154 



THE INDIVIDUAL ORGANISM 



a 



t e 



1 



i 



annular 

 vessel 

 spiral vessel 



sclerenchyma 



pitted 

 vessel 





X 



I 



cambium 



i 



xylem 



companion 

 cells 



sieve tube 



J 



I 



Iril 



parenchyma 



sclerenchyma 



collenchyma 

 epidermis 



chlorenchyma 



cambium epidermis 



Fig. 11.2. Longitudinal section of a part of a dicot stem. The lower drawing shows the 

 tissues in place; in the upper figure they are separated to show the kinds of cells that com- 

 pose them. (Modified from Brown, The Plant Kingdom, courtesy Mrs. Mary A. Brown.) 



