162 MARVELS OF THE ANIMAL WORLD 



first ones exhibited in this country arrived at the 

 London Zoological Gardens in 1817. Their span 

 of life, however, was of a very brief duration, both 

 of the animals dying before two months had elapsed. 

 Since then several others have arrived, but none 

 lived for long. 



The narwhal or sea-unicorn is a remarkable 

 animal inasmuch as the female is entirely unpro- 

 vided with teeth, except for those which it possesses 

 when first born and sheds almost immediately after- 

 wards. Even the male passes through a toothless 

 stage during its early life, but as it grows up two 

 new teeth are developed. One of these pierces 

 through its upper lip and ultimately forms a 

 straightly-aligned, spirally-twisted, and tapering 

 tusk which attains to a length of seven or eight 

 feet ; while the other one usually remains within 

 its socket and does no^ even pierce the gum. Occa- 

 sionally, however, individuals have been known to 

 possess two tusks. Many suggestions have been put 

 forward as to the exact utility of this enormous 

 tooth ; some authorities believing that the narwhal 

 makes use of it for spearing the fish upon which it 

 feeds ; others stating that it serves as a weapon 

 when the creature is engaged in combat with its 

 fellows for the possession of the females ; while it 

 has been further suggested that it is employed for 

 the purpose of making cavities in the ice to serve as 

 breathing-holes for, being a mammal and not a 

 fish, the animal is unable to remain under the water 

 for any length of time without coming to the surface 

 for a supply of air. It is a known fact that narwhals 



