PORPOISES AND DOLPHINS 285 



Scoresby gives the adult length as from 13 to 16 feet, 

 exclusive of the tusk, but some other writers have not been so 

 conservative in their estimates. Confusion has no doubt 

 sometimes been caused by the tusk length being included with 

 that of the body in statements of total length. 



The Narwhal is an Arctic species, seldom found far from 

 the icy regions of the northern polar seas, but stragglers 

 occasionally wander away so that we have a few records of 

 strandings on the coast of Norway, Holland and the shores of 

 Great Britain. 



" Narwhals," says Scoresby, " are quick, active, inoffensive 

 animals. They swim with considerable velocity. When 

 respiring at the surface they frequently lie motionless for 

 several minutes, with their backs and heads just appearing 

 above the water. They are of a somewhat gregarious dis- 

 position, often appearing in numerous little herds of half a 

 dozen, or more, together. Each herd is most frequently 

 composed of animals of the same sex." 



The function of the tusk is not certainly known, although 

 several ingenious suggestions have been advanced as to its 

 probable use ; as an instrument for breaking ice for the animal 

 to come to the surface to breathe in frozen regions, as a rake 

 for obtaining food from the bottom of the sea, even as a sort 

 of skewer for transfixing the animals upon which the Narwhal 

 feeds ; but most of these suggested reasons for having a tusk 

 are open to the objection that the females manage to survive 

 equally well without. Another suggestion, and the most 

 likely, is that the tusk is a sexual specialization of the male 

 used when in combat with his fellows for the possession of the 

 females. 



Cuttlefishes are the main food of Narwhals, but fishes and 

 crustaceans have occasionally been found in their stomachs. 



This species was formally of considerable economic impor- 

 tance, chiefly on account of the ivory obtained from the tusks, 

 but also because of the rather superior quality of the oil 

 secured from the blubber. The whalers hunted it by methods 

 similar to those employed in pursuit of the Greenland Right 

 Whale, and Scoresby tells us that when harpooned the Narwhal 

 dives in the same way and with almost the same velocity as 

 the Greenland Whale, but not to the same extent. " It 



