304 The Effect of Potassium Salts on Dactylis glomerata 



Mayl6 



31 Junes 15 2-6 



Fig. 20. Mean ratio of lumen diameter to wall thickness, in presence of added nitrogen. 



Full line ^^~ Plot 9, with added potassium salts. 



Broken line - • - Plot 10, without added potassium salts. 



2/^ 



ly" 



^tash , 



^'<ded. --' 



No potash 



± 



_L 



_L 



May 31 Junes 15 2.6 



Fig. 21. Mean thickness of walls, xylem, in presence of added nitrogen. 



Full line — ^ Plot 9, with added potassium salts. 

 Broken line - - - Plot 10, without added potassium salts. 



