SHARKS 37 



or swimming aoout in shallower water, often quite close to 

 the shore, they readily catch the eye. Nearly all the sharks 

 described in books of travel belong to this genus, and those 

 observed by the voyager following in the wake of a vessel are 

 almost always Blue Sharks. They have more than once 

 been compared to hungry dogs in search of food when seen 

 from the deck of a ship, and they well merit the names of 

 " wolves of the sea " or " chien de mer " that have been 

 bestowed upon them. 



The Great Blue Shark visits the coasts of the British Isles 

 during the summer months, and small individuals may be 

 seen on calm, warm days swimming lazily near the surface, 

 often with the tail and the tips of the dorsal fins projecting 

 from the water. When in pursuit of prey, or when otherwise 

 excited, they have been observed repeatedly to cover and 

 uncover their eyes with the third eyelids, and it seems that 

 this is a kind of " blinking " caused by the irritation of the 

 intense light. At night their activity is greatly increased, 

 and at such time they hunt their prey mainly by scent. The 

 tiny pores with which the surface of the snout is pitted probably 

 serve some sensory function. 



The Blue Sharks are both fierce and voracious, and their 

 appetite^ are well nigh insatiable. Other fishes form the 

 principal food, and they may even include their own kind in 

 their dietary, but no kind of animal food, whether alive or 

 dead, comes amiss to them. The larger species of the op<m 

 sea chase and seize the pelagic fishes, while their smaller, more 

 thick-set shore-dwelling relatives feed on bottom fishes, 

 crabs, lobsters and shellfish, which they are able to locate by 

 means of their acute sense of smell. Wounded sea birds are 

 often carried down, and offal of all kinds is not disdained. 

 The Cub Shark is notorious as a scavenger, especially in the 

 neighbourhood of harbours and wharves, and hordes are soon 

 attracted by the smell of blood or decomposing flesh. The 

 shark fishermen of Florida, knowing how keen is the sense of 

 smell of these creatures, make use of such baits as rank meat 

 or slaughter-house offal to draw them within striking distance. 



Whaling men are familiar with the huge congregations of 

 sharks that gather like vultures when a whale has been killed 

 and greedily await the process of " cutting in " One authority 



