DUGONGS, MANATEES, WHALES, PORPOISES, DOLPHINS 329 



THE WHALES, PORPOISES, AND DOLPHINS 



Although anatomists have good reason for suspecting that all the members of the Whale 

 Tribe are directly descended from river-dwelling forms, if not indeed, more remotely, from 

 some land animal, there is something appropriate in the fact of the vast ocean, which 

 covers something like three-quarters of the earth's surface, producing the mightiest creatures 

 which have ever lived. There should also be some little satisfaction for ourselves in the 

 thought that, their fish-like form notwithstanding, these enormous beings really belong to 

 the highest, or mammalian, class of animal life. 



One striking feature all these many-sized cetaceans have in common, and that is their 

 similarity of form. Though they may vary in length from 70 to 7 feet, their outline shows 

 a remarkable uniformity. Important internal and even external differences there may be. 

 A whale may be toothed or toothless ; a dolphin may be beaked or round-headed ; either may 

 be with or without a slight ridge on the back or a distinct dorsal fin ; but no cetacean could 

 well be mistaken for an animal of any other order. It is as well to appreciate as clearly as 

 possible this close general resemblance between the largest whale and the smallest dolphin, 

 as the similarity is one of some interest ; and we may estimate it at its proper worth if we 

 bear in mind that two species of cetaceans, outwardly alike, may not, perhaps, be more closely 

 allied than such divergent ruminant types as the elephant, the giraffe, and the gazelle. 



Reference has already been made to the fact that the whales are true mammals, and we must 

 now clearly set before us the justification for separating them from the Fishes to which anyone 

 with a superficial knowledge of their habits and appearance would unhesitatingly assign them 

 and raising them to the company of other mammals. Let us first separate them from the 

 Fishes. The vast majority of fishes, with some familiar exceptions like the conger-eel, are covered 

 with scales : whales have no scales. The tail of fishes, often forked like that of whales, is 

 set vertically : in whales the tail is set laterally, and for this a good reason will presently be 

 shown. Fishes have anal fins : whales not only have no anal fins, but their so-called pectoral 

 fins differ radically from the fins of fishes. Fishes breathe with the aid of gills : whales have 



Photo kj A. S. Rudland &> Sent 



NARWHAL 



An Arctic luhale, with one or rarely two long sfean of bone frojtcring from the head 

 42 



