540 OYSTERS, AND ALL ABOUT THEM. 



The bed of the river is composed almost entirely of 

 sand mixed with shells, and is very rich in calcareous 

 matter. The flux and reflux of the ocean, while causing- 



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an incessant agitation in the water, give rise to perpetual 

 currents. 



The concession is divided : First, into pares, in which 

 are placed the cases containing the spat, and which are 

 only uncovered at spring tides ; they are generally situated 

 in the lower parts of the river. Secondly, into pares, where 

 the adult oysters are spread to make them grow, thicken, 

 and fatten ; the ground on which the adult oysters are 

 placed is every year improved by the deposit of a load of 

 shelly sand containing 80 per cent, of calcareous matter. 

 Thirdly, into basins, capable of submersion, which receive 

 the water at each tide, and are intended to shelter the 

 cases during the winter, and serve equally as depots for the 

 marketable oysters which are being prepared for sending 

 away ; these basins communicate with each other, and can 

 be easily emptied and cleaned at low tide. Lastly, in a 

 large reservoir, which cannot be submerged, constructed 

 in a bend of the river, are enclosed other cases and 

 cemented basins, suitable for preserving and rearing the 

 oyster. 



The spat comes from Auray, from the pares of repro- 

 duction situated at Fort Espagnol, belonging to MM. de 

 Mauduit and de Solminihac ; on its arrival it is poured 

 into oyster-boxes, which remain at 25 or 30 centimetres 

 from the bottom, on pickets driven into the ground, and 

 also on cross-pieces of wood secured by stakes. 



The spat remains in the cases in deep water from the 

 month of April to the month of October. It is transferred 

 to the reserve basins for the winter, and in the spring is 

 spread on the bottom of the pares for fattening. 



