218 MOLLUSCA. 



at the tables of the rich. In many places, they in a great 

 measure support the children of our maritime population, 

 and, in the Western and Northern Islands of Scotland, have, 

 in years of scarcity, prevented the death of thousands. 



The kinds chiefly used in this country, as articles of sub- 

 sistence, are bivalves, belonging to different genera. Among 

 these the Oyster (Qsirea edulis) holds the most distin- 

 guished place. This shell-fish is very widely distributed in 

 nature, being found in the seas of Europe, Asia, and Africa. 

 But, since the days of the luxurious Romans, the oysters of 

 Britain have been held in the highest estimation. They 

 are found on various parts of our coasts, from the southern 

 shores of England, to the sheltered bays among the Zetland 

 Islands. They prefer a rough or rocky bottom, in from 

 five to twenty fathoms water. They are fished up with a 

 dredge and an open boat; sometimes, when in shallow 

 water, with a rake or tongs. They are either conveyed 

 directly to the market, or are placed in artificial ponds of 

 sea water, where they increase in size, and acquire a fine 

 green colour. In England this process of fattening, as it is 

 termed, is chiefly conducted at Colchester, but the oysters 

 are obtained from the little creeks between Southampton 

 and Chichester. This fishery on the coast of England is 

 supposed to give employment to ten thousand people, so 

 that, independent of the addition which it makes to the 

 articles of subsistence, it must be regarded as a valuable 

 nursery for seamen. As an article of food, oysters are 

 light and easy of digestion, and may be eaten in great num- 

 bers without inconvenience. They are used either raw or 

 when pickled. In the last form, they are sent to different 

 parts of the country, and even constitute an article of ex- 

 port. In Scotland, the principal oyster fishings are in the 



