376 EXTINCTION OF THE BISON AND WHALES 



like, the skin smooth and hairless. It is a remarkable 

 conclusion arrived at by the investigators of the remains 

 of extinct animals that a little four-legged creature the 

 size of a spaniel, and intermediate in character between a 

 hedgehog and a dog, was the common ancestor from 

 which have been derived such widely different creatures 

 as the whale and the bat, the elephant and the man. We 

 can at the present day trace with some certainty the 

 gradual modifications of form by which in the course of 

 many millions of years the change from the primitive, 

 dog-like hedgehog to each of those four living " types " 

 has proceeded. 



The whales of to-day are divided into the toothed whales 

 and the whalebone whales. The great cachalot or sperm 

 whale is captured, chiefly in the Southern Ocean, and 

 killed in large numbers for the sake of the " spermaceti," 

 or "sperm oil," which forms the great mass of its head, 

 but he is so fierce and active that he is not easily captured, 

 and is not in immediate .danger of extinction. The 

 smaller toothed whales, the killers, dolphins, and porpoises 

 (though one of them the bottle-nosed whale is being 

 killed out), are not as yet seriously threatened by com- 

 mercial man. But the whalebone whales are in a parlous 

 state. The right whales as they are called are the chief 

 of these. They are huge creatures, 60 ft. in length, with 

 an enormous head : it is as much as one third of the total 

 length in the Greenland whale. Besides the Greenland 

 species there are four other " right whales," which may be 

 considered as four varieties of one species. The head is not 

 quite so large in them. The Biscay whale is one of them, 

 and was hunted until it was exterminated in the Bay of 

 Biscay, when the whalers, extending their operations 

 further and further north, came upon the Greenland whale, 

 which proved to be even more valuable than the Biscay 

 species. The huge mouth in these two whales has hang- 



