6 14 E. C. ABEND AN ON 



Thus, when we appeal to the antecedent theory we must accept 

 the fact that this antecedent river not only had the power of cutting 

 its course through a succession of parallel folds but even could keep 

 the better of a general rising of the land contrary to its way from south 

 to north, from far upstream Chung-king till Wan-hien. Nothing 

 opposes itself to this combined movement of the earth's crust, viz., its 

 being folded and at the same time pressed up against the Tsin-ling- 

 shan; on the contrary the observations lead to this inference as is 

 explained in the above. To account for the last-mentioned discrep- 

 ancy we must suppose that the river had a sufficient power, as the 

 result of a considerable fall anywhere in its course and that there was 

 no possibility of going another way, for a river does its work only 

 when it is forced to it. Now, it is almost certain that east of I-ch'ang, 

 where nowadays still exists the low east China plain with its many 

 lakes (Tung-ting, Po-yang, etc.,) ever since the filling up of the Red 

 Basin there was a considerable difference in height from west to east. 

 Might any obstruction have occurred in the antecedent river by the 

 rising of the country from south to north, it still would be possible 

 that a more intensive erosion in the watercourse took place from 

 I-ch'ang in an upriver direction. But here we already appeal to 

 the regression theory, for it may be that the rate of land-folding and 

 uplifting have been the same as that of the cutting-power of the river 

 water, or the first may have stopped the last till regression of the old 

 watercourse redressed the former river-way, which then could con- 

 tinue its work in the old direction. 



As to the second condition necessary for the absolute maintenance 

 of the antecedent theory, viz., the impossibility for the river water of 

 going another way, we cannot say very much because of the very 

 incomplete geographical and geological investigations of southern 

 China. When we look at the map we see that all great tributaries 

 of the Yang-tzi, and its headwaters too, run in general lines from 

 north to south. This makes me feel quite inclined to suppose that the 

 hydrographical system of the province Ssi-ch'uan once must have 

 found an outlet toward the south according to the general incline of 

 the earth's surface from north to south. If this is true, then we must 

 consider one or more of southwestern China's big rivers as beheaded 

 ones by a retrogressed river system, which now is that of the Middle 



