PLATE LXIX. 



PAGE 



Figs. 1-6, CuPRESsiKOXYLON McGeei Knowlton. Washington, D. C. (after 



Knowlton) 417 



1. Transverse section showing annual ring, a, cells of fall wood; &, 



typical cell of spring wood; c, large intercellular space; d, 

 smaller intercellular spaces. X 67. 



2. Tangential section, a, resin-duct; 6, bordered pits on tangential 



walls; c, sections of pits of radial walls. X 67. 



3. Radial section, a, point at which the structure has disappeared; 6, 



medullary rays, mostly showing oblong pores. X 67. 



4. Radial section. Same section as Fig. 3. X 242. o, pits on walls 



of medullary rays; &, pits on walls of tracheids. 



5. Transverse section further enlarged, a, medullary ray; 6, cells of 



spring wood; c, section of pits on radial walls; d, section of 

 pits on tangential wall. X 242. 



6. Tangential section, a, resin-duct; &, bordered pits on tracheids; c, 



bordered pits on resin-duct connected by spiral lines. 



Figs. 7, 8. CuPEESsiNOXYLON Wardi Knowlton. B. & O. R. R. Cut, D. C. 



(after Knowlton) 415 



7. Radial section, a, medullary rays; &, single row of pits on tra- 



cheids. X 67. 



8. Tangential section, a, resin-duct; 6, medullary two cells broad. 



X67. 



563 



