OYSTER CULTURE IN FRANCE. 6oi 



only at spring-tide. Some are even a long way from the 

 banks of the river. They are so worked that some are in a 

 state of preparation whilst others are in use. 



The preparation of the ground generally goes on in 

 March. It includes two operations : gralage and la mise en 

 humeur. 



Gralage has for its object the purification of the soil 

 by evaporation ; it lasts from six weeks to two months. 

 The claires are cut ; that is, the water is no longer kept in 

 them, and they are not visited by the sea except at high 

 tides. They dry in the sun. 



When the claire is gralee, or, in other words, covered 

 with a well-drained bed, 1 5 days are spent in bringing it 

 into condition. 



A small quantity of water is allowed to enter, and the 

 retention is resumed. 



The dry crust dissolves in the water, produces a kind 

 of effervescence, and the final result is a uniform deposit 

 on the claire of a creamy precipitate, which is called humeur. 

 The oysters may now be laid down, and they begin to turn 

 green at the end of a fortnight. 



This operation must be conducted every year. The 

 oysters are laid down at the bottom of the claire, and placed 

 at a proper distance from each other by hand. About 5000 

 are placed in an area of 33 ares. 



Down to the present time the industry of Marennes 

 has been confined to rearing and fattening. It is to be 

 hoped that before long production will be introduced into 

 the locality. 



The Commissary of Marine of this quarter is indeed 

 actually engaged on this question. 



Having resided for a long time at Auray, M. Senne- 

 Desjardins is conversant with every question pertaining to 



