332 



BOTANICAL GAZETTE 



[may 



The mature wet meadow is thus of a decidedly mesophytic char- 

 acter. Composed as it is of a thick bright-green turf of sedges, grasses, 

 and other flowering plants, it has a truly meadow-like appearance. 



It must be borne in mind that only the depressions have been 

 thoroughly taken possession of by vegetation {fig. 6). The higher 

 and drier portions of the canon floor— the roches moutonnees 

 including much more than half of the total area, are still bare, save 

 for a sparse covering of lichens, and a few xerophytic herbs in the 

 crevices. These areas, of course gradually decreasing, but with 



r 



Fig. 6.— View looking do^^•n Glacier Gorge; the dark areas in the foreground 

 are wet meadow occup}-ing depressions in the canon floor; scattered over the meadow 

 areas are still darker patches, the Picea Krummholz; farther down the canon may 

 be seen the Picea-Abies forest surrounding two glacial lakes. 



exceeding slowness, are destined to remain very much the same for 

 a long time. Far down the canons, in the midst of the forest, there 

 are many places where the bare floor is still exposed, more incrusted 

 wqth lichens and slightly more decomposed, but nevertheless surpris- 

 ingly similar to the bare areas at the canon heads. 



B. THE FOREST 



For the present purpose we need to consider only the upper forest 

 zone, which in this region is composed of two societies governed by 



