BULLETIN OF THE UNITED STATES FISH COMMISSION. 237 



embryos in the condition of black spawn lield out eight or ten days. 

 But as they approached that time they coakl be seen to grow more 

 leeok'. every day, and liually to succumb, none of them having become 

 fixed to the collectors placed in the boxes. 



Thinking that the location (light and air being lacking) was not favor- 

 able for such delicate experiments, we went to Arcachou to repeat them 

 there. Messrs. de Montauge extended to us the hospitality of their 

 establishment of St. Joseph; they placed at our disposal the laboratory 

 which they had organized, and the reservoirs surrounding this labora- 

 tory, reservoirs in which the water could be renewed at every tide. 



Ae apparatus on the same model as that which we had used at the 

 College of France was constructed, and eggs and embryos were placed 

 in it as at the first experiment. The result did not answer our expec- 

 tations any better, and it became necessary to change our method of 

 experimenting. Wo now determined to establish ourselves at the large 

 reservoirs referred to. The difficulty was to keep the spawn in compart- 

 ments spacious enough to make them feel just as much at their ease as in 

 open water and at the same time to have a constant renewal of water in 

 all the compartments. Two board frames, i^erf orated, the one measuring 

 3^ meters long and broad by 70 centimeters high [llA x Hi X 2^ feet, 

 about], the other measuring 2i meters long and broad and 70 centimeters 

 high [Si- X 8-i- X 2^ feet, about], were placed one within the other and 

 deposited on the stone edge of the sheet of water. We piled fine sand, 

 which had been washed, into the space of 50 centimeters [nearly 20 

 inches] between the outer wall of the smaller frame and the inner wall 

 of the larger one. The apparatus worked to our complete satisfaction, 

 and the level of the water rose and fell according to the condition of 

 the sea. We scattered inside black spawn of several oysters, and fear- 

 ing that the elements of nutrition contained in the water and coming 

 from outside should be retained by the sand, thus depriving the captive 

 embryos of their food, we took care to pour into their compartments 

 several times a day several buckets of water taken from the sea when 

 the tide came in. When the collectors were examined two weeks later 

 there was nothing on them, and at the end of a month they were still 

 empty. We were obliged to consider the experiment a failure; but at- 

 tributed our lack of success to rain, which set in during our operations, 

 and also to the want of heat. 



Last year we resumed our experiments. We found ourselves under 

 conditions almost identical with those of the bay of Arcachou. Thanks 

 to the kindness of Mr. Johnston, we commenced new experiments in the 

 vast lagoons of La Teste. In these lagoons the water is not stagnant 

 and oysters are naturally produced there. In the very center of one 

 of the largest sheets of water we constructed two vast basins, measiu^- 

 ing to 8 meters [about 20 to 2.5 feet] square, and working in the same 

 manner as those described above. (See Plate V.) Surrounded by M'ater 

 on every side, infiltration, which constituted the only way of feeding the 



