322 



L. A. GIDDINGS 



TABLE 7 



The transpiration {in grams per 100 sq. cm.) of four leaves of Silphium from differ- 

 ent heights, with the concurrent evaporation {in cubic inches) from two Piche 

 evaporimeters at different heights, the relative humidity and the wind velocity {in 

 miles per hour). August 21, 1912 



leaf lost the greatest amount of water, above the second leaf 

 the loss invariably became less with the increased height of the 

 leaves above the ground. Again taking the lowest leaf as 100%, 

 the loss of the other leaves was 129.8%, 316.6%), and 107.07%o. 

 In the graphs for this experiment the leaves are numbered in 

 order from the lowest to the highest. The evaporimeters are 

 also numbered from the lower to the higher (f g. 7, f g. 8). 



In table 8 are given the totals for two other experiments with 

 leaves from different heights. From these data it is evident 

 that leaves from different heights do not behave in exactly the 

 same manner when placed under similar conditions. 



TABLE 8 



The transpiration {in grams per 100 sq. cm.) of leaves from different heights {in 



centimeters.) 1912 



