THE WHALE TRIBE. 113 



then dive down, as they chase each other in their gam- 

 bols. The Dolphin is quite as sportive as the Porpoise, 

 and much more agile. It often follows ships in numer- 

 ous herds, executing its playful movements. The stories 

 about the beautifully-changing hues of the dying Dolphin 

 are untrue; this voracious animal is altogether unpoet- 

 ical even to death. Its colors are black and white, and 

 the only change which occurs is that the black, after a 

 time, becomes brown, and the white gray. 



194. There are some aberrant genera of the Dolphin 

 family. One of the most remarkable we have in the 

 Narwhal, or Sea Unicorn, as it is commonly called, Fig. 

 94. Its body is from thirty to forty feet long. It has 



Fig. 94. The Narwhal. 



a long, straight, pointed tusk, from five to ten feet in 

 length. It really has two tusks, but only one of them 

 becomes long, the other not projecting sufficiently tp be 

 seen. There is much question about the use to which 

 the animal puts this tusk. Some suppose that its chief 

 purpose is to dig up sea-weed for food. Others suppose 



