12 BIRD'S-EYE VIEW OF INNERMOST ASIA CH. I
These explorations have familiarized me with the uniformity which prevails in the character of this huge desert, probably the most formidable of all the dune-covered wastes of this globe. Whether the traveller enters it from the edge of cultivated ground in the oases or from jungle belts along the river-beds, he first passes through a zone with desert vegetation, mostly in the shape of tamarisks, wild poplars or reeds, surviving amidst low drift-sand. A very peculiar and interesting feature of this zone consists of `tamarisk-cones', hillocks of conical form and often closely packed together (Fig. 6) . The slow but constant accumulation of drift-sand around tamarisk growth, at first quite low, has in the course of centuries built them up to heights reaching fifty feet or more. Farther out in the Taklamakan there emerge from the dunes only shrivelled and bleached trunks of trees, dead for ages, or sand-cones with tamarisk growth from which life has departed even at their top. These too finally disappear among utterly bare accumulations of sand, in places heaped up into ridges rising 30o feet or more
(Fig. 7).
It is erosion by the winds which produces the material composing these dunes, all fine disintegrated clay and in itself perfectly fertile. The winds which during a considerable portion of the year blow with great force across the desert basin, especially from the north-east, constantly abrade the surface of the soft clayey soil, wherever there is a bare surface of ground not actually covered by dunes or protected by desert vegetation.
Farther on I shall have occasion to show how at ancient sites in the desert all ruins of dwellings (Figs. 37, 59) or even the remains of ancient orchards and arbours often
IIIF Color HighRes
