reason enough to make the soil soft as there are no roots to make it solid. Due to the same reason, the rabbits are particularly numerous in the west as they live on the roots. Curiously enough we had not seen a single marmot on the western route, whilst such animals were common farther east. Nor had we seen a single bear on the western route, only on the eastern ones, which seems to be due to the
bear's liking the marmots' flesh.
The material filling the latitudinal valleys and depressions in the east, is as a rule, finer than that in the western parts of the plateau-land, which is due to the sorting action of the prevailing winds. Probably the S. W. and W. S. W. wind is, as a rule, stronger in the western parts of High Tibet than in the eastern. The fine material is, therefore, carried away from west to east, and reaching the eastern regions, it settles down and is deposited in the depressions. Valleys and plains covered with gravel are, therefore, more numerous in the west than in the east, due to the sorting power of the wind. It may also depend on the greater corrasive action of the wind, that the levelled plateau-like character with rounded flat mountains and small relative differences of altitude between crests and valleys, is more pronounced in the west than in the east. On the eastern routes I crossed higher and more difficult passes than on the route of 1906, on which we did not cross a single difficult pass. By purely morphological reasons and on account of the existence of grass, the western route is, therefore, easier. The great mortality among the caravan animals, only I o°/o of them reaching Camp CIVIII, is caused chiefly by the wind.
We had not crossed a single high pass or a single mighty range that could be suspected of being the south-eastern continuation of the Kara-korum Mountains. In my Scientific Results, I had expressed the opinion that this mighty system must cross the whole of High Tibet and reappear in the Tang-la System in the east. But in 1905, when this theory was written down, nearly nothing was known of the central Transhimalaya. At the end of this work, I shall have to enter upon this most important and interesting problem.
The continuation of my journey from Camp CIIII the whole way to Gar/0k, including the first five crossings of the Transhimalaya, has been described in Vol. III p. 247 et seq. In Vol. II, I have described my researches in the valley of the Tsangpo and on and around the Manasarovar and Rakas-tal, as well as the sources of the Brahnzajutra, the Satlej and the Indus. The only thing that remains to do is, therefore, to describe the physical geography and morphology of my route from Gartok, through the Indus valley, back to Ladak and up through the Slzayok valley to Chang-tang where the second great crossing of High Tibet begins and stretches the whole way down to Chunit-tso, where we again come into contact with the last three crossings of the Transhimalaya, described in Vol. III.
IIIFカラー高解像度
