CARNIVORA 489 



plantigrade and have lost the carnassials and acquired crushing 

 bunodont cheek teeth. They are largely herbivorous in diet. 

 The brown bear (Ursus arctos) disappeared from the British 

 fauna probably about the tenth century. 



The remaining British land carnivores all belong to the family 

 Mustelidae, which is somewhat intermediate between the dogs 

 and the bears. The badger (Meles meles) is plantigrade and has 

 crushing molars. It is partly carnivorous, but largely digs for 

 inactive prey such as young rabbits, and also takes much inver- 

 tebrate and vegetable food. The weasel [Mustela nivalis), stoat 

 [M. erminea), polecat (M. putoriiis), and marten (Martes martes) 

 are in general similar and form a series ascending in size in the 

 order given. All are active hunters, feeding on other mammals 

 and birds, and at least to some extent arboreal. They are com- 

 pletely or partially digitigrade, with partially retractile claws, 

 and although the molars are crushing the canines are sharp. 

 The weasel and stoat are common, but the other two are confined 

 to the mountains. Northern stoats become white in winter, 

 when their fur is ermine, but the change seldom happens in 

 England. The last member of the family, the otter [Liitra Intra), 

 is aquatic and piscivorous, living chiefly in rivers but also on 

 the seashore. It takes also shellfish and occasionally land animals. 

 The cheek teeth are pointed and suitable for holding, not crushing. 

 The shoulders are inconspicuous and the feet webbed, but not 

 quite completely. 



The seals and walruses are carnivora which have become 

 almost completely aquatic, although they still come to land for 

 copulation and parturition, as well as for rest. The cheek teeth 

 are either peg-like, or have three points in a longitudinal row, 

 so that they approach the condition of those of the toothed 

 whales and are suitable for holding fish. The fore-limbs are reduced 

 to flippers, by means of which swimming is carried out and a 

 jerky but surprisingly rapid movement is possible on land, and 

 in all the normal British species the hind-Hmbs are held per- 

 manently backwards alongside the tail. Six species are recorded as 

 being found on British coasts, the commonest being Phoca vitulina, 

 which is one of the smaller sorts, about four or five feet long. 



Many of the Mustelidae, such as the stoat and the badger, 

 agree with the bats in having a long interval between copulation 

 and birth, but here the pause is brought about in a different 

 way. Fertilisation occurs at once, and segmentation begins, 



