OYSTER CULTURE IN FRANCE. 561 



grow. The bottom is sand and clay, and the mud forms 

 at the surface a layer of 20 or 30 centimetres thick, and 

 firm enough to prevent the oysters from sinking in it. 



The claires of Le Martray are cleaned once or twice a 

 year, and are used for rearing and fattening. 



The oysters in them come from Arcachon, or are bred 

 in the reproduction pares which M. Dupeux-Boyer possesses 

 in another part of the isle, at a place known as La Mouli- 

 natte ; or else they have been gathered on the coast by 

 fishers on foot. Although for a long time the banks in the 

 neighbourhood of the isle have been exhausted, there exist 

 a few stray oysters, the spawn of which attaches itself 

 either to the rocks or to pebbles which the waves roll and 

 cast upon the shore. The fishers by hand call them native 

 oysters, or wandering oysters. Their shell is rough, but 

 regular and deep. 



In the pares of reproduction, where it would be im- 

 possible, having regard to the state of the sea, to fix col- 

 lecting apparatus, the spat is received on boulders simply. 

 The picking it off at the first stage is difficult. Two or 

 three years are necessary for the Arcachon oyster to become 

 edible in the claires at Le Martray. Native oysters are 

 less subject to mortality, and they grow more in the same 

 space of time, the shell becomes deeper, and the fish 

 larger. 



The pares of Le Martray have the property, like those 

 of Marennes, of greening the oyster. Certain specimens 

 at the He de Re never take the green colour, which begins 

 to show itself amongst the greater number of oysters 

 towards the September equinox. 



