CLIMATE OF HIMALAYA. 257 



feet, to the east about 1000 feet higher. Above 9000 feet, how- 

 ever, the temperate region is characterized by many remarkable 

 forms, which do not extend lower; these are generally, in the 

 west especially, of very European type ; but in the eastern flora 

 it is at such levels that the magnificent Rhododendrons of Silckim, 

 which form so striking a part of its flora, principally occur. In 

 this zone a great part of the trees are of European genera. Alders, 

 Oaks, Birch, Hazel, Hornbeam, Horse-chestnut, and Cherry 

 being characteristic forms. It is also especially the region of 

 coniferous trees, very few of which extend either below or 

 above it. Tlie Pine which descends to the lowest level in the 

 Himalaya, is Pinus longifolia, which is a common tree through- 

 out the whole region from the mountains of the Punjab to the 

 east of Bootan. It is confined in a great measure to the outer 

 ranges of the mountains, and commences as low as 1000 feet 

 above, the level of the sea, rarely, if ever, attaining a greater 

 elevation than 7000 feet. This tree appears to have a very 

 great power of enduring varieties of climate, for it seems equally 

 at home in the hot, damp valleys of Sikkim, surrounded by an 

 entirely tropical vegetation ; and on the dry, stony hills of the 

 Punjab, where rain hardly ever falls, and it is at all seasons 

 exposed to a powerful and scorching sun. The only other 

 coniferous tree of low elevations in the Himalaya is Podocarpus, 

 one species of which is a native of the lower ranges of Nepal 

 and Sikkim. 



Pinus excelsa, which is allied to P. strobus, and Pinus 

 Smithiana, which is near abies, are the more common species of 

 the central zone, which are distributed throughout the whole 

 extent of the Himalaya. In the same zone, the Deodar (Cedrus 

 deodara) is confined to the western mountains, not being, I 

 believe, to be found indigenous in any part of Nepal ; while 

 P. Brunoniana, on the other hand, commences in the eastern 

 parts of Kamaon, and extends as far east as Bootan. The most 

 Alpine species of the family are P. Gerardiana, P. Webbiana, 

 and several species of Juniper, of which all but the first, which 

 is a western tree, seem universally distributed. 



It would be needless to dwell at any length on the Alpine 

 zone, because, luxuriant as is the vegetation, and beautiful as are 

 the plants, the forms at least must be familiar to most of my 

 auditors. 



I must be content, in conclusion, with drawing your attention 

 to the change produced in the vegetation in tlie temperate and 

 sub-Alpine zones as we advance towards the interior of the 

 mountains, in consequence of the diminution in the amount 

 of rain. 



If in travelling through the Himalaya we ascend a great river, 



VOL. VI. T 



