80 



JOHN W. SHIVE AND WILLIAM H. MARTIN 



* The letters U, L, and E here denote upper surface, lower surface, and entire 

 surface, respectively. 



The low value indicated in the last column of the table for the 

 seventh hour, August 14, is not explained. The average value 

 of the ratios of indices for entire leaf surfaces of the sprayed 

 leaves (series A), to the corresponding indices for the leaves 

 of the unsprayed plant (series C), for August 10, is 1.25. The 

 indices of transpiring power for the sprayed leaves average, 

 therefore, 25% higher on this day than the corresponding in- 

 dices for the leaves of the unsprayed plant. The average ratio 

 value of the indices of the sprayed leaves (series A) to those of 

 the unsprayed leaves on the same plant (series B), for August 

 14, is 1.23. The corresponding average ratio value of the 

 sprayed leaves to the leaves of the unsprayed plant for the 



