It is, and will here be made, quite clear that the whole of the left bank of the Yellow River was in possession of various Turkish and Tartar-Tibetan tribes. The only exception is that the south- west corner of Shan Si province, notably the territory enclosed between the Yellow River and the River F&n (which, running from the north, bisects Shan Si province and enters the Yellow River about lat. 35" 30' N., long. 110 degrees 30' E.) was colonized by a branch of the imperial family quite capable of holding its own against the Tartars; in fact, the valley of this river as far north as P'ing-yang Fu had been in semi-mythical times (2300 B.C.) the imperial residence. It will be noticed that the River Wei joins the Yellow River on its right bank, just opposite the point where this latter, flowing from the north, bends eastwards, the Wei itself flowing from the west. This Wei Valley (including the sub- valleys of its north-bank tributaries) was also in 842 B.C. colonized by an ancient Chinese family--not of imperial extraction so far as the reigning house was concerned--which, by adopting Tartar, or perhaps Tartar--Tibetan, manners, had for many generations succeeded in acquiring a predominant influence in that region. Assuming that--which is not at all improbable--the nomad horsemen in unchallenged possession of the whole desert and Tartar expanse had at any time, as a consequence of their raids in directions away from China westward, brought to China any new ideas, new commercial objects, or new religious notions, these novelties must almost necessarily have filtered through this semi- Chinese half-barbarous state in possession of the Wei Valley, or through other of their Tartar kinsmen periodically engaged in raiding the settled Chinese cultivators farther east, along the line of what is now the Great Wall, and the northern parts of Shan Si and Chih Li provinces.