134 THE MOUNTAINS OF CALIFOKNIA 



and fervid summer life comes surging on, seemingly 

 yet more glorious than before. 



This is a perfect meadow, and under favorable 

 circumstances exists without manifesting any 

 marked changes for centuries. Nevertheless, soon 

 or late it must inevitably grow old and vanish. 

 During the calm Indian summer, scarce a sand-grain 

 moves around its banks, but in flood-times and 

 storm-times, soil is washed forward upon it and laid 

 in successive sheets around its gently sloping rim, 

 and is gradually extended to the center, making it 

 dryer. Through a considerable period the meadow 

 vegetation is not greatly affected thereby, for it 

 gradually rises with the rising ground, keeping on 

 the surface like water-plants rising on the swell of 

 waves. But at length the elevation of the meadow- 

 land goes on so far as to produce too dry a soil for 

 the specific meadow-plants, when, of course, they 

 have to give up their places to others fitted for the 

 new conditions. The most characteristic of the new 

 comers at this elevation above the sea are prin 

 cipally sun-loving gilias, eriogonge, and composite, 

 and finally forest-trees. Henceforward the obscur 

 ing changes are so manifold that the original lake- 

 meadow can be unveiled and seen only by the 

 geologist. 



Generally speaking, glacier lakes vanish more 

 slowly than the meadows that succeed them, be 

 cause, unless very shallow, a greater quantity of ma 

 terial is required to fill up their basins and obliterate 

 them than is required to render the surface of the 

 meadow too high and dry for meadow vegetation. 



