CHAPTER XTX 
THE LAND OF DEEP CORROSIONS? 
In the following chapter I have collected together some 
of the botanical and geological facts mentioned in the pre- 
ceding pages and have attempted to draw certain conclusions 
from them respecting the geological history of the strange 
country I have been describing. 
Stand on any one of the high passes which notch 
the Yang-tze-Mekong watershed—little crenellations they 
appear from below in this great rock-wall, buttressed by 
tremendous towers of limestone and crested with jagged 
spires—then, with the dawn behind and a clear winter sky 
overhead, look out over the wilderness. 
Straight across the deep gulf in front, so near that it 
seems almost within hail, a mountainous ridge rises up 
from invisible depths below, its barren slopes, scorched and 
shrivelled by a wind as from hell’s mouth, flashing in the 
sunshine, but crowned above by dark green clustering 
forests growing thinner and thinner as the dwarfed trees 
struggle up towards the foot of the screes. Behind it, 
slashed from base to summit by dark ravines which separate 
spur from spur, rises another ridge; and beyond that 
another, and another—range beyond range peeping up out 
of the west to grow dimmer and bluer till earth and heaven 
meet, while to north and south they fade away and finally 
melt into the infinite distance ; here and there sombre forest 
and shining scree being broken by a pyramid of snow 
glittering in the morning sunlight. 
How near they look, these clear-cut ridges huddled 
together like waves crowding up the shore out of a rough 
1 I have used ‘corrosion’ in preference to the more obvious term ‘erosion’ 
in accordance with the latest definitions. ‘Corrosion’ is now limited to the 
vertical digging work of rivers or glaciers, and implies wear and tear by 
mechanically transported material, by which means gorges are formed (vide 
Paper by Prof. J. W. Gregory, F.R.S. in the Geographical Journal, February 
IQII). 
