PLATE LV 
Fig. i.—A pot of alfalfa showing the growth and size of plants used in the transpira¬ 
tion experiments. The ppt is 26 inches high and 16 inches in diameter. 
Fig. 2.—A pot of Amaranthus retroflexus of the type used in the transpiration 
measurements. 
Fig. 3.—Evaporation tank mounted on automatic balance. The reservoir is shown 
above in the back. The tank has an area of 6,540 sq. cm. and the water is maintained 
at a depth of 1 cm. The balance recorder is shown at the right and the anemometer 
at the left in the background. 
