70 Canadian Record of Science. 



tree, prickly ash, sassafras, and flowering dog-wood, which 

 are found only in a small area in the southern part of 

 Ontario ; (4) a western group, consisting of the ash-leaved 

 maple, bur-oak, cotton-wood, and green ash, which are 

 scattered sparingly over the prairie and partially-wooded 

 regions west of Eed Eiver and Lake Winnipeg. 



The Ad est timber of the second group within the limits of 

 Canada is to be met with along the east side of Lake 

 Huron in the counties of Lambton, Huron and Bruce, where 

 the button-wood, elm, maple, yellow birch, cherry, bass- 

 wood and hemlock attain a height of one hundred feet and 

 upwards. Although the Ottawa valley has produced more 

 white pine timber than any other region in the Dominion, 

 the largest and finest trees grow on the sandy soils of the 

 counties bordering the northern sides of Lake Erie and of 

 the western part of Lake Ontario, where extensive and splen- 

 did pineries stood when these regions were first invaded by 

 the white man. In the Northwest Territories, the largest 

 trees are the elms along the rivers (which, however, do not 

 extend far north) and the rough-barked poplars, which, even 

 as far north as the Laird and the lower Mackenzie, have 

 trunks five feet in diameter. Along Athabasca Eiver the 

 author had seen spruces which measured ten and twelve 

 feet in girth. 



The distribution of our forest trees affords us one of the 

 most obvious tests of climate, and although it may not be 

 more reliable than that of the smaller plants, it is more 

 noticeable by the common observer. In the older provinces 

 of Canada the settlers are often guided to a great extent in 

 their selection of land by the kinds of trees it supports, a 

 thrifty growth of beech and sugar-maple, for instance, being 

 generally considered a good sign ; but such tests must neces- 

 sarily be only of local application. In the prairie region, 

 timber may be entirely absent from the finest soil, while the 

 least hardy trees of the west flourish in the stiff clay-banks 

 or among the stones along the rivers on account of the mois- 

 ture and heat derived from the water. 



The map which has been referred to is useful in defining 

 the extent of country over which each kind of timber was 



