78 



A MILL SCALE STUDY OF WESTERN YELLOW PINE. 



3.0 



LOW 1O* 



2O 3O 4O 5O 60 7O BO 

 PERCENT OF TOTAL NUMBER OF TREES 



FIG. 83. Curves showing the rate of growth per decade of diameter breasthigh of 

 immature trees. The top curve marked 20" is based upon as many trees as there are 

 points on the curve (12), and is constructed by arranging these trees in order of rate 

 of growth from the minimum to the maximum, and plotting rates of growth per 

 decade for ordinates and per cent of the total number of trees, which constitutes the 

 sample, for abscissa. The other curves shown in this figure were constructed in like 

 manner. 



