TREES AND FORESTRY 



19 



From the leaf the food 

 substances pass upward to 

 the buds, downward to the 

 cambium and to the tips 

 of the roots to supply all 

 living parts with material 

 for growth. 



The food from the root 

 passes upward to the leaves 

 through the wood (sapwood). 



Inner Bark 



(Bast) 



Inorganic food sub- 

 stances, i. e. water carrying 

 soluble mineral substances, 

 enter at the roots ( by 

 osmosis through the root 

 hairs ). 



DIAGRAM SHOWING COURSE OF THE SAP 



It passes from the roots through the wood to the leaves, and after its chemical 

 change there, through the inner bark (bast) to all growing parts 



