598 W. M. DAVIS PENEPLAINS AND THE GEOGRAPHICAL CYCLE 



present than any empirical description does. Both the mountains here 

 named exhibit the subdued forms of late-mature normal erosion ; that 

 is. dome-like summits from which rounded spurs descend in various direc- 

 tions ; and in both these normal features are greatly modified by the 

 recent excavation of huge glacial cirques in the valley heads between 

 the diverging spurs ; hence the present remnant of the dome-like summit 

 is undercut on several sides by great cirque-head cliffs, and not far below 

 the summit remnant the deepening and widening of the glacial troughs 

 reduces the sloping spurs to sharply serrate, coxcomb-like crests. The 

 single word "recent/ 3 used to qualify the excavation of the cirques and 

 troughs, suffices to show that postglacial changes are small. The dis- 

 tinction here made between the use of the cycle scheme for geological and 

 geographical purposes deserves more attention than it usually receives. 



