Nutrition of Multicellular Plants - 247 



NUCLEUS _ 



VACUOLE 



CELL WALL 

 CYTOPLASM 

 SOIL AIR 



Fig. 13-12. Relation of root hairs to 

 the soil. Note particularly the air spaces 

 in the soil, and the film of soil water 

 that clings to the soil particles. 



EPIDERMIS 

 CORTEX 



- '^ SCLERENCHYMA 



j— SIEVE TUBES 



Was 



"ducts and 

 sclerenchyma 



PHLOEM 



XYLEM 



VASCULAR 

 BUNDLE 



PITH 



Fig. 13-13. Photomicrograph of one quadrant of a cross section of stem of a dicotyledonous 

 plant (clover). Note particularly the circular arrangement of the vascular bundles and the 

 disposition of the cambium. 



