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JOURNAL OF FORESTRY 



small, and those that were decayed at the center on the stump, which 

 were usually large, but amounted to less than 5 per cent of the total. 

 Average measurements were made on all diameters. 



The trees were for computation separated into age classes and decade 

 measurements were mathematically averaged. (The fallacy of this 



FIG. i. Diameter growth on the stump for balsam fir, by age classes, from 208 trees taken on 

 swampy-bench land, Brandreth I<ake, N. Y. : 



(a) 50- 60 year age class, 



(fr) 60 70 year age class. 



(c) 70- 80 year age class. 



(d) 80 90 year age class. 

 (?) 90100 year age class. 

 (/) 100 no year age class. 



method is more than counterbalanced by the advantages in this case.) 

 Results were plotted for comparison only, and the curves have not been 

 varied from the points mathematically determined. 



