404 INTRODUCTION TO ZOOLOGY. 



animals, may be traced originally to the countries of Wes- 

 tern Asia. They herd in flocks in a wild state on the 

 inaccessible mountainous districts of Asia, Europe, Africa, and 

 America." 



The elevation at -which some of these creatures habitually 

 live is very remarkable, and to the zoologist a subject of 

 philosophic interest. The Chamois is found between the 

 upper limit of the trees, and the line of perpetual snow, which 

 in the Alps is 8,900 feet; and is 700 feet less on the northern 

 than on the southern deehvities of these mountains. The Goat 

 of Cashmere browses on the comparatively naked table-lands 

 of Thibet, at the height of from 10,000 to 13,000 feet above 

 the level of the sea. The Pamir Sheep, or Eass {Ovis j)olii) , 

 lives at the still greater height of 15,600 feet in the table- 

 land of Pamir, eastward of Bokhara ; and the Burrhel {Ovis 

 hurrhel) inhabits the highest ridges of the Himalayan chain, 

 where it is described as " bounding Hghtly over the incrusted 

 snows, at an altitude where its human pursuers find it difficult 

 to breathe." 



Fig. 319.— Bison. 



IX. (^Bos.) — The present group may be represented by our 

 domestic Oxen, which have ever been associated with the 

 field labours and the domestic comforts of m;m. But the 

 species most celebrated are probably the ferocious Buffalo of 

 Southern Africa, and the Bison {Fig. 319), which roams in 

 vast herds over the trackless prairies of America. 



The extinct animals of this tribe afibrd another examj^le of 

 the manner in which the historian and the naturalist may at 

 times assist each other's researches. The Eomans, when they 



