MIGRATIONS OF THE TARIM. 367
would appear to be a case of unequal distribution. If the plateau regions of all the continents are undergoing desiccation, as seems probable, there must be an increase of precipitation in some other parts of the world.»
I have already stated that, according to my opinion, the Lop-nor-and-Karakoschun has probably altered but little in size during the historical period, and that such oscillations as are proved to have taken place in its area have been purely accidental. Suppose we start from the assumption, that theoretically the terminal lake received in former times the same volume of water that it receives now, the lake must then have been greater than it is at present, because the numerous marginal lakes which we now find beside the lowermost Tarim did not at that time exist. But as we likewise know, from Chinese documentary evidence, that the lake was formerly small, it is clear that some other factor must then have lessened the volume of the water that entered it. What that factor was it is difficult to say, but with the help of the story we read in Abel Rémusat's Historie de la Ville de Khotan and such statements as this: »Khotan zählte damals [um 64o A. D.] zwar noch loo Klöster, aber nur 5,000 Mönche, ein Viertel so viel als zwei hundert Jahre zuvor»,* we may infer that the population of at least this part of the country was in ancient times more numerous than it is now. There exist numerous indications that Chotan was a very prosperous and densely inhabited kingdom, and we may assume also that the other oases in the basin had at the same time — at all events larger populations than they have now. That population can only have existed by means of irrigation; it is this which lessened the area of the terminal lake, in the same way as the marginal lakes of the Tarim exercise a drain upon that river at the present time. The fact of the population being smaller now than it was formerly is not due, as Krapotkin asserts, to »the rapid desiccation of this region, which compelled its inhabitants to rush down to the Jungarian Gate, down to the low lands of the Balkhash and the Obi», but it is caused, not only by the migrations of the existing drift-sand, which encroaches upon the former cultivable ground, but also by the circumstance that the present inhabitants are an inferior and less enterprising race than that which formerly dwelt there. Climatic changes do not take place so rapidly in the heart of a continent as to give occasion to wholesale migrations of people, but on the contrary they proceed so slowly, that the human stock decreases parallel with the deterioration of the climate. But in East Turkestan there has not even been a deterioration of climate; for it is undoubtedly true, that if the possibilities of irrigation were exploited in a more rational manner, and even now with a more intelligent conception of the object to be attained, East Turkestan would be able to support a much more numerous population than it actually does. It is true, the towns which I discovered in the desert immediately west of the lower Kerija-darja, and which are now almost entirely smothered under the drift-sand, do seem to point to an enlargement of the area of the desert; and so too do the relics of antiquity which Stein discovered and thoroughly explored during his wonderful and remarkably successful journey. Moreover in several places it is easy to see how the caravan-road between Karghalik and Chotan is actually threatened by the advancing drift-sand — in fact, not very long ago the road was
* Koeppen, Die Religion des Buddha, H. p. 35.
He d i n, yourney in Central Asia. H. 47
IIIFカラー高解像度
