1900 



S. S. BUCKMAN— EXCURSION NOTES 



179 



— such valleys being the natural places for such streams, 

 because they were the lowest ground, and the immediate 

 drainage would therefore find its way into them. These 



Oivide 



Divide, 



Fig. 10. Theoretical Diagrams of Stream Development. 



obsequent streams work back more and more, to diminish 

 the already beheaded consequents. 



These are the theoretical cases, — the illustrations of 

 what is supposed to have happened. Fig. 11, which is a 

 tracing from the map of the Severn and its tributaries in 

 the neighbourhood of Gloucester shows how closely the 

 actual river features correspond to the theory. The re- 

 markable point is that the tributaries on the left bank or 

 the Severn are flowing in a direction more or less opposed 

 to the course of the Severn itself; but that curious cir- 

 cumstance is understood if it be conceded that their 

 direction was first marked out by the consequents, now 

 on the right bank of the Severn, continuing their course 



