472 



CONIFERS. 



The trees belonging to this section or genus of the 

 Abietince, of which the Silver Fir is considered the type, 

 are distinguished from the Spruce Firs, or genus Abies, 

 by their leaves being distributed more decidedly in two 

 rows upon the branches, by their cones being upright 

 and having the scales deciduous, and by the irregular form 

 of their seeds. In other respects, as to growth and form, 

 they greatly resemble each other, their heads being as 

 regularly pyramidal, or cone-shaped, during their life as 

 those of the Spruces. The general aspect of the Silver 

 Fir is, however, stiffer and more formal than that of the 

 Spruce, in consequence of the branches, which grow in 

 regular candelabrum-like whorls, being at right angles, 

 and standing out more horizontally in reference to the 

 trunk, a disposition which also extends to all the smaller 

 branches and spray. 



In dimensions and nobleness of appearance the Silver 

 Fir is one of the most striking of the Abietina, rising fre- 

 quently to the height of one hundred and sixty or even 

 one hundred and eighty feet, with a stem perfectly erect, 

 and generally clothed from the base to the summit with 

 regular tiers of horizontal branches, and when at maturity 

 frequently measuring as much as six or eight feet in dia- 

 meter. For many years the bark is smooth and of a 

 green grey colour, but as the tree gains age it becomes 

 rough, with chaps or small fissures ; and, when very old 

 and verging to decay, often throws off the exterior part 

 in large flakes, leaving the newly-exposed cuticle of a 

 deep rich brown. 



A peculiar effect is produced by the colour of the leaves, 

 which are of a deep green above, while underneath they 

 are variegated with two silvery white lines, which run 

 lengthwise on each side of the midrib ; they are from 



