183S.] Report on the Tea Plant of Upper Assam. 3Gi 



vagueness carried to such an extent as in the catalogue of the plant'^ 

 of the H. E- I. Company's Herbarium by Dr. Wallich, in the whole of 

 which scarcely a single instance of indication of elevation will be found, 

 although a great portion of the plants were derived from mountainous 

 countries. It is owing to this vagueness in the habitats, that I have 

 purposely omitted adding to the Chinese catalogue all such plants as have 

 been merely denominated natives of China, which considering that this 

 empire embraces in extent 20 degrees of latitude, is as unsatisfactory as 

 could well be desired. 



Mr. Griffith proceeds at considerable length to the estimation of the 

 relative values of the various forms, indicating a decided tendency to- 

 wards a temperate climate ; and concludes this part of his subject, thus: — 



Avowedly incomplete as my observations are, I trust that sufficient has 

 been shewn to prove the singularity of the flora of Upper As^am, and 

 that in this it approaches to a considerable extent to that of certain 

 portions of China. The singularity alluded to is of such a nature and of 

 such an extent, that I affirm, with tolerable confidence, that it is not to 

 be met with elsewhere in India at the same elevation, even as far north 

 as the thirty-first parallel. 



From the amount of the values that I have ventured to give to each 

 plant of northern or elevational form, it v/ill be seen that China at a 

 lower latitude, so far as the generality of the species is concerned, 

 and with a smaller amount of species, has the greater value. But with 

 regard to this I must mention, that in the first place plants from hilly 

 and mountainous regions are included in the list, and in the second place 

 that in cdmost every case the maximum of value has been given to each 

 such form, which value when the plants shall have been more rigorously 

 determined, will most probably have to suffer a reduction. 



It appears to me to be evident enough, that in the geographical 

 distribution of the component parts of the flora of valleys, instances of 

 irregularity may be expected to occur. That is, that those plants which 

 flourish under certain elevations may be expected to straggle down 

 towards, or even to reach the bases of the boundary hills. Certain 

 circumstances are indeed necessary, but then almost all valleys from 

 their configuration enjoy such circumstances : and in Assam they are 

 highly favourable, for with a mean annual temperature of 67-2, we have 

 a mean summer one of 80, and a mean winter one of 57, and in addition 

 the development of the heat is gradual. Certain it is, that m Assam 

 most of the forms of value have escaped, if I may use the expression, 

 from, the neiohbouving liills. If these views be correct, it follows, 



