Foerste.] 
414 
f April 6, 
lieved, therefore, that the various cirques of the Bernese Jura 
represent parts of an antecedent drainage, and that this drain- 
age during a large part of the period of folding was towards the 
south. This southward drainage will readily be admitted for the 
Suxe river through its Pery and Boujean cirques ; less readily 
perhaps for the Birse and its branches, through their various 
cirques , where such an interpretation requires an inverted drain- 
age. Aside from the fact that the last deposits before folding, 
the Oeningen conglomerates, indicate a southward drainage, the 
Tavannes cirque it is believed also furnishes evidence of south- 
ward drainage until a much more recent date, as the following 
remarks will show. 
In the Pery cirque the Suxe has a quite level bed until it 
reaches the mill directly east of Rondchatel, about two thirds of 
its way through the cirque ; beyond this it has quite rapid de- 
scents to the mouth of the gorge. Thence to the beginning of 
the Boujean cirque the stream has a comparatively level bed. 
This remains true for some distance into the gorge, but along 
the middle, the descents are rapid, and towards the southern end 
the flow is tumultuous, and the rough dashings and whirlings of 
the stream are the main features in the picturesqueness of the 
Taubenloch. Now the Tavannes cirque presents a similar con- 
figuration. From the Pierre Pertuis northward the descents are 
rapid. From the same locality southwards to a point a little 
more than one fourth of the way across the fold, there is a slight 
rise, the result largely of recent drainage backwards through the 
Pierre Pertuis, helped probably in great part by Roman shovels 
or their equivalent. Then there is a quite level stretch, as far as 
the house in the cirque. After this the valley descends, at first 
gradually, then more rapidly, until at its southern end, where 
the valley turns strongly to the west, the descents are quite 
rapid. The configuration of the valley bottom in the Tavannes 
cirque therefore is analogous to those of the Pery and Boujean 
cirques and indicates a southward drainage through the cirque. 
The present stream at its south end is altogether too small to 
have done all the cutting and carrying implied by the cirque. It 
required a larger stream to carry away all the debris to which the 
formation of such a cirque must have given rise, and such a stream 
must have collected its waters from a greater area than that pre- 
sented by the cirque. In other words, the stream must have 
