di OYSTERS IN BAY OF ARCACHON. 935 
they were shaken many of the young oysters fell off. I leave it to the 
reader to imagine what quantities must have been lost in this primitive 
and imperfect practice. Stone blocks were also used, as were tiles, slates, 
- and wooden shingles, but all these collectors were defective and insuffi- 
cient. It was almost impossible to detach young oysters adhering to a 
very hard body without breaking them, or at least doing them much 
damage; wovoden collectors present contrary disadvantages; the point 
of attachment of the oyster being too weak renders them too easy a prey 
to the crab, their most dreaded enemy, which, with its very delicate 
instinct, always attacks this mollusk in its most sensitive part. 
Mr. Michelet, an oysterculturist of Arcachon, and a thoroughly prac- 
tical man, wishing to remedy these two serious inconveniences, con- 
ceived the idea of covering the collectors with a mortar, consisting of 
lime and sand mixed with a small/amount of cement. In this mixture 
half-cylinder tiles are soaked until they are covered with one or more 
layers of it. These tiles thus prepared are dried for several days in the 
sun, and are then carried to the park, where they are placed in five or 
six rows, forming hives of from fifty to sixty tiles; these hives are sur- 
rounded by strong stakes, which are firmly fixed to prevent their being 
overturned or carried away by the rapid currents. The water passing 
through these tiles is arrested there and an eddy formed, which permits 
the young oyster to attach itself to the collectors by means of its little 
vibrating cilia. There the embryo becomes developed, increases in size, 
and attains the adult age, which isa year and a half, and not three years, 
as has been stated by certain parkers, whose opinion in the matter (as we 
know from numerous and thorough experiments) is entirely erroneous. 
Towards the close of the year women detrocate them (this term, when 
used in oyster culture, signifies detaching the oyster) by means of knives 
designed for this purpose, which they very carefully insert between the 
young mollusks and the tile to which they are attached. The young oys- 
ter, thanks to the covering of mortar, is easily loosened without suffer- 
