ILLUSTRATIONS 



PLATE 



Cross section of Quercus alba (white oak) .... Frontispiece 



Map of the United States showing natural forest regions . . I 



Photomicrographs of wood sections II- VI 



TEXT ILLUSTRATIONS 



PIQ. PAGE 



1. Cross section of stem of Quercus prinus (chestnut oak) ... 6 



2. Typical wood cells 19 



3. Radial sections of heterogeneous rays 24 



4. Radial section of ray of Pinus strdbtis (white pine) . . . .25 



5. Radial section of ray of Pinus edulis (pinon pine) . . . .26 



6. Radial section of ray of Pinus resinosa (red pine) . . . .27 



7. Radial section of ray of Pinus ■palustris (longleaf pine) . . .28 



8. Cross section through portions of two growth rings of Pinus ponderosa 



(western yellow pine) 30 



9. Tangential section of fusiform ray of Pinus ponderosa (western yellow 



pine) . . 31 



10. Cross section of a wound area of Tsuga canadensis (eastern hemlock) 32 



11. Schematic representation of pits 33 



12. Bars of Sanio in Pinus murrayana (lodgepole pine) . . .38 



13. Cross section through three entire growth rings of Quercus macrocarpa 



(bur oak) 42 



14. Cross section through one entire growth ring and parts of two others 



of Quercus macrocarpa (bur oak) . . . . . .42 



15. Effects of shrinkage '57 



