Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/122

 110 OYSTER left for ten or fifteen minutes. The chest is then opened and the cars run into the shucking shed, their places in the chest being immediately occupied by othercars. In tlie shed the cars are surrounded by the shuckers, each provided with a knife and a can arranged so as to hook to the upper bar of the iron frame-work of the cur. The steaming having caused the oyster shells to open more or less widely, there is no difficulty in getting out the meats, and the cais are very rapidly emptied. The oysters are then washed in iced water and transferred to the &quot; fillers &quot; table. The cans, having been filled, are removed to another part of the room and packed in a cylindrical, iron crate or basket, and lowered into a large cylindrical kettle, called the &quot;process kettle&quot; or &quot;tub,&quot; where they are again steamed. After this they are placed, crate and all, in the &quot;cooling tub;&quot; and when sufficiently cool to be handled, the cans are taken to the soldering table, and there &quot; capped&quot; that is, are hermetically closed. From the &quot;cappers&quot; they are transported to another department, labelled, and packed in boxes for shipment. The whole steaming pro cess will not occupy an hour from the time the oysters leave the vessel until they aie ready for shipment. The extension of the area of the natural beds is the second step in oyster culture. As is well known to zoolo gists, and as has been very lucidly set forth by Prof. Mdbius in the essay already referred to, the location of oyster banks is sharply denned by absolute physical con ditions. Within certain definite limits of depth, tempera ture, and salinity, the only requirement is a suitable place for attachment. Oysters cannot thrive where the ground is composed of moving sand or where mud is deposited ; consequently, since the size and number of these places are very limited, only a very small percentage of the young oysters can find a resting-place, and the remainder perish. Mb bius estimates that for every oyster brought to market from the Holstein banks, 1,045,000 are destroyed or die. By putting down suitable &quot; cultch &quot; or &quot;stools&quot; immense quantities of the wandering fry may be induced to settle, and are thus saved. As a fule the natural beds occupy most of the suitable space in their own vicinity. Unoccu pied territory may, however, be prepared for the reception of new beds, by spreading sand, gravel, and shells over muddy bottoms, or, indeed, beds may be kept up in loca tions for permanent natural beds, by putting down mature oysters and cultch just before the time of breeding, thus giving the young a chance to fix themselves before the currents and enemies have had time to accomplish much in the way of destruction. The collection of oyster spat upon artificial stools has been practised from time immemorial. As early as the 7th century, and probably before, the Romans practised a kind of oyster culture in Lake Avernus, which still sur vives to the present day in Lake Fusaro. Piles of rocks are made on the muddy bottoms of these salt-water lakes, and around these are arranged circles of stakes, to which are often attached bundles of twigs. Breeding oysters are piled upon the rookeries, and their young become attached to the stakes and twigs provided for their reception, where they are allowed to remain until ready for use, when they are plucked off and sent to the market. A similar though ruder device is used in the Poquonnock river in Connecti cut. Birch trees are thrown into the water near a natural bed of oysters, and the trunks and twigs become covered with spat ; the trees are then dragged out upon the shore by oxen, and the young fry are broken off and laid down in the shallows to increase in size. In 1858 the method of the Italian lakes were repeated at St Brieuc under the direction of Prof. P. Coste, and from these experiments the art of artificial breeding as practised in France has been developed. There is, however, a marked distinc tion between oyster culture and oyster breeding, as will be shown below. The natural beds of France in the Bay of Arcachon, near Auray in Brittany, near Cancale and Gran- ville in Xormandy, and elsewhere, are, however, carefully cultivated,, as it is necessary that they should be, for the support of the breeding establishments. 1 More or less handling or &quot; working&quot; of the oysters is necessary both for natural and transplanted beds. The most elaborate is that which has been styled the &quot; English system,&quot; which is carried on chiefly near the mouth of the Thames, by the Whitstable and Colchester corporations of fishermen and others. This consists in 1 See Report of the United States Fish Commission, part viii. pp. 739-41, 753-59, 885-903, 901-41. laying down beds in water a fathom or more in depth at low water and constantly dredging over the grounds, even during the close time, except during the period when the spat is actually settling. By this means the oysters are frequently taken out of the water and put back again, and it is claimed that in this way their enemies are battled and the ground put in better condition to receive the spat. As a matter of fact, however, the oysters have not for many years multiplied under this treatment, and the system is practically one of oyster-parking rather than one of oyster-culture. One of the advantages of the frequent handling is that the fishermen, in putting the oysters back, can assort them by sizes, and arrange them conveniently for the final gathering for market purposes. American oyster culture, as practised in the &quot;East River&quot; (the western end of Long Island Sound), in eastern Connecticut, and to some extent in Long Island and New Jersey, is eminently success ful and profitable, and there seems to be no reason to doubt its permanence,, conducted as it is in close proximity to the natural beds, and with due regard for preservation. In the Long Island Sound alone, in 1879, the labours of 1714 men produced 997,000 bushels, or perhaps 250,000,000 of native oysters, valued at $847,925, while all France produced in the following season 375,000, worth about $412,000. There was also a side product of 450,000 bushels (122,000,000) of transplanted oysters, worth $350,000, handled by the same men in the American beds, while France employed an additional force of 28,000 people to produce 305,000,000 artificially bred oysters, worth $3,179,000. The Long Island Sound system consists simply in distributing over the grounds, just before the spawning season, quantities of old oyster shells to which the young oysters become attached, and left undisturbed for from three to five years, when, having reached maturity, they are dredged for use. Spawning oysters are frequently put down in the spring, two months before the ground is shelled ; this is done even when the natural beds are near, but is not so essential as when a rather remote piece of bottom is to be colonized. 2 An excellent summary of the methods of planting in different parts of the United States may be found in &quot;Winslow s paper alreadyquoted. The laying down or temporary deposit of dredged oysters in estuaries on floats or in tanks, to fatten, increase in size, or improve in flavour, is a concomitant of oyster culture, and may be used in connexion with any of the systems above referred to. It is in no sense oyster culture, since it has no relation to the maintenance of the supply. A system of this kind has been practised since the 16th century at Marcnncs and La Tremblade on the west coast of France, where oysters from natural beds are placed in shallow basins communicating with the sea during the spring tides, and where they obtain food which gives them a green colour and a peculiar flavour much esteemed by Parisian epicures. 3 Similar methods of parking are practised at Cancale and Granville. In England, brood oysters are laid down in fattening beds on the coast of Essex and in the Thames estuary, where they acquire deli cacy of flavour, and to some extent, especially in the Thames, the green colour already referred to. Belgium has also, near Ostend, fattening beds supplied with foreign spat, chiefly from England. In the United States an extensive business is carried on in laying down seed oysters from the Chesapeake Bay in the estuaries of southern New England and the Middle States. Oyster-culturists practise in many places what is called &quot; plump ing,&quot; or puffing up oysters for market by exposing them for a short time to the effects of water fresher than that in which they grew. By this process the animal does not acquire any additional matter except the water, which is taken up in great amount, but it loses a part of its saltness, and, in flavour, becomes more like an oyster from brackish waters. There are large oyster reservoirs at Husuni in Schlcswig-IIolstein, and at Ostend, whi&amp;gt;-h serve the double purpose of fattening the oysters and of keeping a uniform supply for the markets at times unsuited to the prosecution of the fishery. The artificial impregnation of oyster eggs has been successfully accomplished by many experimenters, and in 1883 Mr John A. Ryder of the United States Fish Commission succeeded in confining the swimming embryos in collectors until they had formed their shells and become fixed. The utility of this experiment seems to consist in the greater facility which it gives to oyster-cnlturists in securing a sure supply of spat, independent of the vicissitudes which currents and changes of weather entail upon those who rely upon its deposit under natural conditions. The spat thus secured can be reared either by the American, English, or French systems. It is not probable that the common European species, Ostrca cdulis, can be so readily handled by this method as the Portuguese species, Ostrea angulata, or the American, Ostrea virginica, though this can only be determined by trial. For the details of Mr Ryder s experiment, see the Bulletin of the United States Fish Commis sion, vol. ii. pp. 281-94. (G. B. G.) 2 The Oyster Industry, by Ernest Ingersoll (Washington, 1881). 3 Mb bius, Die Auster und Die Austemwirthschaft ; and De Bon, Ostrieculture en 1875.