BULLETIN OF THE UNITED STATES FISH COMMISSION. 323 



experiments profitably, nor to settle those questions which were still 

 obscure. At the end of last season we little thought, considering 

 the slowness with which our studies had progressed, that we would be 

 able in a single campaign to solve the problem of artificial fertilization 

 applicable to the ostracultural industry; we were also not at first as- 

 sured of our ability to produce the manifestation of the phenomena 

 which we have observed with so much interest and upon which rested 

 our hope of final success. 



In recom inencing the work we were obliged to make choice of a con- 

 venient station for our experiments. The station of Verdon, situated 

 on the left bank of the Gironde, at a distance of several kilometers from 

 the mouth of the river, seemed to us to combine all the desired advan- 

 tages. We were assured of finding there the oysters fitted for spawning, 

 as well as suitable water. In fact, the first attempt which we made in 

 artificial impregnation in fourteen hours afterwards resulted in the 

 production of mobile larva?, notwithstanding that the season for the fry 

 had not yet arrived, commencing at least a mouth later. 



M. Tripota, one of the veteran ostraculturists, and at the same time 

 one of the most competent, very willingly, at the request of the com- 

 missioner, M. Jouau, placed at our disposal, with a grace and disinter- 

 estedness for which we are under great obligations, two beautiful uii- 

 submersible 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 1 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 fine 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-pipe allowing nothing to pass into the experimental 

 claire except clear water. 



This arrangement completed, the products of artificial fecundation, 

 impregnated in various ways, were poured into the experimental reser 

 voir. This took place in the second week in June. 



According to our belief, we hoped to find some spat on the collectors 

 placed in the experimental claire at the end of the same month or by 

 the beginning of the month of July. M. Tripota, who had taker 

 active part in the work, and who took my place in my absence, contin- 

 ued to supply the claire with fertilized eggs and mobile embryos. 



The time assigned for experimental proof having arrived, the collect- 



