272 GEOGRAPHICAL DISTRIBUTION OF PLANTS. 



tration of this phenomenon ; and we have another in the 

 range of certain species or forms constituting that forest. 

 Thus the Cupressus thyoides is rare beyond the 49th 

 parallel in the eastern district, and terminates altogether 

 along with the Thuya occidentalis on the 53rd, while the 

 magnificent Cupressus or Thuya nutkatensis adorns the 

 forests of Norfolk Sound on the 58 th parallel of the Pacific 

 coast. The distribution of the Pinus mops, Abies cana- 

 densis, Rubus nutkanus, and of some other conspicuous 

 trees and shrubs, show that the vegetation of the district 

 of Sitka on the north-west coast is equal and similar to 

 that of the eastern states of Wisconsin or Minesota eight 

 decrees further south. 



The physiognomy of the woodland district through which 

 the canoe route lies has been incidentally touched upon in 

 the descriptions of several localities that have been intro- 

 duced into the narrative, yet it will not be out of place to 

 recall its general features here. Of this district, which 

 has a breadth of about 600 geographical miles between the 

 50th and 55th parallels, the white spruce is the most 

 abundant and characteristic tree ; yet up to the 54th pa- 

 rallel it is conjoined, and especially on the banks of rivers, 

 with other trees which break the monotony of the dark 

 evergreen forest. Beyond the banks of the Saskatchewan 

 the oaks, elms, ashes, maples, bass-wood, white thorns, 

 Virginian clematis, and various other trees and shrubs 

 cease to grow ; and the white spruce may be said to cover 

 the face of the country, except on the alluvial borders 

 of rivers and lakes, where the aspen, balsam poplar, balsam 

 fir, alder, and multitudes of willows usurp its place, or on 

 the edges of swamps where the black spruce leads a linger- 

 ing, unhealthy existence. With the black spruce the larch 

 is often associated ; though it is not confined to morasses, 

 yet it is too much isolated in its distribution to produce a 



