INTRODtJCTORY ESSAY. 185 



ing its valley from an elevation of 1000 feet^ as far as its 

 sources in the Walanchun and Kanglachem passes (16-17,000 

 feet). This journey was made during winter, and therefore 

 gave less important results botanically than would have been 

 obtained at a more favourable season. 



It is unnecessary to dwell at length on the general charac- 

 ter of the surface of Nipal, as to do so would only be to reca- 

 pitulate what has already been said regarding the Himalaya 

 in general. Little is known of the details of the higher 

 parts of the chain, or of the position of the axis of the Hi- 

 malaya, which probably lies in general very far back. The 

 political frontier of Tibet is usually far to the south of the 

 axis, the upper part of the course of most of the rivers of 

 the Indian slope of the chain belonging almost invariably to 

 Tibet. Two giant masses project from the axis towards the 

 Indian plain, the culminant peaks of which form a conspicuous 

 feature from Kathmandu, and even from the Gangetic plain, 

 so that their elevation has been approximately determined; 

 that of Dhawalagiri being 27,600 feet, and that of Gosaiuthan 

 24,700. feet. By these masses the whole of Nipal is divided 

 into three great river-basins, — that of the Karnali or Gogra 

 to the westward, that of the Gandak in the centre, and that of 

 the Kosi or Aran to the eastwai'd*. These divisions are no 

 doubt highly natural. For our purposes a subdivision is little 

 necessary, from owe very slight acquaintance with the flora of 

 any part of Nipal except that in which Dr. Wallich collected, 

 and it will suffice to distinguish eastern, central, and western 

 Nipal, whenever it appears requisite to assign particular lo- 

 calities to our plants. 



* See an excellent paper by Mr. Hodgson in the Journal of the Asiatic 

 Society of Bengal, in which the importance of the river-basins as geographical 

 divisions is forcibly pointed out. Mr. Hodgson has however misunderstood 

 Captain Herbert's views, which are certainly the same as his own in that re- 

 spect. Captain Herbert's proposition, that the line of the great peaks inter- 

 sects the river-basins (and is therefore not the true axis of the Himalaya), was 

 the first enunciation of a very important fact in physical geography, the true 

 significance of which is not yet duly appreciated. 



2 b 



