VOL. XVII. (I) SOME GL.\CIAL FEATURES IN WALES 43 



The suggestion that some other cause, other than ordinary 

 excavation by the headward growth of streams, must be 

 looked for to account for some of these Cotteswold combs, 

 receives additional support when it is remembered how pre- 

 cipitous would be the back-walls of these combs if the head- 

 cliffs were restored by the addition to them of the angular 

 debris at their foot, and the belt of "granular" gravel were 

 removed. 



