358 AVIFAUNA" OF CHOTA NAGPUR. 



Further west, spurs which lead up to the high-level plateaus 

 of Ranchi and Hazaribagh break up the country into valleys. 



These plateaus have a general average elevation through- 

 out their highest central portion of about 2,000 feet. The 

 former dies away to the south towards Singhbhum, Gangpur, 

 and SambalpUr, and the latter to the north towards Palamow 

 and the valley of the Sone. 



Towards the west the Ranchi plateau is separated from 

 Central Sirguja by a steppe or barrier of hills which rises from 

 1,000 to 1,600 feet higher. This barrier is connected with 

 a considerable extent of high-level country which forms 

 remarkable plateaus locally known as Pats ; of these the Mailan^ 

 and the Main Pats are the principal. Their general elevation 

 is about 3,600 feet above the sea. Being capped with laterite, 

 and having a very inconsiderable deposit of surface soil, tliey 

 generally present the appearance of open plains with a few 

 scattered bushes, thus contrasting strangely with the densely 

 jungle-clad character of their flanks. 



Still further west the country becomes wilder and more 

 broken, until the vicinity of Umerkantak is reached. Umer- 

 kantak is to the natives from the geographical— as Benares is 

 from the religious — point of view, the navel or central point 

 of India 



The above enumerated plateaus and hill ranges break the' 

 division up into a number of very distinct rain-basins or 

 catchment areas as follows : — In the north-west the tributaries 

 of the Sone, of which the principal are the Koel, Kunhur, 

 Her and Banas, drain a large area of country. The highlands 

 of Burwa, the Main Pat and Chang Bokar, form the water- 

 shed which separates their sources from those of the rivers 

 which make their way southwards to the Mahanadi and 

 Brahmini. 



The course of the Koel is a natural one through the sub- 

 division of Palamow to the low valley of the Sone, which it 

 joins a few miles south of Rotas. By natural I mean that 

 the river in taking that course has had few obstructions to 

 overcome, little work to do in establishing its outlet in that 

 direction. It is not so with the Kunhur and Rer. No one 

 entering Sirguja from the east can fail to notice the remark- 

 able gorges through which these rivers penetrate the strong 

 barrier of hills of metamorphic rocks on the north. 



To suppose that these gorges have been formed either by a pro- 

 cess of battering by the river against these huge walls, or by one 

 of those convenient i convulsions of nature 3 which are often 



