reported to have fallen in mid-December. There are said
to be usually two or three slight falls of snow each winter.
In summer, from June to August, more or less rain falls.
At Khotan, in July, 1905, we had some severe showers, but commonly the amount of rain is very slight. It increases rapidly, however, as one approaches the high mountains; and among or close to the main ranges, at an elevation of 10,000 feet or more, there is an abundant fall of rain and snow. The results of the unequal distribution of rainfall are brought forcibly to the traveler's notice as he descends from the plateaus to the basin floor. At an elevation of from 10,000 to 14,000 feet, he is among pasture lands where the grass is thick and even turfy, but lower down, at a height of from 5000 to 10,000 feet, he encounters only sparse
jvegetation of the xerophilous or drought-loving kind, like the sage-brush found in the deserts of Utah and Arizona. The change from this poor growth to the almost complete absence of vegetable life in the main floor of the basin, at an elevation of from 3000 to 5000 feet, is equally significant, though less marked. Certain parts of the basin floor are well covered with plants, which, however, are supported by rivers, or by underground waters from the mountains, and rarely or never by rain. It is probable that in the centre of the basin the annual precipitation does not amount to more than an inch or two; although on the high mountains a hundred miles away it may amount to twenty-five or thirty inches. This fact must be kept in mind, for upon it depend the marked contrasts in the vegetation of the contiguous concentric zones of the Lop basin ; and these, in turn, determine the distribution and many of the habits of man.
IIIF Color HighRes
