294 THE BEAUTIES OF NATURE CHAP. 



Chamouni, the Yalais, the Urseren Thai, 

 and that of the Yorder Khine really form 

 part of one great fold is further shown by 

 the presence of a belt of Jurassic strata 

 nipped in, as it were, between the crystalline 

 rocks. 



This seems to throw light on the remark- 

 able turns taken by the Rhone at Martigny 

 and the Vorder Rhine at Chur, where they 

 respectively quit the great longitudinal fold, 

 and fall into secondary transverse valleys. 

 The Rhone for the upper part of its course, as 

 far as Martigny, runs in the great longitudi- 

 nal fold of the Yalais ; at Martigny it falls 

 into and adopts the transverse valley, which 

 properly belongs to the Dranse ; for the 

 Dranse is probably an older river and ran in 

 the present course even before the great fold 

 of the Yalais. This would seem to indicate 

 that the Oberland range is not so old as the 

 Pennine, and that its elevation was so 

 gradual that the Dranse was able to wear 

 away a passage as the ridge gradually rose. 

 After leaving the Lake of Geneva the Rhone 

 follows a course curving gradually to the 



