Aug. 15, 1914 
Oxidases in Potatoes 
393 
In order to ascertain whether the oxidase content of the leaves of 
these abnormal plants showed with age similar fluctuations to those 
found in healthy plants, curves representing the measurements of these 
oxidases were plotted with the curves representing the oxidase measure- 
Fig. 14.—Curve showing oxidation of a-naphthol in the presence of the juice of potato tubers. 
Fig. 15.—Curve showing oxidation of tyrosin in the presence of the juice of potato tubers. 
ments of the healthy plants. Some of these are shown by the broken 
lines in figures 6 to 12. Plotting both curves on the same system of 
coordinates has the additional advantage of making possible a quick 
observation of the comparative magnitudes of oxidase activity in the 
healthy and diseased juices. 
