330 THE LIVING ANIMALS OF THE WORLD 



no gills. Fishes, in the vast majority of cases, reproduce their young by spawning, the eggs 

 being left to hatch out either in gravel-beds or among the water-plants, lying on the bottom 

 (as in the case of the herring), or floating near the surface (as in that of the plaice) : whales 

 do not lay eggs, but bear the young alive. This brings us to the simple points of resemblance 

 between them and other mammals. When the young whale is born, it is nourished on its 

 mother's milk. This alone would constitute its claim to a place among the highest class. 

 Whales breathe atmospheric air by means of lungs. Hair is peculiarly the covering of mammals, 

 just as scales are characteristic of fishes and feathers of birds. Many whales, it is true, have no 



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Photo h A, S. Rualand &* Sons 



GRAMPUS, OR KILLER 



A carnivorous cetacean ivtth large teeth) often found in the North Sea 



hair; but others, if only in the embryonic stage, have traces of this characteristic mammalian 

 covering. It must, moreover, be remembered that in some other orders of mammals the amount 

 of hair varies considerably as, for instance, between the camel and rhinoceros. 



Having, then, shown that whales are mammals, we must now determine the chief features 

 of the more typical members of the order. The extremities of whales are characteristic : 

 a large head, occupying in some species as much as one-third of the total length ; and 

 the afore-mentioned forked, or lobed, tail set laterally. The flippers, which bear only a 

 slight resemblance to the pectoral fins in fishes, are in reality hands encased in swimming- 

 gloves. In some whales these hands are five-fingered, in others the fingers number only four, 



