PLATE LXVIII. 



Figs. 9 to 19, inclusive, are cross sections of the midrib of a leaf, the 

 sections being cut at intervals from the tip to the base of the leaf blade. 

 The xylem and bast fibers are colered black in figures 9 to 29, inclusive. 

 X 20. 



Fig. 19, b, bast fibers; x, xylem. 



Fig. 20. Cross section of the petiole of a leaf just below the base of 

 the leaf blade, showing two rings of vascular bundles, x 20. 



Fig. 21. Cross section of petiole. This diagram represents the typical 

 arrangement of the vascular bundles in the petiole. X 20. 



Fig. 22. Cross section of petiole a short distance above the base. X 40. 



Fig. 23. Cross section of petiole just above the hollow in which the 

 axillary bud lies. X 20. 



Fig. 24. Cross section of petiole, showing the hollow, h, in which the 

 axillary bud lies. X 20. 



