92 FOLLOW THE WHALE 



nahvalr, which is derived from na-r meaning a corpse. The Dutch 

 whalers called them eenhorn or hoornvisch by reason of their most 

 distinctive feature, their tusk. 



Narwhals have no visible teeth, their jaws being horny and used 

 simply for crushing and not for masticating the fish, squids, cuttles, 

 and crustaceans that they eat. There are, however, in both sexes two 

 amazing tusks that are greatly modified canine teeth which point 

 forward and lie horizontally in the bones of the upper jaw. In the 

 female these remain hidden within the jawbones throughout life, but 

 in the male either one, which is then invariably the left, or both 

 grow into tremendous, long, straight spears with a number of 

 grooves and ridges that extend spirally to the tip like a corkscrew. 

 The strange thing is that this twist is always sinistral, or to the left, 

 and even if two tusks are developed, the grooves on both turn the 

 same way. These tusks may often be more than half the length of the 

 animal, and specimens up to ten feet long have been recorded. One 

 tusk, eight feet long, had a basal girth of seven and a half inches; they 

 are devoid of enamel and have a central pulp cavity that extends 

 almost to the tip. 



The question as to what their use may be to the animal itself has 

 caused a great deal of debate. One observer noticed that the males 

 fenced with them, holding their heads out of the water and crossing 

 their tusks Hke rapiers. It has been suggested that they are used to 

 spear fish, but in this case the female, who has none, must fare rather 

 badly, and we would also like to know how the animal gets the fish 

 off its spear. Narwhals have been seen crowding air holes in the 

 polar ice in order to breathe, and it is believed the tusks may have 

 been developed to keep these holes open during rapid freezes. The 

 structure is, however, undoubtedly a secondary sexual character like 

 the cock's comb. 



The narwhal is an exclusively polar animal seldom seen outside 

 the Arctic Circle. It is found all round the coasts of the Arctic 

 Ocean and travels about in family parties of up to twenty individ- 

 uals. Sometimes narwhals gather together in enormous herds to mi- 

 grate north, as has often been observed in the Davis Strait. They 

 are now greatly reduced in number, the result of centuries of perse- 

 cution, but they are still more common between Europe and Amer- 

 ica than between America and Asia. They are exceedingly fast 



