Bui. 606, U. S. Dept. of Agriculture. 



Plate I. 



Maple (Cross Section, Magnified 50 Diameters). A Diffuse-Porous Wood. 



AR, annual ring; SP, springwood; SIF, summerwood; MR, medullnry ray; P, pith fleck; V, 

 pores or vessels; A, wood prosenchyma (fibers, etc.). 



