A-tun-tst 56 
Lutzu resemble the Mosos, or either of these tribes the 
Chinese. 
At Yang-tsa a woman asked me for medicine, and after 
one of the soldiers had told me what was the matter with 
her, and I had taken her temperature, I gave her certain 
tabloids and directions with magical effect, for next morning 
she was very much better and came out to my tent to thank 
me. This young woman was twenty-three years of age 
and had three children, the eldest being just seven. 
The arid region which we now entered owes its exist- 
ence to a sudden great elevation of the Mekong-Salween 
watershed, a very fine triple-peaked snowy range being 
visible to the west, a little north of Yang-tsa. It is curious 
that Prince Henri d’Orléans who saw this snowy range in 
1895 should call the mountain Doker-la, a mistake which 
has even been perpetuated by the Catholic priests, who live 
on the spot. There can be no question that it is a mistake, 
for Mr Edgar and I independently obtained from the 
Tibetans the name K ‘a-gur-pu for this splendid mountain, 
and I myself crossed the sacred mountain Doker-la, which 
is not covered with eternal snow, and is correctly placed 
south of the snow range on Major Davies’s map of 
Yunnan. 
Major Davies says that he caught sight of these same 
snow mountains from the Mekong below A-tun-tsi, and 
that Captain Ryder calculated their altitude at about 20,000 
feet. I saw them from the same point however, and noted 
that the highest pyramid is not visible from here, so that | 
think the height will eventually prove to be more like 22,000 
feet. This great snow range condenses round itself most 
of the moisture which crosses the Salween from the south- 
west, thus acting as a rain-screen to the Mekong valley 
and to the next range of mountains to the east—the water- 
shed between the Mekong and the Yang-tze. Hence results 
the arid region of the Mekong valley north of Yang-tsa with 
a rainfall of only a few inches—probably less than ten— 
a year, and a greatly curtailed rainfall on the Mekong- 
Yang-tze divide with a consequent elevation of the snow- 
line. 
The arid region is quite devoid of trees, only scattered 
rock plants, stunted bushes of Sephora vicizfolia, and a few 
