392 THE FRESH-WATER LOCHS OF SCOTLAND 
The Central European Alpine Lakes 
In no other zone have the lakes been so closely studied as here ; 
this is mainly due to ForeFs fundamental investigations, but in 
addition to these we may also note the following works : Austrian 
Alpine Lakes (Richter, 1891, p. 189; 1897), Halst fitter see (Lorenz v. 
Liburnau, 1898, p. 1), The halves of Resehen Scheklecl: {mxWnev, 1900, 
p. 1), The High Lakes of the East Alps (Bohm, 1886), The Lakes of 
the Geiinan Alps (Geistbeck, 1884-5, p. 203, with list of literature), 
Starnhergersee (Ule, 1901, p. 1), Lakes of Jura (Delebecque, 1898a, 
and in many small papers). The Siciss Alpine Lakes (Zschokke, 1900 ; 
Bourcart, 1906 ; Bachmann, 1907, p. 1), Zurich (Pfenninger, 1902, 
p. 1), Viericaldstattersee (Amberg, 1904, p. 1), Montiggler Lakes 
(Huber, 1905), Lac cTAnnecy (Marc le Roux, 1907, p. 220), Schoeuen- 
hodensee (Tanner-Fullemann, 1907, p. 15), Bodensee (Bauer and Vogel, 
1894, p. 5 ; Klunzinger, 1906, p. 97, etc.). 
In these, and in a very great number of smaller, partly plankto- 
logical papers, we find exceptional material to judge of the general 
physical conditions in these lakes. Only the following more general 
characteristics need be mentioned here. 
The height above the level of the sea differs greatly ; the great 
majority are over 400-500 m. above sea-level, thus at least three 
times as much as the majority of the Baltic lakes. A great many are 
in the regions of perpetual snow. The country surrounding the 
lakes is frequently covered bv glaciers, but mostly consists of mountain 
slopes, forest ground, and to a less degree of arable land. The rivers 
hollow out their beds mainly in solid rock, not in loose, easily movable 
kinds of soil. 
The lower-lying alpine lakes are often remarkable for their con- 
siderable size and their elongated, often irregular shape and considerable 
depths of 100 m. or more. The high alpine lakes are relatively small, 
with slight depths, often under 40 m.,and mostly much shallower. It 
is principally the greatest depth which is slight ; the mean depth (the 
relation betw^een the volume and area of the lake) is on the other hand 
often great in high lakes (Bourcart, 1906, p. 104). The littoral zone is 
generally narrow ; the shores are frequently formed of high, steep 
mountains, rising abruptly from the lake, with great depths near land ; 
it is mainly in front of the river mouths that we find more evenly sloping 
shores (deltas). The primary lake-bottom is probably everywhere 
covered by soft bottom deposits, less rich in organic material than in 
the foregoing zone, but chemically varying according to the nature 
of the surrounding country — very calcareous in the lakes of the 
Jura mountains, poor in lime especially where the lake is fed from 
melting snow. 
