ranges ascends to , there is great cold even in summer, and a wide daily range of temperature. Above the broad and deep accumulations of the products of denudation which have been brought down by the rivers from the Tian Shan ranges (e.g. the Karlyk-tagh) on the north and from the Nanshan on the south, and have filled up the cauldron-shaped valleys, there rises a broad swelling, built up of granitic rocks, crystalline schists and metamorphosed sedimentary rocks of both Archaic and Palaeozoic age, all greatly folded and tilted up, and shot through with numerous irruptions of volcanic rocks, predominantly porphyritic and dioritic. On this swelling rise four more or less parallel mountain ranges of the Pe-shan system, together with a fifth chain of hills farther south, all having a strike from west-northwest to east-northeast. The range farthest north rises to above the desert and above sea-level, the next two ranges reach above the general level of the desert, and the range farthest south or an absolute altitude of , while the fifth chain of hills does not exceed in relative elevation. All these ranges decrease in altitude from west to east. In the depressions that border the Pe-shan swelling on north and south are found the sedimentary deposits of the Tertiary sea of the Han-hai, but no traces of those deposits have been found on the swelling itself at altitudes of 5600 to . Hence, Futterer infers, in recent geological times no large sea has occupied the central part of the Gobi. Inhabitants Beyond an occasional visit from a band of nomad Mongols, this region of the Pe-shan swelling is entirely uninhabited. And yet it was from this region, according to Grigory Grum-Grshimailo (1889-1890 explorer), that the Yue-chi (Yuezhi), a nomadic people akin to the Tibetans, proceeded when, towards the middle of the second century BC, they moved westwards and settled near Lake Issyk-kul; and from here proceeded also the Shanshani, or people who some two thousand years ago founded the state of Shanshan or Lofi-lan. The ruins of this town were discovered by Sven Hedin in the desert of Lop in 1901. Here, says the Russian explorer, the Huns gathered strength, as also did the Turks (Ch. Tukiu) in the sixth century, and the Uighur tribes and the rulers of the Tangut kingdom. But after Genghis Khan, in the 12th century, drew away the peoples of this region,