WATER IN SOILS 7 



II. The Relative Amount of the Water in the Plant and 

 in the Soils. 



1. The amount of water in healthy plants, and in 



the soil in which they grow. 



2. The amount of water in plants and in the soil 



when they are wilting under measured physi- 

 cal conditions. 



3. The amount of water in plants at or near the 



death point when dying from drought, and the 

 corresponding amount of non-available water 

 in the soil. 



III. The Limit of Physiological Water, (non-available 



water). How affected? 



1. By increased heat and light. 



2. By increased humidity. 



3. By decreased humidity. 



4. By decreased light. 



5. By lowered temperature. 



6. By high temperature. 



7. By different soils. 



8. How varied in different species and individuals? 



IV. Drought Effects. The Manner in Which Mesophytic 



Herbs Die from Drought. 



I. WATER IN DIFFERENT SOILS. 



A. METHODS OF EXPERIMENTATION, ETC. 



1. Soils. The soils used in the investigation were brick 

 clay, quartz sand not quite pure, loam, loess or subsoil, 

 saline soil from the saline lands near Lincoln, and humus 

 consisting largely of leaf mold. The mechanical analyses 

 of these six soils have been appended to this paper in the 

 form received from the assistant agriculturist of the Nebraska 

 Experiment Station, to whom they were sent for analysis. 

 The experiments in attempting to grow plants in the native 

 saline soil proved the futility of such efforts. Only salt- 

 basin plants thrived in it, then only when slightly diluted 

 with loam. The results noted in the summary appended are 

 from a soil consisting of one part saline mixed with three 

 parts of loam. All soils were sifted with a screen possess- 



