106 



THE CANADIAN NATURALIST. 



[Dec. 



where, as already remarked, the P. alba disappears. Michaux the 

 elder, in his manuscript journal, informs us that the black spruce 

 is met with, in a stunted form, upon the hills bordering on Swan 

 Lake, and that it is only on the height of land, or water-shed 

 between the St. Lawrence and Hudson Bay that it entirely dis- 

 appears, giving place to the Pinus rupestris which reigns alone in 

 those boreal regions. 



The Picea nigra in certain localities may reach a height of 

 seventy feet, and a diameter of from fifteen to eighteen inches, 

 but is generally smaller, and seems to diminish in size as we go 



Picea nigra, Link. 



H. Branch with a cone, gathered in January, 1865. 



I. Transverse section of the leaf; g. vascular bundles ; 7;. resiniferous 



canals ; x. parts of the leaf having stomata ; X 50 diameters. 

 K. Point of a leaf, enlarged ten diameters. 

 It. Ripe seed with its wing. 

 N. Seminal scale, dorsal view. 



M. End of a branch with a male flower. (June 5, 1865.) 

 0. End of a branch with a female flower. (Ditto.) 



