BLUE SHARK. 29 



of proceeding has been supposed to arise from a difficulty 

 that is feh in seizing an object with the mouth in a prone 

 position; but which appears to be adopted only that they may 

 obtain a greater advantage in a rolling motion, to cut the 

 object in two parts, or more eflectually with a vibrating action 

 of the head, to separate such a portion as they are prejiared 

 to swallow. On a large substance, with their formidable array 

 of teeth the grasp cannot fail to be successful; but with so 

 slender a bulk as a fisherman's line, it is sometimes otherwise; 

 and when this has escaped the grinding action of the bite, the 

 turning of the body is continued until the whole of the line 

 is twisted round itself, and the fish is thus brought to the 

 surface, even from a depth of forty fathoms. 



The Toper has been known to do the same thing under the 

 like circumstances. 



It appears that this fish pursues its prey by sight rather than 

 by scent, although its nerve of smelling is of large size; but 

 it is known to be sensible to a nauseous smell or taste, for 

 fishermen assert that it may be driven away by pouring bilge- 

 water into the sea where it is: a piece of information that may 

 be of use in reference to the still more destructive White 

 Shark. 



The Blue Shark seems to have a generally rapacious aj)petite, 

 and has been known to leap out of the water to seize a piece 

 of beef hanging on the quJirter of a ship. It is only owing, 

 therefore, to the circumstance that usually it docs not come 

 very close to the land, or enter harbours, that man himself does 

 not suffer from its voracity. Jonston is of opinion that it shews 

 a preference for human flesh; and he records an instance where 

 a soldier was attacked by it, and had a narrow escape from 

 being severely bitten. In a fish of such indiscriminate appe- 

 tite it might appear superfluous to specify particulars; but 

 from the stomach of one of six feet in length I have 

 taken a large Picked Dogfish and a Conger, each bitten 

 across at the middle, and also a Grey Gurnard. In another 

 instance there were found four mackerel, half a garfish, and 

 as many herrings, wholly uninjured, as the fisherman sold for 

 eighteen pence. Yet after such a hearty meal the Sharks 

 devoured the bait. 



It is also remarkably retentive of live, as indeed are the whole 



