THE WORK OF RUNNING WATER. 



211 



The down-stream termini of terraces are rarely distinct. This is 

 partly because the notable meandering of the streams in their lower 

 courses is antagonistic to the preservation of terraces. If all terraces 

 once developed remained, and if delta-building proceeded without 

 interruption from waves, the relations should be somewhat as follows: 

 Traced down-stream, the cliff between the oldest (highest) terrace 

 and the next younger becomes gradually lower until it finally disappears, 

 and the continuation of the two is found in a common plain. The 

 cliff between the second and third terraces should disappear in the 

 same way, and below its disappearance the plain representing their 

 continuation is continuous with that representing the continuation 

 of the first and second. The cliff between the second and third ter- 



FiG. 198. — Diagram looking up the valley, showing two terraces below, one in ths 

 middle, and none above. The relations are purely diagrammatic. 



races may or may not continue farther down-stream than that between 

 the first and second. The plains below the terraces finally become 

 continuous with the lowest fiood-plain and with the delta. These 



