Bui. 523, U. S. Dept. of Agriculture. 



Plate IV. 



Fig. 1. — Transverse section. 



Fig. 2. — Tangential section. 



Fig. 3.— Radial section. 

 Structure of White Ash Wood Magnified 50 Diameters. 



Numbers on photographs rofor to the following: (I) Width of annuiil ring; (2) width of springwood; (3) 

 width of summerwood; (4j medullarj' or pith ray; (5) vessel; (0) wood fiber; (7) wood parenchyma. 



