THE VALAIS. 
139 
one side to the other, and form marshy places by 
damming up the valley. MUnster is built on a 
specially large cone. 
At Ulrichen Calcareous and Dolomitic rocks re- 
appear; they are the continuation of the fold in the 
lower part of the valley. From Baltschieder to 
Ulrichen, however, they have been removed by 
denudation, which has cut down to the Crystalline 
rocks. 
Above Oberwald the true continuation of the 
valley is up the little stream of Gingis. The larger 
one, which comes down from the glacier, is really a 
transverse affluent, but from its greater size is re- 
garded as the source of the river. 
In the wood through which the road rises from 
Oberwald to the glacier the rocks have been much 
worn and rounded by glacial action. 
Just before arriving at the hotel the road enters 
another longitudinal valley, in which lies the beauti- 
ful glacier of the Rhone. At present the front 
of the glacier is about 20 minutes’ walk from the 
hotel , the intermediate plain being an interesting 
illustration of fluvio-glacial deposits. 
Like most of the Swiss glaciers that of the Rhone 
retreated during the first ten years of the century, 
.after which it advanced and in 1820 reached within 
