FROM ROOT TO LEAF 



83 



- Cross section of corn stem showing the scat- 

 tered arrangement of bundles. 



never become so 



large and strong 



as the stems of 



trees which have 



their wood in lay- 

 ers. It is not 



an arrangement 



which is so well 



suited to great 



size and strength. 

 The water as- 

 cends through the 



xylem of the 



stems as readily as Fig. 32. 



through the xylem 



of the roots. It becomes indistinguishable from the sap 

 , of the plant. It is the sap. • It 

 continues to move up. 



If the cut ends of vigorous young 

 branches are immersed in red ink 

 and left in the sunlight for a few 

 hours, the ink will enter the stems. 

 Its color reveals the path which 

 the ascending sap follows. (See 

 Figure 33.) 



The vascular bundles branch 

 out from the stems and enter the 

 leaves. Here they are called veins. 

 Hold a thin leaf to the light and 

 see the delicate tracery of the veins. 

 (See Figure 34.) Into every part 

 of the blade they penetrate. 



Fig. 33. — Apple twigs split to 

 show the course of colored 

 water up the stem. — Alter 

 Hunter. 



