Neglected Principles of Physiography. 93 



one. It is not unreasonable to suppose that many folded areas 

 emerged as practically level plains, and that streams were at least 

 as free to flow along anticlines as synclines. 



In those cases where the rise of any anticline was rapid enough 

 to overtake the erosive action of the waves, that action was still 

 effective on the sides of the resulting islands. Added to this was 

 the work of the subaerial agencies. On the whole, the direction 

 of the resulting small streams was transverse to the anticlines. 

 The anticlines did not everywhere emerge at a uniform rate, but 

 appeared as rows of islands over each of which streams flowed 

 radially. Consequently, some of the streams were, from the start, 

 longitudinal to the direction of the anticlines, and others nearly so. 



If at this stage the streams were still on incoherent material, 

 the longitudinal ones had no particular advantage over the trans- 

 verse ones ; but if the indurated or partly indurated material had 

 been reached, they had the special advantage of being able easily 

 to seek out the soft beds and follow their strike. In the mean- 

 time, the material lapped oft" the sides by the waves and that 

 washed into the sea by the streams was still filling up the adja- 

 cent synclines. 



During the elevation, the synclines were occupied first by 

 lagoons of salt, then brackish, and after complete emergence by 

 those of fresh water. Even during the last stage they continued 

 to be lines of decomposition until the lagoons dwindled into lake- 

 lets and finally disappeared. Meanwhile, the anticlines were lines 

 of degradation, and it is not improbable that as many synclinal 

 lakelets were drained into streams that followed anticlines as into 

 those that followed synclines; and it seems not unreasonable to 

 suppose that in the course of stream adjustment, as many have 

 shifted from anticlines to synclines, as from synclines to anticlines, 

 if, indeed, the former has not been the rule. 



Folds are parallel to the old land areas from which the clastic 

 material of their rocks was derived. In the addition of new land 

 areas to old, the growth was often exogeneous. If a newly added 

 area was folded, and the folds were leveled as above supposed, 

 the streams from the old land gradually extended themselves 

 over the new, and in general were at right angles to the folds. 

 As the clastic sediments were yet incoherent and non-resistant, it 

 seems probable that many streams so thoroughly established 



