OYSTER AND MUSSEL REPORT. 107 



Many of the oysters are sold at this stage to the 

 " eleveurs " who rear and fatten them, but many on the 

 other hand are kept for another year or two in the pares 

 at i^rcachon. These latter after removal from the tiles 

 are placed in flat trays having a floor and a lid of close 

 galvanized wire netting, of about half inch mesh, and these 

 trays are placed between short posts in the sea on the 

 oyster pare so that the tide can run freely through them 

 supplying the oysters with food and oxygen. Such trays 

 are called "ambulances" or " caisses ostreophiles " and 

 are shown in PL I, figs. 4, 5. They measure about 6 feet 

 by 4, and are 6 inches deep. They serve to keep the young 

 oyster during the early period of its life out of the sedi- 

 ment, and they also protect it from its numerous natural 

 enemies, such as the boring sponge (Gliona) which ruins 

 the shell, starfishes and crabs which manage to suck or 

 pick out the soft animal, and whelks (such as Purpura 

 and Nassa) and other Gastropods, which can bore a hole 

 through the shell and prey upon the oyster. 



The ambulances are constantly looked after by the 

 oyster men, and especially women, who come at low 

 tide when the caisses are exposed, open the lid and pick 

 over the contents, removing any enemies or impurities 

 which may have got in, such as crabs, taking out any dead 

 shells, and re-arranging the oysters if necessary so that 

 all may have a fair chance of obtaining food and growing 

 normally. The young oysters grow rapidly in the ambu- 

 lances and have soon to be thinned out. The larger ones 

 are removed to other caisses — or, if large enough, they 

 are thrown into the open enclosures of the pare. Addi- 

 tional young ones may now be added, or all the space may 

 be required for a time by those left. In this way, by 

 thinning out, re-arranging, and adding, relays of young 

 oysters in their first year may occupy the ambulances for 



