EUROPEAN METHODS OF OYSTER-CULTURE. 
385 
of July. Tlie tiles are arranged, as represented in the figure, in a single tier, quite 
different from the method pursued in the muddy waters of Auray or even Arcachou. 
The bottom is firm and unshifting, there is little danger of silt deposit, and accord- 
ingly it would be in a measure needless to raise the tiles in cases or camions. It is 
claimed on the other hand that, even if more oysters be obtained by arranging the 
tiles in layers one above the other, the upper oysters are apt to be lost on account of 
lack of moisture, the tiles over the ground appearing to absorb and retain moisture 
more favorably. 
During the summer tiles are constantly shifted, sometimes changed in position, at 
first perhaps as often as once a week, in order that the silt-covered portions may be 
swept clean by the rising tide, and that the enemies of the oyster (crabs, and espe- 
cially starfish) may be removed. A constant corps of attendants, mainly women, 
is therefore to be employed, whose wages add not a little to the cost of production. 
Shifting of tiles becomes less necessary as fall approaches. As the next process the 
tiles are to be taken into winter quarters to avoid the danger of “frosting” the 
young oysters while in the shallows, a danger which appears to be more feared than 
that of actual water freezing. A term of the contract also prescribes that the tiles be 
entirely removed from the river basin by December 2, a regulation aiming to prevent 
damage to sailing craft. The transferral of tiles is effected as before. They now 
return to the dikes spotted here and there with incrusting oysters. As many as 
forty to a tile is regarded as an exceptionally favorable set, a number so small that 
it is a matter of wonder to the Arcachou culturists that production in Zeeland can be 
profitable. 
In the winter the tiles are arranged in inclosures (parks) at the foot of the dikes 
(PI. lxxxi, Fig. 1), where a water depth of about a meter may be retained to guard 
against the danger of freezing. These inclosures may be in high or low ground, may 
run lengthwise (PI. lxxxi, Fig. 2) or crosswise of the dike, and in many instances have 
been constructed within the dikes in polder laud (Pis. lxxxii and lxxxiii).* The 
plan in general, like that of Marennes or the French culturists generally, seems to 
favor collections of small basins rather than large separate ponds, on account of 
convenience in cleaning and emptying. It is seldom that the young oysters are 
detached from the tiles during the fall, a practice usual throughout southern France. 
The young oysters in Zeeland are said to be much smaller than those of equal age in 
France, and perhaps on this account are able to sustain cold better when attached. 
The process of separation, or detroquage , begins with the end of winter. The scaling 
of the young oysters from the tile is, however, far more carefully performed in Zeeland 
than in France. The set is so scanty that every oyster must be saved and therefore 
the shoving thrusts of the flat knife blade of the Arcachou parquer must be replaced 
by a circling cut outlining the oyster on the limy crust of the tile. A second turn 
of the knife now separates the oyster neatly. It seems to be an object with the 
culturist to have his detroquage performed as early as possible in the spring, so that 
the oyster may not acquire an undesirable flatness and concavity of shell that long 
attachment to tile is sure to give. 
* H. Oclitmann, of Goes, has in the central pond (figured in PI. lxxx) storage capacity for 1,000,000 
oysters. Sp. gr. of these ponds slightly less than that of the Schelde (1021.50, 62° F.). 
F. C. B. 1891—25 
