8 A NATURALIST IN WESTERN CHINA 



personal observations put the responsibility on the main stream 

 itself. During the summer floods the Yangtsze brings down 

 vast quantities of mud and detritus, which it deposits wherever 

 opportunity offers. Flowing as the Yangtsze does, more or less 

 between steep banks, the mouths of tributary streams afford 

 the most favourable places for the deposition of this debris. 

 The volume of the main stream is enormously greater, and its 

 current so much stronger, than that of the tributaries that it 

 simply thrusts them back and silts up their mouths. The 

 small quantity of debris brought down by the tributary streams 

 would also be deposited hereabouts owing to the slacking of 

 the flow consequent upon the damming of their debouchure. 



At Chungking the Yangtsze is j oined on its left bank by the 

 Kialing or so-called " Little River." A glance at a map shows 

 that this river is made up of three streams which unite near 

 Ho Chou. The Kialing River and its tributaries drain a fan- 

 shaped area, in extent more than half of the entire Red Basin 

 situated north of the Yangtsze. Their importance is due to 

 their being navigable for such extreme distances. The most 

 easterly branch is navigable, for small craft, to some 40 miles 

 north of Tunghsiang Hsien ; the next branch is navigable to 

 Tungchiang Hsien ; and the next to north of Pa Chou. The 

 central (Paoning) river is navigable for fairly large boats to 

 Kuangyuan Hsien, and skiffs laden with medicines and other 

 native products descend to this town from Pikou, in the province 

 of Kansu. The most westerly branch is navigable to Pai-shih- 

 pu, a few miles north of Chungpa, and one of its western tri- 

 butaries taps the north-east corner of the Chengtu Plain. 



The Kialing River system is thus the greatest collecting and 

 distributing waterway in Szechuan, and its commercial im- 

 portance, probably greater than that of the Yangtsze itself and 

 its tributaries west of Chungking, is not generally understood. 

 The To kiang, which joins the Yangtsze at Lu Chou, though a 

 natural stream, owes very much of its volume and importance 

 to water artificially lead from Kuan Hsien across the northern 

 part of the Chengtu Plain via Sintu Hsien, and a secondary 

 branch via Han Chou, which meet together at the great market 

 town of Chao-chia-to. In summer it is possible to descend in 

 boats from Han Chou and Sintu Hsien to Lu Chou. 



