173 



TABLE 2. 

 Number of plants observed after 70 minutes 1 1 1 and 



after 60 minutes 114. 



A considération of table 2 suggests that for both obser- 

 vation times the percentage of curvatures of 2 m.m. is 

 rather high, that after 60 minutes the magnitude of the 

 curvatures is still increasing but that after 70 minutes it 

 is already falling off again. If this be so, the extent of 

 curvature after 65 minutes should exceed those after 60 

 and 70 minutes. For this reason déterminations were made 

 after 65 minutes. The results are summarized from table 1, 



as foUows: 



TABLE 3. 

 The total number of plants was 112. 



