AND LLONAKH VALLEYS OF SIKKIM. 151 
the walls of deserted cattle ‘ corrals ’ were evidence that it had 
been a regular route not long before. The rhododendron scrub 
was here troublesome but on the pass there was no snow. The 
ridge was practically barren. 
On the 16th with continued fine weather we ascended to the 
top of the hill behind the camp, taking all our collectors. This 
is about equal in height to the Thangchung La. The top was 
rocky and bare with no snow even at 17,000 feet, while opj>qsite 
and 2,000 feet lower the slopes were covered. 
On the 17th we crossed the snow-bridge again and ascended 
he old yak-track leading to the Yumchho La. The persistence of 
the snow-bridge up to the middle of July is further evidence of the 
absence of heavy rains in the upper valley at this time of the year. 
The tunnel of the bridge was very little larger than the usual 
daily volume of the stream and there could have been no -flood 
during the previous two months. We found the southern slopes 
more thickly covered with rhododendrons. Snow lay at 15,00(1 
feet and on the way to the pass we had to cross over fields of it 
sloping at an awkward angle. A false step would have meant a 
long slide of several hundred yards with ugly pinnacles of rock 
projecting here and there. One of two of the coolies showed a 
little hesitation at the unusual conditions— they would have pre- 
ferred to tackle a precipitous cliff or swaying cane-bridge. 
Crossing the Yumchho La we descended into the valley on the 
o.ther side for about 1,000 feet. Here we met with the herdsmen 
and yaks of the Talung monastery. This valley is much wetter 
with large tracts of marshy land in which Primulas flourish. 
Here we found several species which do not appear to cross into 
the Zemu. Primula Diekieana and its variety Pautlingii were in 
special abundance, the whole sward being covered with them like 
an English meadow with cowslips. There seems no doubt that 
P. Pautlingii is only a form of P. Diekieana. Intermingled were 
whitish-yellow, yellow, mauve and purple forms and with umbels 
varying from one to six flowers. 
Return the same day was out of the question, so we had to camp 
with our men under an over-hanging boulder with our blankets 
as our only protection. 
On the following morning we made a survey of the vegetation 
of the Talung side of the pass including that of two shallow lakes 
which like most of these high altitude * tarns ’’ were practically 
barren. Recrossing the La and the snow-fields we descended to 
where the snow-bridge ought to have been. To our dismay almosf 
