316 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
All these features are clearly seen in Norway.” (’ 96 , 210 ; ’ 98 , 
219). 
Richter on Norway , 1896. — The essay by Richter already 
referred to contains a large number of excellent observations. 
Regarding our special subject, he states that many side valleys in 
Norway mouth high on the fiord walls, as if cut off in the deeper 
erosion of the main valleys; a similar relation being known in the 
Alps, but of less distinctness. The discordance of valley depth in 
Norway is thought to depend on the faster erosion of the main val¬ 
leys by water or ice or both, when the side valleys and the uplands 
were occupied by slow-moving neve. The side streams descending 
from the floors of their hanging valleys have not yet cut even nar¬ 
row clefts in the rock walls of the main valleys (’ 96 , 177-179). 
J. Geikie on Glacial Erosion , 1898. — The recent volume on 
“ Earth Sculpture ” by James Geikie gives a generally available access 
to the results of Richter’s observations on Norway. The following 
quotation comes after a description of the rock walls of the fiords: 
“Numerous tributary waters, some of which are hardly less impor¬ 
tant than the head-stream, do indeed pour into the fiord, but they 
have not yet eroded for fhemselves deep trenches. After winding 
through the plateau-land in broad and shallow valleys their rela¬ 
tively gentle course is suddenly interrupted, and they at once cas¬ 
cade down the precipitous rock-walls to the sea. The side-valleys 
that open upon a fiord are thus truncated by the steep mountain- 
wall as abruptly, Dr. Richter remarks, as if they had been cut across 
with a knife. 
“ If we admit that a fiord is simply a partially drowned land-valley, 
and that the profound hollow in which it lies has been eroded by 
river action, how is it that the side streams have succeeded in doing 
so little work ? Why should the erosion of the main or fiord-valleys 
be so immeasurably in advance of that of the lateral valleys? 
Obviously there must have been a time when the process of valley- 
formation proceeded more rapidly along the lines of the present 
fiords and their head-valleys than in the side-valleys which open 
upon these from the fjelds. At that time the work of rain and 
running water could not have been carried on equally over the whole 
land, otherwise we should find now a completely developed hydro- 
graphic system — not a plateau intersected by profound chasms, but 
an undulating mountain-land with its regular valleys.According 
to Dr. Richter, the remarkable contrast between the deep valleys of 
the fiords and the shallow side-valleys that open upon them from 
