222 THE MOVEMENT OF WATER THROUGH THE PLANT 



cy/i 



xuism rat 



fiber fracheid 



perforaied end 

 wall of vessel 



xulem parenchLjrna 



i^esse/s 



Fig. 57. Radial section of a small portion of the wood of a tulip tree {L'lriodendron 

 tulipifera). Most of the vessels show as a surface view of the walls; two are in sec- 

 tional view. Surface and sectional views of bordered pits show in vessel walls. Simple 

 pits show in surface view in the walls of the xylem ray and xylem parenchyma cells. 

 Adapted from a drawing by L. G. Livingston. 



