i 8 9 2.] 
409 
[Foerste. 
since both the Graitery and the Raimeux fold pitch strongly to 
the west at these cirques , and any point whatever toward the 
west of these cirques (until the highest level between the valleys 
just mentioned is reached) would represent a lower point of out- 
flow than the one chosen. 
Third. It is hardly to be supposed in accordance with this 
theoiy that the same lake should have cut down two outlets. At 
quite an early date, geologically, one of the outlets should have 
gained the advantage over the other, by deepening its channel 
more rapidly, and then drawing away all the overflow from the 
other outlet. And yet between Monto and Graitery folds there 
are three cirques. The Court cirque has already been discussed. 
The Cremine cirque and Balsthal cirque drain the remainder of 
this valley. Both, I think, would have found lower outlets across 
their synclinal barrier on the west than at those points of the 
folds now cut by the cirques. There is only a very slight barrier 
between the Raus and Duennern at present, and even a small 
lake at this point would at once have concealed the same, so that 
it practically could not have existed during the hypothetical lake 
period, and yet two deep cuts have been completed, one at the 
northwestern, the other at the southeastern end of this “lake.” 
Fourth. Under any such theory the existence of the Tavannes 
cirque is truly anomalous, considering that the Monto fold forms 
the drainage divide. 
It must therefore be concluded that this favorite and simple 
method of explaining the cirques , while deductively possible, is 
not actually applicable to the case of the Jura. 
8e. Glacial Streams. It is well known that erratic boulders are 
found on the crests of the more southern of the Bernese Jura 
folds. It is probable that these were carried here by glaciers and 
left by the retreating ice. Sub-glacial streams might have cut the 
cirques crossing the more southern folds, but hardly the Court 
and more northern cirques , which although in part possibly 
reached by the ice hardly came under its influence to any marked 
degree. Even sub-glacial streams, however, would very likely 
have found more ready egress between the Graitery and Moron 
folds, than at the great height presented by the Court cirque. 
8f. Backward Erosion. The backward erosion of the head- 
waters of lateral streams carried on until a cut was made across the 
folds might form the beginning of a cirque. If two such lateral 
