Igtt] SCHREINER & SULLIVAN—REDUCTION BY ROOTS 129 
tion of selenite upon heating, that the reduction is due to the meta- 
bolic activities of the roots, to some unstable non-enzymotic bodies 
comparable to the oxyorganic acids, which have a slight reducing 
power, or to complex, unsaturated compounds comparable to dex- 
trose and levulose or the unsaturated fatty acids. 
In regard to the significance of the reducing power, it may be 
said that reduction in organisms runs in general concurrently 
with oxidation, and is probably just as important an index of life 
activity. A better medium than sodium selenite is required, 
however, for a detailed study of this reducing power. Such a 
medium would be a chromogen which changed color under the 
reducing action, and thus would present a possibility of estimating 
the change colorimetrically and quantitatively. The fact stands, 
however, that the growing root possesses reducing powers. 
Bureau oF Sorts 
U.S. DEPARTMENT OF AGRICULTURE 
WASHINGTON, D.C. 
LITERATURE CITED 
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. Exriicu, P., Das Sauerstoffbediirfniss des Organismus. Berlin. 1885. 
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Nahrgelatine. C.£ B. 1. a:4s8. 2ahy. 
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Wochenschr. 24:391. 1888. 
Mutter, F., — reduzierende Eigenschaften von Bakterien. C. f. B. 
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n uf w N 
_ 
IQOo. 
CaHEN, F., Ueber das Baseteaseee der Bacterien. Ztsch. Hyg. 
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° 
