39° 



George E. Nichols, 



75 per cent, and sometimes fully 85 per cent, of the stand. 

 Individual trees may attain a trunk diameter in excess of six- 

 teen inches with a height approaching seventy feet, but such 

 specimens are exceptional : the bulk of the balsams w^hich go to 

 make up the mature forest run from eight to twelve inches in 



Figure 49. — Primeval coniferous forest of the regional climax type; 

 mainly balsam fir ; mountains north of Barrasois River. 



diameter, mostly about ten, and range around fifty feet in height. 

 The average age of such trees, as ascertained in many cases 

 with the aid of an increment borer, would scarcely exceed seventy 

 years. Occasional specimens are encountered which must be 

 125 or more years of age, but the exact age of these larger 

 specimens it is seldom possible to determine accurately, owing 



