34:2 
THE OCEAN WORLD. 
Everyone has heard of the green oysters of Marennes, the preserva- 
tion, amelioration, and ripening of these oysters, so to speak, repre- 
senting a very considerable branch of industry in France. In order to 
give the reader some idea of its importance, we shall give here a brief 
summary of M. Coste’s voyage of exploration on the French littoral. 
The parks at Marennes, in which the oysters are placed in order to 
acquire the green colour which characterises them, are basins stretch- 
ing along both banks of the Seudre for many leagues. They are 
locally known as claires, and differ from the oyster-parks of other 
countries in this particular — that, while the ordinary parks are so 
arranged as to be submerged at every return of the tide, the basins of 
Marennes are so arranged that they can only be submerged at spring 
tides ; that is, at the new and full moon, when the waters rise beyond 
the ordinary level. 
The basins or claires occupy from two hundred and fifty to three 
hundred square yards of superficies ; two sluices permit of the entrance 
and withdrawal of water at will, so as to maintain it at the level most 
convenient to the industrial wants of the place, or to empty it alto- 
gether when it is necessary to cleanse the basin, pave the bottom, an 
furnish it with a fresh supply of oysters. 
When these necessary works are completed, advantage is taken 0 
the first spring tide to fill the basin. When the tide begins to ebb, 
the sluices are closed, so as to retain sufficient water in the basins , 
and while thus shut up, salt held in solution is deposited, and qualities 
analogous to those of marine bottoms are produced, purged by 
cleansing processes of all products offensive to the bivalves. 
When the basin has been filled with sea-water for the necessary 
time, and the bottom is sufficiently impregnated, it is emptied and le$ 
to dry ; and now, the soil being prepared, it only remains to furnish * 
with oysters of a mellow and ripe age, in order to give them tb el 
green hue. Towards the month of September, at low water, the who 
sea-side population of Marennes go to gather oysters on the pavem eU 
left uncovered by the ebbing tide, or by using a dredger in the deep er 
parts of the claires where the water still remains. A temporal 
magazine for the reception of the oysters thus gathered is erected ° n 
the banks, which the water revisits twice a day. The young 
reserved for cultivation on the parks or claires; the fullest are sold 
consumption in the neighbourhood ; but the quantity of oysters raise 
