GENERAL SUMMARY. 
255 
partly (2) by rival rivers deepening and extending 
their valleys, and thus annexing territory which pre- 
viously belonged to others: for instance, the Land- 
quart has robbed the Landwasser of its head waters 
and carried off the Schlappina, the Vereina, and the 
Sardasca; partly (3) by dams due to river cones or 
glacial moraines, as for instance the Limmat, which 
was driven from the Glatthal and the Sihl from the 
valley of the Lake of Zurich. 
The lakes which contribute so much to the 
beauty of the country fall into several different 
categories. 
1 . Some are due to the inequalities in the glacial 
deposits; as the numerous small pieces of 
water in the curious district of the Pays de 
Dombes. 
2. Some are due to subsidence; strata, generally 
those of gypsum or salt, having been dis- 
solved and removed; as for instance the 
Lakes of Cadagno and Tremorgia. 
3. Some are dammed back by river cones, as 
the lakes of the Upper Engadine; or by 
moraines, as the lakes of Sempach, Baldegger 
and Hallwyl. 
