and the Etsin-gol basin is divided. The broad alluvial fans of the Pei-ta-ho and of
chief physical features of these regions have the smaller rivers which to the east of it
been indicated above in section vi of Chap descend from the Richthofen Range. Fur-
ter II, and brief reference to their extent and ther east the width of the plateau at the
character will suffice here. foot of the range is still great. But the lesser
The mountain region in the south clear volume of water carried by the streams
ly shows the wide trough-like uplands at the here draining it restricts the cultivated area
headwaters of the Su-lo-ho and the Su-chou to a string of minor oases along their allu-
and Kan-chou rivers, as well as the tortuous vial fans, from Chin-fo-ssu (13. 2) to Nan-
narrow gorges in which these rivers have cut ch`üan (D. 2). The rest of the belt consists
their way through the two northern ranges here mainly of scrubby steppe, affording
of the Nan-shan. The increased moisture of ample winter grazing, with interspersed
the climate eastwards is demonstrated by the areas of drift-sand (C, D. 1, 2). Beyond the
forest growth which the map shows at ele lower course of the Hsi-ta-ho (D. 2) a pro-
vations from about 8,000 to 10,000 feet in jecting outer spur of the range, bare and
the valleys approaching the watershed of the much eroded, confines the plateau-like belt
Pacific drainage, as marked by the Ta-t'ung to its narrowest limits near the town of
river (C, D. 4). Kao-t'ai.
In the same direction the change in the The northern edge of the second region
character of the Richthofen Range, from a is formed throughout by a low and utterly
steep mountain rampart into a system of barren hill-range (A-D. 1), representing a
broad spurs with easier slopes at their top, western extension of the Ala-shan. This
becomes noticeable. This change in the hill-range with its slopes of bare gravel or
lateral expansion of the Richthofen Range sand shares throughout the character of the
determines the width of the second region, Etsin-gol basin described in the Notes on
that of the plateau-like belt stretching along Sheets Nos. 44., 45. Cultivation stops above
its northern foot. Owing to the line of the points where the rivers of Kan-chou
oases comprised in it this belt has formed an and Su-chou break through the desert range
important `land of passage' all through (B. 1, D. 1) to unite further down near the
historical times. isolated oasis of Mao-mei (Sheet No. 42.
At the north-western end of the belt we D. 4).
have the large oasis of Su-chou, occupying the Astronomically observed latidndes.
1906-08. Chia-yü-kuan, Camp 200 (near springs, south of eastern gate of