Fig. 68. YELLOW BIRCH, 

 Trunk 8 inches in diameter. 



Fig. 69. GRAY BIRCH. 

 Trunk 4 inches in diameter. 



Fig. 70. BLACK BIRCH (Young.) 

 Trunk 7 inches in diameter. 



Fig. 71. BLACK BIRCH (Old.) 

 Trunk 27 inches in diameter. 



