284 OYSTEE CULTURE. 



should be clean, and not covered with slime^ weed^ &c. I have, 

 therefore, latterly adopted the plan of waiting for a spat of oysters, 

 and then throwing shells broadcast into the ponds. I believe this 

 is a good plan. To show how capricious the oysters are, this last 

 season I bred a few oysters in one pond, and there were none in 

 the other close by, yet both were treated alike. I allow the tide to 

 flow in and out through the sluices while the breeding is going on. 

 Some hold this to be a bad plan, as it allows spat to escape. Some 

 may perhaps, but the continual flow and reflow of fresh water into 

 the ponds is most important. I believe it is true that spat rises to 

 the surface in the day and falls to the bottom at night. I have 

 tried this by experiments in large bottles, and there is no doubt 

 that it did fall to the bottom in the dark, and rose to the surface with 

 great activity on being brought out in the light. 



There is no doubt that an oyster must have innumerable enemies. 

 When it is an established fact that one oyster will emit a million 

 little eggs or spat, it is clear that if it were not for wholesale de- 

 struction the stock of oysters would be always abundant, but it is not 

 so. After maturing on a piece of stone, rock, tile, shell, or any other 

 natural collectors in its youth the oysters are devoured wholesale by 

 crabs, &c. ; but what destroys them almost at their birth ? This is 

 the most important question. The principal cause of our having no 

 spat deposited in this river is the violence of the tide. Unless 

 the oyster spat* attaches itself to something during the lay tide and 

 at neap tides the chances are it is all swept out of this river into the 

 Solent ; it may deposit itself in places there, but I hold this to be the 

 greatest obstacle to spat getting attached to anything in the river. 

 The same reason, I think, applies to spat in the Solent, that part 

 of the Solent between St. Helens and Osborne Bay being quite the 

 best bed for oyster-dredging. It is between these two points that 

 east and west going tides meet, and where there is no great current, 

 and it is on this ground that the Solent oyster-dredgers work. 



I believe that one of the reasons of a yeai'ly fall of spat in the 

 Essex rivers is much due to the same cause, and undoubtedly the 

 Whitstahlef beds are in an equally favorable position. The bay 

 or inland sea of Arcachon is for the same reason most favorable 

 for securing a fall of spat, the tide simply passing up and down 

 the bay, and never running the spat into the sea. The Dutch beds 

 at Bergen-op-Zoom are similarly situated. But I think there are 

 other causes why our oyster beds at home are becoming yearly less 



* I believe that if an oyster spat is really fit, it will fix itself to some object in a very 

 few hours of its being emitted from the parent oyster. 



t Most of the Whitstable natives have for years past been supplied from Arcachon, and 

 laid in the Whitstable grounds. 



