THE OYSTER. 63 



mollusc. We were likewise encouraged by the experi- 

 ments which Brooks, of the Johns Hopkins Univer- 

 sity of Baltimore, had made upon Ostrea virginica, 

 likewise unisexual, and which had enabled him to fol- 

 low the development of the embryos to the formation 

 of the shell." 



" M. Tripota, one of the veteran ostraculturists, and 

 at the same time one of the most competent, very will- 

 ingly, at the request of the commissioner, M. Jouan, 

 placed at our disposal, with a grace and disinterested- 

 ness for which we are under great obligations, two 

 beautiful unsubmersible claires, which received fresh 

 water for several days during the spring tide, and 

 which were soon arranged for our use by means of 

 some slight internal alterations. Separated from each 

 other by a straight, massive wall of earth, these two 

 ponds, with an area of about 100 meters each, and an 

 average depth of 80 centimeters to i meter (27 inches 

 to 3 feet), were placed in communication by means of 

 a pipe, which was closed at either end by a sponge, to 

 keep out any sediment in suspension in the water. In 

 this manner all doubt as to the origin of the spat 

 which was collected was guarded against." 



" For the outlet, an apparatus consisting of a wall of 

 find sand confined by boards permitted the water to 

 percolate through it, but prevented the embryos from 

 escaping with it. The lowermost claire only was 

 utilized in our experiments. The uppermost claire, in 

 which we stored the water whenever it was possible, 

 served as a reservoir from which to decant, the supply 



