[27] THE OYSTER AND OYSTER-CULTURE. 109 
were taken, notwithstanding the dredge was used for three whole days. 
The sea-bottom in the neighborhood of Juist is, therefore, not suited to 
the growth of oysters. It is too muddy, and already in possession of the 
edible mussel (Mytilus edulis). During the last century, and the first half 
of the present one, the Hanoverian Government was accustomed to lease 
the oyster-fisheries along its coast. These fisheries were principally in 
the neighborhood of Juist and Borkum, and from 1841 to 1846, inclu- 
Sive, 193,684 oysters were taken there, making an ,average yield of 
38,727. In 1851, in a survey of the beds, very few oysters were found, 
and in 1855 the beds were so impoverished that no one would rent them. 
The exhaustion of the beds resulted from excessive fishing and from 
the increase of mud upon the ground occupied by the oysters. Whoever, 
therefore, would establish new oyster-beds along the German portion of 
the coast of the North Sea, between the Hider and the mouth of the Ems, 
must begin his difficult work by changing the ebb and flood currents in 
the southern portion of the North Sea, in order to prepareasurface upon 
which oysters can thrive; for to attempt to adapt oysters to a bottom 
of shifting sand or mud is not natural, nor is it conducive to an indus- 
try which is to last for a hundred years. For thousands of years innu- 
merable young oysters have been scattered from the oyster-beds over 
changing mud and sand banks, and yet not one has so altered its or- 
ganization as to become adapted to such a bottom and transmit its new 
nature to its progeny; they have all been destroyed. 
Since the sixteenth century, along the west coast of France, on both 
sides of the mouth of the Seudre, near Marennes and La Tremblade, 
the oyster-breeders have been in the habit of transplanting oysters, one 
year old, from natural oyster-beds to prepared ponds in order to fatten 
them and improve their flavor. These ponds, called claires, are shallow 
excavations of various shapes and sizes. The greater number are square 
or rectangular, and cover from two to three thousand square meters of 
surface. They lie near together, but irregularly, and are divided off 
into sections by deep trenches or canals, by means of which the sea-water 
flows in and out during spring-tides. The bottom of the ponds is some- 
what higher near the center than around the edges. The walls surround- 
ing the ponds are formed of the earth dug from within, and are about one 
meter in height. The neighboring ponds are placed in communication 
with one another by means of ditches or wooden pipes in the walls. 
Flood-gates are placed in the larger trenches, by means of which the 
water can be retained in the ponds from one spring-tide to another. 
In the fall, when fishing upon the sea-beds is permitted, young oysters 
are taken and transplanted to these ponds. From August until the 
breeding season next year, these transplanted oysters acquire a cloudy, 
dark-green color in the tissues of the mantle, gills, liver, and stomach. 
The delicate flavor, for which the green oysters of Marennes are especi- 
ally famous in Paris, is only acquired after three or four years. During 
this time they must often be cleansed from the mud which has accumu- 
