vni RIVEES AND LAKES 307 



The Vorder and Hinter Rhine united then 

 (Fig. 43) as they do now at Reichenau, but at 

 a much higher level, and ran to Mayenfeld, 

 not by Chur, but by the Kunckel Pass to Sar- 

 gans, and so on, not to the Lake of Constance, 

 but to that of Zurich. The Landwasser at 

 that time rose in the Schlappina Joch, and 

 after receiving as tributaries the Vereina and 

 the Sardasca, joined the Albula, as it does now 

 at Tiefenkasten ; but instead of going round 

 to meet the Hinter Rhine near Thusis, the 

 two together travelled parallel with, but at 

 some distance from, the Hinter Rhine, by 

 Heide to Chur, and so to Mayenfeld. 



In the meanwhile, however, the Land- 

 quart was stealthily creeping up the valley, 

 attacked the ridge which then united the 

 Casanna and the Madrishorn, and gradually 

 forcing the passage, invaded (Fig. 44) the 

 valleys of the Schlappina, Yereina, and Sar- 

 dasca, absorbed them as tributaries, and, 

 detaching them from their allegiance to the 

 Landwasser, annexed the whole of the upper 

 province which had formerly belonged to that 

 river. 



