SEALS AND WALRUSES. 105 



sufficient to distinguish the pinnipeds from the true Carnivores, although these 

 animals also possess certain peculiarities in regard to their soft parts, into the con- 

 sideration of which it is unnecessary to enter here. It may be mentioned, how- 

 ever, 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-specialised group, which has 

 originated 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 improbable 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 thoroughly 

 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. Moreover, 

 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 reasonable 

 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 

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

 of being easily domesticated, when placed under favourable conditions. They are, 

 almost without exception, thoroughly carnivorous, " subsisting upon fishes, molluscs, 

 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 favourite 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." 



Only one member of the whole group appears to be strictly tropical, and 

 comparatively few even range into tropical regions; the great majority being 



