324 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



ors were examined, but they did not bear any apparent trace of spat. 

 This was a deception. Meanwhile, thinking that the season for the fry 

 had not yet began in the Gironde, we expected happier results from 

 our final experiments. The claire was emptied, and some modifications 

 were introduced iu the management of the water, and from day to day 

 mixtures of the generative products were again poured into the claire 



On the 24th July the tiles were examined. This time all had spat 

 attached. Jt was therefore evident that the first experiments had not 

 been as unsuccessful as we had supposed. In fact, each of the tiles 

 immersed had young oysters attached to the number of twenty or thirty, 

 measuring about a centimeter [two-fifths of an inch] in diameter. This 

 spat was evidently derived from the spawn put out during the end of 

 June or the commencement of July ; but their small size had prevented 

 us from seeing them when the inspection was made at that time. On 

 the 24th July we had specimens about a month old. This fact was all 

 the more remarkable, in that, up to that same time, the collectors placed 

 in the Gironde, in the very center of the spawning beds, did not show 

 a sign of spat. 



The problem which we had put before ourselves had accordingly re- 

 ceived, from a scientific and practical point of view, a solution iu con- 

 formity with our hopes. It was possible to obtain spat by means of 

 artificial fecundation and to capture it in confined waters. And we 

 no longer had the slightest reason to doubt the identity of that which 

 had caught on our tiles, nor to suppose that it came from the waters 

 without, since there was as yet none apparent in the Gironde, and 

 the tiles in the upper claire, which served to feed the experimental 

 claire, were completely exempt. 



If in forcing nature's processes we arrive at the same result, that 

 is, provoke the birth of the young before the time of the normal emis- 

 sion of the spawn, there is all the more reason for us to suppose that 

 we have an excellent means to aid and favor her. 



In pursuing our researches in the establishment of M. Tripota, we 

 did well to vary our means of investigation whenever the same bore 

 upon the industrial aspects of the work. 



On the rights [parks] along the Canal du Conseiller, and fed by it, 

 there exist old salt marshes, for the most part abandoned, or used for 

 other purposes than formerly, some of which have been transformed 

 into reservoirs for fishes. Those which we appropriated were about 

 two kilometers from the river and from the locality chosen at Verdon, 

 and received fresh supplies of water during the spring tides. They con- 

 sisted of numerous compartments, varying in depth and communicating 

 by wide trenches cut into the banks separating them from each other. 

 Their total extent somewhat exceeded a hectare. During the new and 

 Cull moon the gate controlling the supply was opened to allow the fish 

 carried by the current to enter and to renew the water. This maneuver 

 was repeated many times during the tide. On account of the situation 



