900 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [16] 
supply them with air, by opening the boxes when the weather will per- 
mit. They are then conveyed to the breeding claires and scattered over 
the bottom, where they should be placed as far apart as possible, in 
order that they may become the better developed. The claires are pro- 
tected by means of fine mesh nets against the attacks of the various ani- 
mals which prey upon the oyster; these nets cover or surround the 
claires. The water is kept at aheightof 20 centimeters (8 inches) above 
the oysters during the extremes of heat and cold, but during mild 
weather this height is lessened, so that the oysters may come more 
directly under the influence of the air and light. When this cannot be 
done it is well to change the oysters from one claire to another once or 
twice a year, placing them in well-cleansed basins, the bottoms of which 
have been renewed by allowing them to remain unused for several 
months. 
Final care to be bestowed upon the oysters. “SN fter two years of this 
treatment the oysters have attained an edible size, but before being 
taken to market they must be accustomed to remain without water. 
The parker, therefore, at each low tide for a certain length of time, 
drains the claire containing the oysters to be sent to market; these 
oysters gradually acquire the habit of retaining the water within their 
shells by not opening their valves, and become able to stand a journey 
of several days without losing their freshness. 
Another method.—According to another method the oyster is not sep- 
arated from the collector to which it is attached, until it has attained 
the age of eighteen months. Two sets of tiles are necessary in this case, 
the first remaining in the claires until the time of detaching, while the 
second is made ready to receive the spawn of the next season. Accord- 
ing to this system the waste is very small, because the oyster is much 
stronger when it is separated from its point of adhesion. When allowed 
to remain too long upon the collectors, however, they often become mal- 
formed, and this diminishes their market value. 
Guar produced upon the bottoms of parks.—The oysters produced upon 
the bottoms of parks, or upon the shells deposited there, are easily sep- 
arated from one another, or from the collector to which they have ad- 
hered. They are scattered in grassy places and are taken up from time 
to time in order to secure those which are marketable, the others being 
returned to the park. Sometimes, with a view to diminishing the waste, 
they are placed in claires, where they are raised like those on the tiles. 
USUAGES AT THE PARKS OF MORBIHAN. 
Such, in brief, is the manner in which oyster culture is conducted in 
the basin of Arcachon. The methods of breeding are nearly the same 
everywhere, with some exceptions rendered necessary by the climate 
and nature of the soil or water of different localities. Thus, in the dis- 
trict of Auray, the plank collectors succeed perfectly and are much used. 
