148 REPORT OP OFFICE OF EXPERIMENT STATIONS. 



effect of huiniis at different depths and on different types of soil were 

 also investigated. 



Work on the soils of the transition region included studies on the 

 hygroscopic coefficient and a means of determining it readily. The 

 minimum water capacity of soils was determined, and vegetation ex- 

 periments in 6-foot cylinders were carried on with wheat, beans, milo 

 maize, and desert plants under different moisture conditions to deter- 

 mine the moisture content of surface soil at which plants will die. 

 Advantage was taken of the prevalence of dry w^eather to carry this 

 work well tow^ard completion. In connection with the hygroscopic 

 studies, observations were made on the upward and downward move- 

 ment of soil moisture. 



Good progress was made in the studies on transpiration, or the 

 relation between leaf area in the com plant and the water used in 

 groAvth. The methods for carrying on the work have been in- 

 geniously worked out, and the study as carried on included tran- 

 spiration under different conditions of soil fertility and adaptation of 

 varieties or strains in its relation to transpiration. In addition to 

 this work, seepage and run-off were determined in lysimeter experi- 

 ments, and corn, sweet sorghum, and milo maize were included in the 

 investigation. A study of the relation of water loss through tran- 

 spiration to weather factors — wind, humidity, and temperature — indi- 

 cated that transpiration follows evaporation from free water surfaces 

 quite closely. The relation of the humidity of the air to the quantity 

 of water required to produce 1 pound of gain was studied in experi- 

 ments conducted in the greenhouse with the factor of humidity under 

 control. 



Work on close breeding in maize included five different lines of 

 investigation for the purpose of studying different phases of the 

 subject. These experiments on inbreeding brought out the elemental 

 strains of the variety, resolving it into its original elements, and 

 showed that the vigor of the plant is impaired in a varying degree. 

 Field tests conducted with the inbred progeny showed that the first 

 inbreeding reduced the yield about one-half. 



The results of studies on the competition of cereals showed that 

 under a thick rate of planting a certain percentage of the plants were 

 crowded out and failed to produce seed. A larger jiercentage of plants 

 originating from shrunken seed than of those coming from plump 

 seed were crowded out, thus indicating the possible importance of 

 natural selection in maintaining the vigor and yield of cultivated 

 cereals. With corn. a higher yield was obtained with seed grown 

 under thick planting than with seed from a thinly planted crop. 



In his hog-cholera studies the veterinarian used horse-blood serum 

 for hyperimmunization on over 1,400 pigs with a loss of 7^ per cent. 



