O. N. Purvis 



359 



May 16 31 Tunc 8 15 2.6 



Fig. 10. Mean diameter of lumina in xylem. 



Full line ^^ Plot 7, with added potassium salts. 



Broken line - - • Plot 8, without added potassium salts. 



Mayie. 31. June 6. IS. -2.6. 



Fig. II. Mean ratio of lumen diameter to wall thickness in sclerenchyma. 



Full line Plot 7, with added potassium salts. 



Broken line - - - Plot 8, without added potassium salts. 



24—12 



