MOLLUSCA. 1 75 



beds. The fisheries are at present, however, regu- 

 lated by a convention entered into between the 

 English and French Governments, and an Act 

 (6 and 7 Viet. c. 79) passed to cany the same into 

 effect, which enacts that the fisheries shall open on 

 the 1st of September, and close on the 30th of 

 April. 



It has been said that the Romans formerly dis- 

 covered that different varieties of oysters could be 

 intermixed so as to produce cross-breeds superior 

 in every respect to the stocks whence they sprang. 

 Of late years, a medical man of Morlaix, in France, 

 took some of those large unpalatable oysters termed 

 pied-de-cheval, and crossed them with some small 

 Ostend oysters. The result exceeded his expecta- 

 tions, and he produced a new breed of large oysters, 

 equal in delicacy to the small ones of Ostend. 



The Ostend oysters, which are in such high 

 repute in Belgium, are fished upon the English 

 coast, and bred in artificial oyster-beds at Ostend. 



Mr. Robert Macpherson, speaking of the common 

 oyster, says : " The Ostrea edulis of Linnaeus is 



t/ ' / 



subject to much variation, which has occasioned the 

 making of one or two questionable species, and 

 rendered uncertain the limits of its distribution. 

 The common English and Welsh oyster is, however, 

 certainly abundant and of excellent quality at 

 Redondela, at the head of Vigo Bay ; and I have 



