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VI. — On the Climate and Vegetation of the Temperate and 

 Cold Regions of East Nepal and the Sikkim Himalaya 

 3Iountains. By J. D. Hooker, M.D., F.E.S. 



The following notes were collected, and have here been thrown 

 together, with the view of facilitating the cultivation of Hima- 

 layan plants, and of those of Sikkim and the adjacent mountains 

 of Nepal in particular, by supplying accurate data obtained on 

 the spot, relative to the various conditions of soil and exposure, 

 the degrees of temperature and amount of humidity under which 

 they flourish in their native country. 



As the genus Rhododendron is the most prominent of these 

 plants, and that about which inquiries are constantly directed to 

 me, I shall commence wdth a description of it, prefacing this with 

 some observations, wliich are called forth by a visit to several 

 nurseries where many species are cultivated with more or less 

 success. 



The Sikkim species of Rhododendron have now all been de- 

 scribed, as far as tiiey are known, and with few exceptions 

 figured, in a manner that will ensure the recognition of our 

 seedlings when they blossom ; but it must not be expected that 

 the flowers, so impatiently looked for, will in all or perhaps in 

 most cases equal, in number and size, those of the dra^nngs 

 made on the spot, which were in many instances from the 

 choicest bouquets that could be procured over a large extent of 

 country. 



Unexampled success has attended cultivators in the germina- 

 tion of the seeds. Seedlings liave been raised in quantities ; but 

 whereas in some cases the young plants have, with few exceptions, 

 been all reared, in others the whole crop has been lost tlirough 

 injudicious treatment. The different kinds are at present kept 

 together and treated alike ; there is no discrimination exercised 

 in their culture ; the same amount of light and heat as is given 

 to the natives of 6000 and 7000 feet elevation, wliich are in full 

 leaf throughout the year, is also given to those from ] 5,000 feet, 

 whose vegetative organs are in activity for only five or six 

 months of the twelve. This course will eventually prove preju- 

 dicial, for it is not possible that the alpine kinds can long endure 

 the excitement of perennial heat and moisture. 



Variatioji. — There is a prevailing disposition to limit the 

 species of this genus by characters presented in the seedling 

 plants, and to argue, from my inability to pronounce arbitrarily 

 on the same in our greenhouses, the probability of there being 

 fewer or more species than of names received with the seeds. In 

 some cases an undue value is given to these names. Slight varia- 



