Enemies of the American Oyster 155 



presence may not be discovered until the damage is done. 

 It is thus necessary for the culturist to exercise eternal 

 vigilance. The number of these enemies that must be 

 dealt with in certain localities may be imagined when it is 

 stated that one oyster planter in six years removed from 

 his deep water beds ten thousand bushels of them. 



There is considerable variation in their number, due to 

 changes in environment. It sometimes happens that a 



FIG. 39. Tangle of frayed rope or 

 pieces of cotton waste used in col- 

 lecting starfish on oyster beds. 

 Drawn from a figure published by 

 the U. S. Fish Commission. 



year or even more may pass without the appearance of 

 great numbers. At another time they become very 

 abundant. 



The removal of these pests has always been a very 



