CHAP. VIIT.] OYSTER-GROWTH. 361 



anxious to be soon rich, content themselves with placing 

 adult oysters only in these claires, and these become green in 

 a very short time, and thus enable the operator to have 

 several crops in a year without very much trouble. The 

 claires of Marennes furnish about fifty millions of green oysters 

 per annum, and these are sold at very remunerative prices, 

 yielding an annual revenue of something like two and a half 

 millions of francs. 



As to the kind of ground most suitable for oyster-growth, 

 Dr. Kemmerer, of St. Martin's (He de Ee), an enthusiast in 

 oyster-culture, gives us a great many useful hints. I have 

 summarised a portion of his information : The artificial cul- 

 ture of the oyster may be considered to have solved an im- 

 portant question namely, that the oyster continues fruitful 

 after it is transplanted from its natural abode in the deep sea 

 to the shores. This removal retards but never hinders fe- 

 cundation. The sea oyster, however, is the most prolific, as 

 the water at a considerable depth is always tranquil, which 

 is a favourable point in oyster-growth ; but the shore oyster- 

 banks will also be very productive, having two chances of re- 

 plenishment namely, from the parent oysters in the pares, 

 and from those currents that may float seed from banks in 

 the sea. Muddy ground is excellent for the growth of oysters ; 

 they grow in such localities very quickly, and become saleable 

 in a comparatively short space of time. Dry rocky ground 

 is not so suitable for the young oyster, as it does not find a 

 sufficiency of food upon it, and consequently languishes and 

 dies. Marl is the most esteemed, and on it the oyster is said 

 to become perfect in form and excellent in flavour. In the 

 marl the young oyster finds plenty of food, constant heat, and 

 perfect quiet. Wherever there is mud and sun there will be 

 found the little molluscs, Crustacea, and swimming infusoria, 

 which are the food of the oyster. The culture of the oyster 

 in the mud-ponds and in the marl a culture which ought 



