160 
THE vegetation OF THE ZEMV 
corner and they all come by the Naku La. On the higher hills here, 
once away from the vicinity of the yak-herds, flocks of Ovis nahura 
are occasionally seen. In the sandy tracks by the stream colonies 
of the Tibetan Marmot are fairly common. 
We were not quite satisfied that we had got all that was to be 
obtained from the higher cliffs. Supplies, however, were short and 
the Nangma La (Lungnak La) trying to Li Jen coolies. It was 
agreed that C. should take the five fittest men and the available 
provisions, camp as far up the west valley as possible, and give 
two or three days to the higher cliffs and screes while S. made two 
forced marches down to Lachen with the remaining men and one 
day’s rations.. On the 8th August therefore S. crossed the !N'angma 
La, 17,590 feet, a very stony pass but not difiScult in good weather, 
though not practicable for ponies. A change is seen in the vegeta- 
tion on crossing the ridge. The valley leading down to Thango 
and the Lachen is narrow, sheltered, and moist with no trace of the 
stunted Llonakh vegetation. 
C. was successful in traversing the upper valley to nearly 18,000 
feet — to the limit of vegetation. Heavy falls of snow covered his 
temporary camp and made collecting difficult. A fairly complete 
collection of the limited flora was, however, secured. Ascending 
the main valley on the 8th he pitched his camp on the river terrace 
at the highest level for juniper. In the afternoon the screes 
around the glacier to the north were explored but sleet and snow 
prevented much botanizing. Flocks of 'wild sheep and herds of wild 
goats were not uncommon and in such weather are easily approached. 
The herdsmen at the highest Dok reported that yaks carrying rice 
from. Khangbachen (Nepal) in exchange for salt had arrived md 
the. Jongsong La, the first arrival of the season and probably the’ 
last. In the morning the camp was covered with snow. The 
lower stream and flats were traversed and by 1 p.m. the permanent 
snow was reached. Avalanches were frequent. Alternate sleet and 
snow drove the party back to camp. On the following day in xather 
better weather the Jongsong La side was visited and explored up 
to the limit of vegetation. The slopes here are scarcely free from 
snow for sufficient time to give an opportunity to even the hardiest 
plants. Several inchcj of snow fell on the 11th and it was evident 
that nothing more c^nld be done. A return was made by two long 
marches to Thango. 
The upper part of the Lungma Chu is scarcely so rapid as the 
Naku Chu. The lake basins in its course are not swampy to the 
extent which prevails in the Naku valley. Tracts of alluvium in 
