July 2,1917 Variation of Water in Leaves of Corn and Sorghums 15 



determined every two hours for 22 days and 10 nights. The amount of 

 water in the leaves at any period of the night could be accurately deter- 

 mined, owing to the fact that dew is very rare during the summer in this 

 portion of the Great Plains. Com, kafir, and milo were used in all the 

 experiments, with but two exceptions in 191 6. In these two experiments 

 only com and milo were used. The results for the three years are shown 

 in Tables III and IV. The amount of water in the leaves is expressed 

 in grams per square meter of leaf; percentage on a wet basis and dry 

 basis for each 2-hour period of the experiment. The amount of dry 

 matter is expressed in grams per square meter of leaf and in percentage 

 of the moist weight of the leaf. The data shown in Tables III (July 28, 

 1914-Aug. II, 1916) and IV are expressed graphically in figures i to 10. 

 In discussing these data the day periods include the determinations made 

 from 7 a. m. to 7 p. m., inclusive, and the night periods include the observa- 

 tions made from 7 p. m. to 7 a. m., inclusive. 



