1 014 OYSTERS, AND ALL ABOUT THEM. 



human care and attention, whilst others can be trusted to 

 take care of themselves. 



If the grounds are situated where they are liable to 

 become rapidly silted up, as in the case of most of the 

 beds in and about the estuary of the Thames, it would be 

 folly not to keep them constantly worked, as they would 

 otherwise become useless in a very short time. On the 

 other hand, where the grounds are so situated that they 

 keep clean by the scour of the tide and the absence of 

 deposits, the less interference they meet with the better. 

 Lost fertility may be restored to an oyster bed by a close 

 season being rigidly enforced, whilst constant dredging is 

 not only desirable, but absolutely necessary where weed, 

 mud and vermin accumulate rapidly. 



It may seem hardly intelligible why, if at one period 

 oyster beds were productive without artificial aid, they should 

 require it afterwards ; but there are various reasons why this 

 is so. When beds have been abandoned by dredgers, owing 

 to their being able to obtain a greater number of oysters 

 elsewhere, they may and do become ruined by the collec- 

 tion of mud and weeds that is formed ; the soil having 

 been once disturbed by dredging, becomes looser and 

 more liable to shift, and thus weed, " slub," &c., drifts 

 easily into the depressions caused by the abstracted oysters, 

 or the drift of mud, organic matter, &c., attracts vermin in 

 large numbers, just as a fisherman rakes the bottom to 

 attract fish. In whatever way it may be accounted for, the 

 facts that beds once worked have been ruined are certain 

 witness the examples of the Jersey and Granville beds. 



All cultivated beds vary between the two following 

 conditions : of being overcrowded with oysters, ware, and 

 brood, &c. ; and of having only a few parent oysters left on 

 them. 



