Ii8 REGINALD A. DALY 



of river corrasion was first adequately realized, the lowland view of 

 earth sculpture became fruitful. It has led to the correct inter- 

 pretation of land forms in every continent. Still later, the highland 

 view that the alps of the world owe much of their form to conditions 

 of erosion quite peculiar to high mountains, was first clearly taken 

 by Penck, Dawson, Richter, and others. That their generalization 

 came later than the brilliant statement of general erosion by Gilbert 

 and Powell is natural, for man is a dweller in the lowlands; but 

 science must know no such subjectivity. In the future the highland 

 view must be sharpened and extended. 



Local glaciers are characteristic of lofty, alpine mountains. High- 

 lying cirque glaciers exist today by the hundreds in the Swiss Alps, 

 by the thousands in the alps of British Columbia and Alaska. Pleis- 

 tocene glaciers in vastly greater number and erosive power covered 

 those same regions and, in fact, all the others where summit-level 

 accordance in really alpine mountains has been described. Is there 

 any connection between such glaciation and accordance ? 



The interesting problem of the origin of cirques or corries is not 

 yet fully solved, but that they, by a vast majority, have been chiefly 

 formed through glacial excavation is certain. In each glacier there 

 are two loci of maximum erosion; one at the head of the glacier 

 where the great bergschrund separates the ice from the solid rock 

 of the head-wall; the other beneath the central zone of the glacier 

 itself some distance upstream from the foot of the glacier. One 

 result, noteworthy in the present connection, is to drive the head- 

 wall of the growing cirque farther and farther into the mountain. 

 In the nature of the case, it will be the higher peaks which are most 

 vigorously attacked. From every side, it may be, comes the attack 

 on the massif which, for any cause, specially projects above the 

 general level of the range. Owing to the rapidity of the ice-erosion, 

 that summit must tend to fall and reach something like accordance 

 with its formerly lower, unglaciated or but lightly glaciated neighbors. 



There seems to be no possible doubt that existing glaciers are 

 thus working favorably with all the. other methods of spontaneously 

 producing summit-level accordance. How much more important 

 has been the product of ancient glaciations in Europe and in America ! 

 Richter even makes local glaciation of the Pleistocene period 



