelve, who regulate the times of dredging, the price at which sales are to be made, and are generally responsible for the practical working of the trade. Here, and at Faversham, Queenborough, Rochester, and other places, ‘natives’ are grown which rival those of Whitstable.

There can be no question, however, that the cultivation of oysters by the French is far more complete and efficient than our own, and has reached a higher degree of scientific perfection combined with economy and solid profits. And yet, between 40 and 50 years ago, the French beds were utterly exhausted and unproductive, and showed every sign of failure and decay. It was in 1858 that the celebrated beds on the Ile de Ré, near Rochelle, were first started. Their originator was a certain shrewd stone-mason, by name Boeuf. He determined to try, entirely on his own account, whether oysters could not be made to grow on the long muddy fore-shore which is left by the ebb of the tide. Accordingly, he constructed with his own hands a small basin enclosed by a low wall, and placed at the bottom a number of stones picked out of the surrounding mud, stocking his ‘parc’ with a few bushels of healthy young brood. The experiment was entirely successful, in spite of the jeers of his neighbours, and Boeuf’s profits, which soon began to mount up at an astonishing rate, induced others to start similar or more extensive farms for themselves. The movement spread rapidly, and in a few years a stretch of miles of unproductive mud banks was converted into the seat of a most prosperous industry. The general interests of the trade appear to be regulated in a similar manner to that at Whitstable; delegates are appointed by the various communities to watch over the business as a whole, while questions affecting the well-being of oyster-culture are discussed in a sort of representative assembly.

At the same time as Boeuf was planting his first oysters on the shores of the Ile de Ré, M. Coste had been reporting to the French government in favour of such a system of ostreiculture as was then practised by the Italians in the old classic Lakes Avernus and Lucrinus. The principle there adopted was to prevent, as far as possible, the escape of the spat from the ground at the time when it is first emitted by the breeding oyster. Stakes and fascines of wood were placed in such a position as to catch the spat and give it a chance of obtaining a hold before it perished or was carried away into the open sea. The old oyster beds in the Bay of St. Brieuc were renewed on this principle, banks being constructed and overlaid with bundles of wood to prevent the escape of the new spat. The attempt was entirely successful, and led to the establishment or re-establishment of those numerous parcs, with which the French coast is studded from Brest to the Gironde. The principal centres of the industry are Arcachon, Auray, Cancale, and la Teste.

It is at Marennes, in Normandy, that the production of the celebrated ‘green oyster’ is carried out, that especial luxury of the French epicure. Green oysters are a peculiarly French taste, and, though they sometimes occur on the Essex marshes, there is no market for them in England. The preference for them, on the continent, may be traced back as early as 1713, when we find a record of their having been served up at a supper given by an ambassador at the Hague. Green oysters are not always green, it is only after they are placed in the ‘claires,’ or fattening ponds, that they acquire the hue; they never occur in the open sea. The green colour does not extend over the whole animal, but is found only in the branchiae and labial tentacles, which are of a deep blue-green. Various theories have been started to explain the ‘greening’ of the mollusc; the presence of copper in the tanks, the chlorophyll of marine algae, an overgrowth of some parasite, a disease akin to liver complaint, have all found their advocates. Prof. Lankester seems to have established[221] the fact,—which indeed had been observed 70 years before by a M. Gaillon,—that the greening is due to the growth of a certain diatom (Navicula ostrearia) in the water of the tanks. This diatom, which is of a deep blue-green colour, appears from April to June, and in September. The oyster swallows quantities of the Navicula; the pigment enters the blood in a condition of chemical modification, which makes it colourless in all the other parts of the body, but when the blood reaches the gills the action of the secretion cells causes the blue tint to be restored. The fact that the colour is rather green than blue in the gills, which are yellowish brown, is due to certain optical conditions.

Not till the young white oyster has been steeped for several years in the muddy waters of the ‘claires’ does it acquire the proper tint to qualify it for the Parisian restaurant. The ‘claires’ are each about 100 feet square, surrounded by low broad banks of earth, about 3 feet high and 6 feet thick at the base. Before the oysters are laid down, the gates which admit the tide are carefully opened and shut a great many times, in order to collect a sufficient amount of the Navicula. When this is done, the beds are formed, and are not again overflowed by the sea, except at very high tides. The oysters are shifted from one ‘claire’ to another, in order to perfect the ‘greening’ process. About fifty million of these ‘huitres de Marennes’ are produced annually, yielding a revenue of 2,500,000 francs.

It appears, from the experience of one of the most enthusiastic of French oyster-growers (Dr. Kemmerer), that oysters grow best in muddy water, and breed best in clear water. Thus the open sea is the place where the spat should fall and be secured, and, as soon as it is of a suitable size, it should be transferred to the closed tank or reservoir, where it will find the quiet and the food (confervae, infusoria, minute algae) which are so requisite for its proper growth. In muddy ground the animal and phosphorous matter increases, and the flesh becomes fatter and more oily. A sudden change from the clear sea-water to the muddy tank is inadvisable, and thus a series of shiftings through tanks with water of graduated degrees of nourishment is the secret of proper oyster cultivation.

The American oyster trade is larger even than the French. The Baltimore oyster beds in the Chesapeake River and its tributaries cover 3000 acres, and produce an annual crop of 25 million bushels, as many as 100,000 bushels being sometimes taken from Chesapeake Bay in a single day. Baltimore is the centre of the tinned oyster trade, while that in raw oysters centres in New York. Most of the beds whose produce is carried to New York are situated in New Jersey, Connecticut, Delaware, or Virginia. The laws of these states do not allow the beds to be owned by any but resident owners, and the New York dealers have consequently to form fictitious partnerships with residents near the various oyster beds, supply them with money to buy the beds and plant the oysters, and then give them a share in the profits. It has been estimated that from the Virginia beds 4,000,000 bushels of oysters are carried every year to Fair Haven in New England, 4,000,000 to New York, 3,000,000 to Providence, and 2,000,000 each to Boston, Philadelphia, and Baltimore. The American ‘native’ (O. virginica) is a distinct species from our own, being much larger and longer in proportion to its breadth; it is said to be also much more prolific.

According to Milne-Edwards,[222] in the great oyster parks on the coasts of Calvados, the oysters are educated to keep their shells closed when out of water, and so retain water enough inside to keep their gills moist, and arrive at their destination in good condition. As soon as an oyster is taken out of the sea, it closes its shells, and keeps them closed until the shock of removal has passed away, or perhaps until the desirability of a fresh supply of water suggests itself. The men take advantage of this to exercise the oysters, removing them from the sea for longer and longer periods. In time this has the desired effect; the well-educated mollusc learns that it is hopeless to ‘open’ when out of the water, and so keeps his shell closed and his gills moist, and his general economy in good condition.

Oysters have been known to live entirely out of water for a considerable time. Prof. Verrill once noticed[223] a large cluster of oysters attached to an old boot, hanging outside a fish-shop in Washington. They had been taken out of the water on about 10th December, and on 25th February following some of the largest were still alive. It was noticed that all those which survived had the hinge upward and the ventral edge downward, this being the most favourable position possible for the retention of water within the gill-cavity, since the edge of the mantle would pack against the margins of the shell, and prevent the water from leaking away.

Such a succulent creature as the oyster has naturally many enemies. One of the worst of these is the ravenous Starfish, or Five-finger. His omnivorous capacities are well described by a clever writer and shrewd observer of nature: “Here is one doubled up like a sea-urchin, brilliant of hue, and when spread out quite 16 inches in diameter; where, and oh where, can you obtain a prey? The hoe we carry is thrust out and the mass dragged shorewards, when the rascal disgorges two large dog-whelks he has been in the process of devouring. We feel a comfortable glow of satisfaction to think that this enemy of our oyster-beds is also the enemy of our other enemy, this carnivorous borer. Here, quite close alongside, is another, only inferior in size, and we drag him ashore likewise, to find that the fellow has actually had the courage and audacity to suck the contents out of a large horse-mussel (Modiola), the strong muscle alone remaining undevoured. We proceed along but a short way when we meet with still another in the curled-up condition in which they gorge themselves, and as we drag it shorewards the shell of a Tapes pullastra drops from the relaxing grasp of the ogre. Slowly the extended stomach returns to its place, and the monster settles back to an uncomfortable after-dinner siesta on an exposed boulder; for the starfish wraps its turned-out stomach around the prey it has secured, in place of attempting to devour the limey covering in which most of its game is protected. Once the mouth of the shell is enclosed in the stomach of the starfish, the creature soon sickens, the hinge-spring relaxes its hold, and the shell opening permits the starfish to suck out the gelatinous contents, and cast free the calcareous skeleton.”[224]

According to other observers the starfish seizes the oyster with two of his fingers, while with the other three he files away the edge of the flat or upper valve until the points of contact with the round valve are reduced almost to nothing; then he can introduce an arm, and the rest is easy work. Others suggest that the starfish suffocates the oyster by applying two of its fingers so closely to the edge of the valves that the oyster is unable to open them; after a while the vital powers relax and the shell gapes. The Rev. J. G. Wood holds[225] that the starfish pours a secretion from its mouth which “paralyses the hinge muscle and causes the shell to open.” Sometimes in a single night a whole bed of oysters will be totally destroyed by an invasion of starfish. Another dreaded enemy is the ‘whelk,’ a term which includes Purpura lapillus, Murex erinaceus, Buccinum undatum, and probably also Nassa reticulata. All these species perforate the shell with the end of their radula, and then suck out the contents through the neatly drilled hole. Skate fish are the cause of terrible destruction in the open beds, and a scarcely less dangerous visitant is the octopus. Crabs crush the young shells with their claws, and are said to gather in bands and scratch sand or mud over the larger specimens, which makes them open their shells. Yet another, and perhaps unconscious, foe is found in the common mussel, which takes up room meant for the young oysters, grows over the larger individuals, and harbours all sorts of refuse between and under its closely packed ranks. Cliona, a parasitic sponge, bores in between the layers of the oyster’s shell, pitting them with tiny holes (corresponding to its oscula), and disturbing the inmate, who has constantly to construct new layers of shell from the inside. Weed, annelids, ‘blubber,’ shifting sand or mud, sewage or any poisoning of the water, are seriously harmful to the oyster’s best interests. A very severe winter is often the cause of wholesale destruction in the beds. According to the Daily News of 26th March 1891, the Whitstable oyster companies lost property to the value of £30,000 in the exceptionally cold winter of 1890–91, when, on the coast of Kent, the surface temperature of the sea sank below 32°, and the advancing tide pushed a small ice-floe before it. Two million oysters were laid down in one week of the following spring, to make up for the loss. During the severe winter of 1892–93 extraordinary efforts were made at Hayling I. to protect the oysters from the frost. Twenty million oysters were placed in ponds for the winter, and a steam-engine was for days employed to keep the ponds thawed and supplied with water, while large coal and coke fires were kept burning at the edge of the ponds.[226] On the other hand, the unusually warm and sunny summer of 1893 is said to have resulted in the finest fall of spat known in Whitstable for fifty years.[227]

The reproductive activity of the oyster is supposed to commence about the third year. Careful research has shown[228] that the sexes in the English oyster are not separate, but that each individual is male as well as female, producing spermatozoa as well as ova in the same gland. Here, however, two divergent views appear. Some authorities hold that the oyster does not fecundate its own eggs, but that this operation is performed by spermatozoa emitted by other specimens. It is believed that, in each individual, the spermatozoa arrive at maturity first, and that the ova are not produced until after the spermatozoa have been emitted; thus the oyster is first male and then female, morphologically hermaphrodite, but physiologically unisexual. Others are of opinion that the oyster does fecundate its own eggs, ova being first produced, and passed into the infrabranchial chamber—the ‘white-sick’ stage—and then, after an interval, spermatozoa being formed and fecundating these ova—the ‘black-sick’ stage. In this latter view the oyster is first female and then male, and is, both morphologically and physiologically, hermaphrodite. The old view, that ‘black-sick’ oysters are the male, and ‘white-sick’ the female, is therefore quite incorrect.

The ova, in their earliest stage, consist of minute oval clusters of globules floating in a transparent mucus. They pass from the ovary into the gills and folds of the mantle, and are probably fecundated within the excretory ducts of the ovary, before arriving in the mantle chamber. In this stage the oyster is termed ‘white-sick.’ In about a fortnight, as the course of development proceeds, the fertilised ova become ciliated at one end (the so-called veliger stage, p. 131), and soon pigment appears in various parts of the embryos, giving them a darker colour, which varies from grayish to blue, and thus the white-sick oyster becomes ‘black-sick.’ When the black spat emerge, they are still furnished with cilia for their free-swimming life. This is of very short duration, for unless the embryo finds some suitable ground on which to affix itself within forty-eight hours, it perishes. As the spat escapes from the parent oyster, which slightly opens its valves and blows the spat out in jets, it resembles a thick cloud in the water, and is carried about at the mercy of wind and tide. April to August are the usual spawning months, warm weather being apparently an absolute necessity to secure the adhering of the spat. A temperature of 65° to 72° F. seems requisite for their proper deposit. Thus on a fine, warm day, with little wind or tide running, the spat will fall near the parents and be safely secured, while in cold, blustering weather it will certainly be carried off to a distance, and probably be altogether lost. The number of young produced by each individual has been variously estimated at from 300,000 to 60,000,000. Either extreme seems enormous, but it must be remembered that besides climatal dangers, hosts of enemies—other Mollusca, fish, and Crustacea—beset the opening career of the young oyster.

As soon as the spat has safely ‘fallen,’ it adheres to some solid object, and loses the cilia which were necessary for its swimming life. It begins to grow rapidly, increasing from about ¹/₂₀ inch in diameter to about the size of a threepenny piece in five or six months, and in a year to one inch in diameter. Roughly speaking, the best guide to an oyster’s age is its size; it is as many years old as it measures inches across.

The oyster is at its prime at the age of five; its natural life is supposed to be about ten years. The rings, or ‘shoots’ on a shell are not—as is frequently supposed—marks of annual growth; cases have been noticed where as many as three ‘shoots’ were made during the year.

An oyster is furnished, on the protruding edges of the mantle, with pigmented spots which may be termed ‘visual organs,’ though they hardly rise to the capacities and organisation of real ‘eyes.’ But there is no doubt that they are sufficiently sensitive to the action of light to enable the oyster to apprehend the approach of danger, and close his doors accordingly. ‘How sensitive,’ notes Mr. W. Anderson Smith,[229] ‘the creatures are to the light above them; the shadow of the iron as it passes overhead is instantaneously noted, and snap! the lips are firmly closed.’

The geographical distribution of Ostrea edulis extends from Tränen, in Norway, close to the Arctic circle, to Gibraltar and certain parts of the Mediterranean, Holland, and N. Germany to Heligoland, and the western shores of Sleswick and Jutland. It occurs in Iceland, but does not enter the Baltic, where attempts to colonise it have always failed. Some authorities regard the Mediterranean form as a distinct species.

The literature of oyster-cookery may be passed over in silence. The curious may care to refer to M. S. Lovell’s Edible British Mollusks, where no less than thirty-nine different ways of dressing oysters are enumerated. It may, however, be worth while to add a word on the subject of poisonous oysters. Cases have been known where a particular batch of oysters has, for some reason, been fatal to those who have partaken of them. It is possible that this may have been due, in certain instances, to the presence of a superabundance of copper in the oysters, and there is no doubt that the symptoms detailed have often closely resembled those of copper poisoning. Cases of poisoning have occurred at Rochefort through’ the importation of ‘green oysters’ from Falmouth. It would no doubt be dangerous ever to eat oysters which had grown on the copper bottom of a ship. But copper is present, in more or less minute quantities, in very many Mollusca, and it is more probable that a certain form of slow decomposition in some shell-fish develops an alkaloid poison which is more harmful to some people than to others, just as some people can never digest any kind of shell-fish.[230] These alkaloid developments from putrescence are called ptomaines. In confirmation of this view, reference may be made to a case, taken from an Indian Scientific Journal, in which an officer, his wife, and household ate safely of a basket of oysters for three days at almost every meal. The basket then passed out of their hands, not yet exhausted of its contents, and a man who had already eaten of these oysters at the officer’s table was afterwards poisoned by some from the same basketful.

The cultivation of the common mussel (Mytilus edulis L.) is not practised in this country, although it is used as food in the natural state of growth all round our coasts. The French appear to be the only nation who go in for extensive mussel farming. The principal of these establishments is at a little town called Esnaudes, not far from La Rochelle, and within sight of the Ile de Ré and its celebrated oyster parks. The secret of the cultivation consists in the employment of ‘bouchots,’ or tall hurdles, which are planted in the mud of the fore-shore, and upon which the mussel (la moule, as the French call it) grows. The method is said[231] to have been invented as long ago as 1235 by a shipwrecked Irishman named Walton. He used to hang a purse net to stakes, in the hope of capturing sea birds. He found, however, that the mussels which attached themselves to his stakes were a much more easily attainable source of food, and he accordingly multiplied his stakes, out of which the present ‘bouchot’ system has developed. The shore is simply a stretch of liquid mud, and the bouchots are arranged in shape like a single or double V, with the opening looking towards the sea. The fishermen, in visiting the bouchots, glide about over the mud in piroques or light, flat-bottomed boats, propelling them by shoving the mud with their feet. Each bouchot is now about 450 yards long, standing 6 feet out of the mud, making a strong wall of solid basket-work, and as there are altogether at least 500 bouchots, the total mussel-bearing length of wall is nearly 130 miles.

The mussel-spat affixes itself naturally to the bouchots nearest the sea, in January and February. Towards May the planting begins. The young mussels are scraped off these outermost bouchots, and placed in small bags made of old canvas or netting, each bag holding a good handful of the mussels. The bags are then fastened to some of the inner bouchots, and the mussels soon attach themselves by their byssus, the bag rotting and falling away. They hang in clusters, increasing rapidly in size, and at the proper time are transplanted to bouchots farther and farther up the tide level, the object being to bring the matured animal as near as possible to the land when it is time for it to be gathered. This process, which aims at keeping the mussel out of the mud, while at the same time giving it all the nutrition that comes from such a habitat, extends over about a year in the case of each individual. Quality, rather than quantity, is the aim of the Esnaudes boucholiers. The element of quantity, however, seems to come in when we are told that each yard of the bouchots is calculated to yield a cartload of mussels, value 6 francs, and that the whole annual revenue is at least £52,000.

In this country, and especially in Scotland, mussels are largely used as bait for long-line fishing. Of late years other substances have rather tended to take the place of mussels, but within the last twenty years, at Newhaven on the Firth of Forth, three and a half million mussels were required annually to supply bait for four deep-sea craft and sixteen smaller vessels. According to Ad. Meyer,[232] boughs of trees are laid down in Kiel Bay, and taken up again, after three, four, or five years, between December and March, when they are found covered with fine mussels. The boughs are then sold, just as they are, by weight, and the shell-fish sent into the interior of Germany.

Mussels are very sensitive to cold weather. In 1874, during an easterly gale, 195 acres of mussels at Boston, in Lincolnshire, were killed in a single night. They soon affix themselves to the bottom of vessels that have lain for any length of time in harbour or near the coast. The bottom of the Great Eastern steamship was at one time so thickly coated with mussels that it was estimated that a vessel of 200 tons could have been laden from her. In some of our low-lying coast districts mussels are a valuable protection against inundation. “An action for trespass was brought some time ago for the purpose of establishing the right of the lord of the manor to prevent the inhabitants of Heacham from taking mussels from the sea-shore. The locality is the fore-shore of the sea, running from Lynn in a north-westerly direction towards Hunstanton in Norfolk; and the nature of the shore is such that it requires constant attention, and no little expenditure of money, to maintain its integrity, and guard against the serious danger of inundations of the sea. Beds of mussels extend for miles along the shore, attaching themselves to artificial jetties running into the sea, thereby rendering them firm, and thus acting as barriers against the sea [and as traps to catch the silt, and thus constantly raise the level of the shore]. Therefore, while it is important for the inhabitants, who claim a right by custom, to take mussels and other shell-fish from the shore, it is equally important for the lord of the manor to do his utmost to prevent these natural friends of his embankments and jetties from being removed in large quantities.”[233]

The fable that Bideford Bridge is held together by the byssi of Mytilus, which prevent the fabric from being carried away by the tide, has so often been repeated that it is perhaps worth while to give the exact state of the case, as ascertained from a Town Councillor. The mussels are supposed to be of some advantage to the bridge, consequently there is a by-law forbidding their removal, but the corporation have not, and never had, any boat or men employed in any way with regard to them.

Poisoning by mussels is much more frequent than by oysters. At Wilhelmshaven,[234] in Germany, in 1885, large numbers of persons were poisoned, and some died, from eating mussels taken from the harbour. It was found that when transferred to open water these mussels became innocuous, while, on the other hand, mussels from outside, placed in the harbour, became poisonous. The cause obviously lay in the stagnant and corrupted waters of the harbour, which were rarely freshened by tides. It was proved to demonstration that the poison was not due to decomposition; the liver of the mussels was the poisonous part. In the persons affected, the symptoms were of three kinds, exanthematous (skin eruptions), choleraic, and paralytic. Cases of similar poisoning are not unfrequent in our own country, and the circumstances tend to show that, besides the danger from mussels bred in stagnant water, there is also risk in eating them when ‘out of season’ in the spawning time.

Whelks are very largely employed for bait, especially in the cod fishery. The whelk fishery in Whitstable Bay, both for bait and for human food, yields £12,000 a year. Dr. Johnston, of Berwick, estimated that about 12 million limpets were annually consumed for bait in that district alone. The cockle fishery in Carmarthen Bay employs from 500 to 600 families, and is worth £15,000 a year, that in Morecambe Bay is worth £20,000.

Cultivation of Snails for Food; Use as Medicine.—It was a certain Fulvius Hirpinus who, according to Pliny the elder,[235] first instituted snail preserves at Tarquinium, about 50 B.C. He appears to have bred several species in his ‘cochlearia,’ keeping them separate from one another. In one division were the albulae, which came from Reate; in another the ‘very big snails’ (probably H. lucorum), from Illyria; in a third the African snails, whose characteristic was their fecundity; in a fourth those from Soletum, noted for their ‘nobility.’ To increase the size of his snails, Hirpinus fed them on a fattening mixture of meal and new wine, and, says the author in a burst of enthusiasm, ‘the glory of this art was carried to such an extent that a single snail-shell was capable of holding eighty sixpenny pieces.’ Varro[236] recommends that the snaileries be surrounded by a ditch, to save the expense of a special slave to catch the runaways. Snails were not regarded by the Romans as a particular luxury. Pliny the younger reproaches[237] his friend Septicius Clarus for breaking a dinner engagement with him, at which the menu was to have been a lettuce, three snails and two eggs apiece, barley water, mead and snow, olives, beetroot, gourds and truffles, and going off somewhere else where he got oysters, scallops, and sea-urchins. In Horace’s time they were used as a gentle stimulant to the appetite, for