SUPPLEMENT. 1223 



powerful beaks for perforating the shell. We think that a 

 burr would have to pound away for a long time without 

 gaining any admittance to an adult oyster's closed doors, 

 but they are possibly capable of destroying the young 

 brood. 



CRUSTACEA (CRABS, LOBSTERS, PRAWNS, SHRIMPS). 



At different stages of an oyster's life all these animals 

 are more or less enemies to it : the worst are undoubtedly 

 crabs ; they will eat oysters whenever and wherever they 

 get a chance. 



Fishermen have a superstitious regard for the cunning 

 and cleverness of the wily crab, and marvellous stories are 

 told of its " legal " qualities. The two following examples 

 of such tales will suffice. A friend told us that a crab in 

 'his aquarium would take up young oyster brood, which had 

 lately been removed from the layings, turn them over one 

 by one, and examine them narrowly to see whether they 

 had been injured by removal. If uninjured, the crab 

 dropped the oyster with an apparently disgusted air, and 

 seized another. Should this one by chance show marks of 

 abrasion, the crab pounded away with his heavy claw at 

 the weakened spot until the shell gave way, when the other 

 claw was immediately inserted, the fish dragged out and 

 devoured. Was this instinct or reasoning power ? may well 

 be asked ; the latter, if we are to believe the yarn of another 

 raconteur, who gravely informed us that he had seen a 

 crab hovering above a feeding oyster, holding in one claw 

 a small stone, which he poised over the unconscious bivalve. 

 When a favourable opportunity occurred the crab let go, 

 exactly plumbing the entrance of the gaping shells ; the 

 stone fell, " wedging them open," and the crab descended 

 into his oyster bar ! 



