Aug. 15, 1914 
Oxidases in Potatoes 
385 
With all of the reagents except guaiaeol and metacresol, the rise in the 
oxidase content observed during the second half of the period of examina¬ 
tion coincides approximately with the stoppage of growth, which point 
is shown in figure 1 to be about the sixty-seventh day. In this respect, 
therefore, these results are in striking harmony with those obtained while 
working on diseased sugar beets. In the case of sugar beets the writer 
has shown that the factors which had a retarding influence on the growth 
of the plants also caused the oxidase content of the juice of their foliage 
Fig. 10.—Curve showing oxidation of m-cresol in the presence of the juice of potato foliage. 
to increase. It is possible that the same factors which led to an increased 
oxidase content during the retardation of growth of sugar beets will lead 
to a similar rise during normal cessation of growth in potato plants. 
OXIDASE) ACTIVITY OF THE) JUICE OF THE SPROUTS AND OF THE TUBERS 
FROM WHICH THE SPROUTS HAD BEEN REMOVED 
The relatively high oxidase content of very young potato plants sug¬ 
gested an examination of the sprouts from the tubers. Seed tubers of 
the Green Mountain variety of the same stock as was used for all of the 
