24 TKANSACTION.S OF THE [Sess. lxxx 



floras are markedly dissimilar, especially in the forest belt, 

 where rainfall counts for more than at higher altitudes. 

 What evidence is there that these floras ever were similar ? 

 Overwhelming evidence, in my opinion. 



I have hitherto spoken of the Mekong-Salween divide 

 as if it were a single entity as regards its flora ; in future 

 it will be necessary to distinguish between the range south 

 of Ka'-gur-pw — the elevated snow}" portion referred to 

 above ^ — and that north of it. North of Ka'-gur-pw the 

 appearance and flora of the range are identical with what 

 we are accustomed to on the Mekong- Yangtze divide, prov- 

 ing conclusively the common origin of the two floras. This 

 unexpected but welcome discovery, besides setting at rest 

 any lingering doubts on the latter point, satisfactorily ex- 

 plains another curious fact. We have seen that the principal 

 formation on the Mekong-Salween divide is the temperate 

 rain-forest, which contains some elements at least of the 

 monsoon forests further west, though lacking its most 

 characteristic features, and that this formation is wanting 

 on the Mekong- Yangtze divide, being represented by scrub 

 oak and conifer forest ; further that there ai'e on the former 

 range alpine meadows, also represented in the monsoon 

 country to the west, which have no counterpart on the 

 Mekong - Yangtze divide. On exploring the Mekong- 

 Yangtze divide in more detail, however, I came across 

 plants from time to time which seemed to have no business 

 there — plants in specialised situations hidden away in pro- 

 tected gullies, or on an outlier of the divide which captui'ed 

 more than its share of the rainfall. Thei-e was, for instance, 

 a plant of R'lhcs mcnvplnansc, Francli. I found a single 

 busli of it on a shady mountain slope, outlier of the main 

 divide, and in the same place were sevei-al buslu;s of a species 

 of Euonymufi, which further research revealed in small 

 numVjers in a favoured gulley on the main divide. Both 

 are common in the temperate rain forest on the Mekong- 

 Salween divide. On the outlier aljove referred to I found 

 Piit(jii/iciila alpina, Linn., a lucky discovery, though some 

 clifls on the Mekong-Salween divide were yellow with it; 



1 Ka'-giir-j)w is a lange of snow peaks, the liigliest about 19,000 feet, 

 some thirty miles in length from north to south. To the Tibetans this 

 range is sacred. 



