86 Through the Lutzu Country to Men-kong 
seen it so far north. Amongst the undergrowth was a big 
erect selaginella (perhaps S. grandis), and here many of 
the orchids were in flower, amongst them being a Dendro- 
bium with long pendent sprays of orange flowers. Yet, in 
spite of the heavy rains in the Salween valley, it is only 
the deep gorges and gullies which are filled with this dense 
monsoon jungle, the fully exposed mountain sides being 
covered with bracken, grass, scattered pine trees and low 
scrub. 
The obvious inference is that rain alone does not satisfy 
the monsoon forest, for it cannot stand full exposure during 
the dry winter, the reason being that the only source of 
water, namely the heavy dews, are rapidly evaporated in 
the hot sunshine. Hence on the exposed slopes of the 
broad open valley there are found chiefly Conifers (Pzuzs) 
and semi-xerophytes, for most deciduous-leaved trees of 
the north temperate forests require water at all seasons 
of the year. Similarly, higher up on these exposed slopes 
are forests of spruce only, while in the deep narrow valleys 
are alder, birch, maple, and many others. 
Just above the gorge is the village of Lang-chi, and 
here a big torrent pours itself into the Salween from the 
west, the latter tumbling several feet over an enormous 
accumulation of boulders, with a noise like thunder. It 
was the first big rapid we had seen on the Salween. 
A little further up on the other side is the village of 
Wu-li, and now we came upon two rope bridges, by the 
second of which we crossed to the left bank. Here I was 
interested to observe that the Lutzu when crossing the 
rope bridge always carries with him, fastened by a loop to 
his wrist, a bamboo tube full of water which he tilts just in 
front of the slider. This doubtless reduces the friction and, 
by keeping down the temperature, lessens the wear and 
tear on the rope. 
Seeing the rope bridge here in the dense jungle, set me 
thinking of its origin. I surmise that it is the practical 
application of the natural liana bridges probably to be 
found stretching across the headwaters of the Upper Irra- 
waddy, as they certainly do in jungles elsewhere. If so, 
this would lend more colour to the suggestion that the 
Lutzu are immigrants to the Salween from the west, the 
