PLATE XXII. 



Fig. 60. Cross' section of root of X. globosum. X 17. G, bark; H, 

 phloem; /, resin duct; ./, medullary ray; K, tracheal tube. 



Fig. 61. Cross section of root of X. pennsylvanicum. x 17. L, 

 bark; M, phloem; A 7 , resin duct; O, medullary ray; P, tracheal tube. 



Fig. 62. Cross section of bast of X pennsylvanicum. X 193. Q, 

 starch sheath; R, bast. 



Fig. 63. Cross section of bast of X. globosum. x 193. S, starch 

 sheath; T, bast. 



Fig. 64. Longitudinal section of bast of X. globosum. x 193. 



