EFFECT OF BORDEAUX MIXTURE ON TRANSPIRATION 77 



face type, the indices of transpiring power for the entire leaf 

 surfaces, these being derived by taking the mean of the aver- 

 age indices for the upper and lower foliar surfaces. These are 

 followed on the same line in the last two columns of the table, 

 by the ratios of the indices for the entire leaf surfaces of series 

 A to the corresponding indices of each of the other two series. 



It wall be observed from the last two columns of table 1 that 

 the ratios of the index values for entire leaf surfaces of the 

 sprayed leaves (series A) to the corresponding values of each of 

 the other two series (series B and series C), while by no means 

 constant, show comparatively small differences. The average 

 indices of the relative transpiring power of the sprayed leaves 

 (series A) may, therefore, be considered roughly proportional 

 to the corresponding indices of each of the other two series (series 

 B and series C). The average of the values of the first of the 

 two sets of ratios here considered is 1.21, 'and of the other it is 

 1.18, as given at the end of the last two columns of table 1. 

 The indices of transpiring power of the sprayed leaves average, 

 therefore, 21 per cent, higher than the corresponding indices of 

 the unsprayed leaves of the same plant, and 18 per cent, higher 

 than the corresponding indices of the leaves of the unsprayed 

 plant, for the day during which the tests were made (August 18). 



The average nmnerical data for the tests made on August 

 10 and on August 14 are brought together in table 2, where the 

 individual time coefficients for the two leaf surfaces and the 

 corresponding individual indices are omitted. On August 10, 

 readings were taken on the upper and lower foliar surfaces of 

 the leaves of a sprayed plant and of an unsprayed plant, only. 

 Series B, therefore, does not appear in the table for this date. 

 Each index of transpiring power for both upper and lower leaf 

 surfaces, as given in table 2, represents the average value of 

 three individual indices, and was obtained in precisely the same 

 manner as were the average indices in table 1. The ratios pre- 

 sented in the last two columns of the table correspond to those 

 which appear in the last two colimins of table 1. 



The ratios given in the last two columns of table 2 are quite 

 as uniform in value as are the corresponding ratios in table 1. 



