DISTRIBUTION OF BOULDER STONES. 349 



Zurich, and the valley of Limmat ; and these in their 

 turn are equally well distinguished from the great accu- 

 mulations in the valley of the Reuss. It rarely happens 

 that intermixtures take place among these different accu- 

 mulations of debris, and this is a circumstance which must 

 be attended to in our investigation. 



It results from an accurate comparison of these loose 

 blocks with those mountain rocks which occur in exten- 

 sive chains in the high Alps ; that the loose blocks of 

 every known river basin agree with the rocks which form 

 the sides of the upper parts of those high Alpine valleys, 

 which are in immediate connection with these great water 

 basins. Thus the loose blocks of the water basin of the 

 Rhine are similar to the rocks of Bundten. We find in 

 the Lake of Zurich, and in the Limmat valley, the rocks 

 of the Glarner land in loose blocks. The debris in the 

 basin of the Reuss consists of rocks of the mountains from 

 which the Reuss takes its rise. The loose blocks of the 

 water basin of the Aare are similar to the mountain rocks 

 of the high Alps of Bern ; and the loose blocks, found in 

 the course of the Rhone, occur in fixed rocks in the Val- 

 lais. 



It thus appears that the loose blocks are by no means 

 irregularly dispersed over the great valley between the 

 Alps and the Jura, but are distributed in the direction of 

 distinct water basins. It also appears, that the loose 

 blocks are not irregularly distributed in these different 

 basins ; on the contrary, that, in some parts of the basin, 

 they are accumulated in great numbers ; in other places 

 they are rare, and in some situations none occur. 



From the preceding observations, we may obtain some 

 hints of importance in respect of the cause of this remark- 



2 



