﻿BOTANICAL GAZETTE 



equaled. The river and its large tributaries are at altitudes of 

 from 500 m. to nearly 1000 m. The peaks range from 2500 m. to 

 nearly 4000 m. Mountain flanks with a rise of 1000 m. are com- 

 mon, and in certain cases a difference of as much as 2600 m. of 

 altitude occurs within a horizontal distance of two or three miles. 

 Needless to say, such a mountain side presents the most varied 

 forms of vegetation, from tangled forests below to the dwarfed 

 plants of the cold deserts above. 



In obtaining an idea of the surface features of the country, it 

 will be helpful to keep in mind again the course of the Columbia. 

 The lakes in which it rises, as well as the first 100 miles of its 

 course, lie in a broad and terraced valley, evidently the site of an 

 ancient lake. Near Donald the river turns abruptly out of this 

 valley into a narrow canyon, and from that point it completes its 

 bend in a series of wild gorges, alternating occasionally with wider 

 and more level valleys. Most interesting problems of captured 

 drainage and reversed flow here await investigation. At one 

 point some 30 miles above the bend, the river expands into Kin- 

 basket Lake. The course of the smaller streams will be apparent 

 from the map. For the most part they descend swiftly as torrents, 

 but in a few places, notably on the Beaver, Downie, and Goldstream, 

 there are portions that have been nearly base-leveled, and in 

 these the activity of the beavers has given rise to extensive 

 swamps. 



Climate 



Adequate meteorological records have never been made, but the 

 following may give some idea of climatic conditions. 



Temperature.— This factor varies greatly, of course, in con- 

 nection with altitude, exposure, etc. At the level of the river, 

 summer temperatures of 33 0 C. are by no means rare, and once I 

 recorded 38 0 C. At high altitudes, as is usual, temperatures are 

 always low except at noonday in the direct sunlight. 



In the season of 1908 two thermographic records were made 

 on Mount Plainside near Beavermouth on the same hillside and 

 exposure, at altitudes of 800 and 1700 m. respectively. The 

 lower station was about 100 m. above the river level; the upper, 



