EARED SEALS, WALRUSES, AND SEALS 693 



use to their owners, and being not ^infrequently shed previous to birth. The fore- 

 going characteristics are amply sufficient to distinguish the pinnipeds from the true 

 Carnivores, although these animals also possess certain peculiarities in regard to 

 their soft parts, into the consideration of which it is unnecessary to enter here. It 

 may be mentioned, however, that all the members of the group have very short 

 tails, while they are all remarkable for the large size and prominence of their eyes, 

 this being probably necessary in order to secure accurate vision under water. It is 

 also noteworthy that in all the members of the group the rudimentary collar bones 

 found in most of the true Carnivores have completely disappeared. 



Those who admit the doctrine of the evolution of organic nature can have no 

 hesitation in regarding the pinnipeds as a highly-specialized group, which has origi- 

 nated either from some section or sections of the true Carnivores, or from an extinct 

 group, to be noticed later on. In the structure of their skulls the eared seals come 

 nearest to the bears; and it is quite evident that the whole group must have 

 descended from Carnivores which still retained the typical five digits on each foot. 

 On the other hand, the true seals present some points of resemblance to the otters, 

 and the sea-otter shows us how easily the transition from the ordinary otter type to 

 the pinnipeds might have taken place. The sea-otter, however, is clearly (from the 

 structure of its teeth) in no sense a "missing link"; and it is by no means im- 

 probable that the pinnipeds will be found to trace their origin directly to the extinct 

 group of Carnivores to which allusion has been already made. 



The pinnipeds are divided into three distinct families, namely, the eared seals, 

 the walruses, and the true seals. Before proceeding to the consideration of these 

 several families, we may refer, however, to a few characteristics common to the 

 whole group. In the first place, the pinnipeds, as already mentioned, are thor- 

 oughly aquatic in their habits, resorting to the land only for the purpose of repose 

 or breeding, and when there moving in an awkward and clumsy fashion. More- 

 over, they are, as a rule, marine; although some ascend tidal rivers, and a few are 

 found in inland seas and lakes. In the latter instance there is, however, no reason- 

 able doubt but that access to the ocean has been cut off since the date when the 

 seals first reached the waters in which they are now confined. 



In regard to their general characteristics, Mr. J. A. Allen, who has paid special 

 attention to the American representatives of the group, observes that all the pinni- 

 peds are distinguished by their high degree of intelligence, and are all capable of 

 being easily domesticated, when placed under favorable conditions. They are, 

 almost without exception, thoroughly carnivorous, "subsisting upon fishes, mol- 

 lusks, and crustaceans, of which they consume enormous quantities. The walruses 

 and eared seals are polygamous, and the males greatly exceed the females in size. 

 The ordinary or earless seals are commonly supposed to be monogamous, and there 

 is generally little difference in the size of the sexes. The walruses and eared seals 

 usually resort in large numbers to certain favorite breeding grounds, and, during 

 the season of reproduction, leave the water, and pass a considerable period upon 

 land. The earless seals, on the other hand, with the exception of the sea-elephants, 

 do not so uniformly resort to particular breeding grounds on land, and leave the 

 water only for very short intervals. ' ' 



