THE OYSTER. II5 



or shallow water. On the French coast they are 

 chiefly employed above low-tide mark or in very shal- 

 low water, and they are then spread out so as to 

 cover a considerable area. In some cases lines of 

 stakes are driven into the ground, about a foot apart, 

 transverse string-pieces are fastened to them about a 

 foot above the bottom, a row of tiles is laid upon 

 them, concave surface down, another row of tiles is 

 placed at right angles upon the first layer, and the 

 whole is weighted with stones. Other ways of arrang- 

 ing the tiles are shown in Figs. 5, 6, and 7. 



As soon as the oysters are large enough to handle, 

 they should be removed from the tiles and distributed 

 on the planting ground, for they usually become so 

 crowded together on the tiles that they have no room 

 to grow. 



When used in deep water they may be fastened to 

 a frame, which may be sunk upon or near a natural 

 oyster-bed. So far as I am informed, Lieut. Francis 

 Winslow is the only person who has ever made use 

 of tile-collectors in American waters, but the remark- 

 able results which he obtained with them in Tangier 

 Sound, in 1879, show that they are well suited for 

 use in the waters of the bay, where they are perfectly 

 successful as spat-collectors. 



Lieut. Winslow's interesting figures of these tiles 

 form the most complete record of the rate of growth 

 of oysters in the Chesapeake Bay which has ever been 

 obtained, and his results are so valuable that I have 

 copied six of his plates. He made use of a collector 

 which was made by lashing eight or sixteen tiles to a 

 wooden frame, which rested on the bottom upon a 



