DAVIS: GLACIAL EROSION. 
321 
The descent of a glaciated valley floor is effected by a series of 
steps; the stretches of more gentle fall alternate with almost pre¬ 
cipitous falls where the floor is let down several hundred feet. 
Corries with tarns in their floors are well developed ( 1900 , 42-57) . 
Several essays by Norwegian authors remain to be considered. It 
has not been possible to make reference to them without postponing 
the appearance of this paper, and consideration of them is there¬ 
fore deferred to another occasion. 
With all these new contributions to the subject, it may be 
expected that hanging lateral valleys and overdeepened main valleys 
will soon gain the importance that they deserve in geographical 
literature. 
LITERATURE. 
Barrett, R. L. 
1900 . The Sundal drainage system in central Norway. Bull. Amer. geogr. 
soc., 32, (in press). 
Blanford, W. T. 
1900 . On a particular form of surface, apparently the result of glacial ero¬ 
sion, seen on Loch Lochy and elsewhere. Quart, journ. geol. soc., 56, pp. 
198-204. 
Boule, M. 
' 96 . La topographic glaciaire en Auvergne. Ann. de g6ogr., 5, pp. 277— 
296. 
Bruckner, E. 
’ 85 . Die Vergletscherung des Salzachgebietes. Geogr. Abhandlungen, 
Vienna, 1, pp. 1-183. 
Davis, W. M. 
1900 . Glacial erosion in the valley of the Ticino. Appalachia, 9, pp. 136-156. 
Forbes, J. D. 
’ 53 . Norway and its glaciers. Edinburgh. 
Forel, E. A. 
’ 97 . Fleuves et glaciers. Bull. soc. vaud. sci. nat., 33, pp. 202-204. 
Gannett, H. 
' 98 . Lake Chelan. Nat. geogr. mag., 9, pp. 417-428. 
Geikie, J. 
’ 95 . The great ice age. New York. 3d ed. 
' 98 . Earth sculpture. London. 
