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14 THE CANADIAN NATURALIST. [Vol. 



for grazing flocks and herds. The soil of the central, the 

 western and southwestern districts is more varied in its o-ene- 

 ral characteristics, there being considerable areas of arable land 

 capable of sustaining a vigorous vegetation, alternating with the 

 sage brush plains. 



The winter climate of the eastern part of the Great Plains is 

 subject to sudden changes of heat and cold, with a dry atmos- 

 phere in the north more or less humid in the south. The snow 

 drifts over an area hundreds of miles in extent. By such con- 

 stant motion and atrition the flakes of snow become comminuted 

 into minute particles. When in this condition accompanied by 

 a low temperature and violent winds it fills the atmosphere so 

 completely as to obstruct the vision. These terrific drifting snows 

 are denominated blizzards, and often prove destructive to man and 

 beast. The meteorological conditions prevailing in the summer 

 are high temperature during the day, low temperature and heavy 

 dews at night, constant winds varying from the moderate velocity 

 of zephyr breezes to tornadoes and cyclones, slight rain falls or 

 torrential floods and occasionally hailstorms, nearly all of the sum- 

 mer storms being accompanied with electrical disturbances unusual 

 in forest regions. On the western portions of the Great Plains 

 the aridity is so great that no certain reliance can be placed upon 

 the productions of cereals and vegetables without irrigation. 

 The constant winds of the Great Plains moving over the thou- 

 sands of miles of space with no great chains of mountains or 

 forests to impede their progress, and with nothing but the di- 

 minutive native weeds and grasses, to shield the earth's surface 

 from the intense heat of the sun's rays, penetrating through an 

 arid atmosphere, cause rapid evaporation of moisture from the 

 soil. This moisture is wafted by the winds to where Nature's 

 forest garb, by means of its cooling atmospheric influence lowers 

 the temperature and enables Mother Pjarth to appropriate from 

 the clouds formed in unforested climes, the moisture required 

 for the sustenance of the vegetation clinging to her bosom for 

 support. 



The soil of the Great Plains containing nil the constituents 

 requisite for a varied vegetation, is capable of supporting an im- 

 mense agricultural and pastoral population, to grow surplus pro- 

 ducts to meet the requirements of the commercial, mining and 

 manufacturing population of othej* portions of the continent. In 

 order to accomplish this, climatic conditions must be modified. 



