SOLIFLUCTION 97 



Swenander gave an explanation of this scantiness of the flora: 

 All the phanerogamic plants of Bear Island — with the exception 

 of a single species — are perennial, and these forms cannot endure 

 upon the flowing soil, where they are easily drowned in the moving 

 mud. The sterility of the areas of sohfluction is quite a striking 

 feature of the island. On many slopes small hills of the solid rock 

 crop out of the covering of moving waste, and, though the soil is 

 very scant in the small fissures and crevices of the rock, here the 

 plants grow more wilhngly than upon the perfidious flowing ground. 

 Thus these small rocky hills form cheerful verdant patches scat- 

 tered over the barren slopes. In the rare cases when Swenander 

 found single plants growing upon the moving waste, he could dem- 

 onstrate a remarkable adaptation to this . mode of life. The root 

 system of these specimens was exceptionally developed in order 

 to keep the plant afloat on the moving medium. These roots were 

 stretched out in the direction of the movement of the soil, and in 

 some cases where the slope was very steep it was noticed that the 

 proximal part of the root system, carried by the more rapid flowing 

 of the superficial layer of the mud-stream, had reached a lower 

 level than the distal branches, which, joining the slower movement 

 of deeper parts of the stream, were left behind in the displacement 

 down-hill. These facts, which I owe to my friend Dr. Swenander, 

 illustrate better than anything else the mode of progress and 

 the importance of solifluction in Bear Island. Evidently, then, 

 this process is a chief " agent of the denudation. Every summer 

 large masses of detritus in this way flow down-hill into the bottom 

 of the valleys, where the streamlets undertake the work of trans- 

 port. It is characteristic for this hitherto undervalued component 

 of subaerial denudation, which I have named "solifluction," that — 

 in contrast to the wind and the running water — it does not lift its 

 material, but like the glacier-ice — with which it has been already 

 compared — it removes blocks and gravel almost as well as the fine 

 mud. 



THE STONE-RIVERS OF THE FALKLAND ISLANDS 



This island group, situated in 52° S. L. in the South Atlantic, 

 consists of two large and a great number of small islands. The 

 East Falklands, and to some extent also the western large island, 



