xvi Life and Living Creatures 321 



Ethiopian, the Oriental, the Nearctic or New Northern, 

 the Neotropical or New Tropical, and the Australian. 

 Professor Heilprin, another eminent authority, prefers to 

 class the Palasarctic and Nearctic realms together, on 

 account of their general similarity, as the Holarctic or 

 Entire Northern. He also recognises a region of transi- 

 tion to the Neotropical realm occupying the south of North 

 America, and another of much greater extent forming a 

 transition to the Ethiopian and Oriental realms and in- 

 cluding the whole Mediterranean region. 



411. Northern Realms. In both the Old and the New 

 Northern realms the white polar bear frequents the northern 

 snow-deserts. Farther south occur reindeer and elks, 

 bears black, brown, or grizzly, foxes, wolves, beavers, 

 hares and squirrels, and the bison, now almost extinct in 

 Europe and rapidly being exterminated in America. The 

 representatives of various families become more unlike each 

 other toward the southern border. Moles, rats and mice, 

 badgers, sheep and goats, the camel and the yak, are con- 

 fined naturally to the Palaearctic realm. On the other 

 hand, the musk-ox, skunk, prairie dog, racoon, and jump- 

 ing mouse, are exclusively restricted to the Nearctic realm. 

 Compared with the southern realms, those of the north are 

 remarkable for the high place in the scale of development 

 occupied by their most common animals. But the very 

 complete study of the fossil forms of life preserved in the 

 rocks shows that in past ages the northern lands were 

 inhabited by a gradually developing series of more primi- 

 tive types, from which the existing creatures are evidently 

 descended. 



412. Ethiopian Realm. -Africa, south of the Sahara, 

 and Arabia, contain Jew or none of the animals which make 

 their home round the Mediterranean at the present time. 

 There are no wolves, foxes, bears, or tigers, the flesh-eating 

 animals being represented by the lion, " the king of beasts," 

 the leopard, panther,, hyaena, and jackal. This purely tropical 

 realm is the exclusive home of the hippopotamus and the 

 giraffe, tallest of living animals. The elephant and rhino- 

 ceros are common also to the Oriental realm. Swift-footed, 



Y 



