ARTIFICIAI OYSTER-BEDS. 



XXI 



said of liiiii, in allusion to tlie suspended banks of 

 which he was the inventor, that if he were forbidden to 

 raise oysters in the Lucrine Lake lie would contrive to 

 make them grow upon the house-tops. 



\Vhat has become of this famous lake ? Alas I it no 

 lonjjer exists; it has wholly disappeared. The presi- 

 dent Des Brosses, that witty but somewhat spiteful 

 traveller and accomplished gourmand, was desirous of 

 seeing a locality so celebrated. He found it, however, 

 as he tells us, nothing more than a foul miry morass. 

 " Those precious oysters of Catiline's grandfather," he 

 Bays, " which mitigated in our eyes the horror of his 

 grandson's crimes, are metamorphosed into unhappy 

 little eels, frisking about in the mud. An unsightly 

 mountain of cinders, charcoal, and pumice-stone, which 

 in 1538 thought fit to issue from the earth all in one 

 night, like a mushroom, had I'educed this poor lake to 

 the sad condition I have described." 



Rondelet speaks of a fisherman who had acquired the 

 art o{ sowing 03'sters. And we know that now-a-days 

 the terrible Acheron of the poets, the Lake Fusaro of 

 the Neapolitans, is a very extensive o_vster farm, where 

 industry assists nature in the multiplication of her pro- 

 ducts. Its inclosure is occupied by rounded fragments of 

 rock ; hither are brought the oysters of Tarentum, and 

 each of them is transformed into a small artificial bank ; 

 Piles are suidc in the mud all around, at very short 

 intervals from one another. These piles are slightly 

 elevated above the surface of the water, so that they 

 can be easily caught hold of with the hand and drawn 

 out, when necessary. Other piles, arranged in rows, 

 are bomid together with ropes, whence lian,:j numerous 

 other ropes suspending bundles of fascines deep in the 

 water. The object of the latter is to collect the spat, 

 or niicroBCO])ic larvfe, diffused yearly in the sea. At 

 fixed seasons, the bundles are drawn up and the oysleis 

 collected. 



In the last century the Mi-rquis de Ponibal, having 

 caused some ship loads of oysters to be thrown into 

 the water along the coast of his native county, which 

 was not Idessed with these molluscs, they multiplied to 

 such an extent that they are now very common there. 

 About the same epoch an English land-owner, the 

 earl of Carnarvon, having distributed a certain quantity 

 of these molluscs in the Menai Shait, they propagated 

 rapidly, and for a considerable lime proved the source 

 of an ample additional revenue. Stimulated by this 

 Buccess, the British government caused several cargoes 

 of oysters to be transported to various points of the 

 Kn-lish coast, where they equally prospered. 



The creation of artificial oyster-beds has multiplied, 

 and, to some extent, regulated the production of these 

 molluscs. Oil the coasts of Kent and Essex oyster- 

 culture is methodically carried on, and the art, if such 

 we may call it, is being more and more extensively 

 cultivated in Great Britain every year. 



Following the example of the Romans, oysters are 

 deposited in great reservoirs to be fatteued and grow 

 green. This is cMed parlcing oysters. 



AtMarennes, in France, where the process is cliiefly 

 carried on, these reservoirs are named ctaires. They 

 are, in reality, an area of inundated level ground on 

 tiie two banks of the Seudre. They differ from the 



oyster basins and oyster farms in not being submerged 

 at every tide. An oyster of six or eight months old 

 must remain here two years, to attain a proper size and 

 standard of perfection. But most of those which are 

 sent to market are far from possessing the requisite 

 qualifications. Placed in the reservoirs, when full- 

 grown, they acquire a green hue in a few days. 



We know that the colouring of the green oysters is 

 not general. It is more particularly conspicuous on the 

 four respiratory valves. Traces may also be found on 

 the inner surface of the first pair of the labial papillae, 

 on the outer surface of the second pair, and in a part 

 of the digestive tubes. 



It was long believed that the greenness of the oyster 

 was due to the soil of the reservoirs, or rather to the 

 decomposition of ulvse and other aquatic plants, or, 

 perhajis, to a disease of the liver, a kind of jaundice 

 (should we not say, verdice?) wdiich communicated a 

 green tint to the parenchyma (or porous substance) of 

 the respiratory apparatus. 



Guillon pretends that it arises from a species of infu- 

 soria animalcule, shaped like a rajie-seed (f« mivclle), 

 which penetrated into the substance of the mollusc. 

 But the eminent French physiologist, Bory de St. 

 Vincent, has proved that the infusoria in question was 

 not formally green, but became coloured under certain 

 circumstances, like the oyster, and by the same cause. 

 According to this naturalist, the source of the green- 

 ness is a molecular substance (the "green matter" of 

 Priestley), which is developed by the action of light in 

 all waters. According to Valenciennes, this colour is 

 formed by an animal product wholly dislinct from all 

 the organic substances hitherto studied. M. Berthelot 

 has analyzed this matter, and lias ascertained that it 

 does in truth present some distinctive characteristics. 

 It neither resembles the colouring element of bile, nor 

 that of blood, nor the majority of organic colouring 

 matters. 



The green molecules of which we have spoken are 

 absorbed into the branchiae of the mollusc by the effect 

 of. the respiratory movement, are there arrested, swell 

 them, obstruct them, and colour them. At the same 

 lime, the poor animal, impeded in one of its essential 

 functions, infiltrates and expands itself, undergoes a 

 kind of anasarca, wdiich renders its tissue more tender 

 and more delicate.* 



THE PEARL OYSTER {Avicula margarltlfera). 



Tlie Pearl Oyster has been found in almost every 

 division of the globe. It has been met with on the 

 coast of Coroniandel, in the Persian Gulf, on the 

 Arabian coast, and in Japan ; it is fished extensively 

 oQ' Algiers, in the West Indies, and in the Biiy of 

 Panama ; it has even been discovered in small quantities 

 on the chores of Scotland. But the most extensive 

 fisheries are in the Indian Ocean, where the oyster is 

 abundant, and where operations are carried on iqion a 

 large scale. Tlius the natives of Bengal, the Chinese 



■• Fr^Jol, I.e Monde de U Mcr, to which, in tlie preceJing 

 pages, we iiave been considerubly indebted. 



