Tue NATURE AND REACTION OF WATER FROM HyYDATHODES 1) 
The exuded water from various plants was a good medium for the 
_ growth of bacteria. This was evidenced by an increase in the number 
of bacteria in inoculated water. 
~The hydrogen ion concentration of water from hydathodes of maize, 
- oats, and timothy is nearly neutral when the water is exuded by young 
_plants. The acidity increases as the plants become older, until a maxi- 
mum is obtained. 
CONCLUSION 
From the data presented it seems logical to conclude that the water 
_ from hy rdathodes of plants contains both inorganic and organic materials, 
and that it is a good medium for the growth of certain soil organisms. 
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Memoir 57, A Study, by the Crop Survey Method, of Factors Influencing the Yield of Potatoes, the eighth 
preceding number in this series of publications, was mailed on September 27, 1922. 
