34 STUDIES IN THE VEGETATION OP THE STAT 



temperatures of the plant house during the last few days of 

 experimentation. Yet in summing up the results it can 

 hardly be claimed that the light in the plant house at any 

 time was too intense for the best development uf the plants. 

 The maximum amount of light was slightly over 40 per 

 cent of the standard of June 22. The temperature 

 however was high, the average maximum for the last twelve 

 days was 100° for the air, and 101° for the soil. Plants dy- 

 ing under these conditions had a higher limit of physiologi- 

 cal water and of plant water than plants dying under cooler 

 conditions with less light. The following table gives the 

 results from Comparative Plot III. from plants grown in the 

 plant house during May, 1901, in loam, loess and sand. 



Comparative Plot III. {Increased heat and light). 



Physical factors during the drought period. 



Average maximum heat 100 ° 



Average minimum humidity 51% 



Average maximum soil temperature 101 ° 



Average maximum light 38% 



Phaseolus vulgaris. 



Loam , 

 Loess. , 

 Sand. . 



NON-AVAILABLE 

 WATER. 



8.7 

 0.26 



WATEK rS 

 DYING PLANT. 



53 



53.8 

 38.8 



