404 SWINE GROUP 



rather than of an inherent nature. Among the more striking features 

 of these animals may be mentioned the clumsy, long, barrel-like body, 

 the enormous head, with a broad, squared muzzle, and the short thick 

 legs, each terminating in four toes encased in rounded hoofs, all of 

 which touch the ground in walking. The hoofs of the middle pair of 

 toes, unlike those of swine, are not flattened on their adjacent surfaces, 

 and the outer pair is not disproportionately small. In the head notable 

 features are the slit-like nostrils, placed rather close together on the 

 highest part of the muzzle, the prominent eyes, which project above 

 the plane of the face, and the small erect ears. The small tail is 

 laterally compressed. Very conspicuous are the huge curved tusks in 

 each jaw, between which, in the lower jaw, the large incisors project 

 almost straight forwards. Very characteristic, too, are the cheek-teeth, 

 the hind ones of which show a distinct trefoil-pattern on their grinding 

 surface, while the last pair in the lower jaw has not the elongated 

 form characterising the swine. With the exception of bristles on the 

 muzzle, face, neck, and tail, the coarse and somewhat warty skin is 

 bare. The hind angle of the lower jaw has a large descending flange 

 terminating in front in a hook ; such flange being quite unrepresented 

 in the jaw of the swine. 



Although restricted at the present day to Africa, where they are 

 represented by two species — one large and the other small — 

 hippopotamuses in former times had a wide distribution in the Old 

 World. During the latest, or Pleistocene, geological epoch the larger 

 African species flourished, for instance, in the rivers of Europe inclusive 

 of England ; while smaller species more or less nearly akin to the living 

 pigmy hippopotamus abounded in the islands of the Mediterranean. 

 Still earlier (in the Pliocene) there occurred in India, Burma, and North 

 Africa other species with three pairs of lower front, or incisor, teeth of 

 relatively small size. 



The ordinary African hippopotamus is sufficiently characterised by 

 its enormous bulk, and the presence of only two pairs of lower incisor 

 teeth, of which the innermost is much larger than the outer pair. 



Formerly hippopotamuses were to be found in all the larger rivers of 

 Africa south of the Sahara, but they have long since been exterminated 

 in the lower portion of the Nile valley, while they are yearly becoming 

 scarcer in South Africa. That there are local races of the species can 

 scarcely be doubted. Indeed, this was practically demonstrated by 

 two individuals living in the Berlin Zoological Gardens in 1907, one of 

 which had the lips, rings round the eyes and ears, and the folds at the 

 point of insertion of the limbs and tail flesh-coloured, while in the other 



