50 TRANSACTIONS OF THE [Sess. lxxx 



Salween-Irrawadch' divide, as previously stated, I found not 

 only Primulas but Rhododendrons, species of Polygonwm, 

 Orc/iAS, Tltallctruin, Androsace, and other plants, identical 

 with those found at Doker-la on the Mekong-Salween divide, 

 latitude 28^, besides Meeonopsis, Saxifraga, Pedicularis, 

 Cremant/i odium, Allium, and other typical genera of plants. 



On this view, such Primulas and alpines as have already 

 been found on the Assam-Burma frontier, and such as may 

 yet be found on the mountains of Far Northern Burma — 

 and I think that the Primulas, at least, west of the "Nmai 

 will not be numerous — are mere outliers, stranded and 

 isolated, having no connection with the source of supply 

 and failing to tind their feet under conditions of climate 

 which are not typically alpine, using that term in a re- 

 stricted sense. In the same way, the comparative poverty 

 of the eastern end of the original Sino-Himalayan range 

 may be ascribed to the fact that, in spite of the two floras 

 which have swept across it, one from the west and one from 

 the east, it is nevertheless a blind alley, isolated from the 

 present main line of migration of the Primulas. Personally 

 I have never seen a finer alpine hunting-ground than the 

 limestone mountains of Kansu and Shensi, on the great 

 backbone of China ; unfortunately I climbed there in the 

 depth of winter when everything was under many feet of 

 snow. However, it does not seem to be rich in Primulas, 

 and the flora is more Chinese than Himalayan, and has 

 probably derived much of its flora from America, which is 

 poor in Primulas. The fact that the great plain of Northern 

 Burma must have been a big lake previous to any great 

 ridging of the Burma-Yunnan frontier took place (for the 

 lake bottom itself is now included in the .system of parallel 

 ranges), and therefore previous to the breaching of the Sino- 

 Himalayan range, is sufficient proof that there could have 

 been no communication directly acro.ss the Burmese hinter- 

 land south of the Irrawaddy headwaters. 



But if these arguments hold good, and if there is to this 

 day some line of communication between the Himalayas and 

 the westernmost of the parallel divides {i.e. the Salween- 

 Irrawaddy divide) which has not been completely severed, 

 as the divides seem to have been from each other, there 

 must be some remnants of this range, which is nothing less 



