An introduction to conchology; or, elements of the natural history of molluscous animals / By George Johnston.

  • George Johnston
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to conchology; or, elements of the natural history of molluscous animals / By George Johnston. Source: Wellcome Collection.

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    maritime counties, even as far as Scotland, and laid in the beds or layings in the creeks adjoining those rivers. ‘The number of vessels immediately employed in the dredging for oysters are about 200, from twelve to forty or fifty tons bur- den each, employing from 400 to 500 men and boys. ‘The quantity of oysters bred and taken and consumed annually, mostly in London, is supposed to amount to 14,000 or 15,000 bushels. All the other fisheries connected with this part of the coast are stated to employ a capital supposed to amount from 60,0002. to 80,0002.” In various parts of Milford Haven there are likewise inexhaustible beds of oysters, of superior excellence.* But so important are the oyster-fisheries of Britain, that they have long been an object of attention to the Legislature ; and they are regulated by a Court of Admiralty. In 1375 (Edward IIT.) it was illegal to dredge for oysters or mussels between May and Holyrood day, the 14th of Sep- tember ; or to keep the fry of those fish in any season.+ In the month of May, the fishermen are allowed to take the oysters, in order to separate the spawn from the cultch, ¢ the latter of which is thrown back, to preserve the bed for the future. After this month it is felony to carry away the cultch, and punishable to take any oyster, unless, when closed, a shilling will rattle between its valves. The spawn is then deposited in beds or layers formed for the purpose, and furnished with sluices, through which, at the springtides, the water is suffered to flow. This water, being stagnant, soon becomes green in warm weather ; and, in a short time, the oysters acquire the same tinge, which renders them of greater value in the market. Three years, at least, are re- quired to bring them to a marketable state; and the longer they remain, the more fat and delicate they become.§ ‘These artificial beds, as Pliny informs us, were invented by one Ser- gius Arata, and first established on the Lucrine Lake, a. vu. 660 ; and, from some circumstances mentioned by the natura- list, we may infer that the said Sergius was no loser by the * Encyclop. Brit. Supp. iv. 269, 270. + Nicolas’s Hist. Roy. Navy, il. 205. +t By this term are meant the stones, gravel, old shells, &c., to which the spawn adheres ; and the reason for punishing its destruction is, that, when taken away, the ooze increases, and mussels and cockles breed on the bed, and destroy the oysters, gradually occupying all the places on which the spawn should be cast. § See Sprat’s Hist. Roy. Soc. 308 ; Pennant’s Brit. Zoology, iv. 227, &c.; Bingley’s Animal Biography, art. Oyster ; Thomson’s Annals of Philosophy for January, 1818, 70; and the Brit. Cyclop. Nat. Hist. it 38].—M. Carbonnel received a patent for a new and simple method of establishing oyster-banks on the coasts of France, of which there is a short account in Chenu’s Traité de Conchyliologie, p. 111.
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