BULLETIN OF THE UNITED STATES FISH COMMISSION. 325 



occupied by this marsh along the exposed shores of the Gironde the 

 water is never stagnant, even at the time of the neap tides. The sea- 

 breezes and winds which follow the course of the river aerate it per- 

 petually and agitate its surface. Those which we had chosen measured 

 5 to 6 feet in depth at the center and 2 to 3 along the margin. Stakes 

 placed at intervals supported the fragments of tiles suspended with iron 

 wire. 



From the beginning of July to the end of August, M. Gassiau, school- 

 master at Verdou, who assisted us during the entire campaign, with an 

 intelligence, zeal, and devotion worthy of the highest praise, took care 

 to pour into the inclosures, several times a week, the products of the 

 artificial fecundations which he prepared with rare skill and certainty. 

 Three hundred oysters only were used iu these experiments. 



On the 8th of August he visited the collectors, and observed on all 

 of them, without exception, hundreds of young oysters, measuring one- 

 half to two millimeters in diameter [^ to ^ of an inch]. The spat 

 grown from each of the successive lots of fertilized spawn could be dis- 

 tinguished by its size, which corresponded to its age. Having the 

 curiosity to know how many fixed themselves to one tile, we counted 

 more than eight hundred on a single piece of tile, of which the size was 

 one-fifth that of an entire one. This time our success was complete. 



Up to the end of August, the time when the oysters had nearly all 

 spawned, the spat continued to attach itself just as abundantly to all 

 kinds of collectors with which it came in contact indiscriminately, frag- 

 ments of ti les, pieces of wood, boards, &c. 



Doubt was no longer possible. The pessimists asked whether our 

 nurslings would grow and develop equal to those which were naturally 

 collected on the banks of the Gironde. We responded to this objection 

 by sending some of the tiles to be placed in the parks at Arcachon, 

 where they remained for a month and a half. 



These tiles and fragments of tiles figured at the end of September in 

 the exposition at Bordeaux by the side of those which had been brought 

 by MM. Tripota and Gassiau. 



We also found that the spat born in the beginning of July, in the 

 closed claire, measured from three to four centimeters in diameter, and 

 that whicli was collected in the salt-marsh by the end of July and 

 during the month of August had attained the dimension of one centi- 

 meter [two-fifths of an inch] in diameter. Finally, during the early 

 part of October, we had the honor of presenting to the minister of 

 marine a tile upon which two thousand young oysters could be counted, 

 measuring from one to two centimeters [two-fifths to four-fifths of an 

 inch] in diameter. 



It now remained for us to make a final demonstration. It was nec- 

 essary to prove that the spat which was collected did not primarily 

 emanate from the banks in the Gironde, but was the result of the 

 artificial fecundations practiced under our care. This proof was evi- 



