NORTH-WEST MONGOLIA. AND CHINESE DZUNGAIilA. 397' 



C. DZUNGAUIA. 

 Itineniv)/ and General Koles. 



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South of the North-West Mongolian plateau lies an area of coniparativ 

 lowland, bounded on the north liy the wall of the Great or Chinese Altai, 

 and on the south hy the main range of Tian Shan. The average altitude of 

 the plain is about 1500 feet, the highest point being 4000 feet and lowest 

 about 700 feet above the level of the sea. The area is drained in the south 

 by rivers which flow into small evaporating basins, while most of the north is 

 drained by the Upper or Black Irtish and finds its way ultimately to the 

 Arctic. Towards the north-west, therefore, these plains of Dzungaria merge 

 without any perceptible break into the lowlands of Western Siberia. There 

 are, however, three ranges, namely, the Ala Tau, Barlik, and Sair mountains, 

 which cross the plain from north-east to south-west, but which are disjointed 

 and severed by intervening pieces of lowland, so that they do not form an 

 effective barrier to the drainage northward. Eastwards the steppes merge 

 into the Gobi Desert of Central China. The Great Altai range, which 

 bounds the Dzungarian plains on the north, runs south-eastwards towards 

 the main range of the Tian Shan, which, in turn, runs east and west. A gap 

 of over 100 miles separates the eastern extremities of these ranges, and thus 

 the plains of Dzungaria pass into the plains of Central L'hina without a break 

 through this gap. 



Descending from the North-West Mongolian plateau and crossing the Great 

 Altai range, the expedition reached the Chinese town of " Sharasume," or 

 " Tulta," in Sept. 1910, on the southern foothills of the Great Altai 

 mountains. The plains of the Black Irtish were then crossed, leaving Lake 

 Ulun-gur to the east and reaching the valley of Kobuk. Here the southern 

 offshoot of the Sair mountains was crossed, which is one of the disjointed 

 ranges traversing the Dzungarian plain. Ultimately the Chinese town of 

 " Chuguchak," or " Tarbagatai," was reached on the plains of the Emil, 

 whence the route lay direct south to Kuldja, through the Dzungarian gap 

 and over the Tian Shan. 



The floral associations of Dzungaria do not differ widely from those of the 

 North-West Mongolian plateau. During the journey a large number of 

 species were met with common to both districts, but it was found on pro- 

 ceeding southwards that several new species began gradually to creep in. 

 The more southern latitudes, which are exposed to drought and tierce heat 

 of the sun in summer, create conditions favourable for the driest desert floral 

 association. 



After leaving the town of " Sbarasume," an area of rugged, stony hills 

 was traversed, covered with desert floral association, which was in every way 

 typical of those described in North- West Mongolia. Thus the following 

 species were collected in considerable abundance : — Artemisia Lerclieana^ 



