WHAT HAS BECOME OF THE WHALE'S LEGS 



outward but were pressed close to the body as it swam 

 under the ship. 



A whale's flippers must not be compared with the 

 fins of a fish, for in structure the two are quite un- 

 like. The flippers of all cetaceans are merely the fore 



Posterior view of a blue whale on the slip at Aikawa, Japan. 

 The flukes have been cut off and the wide thin caudal portion 

 of the body is well shown. 



limbs of ordinary land mammals, which have become 

 overlaid with blubber to form a paddle in adaptation 

 to an aquatic life and have the bones, blood vessels, 

 and nerves of the human arm. The flipper of the 

 humpback whale has four greatly elongated fingers 

 but in some other species there are five fingers as 

 in the human hand. 



Cetaceans also have rudiments of the hind limbs. 

 These consist of the pelvis, which is fairly well devel- 



149 



