[Vor. 1 
4221 ANNALS ОҒ THE MISSOURI BOTANICAL GARDEN 
water and 1 gram of taka diastase were added, this being per- 
mitted to stand for 5 hours, as in extraction, and the filtrate 
from this extraction was tested upon starch solution. Тһе 
results were positive, indicating that no free substances were 
present which could inhibit diastase action. In another test 
1000 grams of Fucus material were divided into two lots of 500 
grams each. To one of these, 5 grams of commercial malt 
diastase were added, and both were then treated by the alcohol- 
acetone method, and subsequently extracted and precipitated 
in the usual way. The material to which diastase had been 
added gave positive tests for the hydrolysis of carbohydrates 
in an extensive series with dextrin, glycogen, saccharose, and 
laminarin; but a solution of the precipitate from the lot receiving 
no diastase produced no changes in these substrates. These 
experiments included controls of several kinds. With every 
substrate, boiled material was also used, and it is interesting 
to note that the “enzyme” material increased in reducing power 
with boiling. 
The tests referred to in the previous paragraph seemed all the 
more important inasmuch as the Fucus material had been found 
to be strongly acid, and it seemed possible that this acidity 
alone might prove an injurious factor. From the experiments 
just mentioned it is seen, however, that acidity could scarcely 
have been an important consideration. A quantitative deter- 
mination of the acidity was nevertheless made, by titration with 
NaOH, and it was found to be about .0565 N HCl. There із а 
slight increase in the acidity, if the pulp is permitted to remain 
in water 12 hours. 
Owing to the determination by many, as, for example, Miither 
and Tollens (704), Kylin (13), Swartz (711), and others of the 
presence of hemicelluloses, especially pentosans, in the marine 
alge, and, further, since the commoner carbohydrate enzymes 
had not been identified by us, it seemed desirable to examine the 
material for pentosanase. The most available pentosan was 
that of cherry gum, accordingly this material in fresh condition 
was obtained and utilized in many tests with the Fucus prepara- 
tion, the flasks being maintained at temperatures ranging from 
27—40° C. Although the experiments were permitted to run for 
a period of several days, no reduction above the amount found 
