3.-)C JOURNAL OF FORESTRY 



llliitc Pine — Form Class /0.8 — Average g Trees. 



Diam. at 



sec. in per cent 



ofd. b.h. (b.h.) I II III IV V 



White pine 100 95.2 90.6 84.9 78.6 70.8 



Scotch pine 



computed 100 95.4 90.3 84.5 78.1 70.8 



Variation 



in per cent —0.2 +0.3 -\-0A +0.5 



Absolute formf actor, white pine 0.482, Scotch pine, 0.489. 



Average age of trees, 40 years. 



Average height, 52.8 feet. 



Average d. b. h., 6.5 inches. 



White Spruce — Form Class 65.2 — Average 6 Tree.;. 



Diam. at 



sec. in per cent 



ofd. b.h. (b.h.) I II III IV V VI VII VIII IX 



White spruce 100 94.3 87.4 80.6 73.3 65.2 55.5 44.7 32.7 18.2 



Norway spruce, 



computed 100 94.2 87.9 81.0 73.6 65.2 55.8 45.3 32.9 18.2 



Variation 



in per cent +0.1 —0.5 —0.4 — 0.3 —0.3 —0.6 —0.2 ±0 



Absolute formfactor, white spruce 0.441. Norway spruce, 0.444. 



Average age. 45 years. 



Average total height, 53 feet. 



Average d. b. h., 8.3 inches. 



If v\'e compare our series for white pine and red pine, obtained from 

 actual measurements, and the mathematically computed series for 

 Scotch pine, we find that all series agree remarkable well in the lower 

 six or seven-tenths. The series for form classes 60 and 65 coincide 

 with the Scotch pine series also at the eight and nine-tenths. Form 

 classes 70, 75, and 80, however, for white pine arid red pine show a 

 larger taper in the two top sections than Scotch pine. As mentioned 

 above, Jonson had a similar experience with Scotch pine and spruce 

 which were growing rapidly in height, and we are inclined to concur 

 in the view held by Jonson that this is a temporary deviation from 

 the form class curve, which will gradually become less as the trees 

 grow older. We are strengthened in this our opinion by the series 

 obtained in connection with the investigations in British Columbia, 

 where the trees were older and where the curves obtained did not show 

 this tendency to drop in the tops. Furthermore, trees belonging to 



