70 PLANT PHYSIOLOGY AND ECOLOGY 



Experiment 20. Pathway of adjustment. From the cross-section of 

 leaf and root, and the longisection of the stem, construct a schematic 

 drawing in such manner as to show a strip of the cortical tissue of the 

 root in contact with the lower end of the bundle, and a segment of the 

 leaf in contact with the upper end. Indicate upon the drawing the 

 course by which the change due to increased evaporation through a stoma 

 reaches the root-hair, and the course of the return adjustment when water 

 is lacking for absorption. 



