OYSTER CULTURE IN FRANCE. 631 



was obtained at Verdon. Considered in its industrial 

 aspect, the system of capturing the spat in waters shut off 

 would be infinitely more economical than the present 

 system. 



The only collectors which are adapted for large spaces 

 are tiles, which by their weight offer resistance to the cur- 

 rents. Boards, slates and other light bodies have been in 

 turn abandoned. But tiles become costly when they are 

 disposed in hives on the crassats. The mere placing them 

 occasions considerable expense, and cannot be effected 

 except at certain tides and in favourable weather. 



In closed waters collectors could be placed and with- 

 drawn at any phase of the moon, and in any condition of 

 the sea without any risk of breaking them. There is no 

 necessity for fixing them to the soil. More than that, there 

 would be no occasion for the exclusive use of the tile, for 

 the tile, though an excellent collector, has its disadvantages, 

 especially on the banks of the Gironde, where oyster rear- 

 ing is no longer held in estimation. As the weight would 

 render its carriage expensive, it is kept until the spat 

 adhering to it has acquired the dimension fit for detach- 

 ment ; from this arises a delay of a year in the growth of 

 the specimens. 



Not to neglect any of the points of view from which 

 fecundation may be regarded, we shall add that it appears 

 capable of application to : 



1. The introduction and acclimatisation in our 

 waters of unisexual species of oysters, such as the 

 Dakar and American oyster. 



2. The formation of districts on different parts of 

 our coast, which are known to be suitable. 



These works of stocking would not present any 

 difficulties, and would not involve heavy expenditure. If 



