ROLE OF THE MICROSCOPE 187 



EXPLANATION OF PLATES 

 Plate I 



Fig. 1. — Cercocarptis sp. Transverse section of the wood, showing "diffuse" 

 parenchyma. XI 10. 



Fig. 2. — Pygeiim Preslii. Transverse section of the wood, showing "vasicentric' 

 parenchyma. X80. 



Fig. 3. — Ulmns americana. Transverse section of wood taken from a "butt" 

 log, showing arrangement of vessels. X16. 



Fig. 4. — Osmanthus americanus. Transverse section of the wood, showing' 

 "terminal" parenchyma. X90. 



Fig. 5. — Dicotyledon. Transverse section of the wood, showing "para tracheal" 

 parenchyma. X18. 



Fig. 6. Ulmiis americana. Transverse section of wood taken from a "top" log 

 showing arrangement of the vessels. X16. 



Fig. 7. — Prosopis juliflora. Transverse section of the wood, showing "meta- 

 tracheal" parenchyma. X45. 



Fig. 8. — Prosopis juliflora. Transverse section of the wood, showing "para- 

 tracheal" parenchyma. X45. 



Plate II 



Fig. 9. — Prunus inlegrifolia. Transverse section of the wood, showing large 

 rays and vessel arrangement. X45. 



Fig. 10. — Prunus serotina. Transverse section of the wood, showing absence of 

 parenchyma. X150. 



Fig. 11. — Prunus sphaerocarpa. Transverse section of the wood, showing 

 arrangement of parenchyma and vessels. X45. 



Fig. 12. The same. More highly magnified to show parenchyma about vessels. 

 X90. 



Fig. 13. — Prumis inkgrifolia. Transverse section of the wood, showing "diffuse" 

 parenchyma. X90. 



Fig. 14. — Prunus sphaerocarpa. Transverse section of the wood, showing 

 "terminal" band of parenchyma. X90. 



Fig. 15. — Prunus serotina. Transverse section of the wood, showing rays and 

 arrangement of the vessels. X45. 



Plate III 



Fig. 16. — Sequoia sempervirens. Tangential section of the wood, showing uni- 

 seriate rays. X75. 



Fig. 17. — Sequoia sempervirens. Tangential section of the wood, showing 

 biseriate and triseriate rays. X75. 



Fig. 18. — Quercus alba. Transverse section of the wood, showing absence of 

 large rays. X35. 



Fig. 19. — Picea sp. Tangential section of the wood, showing tertiary spiral- 

 thickenings in the tracheids of both early and late formed wood. X180. 



Fig. 20. — Pseudotsuga taxifolia. Tangential section of the wood, showing absence 

 of spiral-thickenings. XIOO. 



Fig. 21. — Castanea dentata. Transverse section of the wood, showing large rays. 

 X130. 



Fig. 22. — Sequoia sempervirens. Radial section of the wood, showing pits between 

 tracheids and ray cells. X400. 



Fig. 23. — Sequoia sempervirens. Radial section of the wood from a different 

 specimen, showing pits between tracheids and ray cells. X350. 



