132 
IOWA ACADEMY OP SCIENCE Vol. XXIV, 1917 
Let ns now summarize such evidence as we have. A glance 
at the accompanying profile of the Yangtze river for the last 
1,500 miles of its course is sufficient to show that it has an inter- 
rupted profile. An intermediate plain exists in the gorges at 
2,200 feet, and one at Suifu at 950 feet. The presence of even- 
crested ridges in the latter region over wide areas suggests a 
peneplain between the two intermediate plains, hence at least 
three erosion cycles. 
Entrenched meanders may be said to exist, since the course 
of the stream seems to ignore completely the rock structures, its 
determination being due to ether factors than these. 
That the river is an efficient worker is attested by the wide 
areas of delta deposits which have formed land where seas once 
were. There stand the gorges, great gashes in the mountains, 
from which the materials have been carried to the ocean floor — 
fitting monuments to the ceaseless toil of one of Nature’s greatest 
artisans. 
< — ' 
Department of Geology, 
State University of Iowa. 
