OYSTER CULTURE IN FRANCE. 579 



of the floodgate, and of the springs which rise here and 

 there on the banks. 



This wholly fortuitous discovery put MM. de Montauge 

 on the track of the truth. Some hundreds of oysters were 

 again placed in the basin, and some collecting apparatus 

 which was laid down became covered with spat. 



It has been denied that these embryos came from the 



> 



specimens experimented on, but from what source could 

 they emanate ? No pare of reproduction is to be found in 

 the neighbourhood ; the tide, which might have served to 

 convey them, must have traversed many kilometres of 

 crassats before entering the establishment ; and this long 

 passage across the emergent grounds,. under the summer 

 sun, so heats the sea water that the spat lose all their 

 vitality in it. But, it has been also urged, how can these 

 very waters, too warm to furnish the embryos with the 

 normal conditions of existence, be fit to preserve the spawn 

 of the captive oyster ? We have an explanation of this 

 apparently contradictory fact, if we remember that the fresh 

 water of the stream, which we have already mentioned, was 

 allowed to enter the canal of the establishment, and by its 

 freshness to lower the temperature of the salt water. 



Another experiment of MM. de Montauge, with the 

 aim of determining what influence the soil could have on 

 the development of the mollusc, was to deposit in one part 

 of their basin some earth taken from the pares at Oleron. 

 Oysters of the same size and age were placed on this earth, 

 and others were put by their side on ordinary soil. The 

 result was that the growth of the specimens was almost 

 equal, but the former were better nourished and more 

 horned. 



All oyster cultivators know that extreme cold and ice 



are prejudicial to oysters. The proprietors of the works at 



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