Our North- West Prairies. 151 



in our North-west is limited. Most of the Ontario and Que- 

 bec species do not range west of Lake Superior or Lake of 

 the Woods and probably Manitoba, west of the Eed Kiver, 

 does not include more than sixteen species. Were there, 

 however, forests in this part of Manitoba as there are in On- 

 tario and Quebec, this paucity of species would probably not 

 be so marked. That there has been a time when the pre- 

 sent prairies of Manitoba and the North-west Territories 

 have been more or less under wood is extremely probable. 

 There seems no reason why the true forests should have 

 extended everywhere northward, often covering, even there, 

 what would be otherwise prairie, and •should have left the 

 vast country to the south an open, more or less treeless, 

 plain. The deep valleys of the Assiniboine, Qu'Appelleand 

 other streams would seem to indicate a greater rainfall to 

 have at one time prevailed, and this greater rainfall would 

 result from extended areas of forest. It is not an argument 

 against this that the prairies with us can hardly be said to 

 have any characteristic trees. The vast forests to the north- 

 ward have none. It is not because trees will not grow, as 

 bluffs of timber are of frequent occurrence and wherever 

 tried, hardy trees, when properly protected, readily thrive. 

 Those who have observed the almost yearly occurrence in 

 almost every part of the prairie country of great fires, sweep- 

 ing sometimes over immense stretches of country, and of 

 the destructive effects of forest fires in Ontario and Quebec, 

 can readily suppose that such fires may have been an im- 

 portant factor in rendering the prairies largely treeless and 

 that, aided by the light rainfall and the dry atmosphere, 

 they have gradually widened the areas originally burned ; 

 until these areas have attained their present extent. The 

 general flatness of the country and consequent exposure to 

 winds has contributed much to the rapid accomplishment of 

 this. In the country bordering the upper reaches of the 

 Peace and Athabasca Eivers and their tributaries there are 

 at present large stretches of prairie land completely sur- 

 rounded by forest, and which suggest an origin resulting 

 from forest fires. Prairie fires are almost invariably the 

 result of human agency, so that the present condition of 



