SUPPLEMENT. 1 243 



that is, dredging to the extreme limit at which it is 

 commercially profitable to dredge is alone competent 

 permanently to destroy an oyster bed or not. That oyster 

 beds have disappeared after they have been much dredged, 

 I do not doubt. But the commonest of all fallacies is the 

 confusion of post hoc with propter hoc ; and I have yet to 

 meet with a case in which it is proved by satisfactory 

 evidence, that an oyster bed has been permanently 

 annihilated by dredging, when the spatting seasons have 

 been good, and when there has been no reason to suspect 

 an inroad of destructive molluscs or starfishes. 



The increasing scarcity and dearness of oysters were 

 subjects of complaint twenty years ago, and the outcry has 

 become louder of late years. Three causes, and only 

 three, so far as I know, have been assigned for this 

 unsatisfactory state of things : first, the increase in the 

 demand for oysters, owing in large measure to modern 

 facilities of transport, consequent upon the vast develop- 

 ment of the means of locomotion ; second, an unusual 

 succession of bad spatting years ; third, over-dredging, 

 that is to say, the removal of so many oysters from the 

 oyster beds that the number left is insufficient to keep up 

 the stock. 



That the first and second of these causes have had a 

 great deal to do with the matter is beyond doubt ; but, 

 whether any harm has resulted from simple over-dredging 

 is a question respecting which very different opinions are 

 entertained, and I have already stated my reasons for 

 reserving my opinion on the subject. But I shall suppose, 

 for argument's sake, that all three influences are in 

 operation, and proceed to ask what can be done by 

 legislation to mitigate their evil effects. 



