290 Lakes 



in >f fivsh water in the world. A similar group 

 of immense lakes is found in Central Africa: Lakes Victoria 

 nza and Albert Nyanza, whose overflow waters go to form 

 the Nile; Lake Tanganyika, at the source of the Congo; and 

 Lake Nyassa, on a tributary to the Zambesi. In Asia the 

 largest freshwater lake is Lake Baikal, on the upper waters of 

 the Lena. All these freshwater lakes of great size are at the 

 sources of large and important rivers; the salt lakes in which 

 Asia also abounds are at the mouths of large rivers, as the 

 Caspian at the mouth of the Volga, and Aral Sea at the mouth 

 of the Oxus. 



Passing from the consideration of these larger lakes, which 

 from their size may be considered inland oceans, and which 

 therefore necessarily occur in small number, we find large 

 numbers of lakes of comparatively small dimensions, and when 

 we consider them attentively we find that they are reducible 

 to a small number of species, and, as in the case of plants and 

 animals, the distribution of these species is regulated chiefly 

 by climate, but also by geological conditions. Perhaps the 

 most important and remarkable species of lakes is that to 

 which the Scottish lakes belong. They are generally charac- 

 terized by occupying long narrow depressions in the valleys 

 of a mountainous country in the neighbourhood of the sea, 

 and in a temperate climate. On the sea-coast, lakes of this 

 character are found in Norway, Scotland, Newfoundland, 

 Canada, the southern extremity of South America, and the 

 south end of the middle island of New Zealand; somewhat 

 removed from the sea we have the Alpine lakes of Switzerland 

 and Tyrol, and the great Italian lakes, all of which display the 

 same features as those of Scotland or of Norway. In many 

 flat countries lakes are extraordinarily abundant, as for instance 

 in the north part of Russia and Finland, in the southern part of 

 Sweden, in the northern parts of Canada, and on a small scale 

 in the Hebrides. 



Lagoons, found on all low sandy coasts, owe their origin to 

 the shifting of the sand under the influence of the wind and 

 tide. They are found at the mouths of large rivers, as on the 

 Baltic and at the mouth of the Garonne. 



