24 



TBI STB KO LOOT OF SOUTH 1ASTHRK AHA. 



chasms, bj the numerous rivers which issue from them. The 

 snowy ranee of the Himalaya, again, forms a barrier between the 

 valley of the Zang-bo and that of the Ganges which must have 

 been insurmountable in the earlier ages of the Tibetan tribes. A 

 large portion of the outer division, as we have seen, consists of 

 prolongations of the middle mountain chains, with roost extensive 

 ramifications. The whole eastern and southern land indeed is com- 

 pacted of bands and groups of mountain chains. China, notwith- 

 standing its two long vallies and the great N. E. plain, is iiiountai- 

 nous for two thirds of its surface, and UUraindia is almost wholly 

 composed of a succession of ranges of lower elevation. The great 

 highways must have long continued to be separated from each other. 

 The inland valley of the Hoang-ho, where it Cows southward 

 between the provinces of Shansi and Shensi, must have been cut 

 off from the low lands of Fiehili on the east, — with which it still 

 communicates by a single route, — and from the basin of the Yang- 

 tse-kiang on the south, while separated by similar barriers from its 

 upper basins between the Khilian-shan and Bavan-khara-oola. The 

 central valley of the Yang-tse-kinng must have been insulated during 

 the greater part of its eastern course between the Nang-lin 

 mountains on the south and the Yon-ling, Tapa-Iing and Pe-ling 

 on the north. The southern maritime provinces must have 

 presented several ethnic districts divided from each other by 

 considerable obstacles, and totally secluded from the valley of the 

 Yang-tse*kiang behind them. Even now there appear to be only 

 three passes by which the Nang-lin chain is crossed. The valley 

 of the Ton-kin river must also have been isolated from those of the 

 Canton river, the Yang-tse-kiang and the Mekong. All these 

 districts must have retained a great degree of ethnic independence 

 long after the numerous subordinate or included ones were united. 

 Amongst the mountainous regions between them many tribes must 

 still longer have continued to be secluded. There are still numerous 

 remnants in the Nang-lin and all the other ranges of 3. E. Asia 

 that lie to the south and west of the Yang-tse-kian^. 



The western or inner division is chiefly occupied by the Tibetan 

 tribes who possess the whole of the great trans-Himalayan depres- 

 sion which slopes westward to the margin of the Hindu-Khush, 

 forming the transalpine basin of the Indus, and eastward to the 

 unknown point where the basin of the Zangbo bends south and 

 tends its waters into the basin of the Brahmaputra or of the 

 Irawadi. They have even extended to the 8. East and entered the 

 upper part of the eastern basin of the Brahmaputra where they are 

 in contact with the Mishmi. Tibetan tribes and others allied to 

 them have spread over the basin of the Ganges, although they are 

 now chiefly confined to the Himalayas, the Vindyas and the basin 

 of the Brahmaputra. In the basin of the Brahmaputra they are 

 blended with allied tribes of the Mayama family. Bude Tibetan 

 tribes of nomadic predacious habits, known in Tibet chiefly under 



