BEST CONDITIONS FOE SPAWNING. 237 



were Firth of Forth oysters from Oockenzie. It is not easy to 

 determine from the external size of the animal the amount of 

 " meat " it will yield — apparently, " the bigger the oyster the 

 smaller the meat." In the early part of the season only very 

 small oysters are sold in Edinbm-gh — the reason assigned being 

 that aU the best dredgers are " away at the herring," and that 

 the persons left behind at the oyster-beds are only able to skim 

 them, so that, for a period of about six weeks, we merely obtain 

 the small fry that are lying on the top. It is quite certain that 

 as the season advances the oysters obtained are larger and of 

 more decided flavour. In the "natives" obtained at Whit- 

 stable the shell and the meat are pretty much in keeping as to 

 size, and this is an advantage. 



The Abbd Diquemarc, who has keenly observed the habits 

 of the principal moUusca, assures tis that oysters, when free, are 

 perfectly able to transport themselves from one place to another, 

 by simply causing the sear-water to enter and emerge suddenly 

 from between their valves ; and these they use with extreme 

 rapidity and great force. By means of the operation now 

 described, the oyster is enabled to defend itself from its enemies 

 among the minor Crustacea, particularly the small crabs, which 

 endeavour to enter the shell when it is half open. " Some 

 naturalists," the Abb^ says, "go the length of allowing the 

 oyster to have great foresight," which he illustrates by an allu- 

 sion to the habits of those found at the sea-side. "These 

 oysters," he says, " exposed to the daily change of tides, appear 

 to be aware that they are likely to be exposed to dryness at 

 certain recurring periods, and so they preserve water in their 

 shells to supply their wants when the tide is at ebb. This 

 peculiarity renders them more easy of transportation to remote 

 distances than those members of the family which are caught at 

 a considerable distance from the shore." 



The secret of there being only a holding-on place required 

 for the spat of the oyster to insure an immensely-increased 

 supply having been penetrated by the French people — and no 

 doubt they are in some degree indebted to our oyster-beds on 

 the Oolne and at Whitstable for their idea — the plan of 

 systematic oyster-culture was easy enough, as I will imme- 

 diately show. A few initiatory experiments, in fact, speedily 

 settled that oysters could be grown in any quantity. Strong 

 pillars of wood were driven into the mud and sand ; arms were 

 added ; the whole was interlaced with branches of trees, and 



