CH. LXXXVIII TROUBLES OF DESERT ENDED 411
four years earlier, had broken through the high sand ridges of Yoghan-kum to the north and formed the head of its new bed. The diversion had caused much trouble to the shepherds ; for the vegetation lower down on the old bed was steadily drying up, and water along the former grazing-grounds was obtainable only from deep wells.
The river bed I had seen in 1901 was completely dry, but no dunes had yet gathered over it. This and the fact that no vegetation whatever had sprung up as yet by the new bed were significant proofs of the time needed to
mature the full results of these riverine changes. That
these changes were produced by the gradual silting up of the beds, which forces the river after a period to seek a new channel or to turn back into one long abandoned,
could be seen here quite clearly. No less than four
large river courses, all dry, diverged above Tonguz-baste, and, no doubt, all in succession had taken generations to develop their belts of jungle, whether now dead or still struggling with the withering dryness. It all helped in forming some estimate as to the length of the ages which had seen the growth of the terrible desiccated delta now happily left behind us.
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