57? OYSTERS, AND ALL ABOUT THEM. 



compartment is lined with cement ; the bed of the second 

 has been re-made, and a layer of clay beaten and dammed 

 up, surmounted by another layer of muddy sand and shells, 

 has been substituted for the original materials. 



These works have been executed to prevent any intro- 

 duction of water from the iron springs which rise in the 

 concession of MM. de Montaug6, the metallic element of 

 which is hurtful to the oyster. The basin is fed by means 

 of a large floodgate opened at the rise of the tide, and 

 closed when it recedes. This floodgate is placed at the 

 head of a channel, the water from which is blended with 

 fresh water at the mouth of a small stream. At first great 

 care was taken lest this fresh water should mingle with the 

 sea water during the refilling of the basin. 



Amongst other experiments made by the MM. de 

 Montauge, they inquired into the aptitude which the captive 

 oyster might have for producing spat capable of develop- 

 ment. For three years the adult oysters parced in the 

 reservoir of observation emitted no embryos, and even grew 

 thin. The experimenters attributed this impoverishment 

 to the too great saltness of the water, which was so great 

 that it deposited salt crystals on the marine plants contained 

 in the basin. The want of success was evident ; the 

 experiments were abandoned, the oysters removed, and the 

 piece of water converted into a fish pond. From this 

 moment care was no longer taken to prevent the mingling 

 of the waters of the stream of which I have spoken with 

 the sea water in the supply canal, and some time after, in 

 raking the soil, a few oysters were found which had been 

 overlooked. It was noticed that they had developed and 

 grown stronger, and a more extraordinary and an unexpected 

 fact was that traces of spat were found in the neighbourhood 



