Note 5 — APPENDICES

It should be noted that the substance of the dunes around Khotan is to be distinguished from the true drifting sand of other Central Asian deserts. For Prof. de Lóczy has shown by analysis that there is almost complete uniformity in composition between the recently formed fertile loess of Yotkan (the site of the ancient capital of Khotan) and the moving "sand" now surrounding and covering the ancient sites in the desert; cf. "Ancient Khotan," I., pp. 127 f., 199, 242. The thickness of pure loess above the culture stratum at Yotkan was no less than from nine to eleven feet, a fact which had led earlier European visitors to suppose that some catastrophe, such as a great flood, had overwhelmed the old town. It is merely a striking example of the manner in which vegetation, under irrigation, catches and retains the floating loess-dust.