ARTIFICIAL OYSTER CULTIVATION. Il8l 



inches thick and the oysters beneath uninjured, in fact it is 

 then a protection. 



One of the most necessary and arduous duties in 

 oyster culture in winter is keeping the ground which is 

 uncovered at low springs clear from oysters. Merchants 

 generally shrink from the labour of moving all their stock 

 into pits, even when they have enough accommodation for 

 them, and those which are left in the river are liable to be 

 killed by frost, or " carted away ' by floe ice. If there 

 happens to be a continuance of easterly winds and a high 

 barometer during spring tides in winter, the water in our 

 estuaries will frequently fall below the low spring-tide water- 

 mark ; then the oysters laid there will get nipped by the 

 frost unless quickly removed into deeper water. 



Floods from melted snow are particularly dangerous ; 

 fresh river-water alone is sufficient to kill oysters, and so, of 

 course, fresh water and cold together are doubly disastrous. 

 Many hundreds of pounds' worth of oysters have been des- 

 troyed by being placed too far up a creek, where the land 

 floods were so powerful that the flowing tide could not 

 dilute them. At Paglesham, Mr. Wiseman says he has 

 known the water of the Roach sweet enough to drink during 

 strong freshets. 



The oysters are taken out of the pits in March or 

 April, and laid in the bank of the river to grow and spat. 

 If kept in the reservoirs during the summer, but little spat 

 is secured from them, as there seems to be too great a 

 variation in temperature, during the summer, between day 

 and night, in these shallow pits. In the pits at Brightl ing- 

 sea, an attempt was made to get the oysters to spat, but 

 very little fell, and that which did fall was all found on the 



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.shells of the parent oysters, by which it seems that animate 



