STRUCTURE OF ROOTS 



295 



467. Microphotograph of cross-section of root of grape one season old; m, medullary 

 rays; a, cambium; a, c, phloem; a, 6, xylem. 



of it. Draw. The relation of bark to woody tissue in pine 

 is shown in Fig. 461. Cork tissue may be studied to 

 advantage in the skin of the potato. 



500. Structure of Roots. At the growing point, the 

 root has a cap (of small compact cells) that protects the 

 delicate tissues from injury. (Fig. 448.) Such a protection 



