1902.J DAVIS— SYSTEMATIC GEOGKAPHY. 249 



ing height along the up-valley side of each spur, so that the spurs 

 have an unsymmetrical cross section as shown in the figure. No 

 flood-plain is developed before grade is reached ; but as soon as 

 this delicately organized condition is attained, further valley deep- 

 ening is practically stopped, although the meander belt continues 

 to widen, and the curves continue to advance slowly down-valley. 

 As a result, narrow strips of flood plain in scroll-like patterns must 

 be developed ; a scroll will begin by lapping around the end of a 

 spur ; it will then follow along the gentle slope on the down-valley 

 side of the spur and end with reversed curvature shortly after reach- 

 ing the next enclosing bluff. As time goes on, the spurs are more 

 consumed and the scrolls are widened. The spurs may be trimmed 

 into sharp cusps, and later reduced to blunt cusps, and then the 

 scrolls must have widened into shield-like patterns. As the river 

 swings more and more freely and opens a valley floor of greater 

 breadth than the meander belt, the separate flood-plain shields are 

 joined ; further than this we need not trace them here. 



Now it is not conceivable that geographical items as systematic as 

 these flood-plain scrolls should be treated empirically, after their 

 origin and their development has once been made out. It suffices 

 in describing the meandering part of the valley of the North 

 Branch of the Susquehanna to say that it has reached the stage of 

 narrow flood-plain scrolls ; for on saying this, the sloping spurs and 

 the enclosing bluff's at once come to mind as elements of form that 

 are necessarily correlated with the flood-plain scrolls. The me- 

 andering valley of the Ranee in Brittany shows a succession of nar- 

 row scrolls in the most orderly arrangement. The valley of the 

 lower Seine by Rouen possesses broader scrolls ; nearer the river 

 mouth, where the tides run strong, the spurs are greatly reduced. 

 The curving valley of the Evenlode, a diminished headwater of the 

 Thames system in the Cotteswold hills of England, has sharply 

 trimmed spurs which prove that the Evenlode was not beheaded 

 until a somewhat advanced stage of valley development was 

 reached. The diminished stream now straggles irregularly about 

 the open valley floor. The valley of the Lot in southwestern 

 France may be described as having nearly reached the stage of con- 

 sumed spurs in one cycle, when a moderate elevation introduced a 

 new cycle in which the stage of wide scrolls is now reached. The 

 essential features of the valley are thus concisely indicated, al- 

 though many individual variations from the suggested type are to 

 be found. 



