hemlock 
magpie 
yellow birch 
a.11 other tree species 
Fig* 13.*- Vector diagrams, illustrating 
approximate equilibrium (in number of individ¬ 
uals) at two points on the north slope of the 
first range: the uppor figure illustrates the 
conditions halfway up tho slope; the lower 
figure shows conditions of balance near the 
top; hemlock has been nearly replaced by maple; 
CD is represented largely by busBv/ood and iron- 
wood 
