PLANTS 



chief regions in which this occurs are the centre of the bud, 

 the cambium layer of the stem and roots and the root tip. The 



FIG. 22. Diagram to show the development of the tissues (differentiation' 

 near the tip of a growing stem. The four figures on the right represent cross 

 sections at different distances from the tip of the stem. The figure shoulc 

 represent the tip of the stem covered by the young leaves. (From Stevens. ] 



growing tissue of the bud lies at the centre of a group of oldei 

 structures and hence is not exposed except that the bud as a 



