[Vor. 1 
424 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
occurring in the Fucus material. More extensive series of tests 
were arranged to determine the presence of proteinases which 
might act upon some more widely distributed native proteins, 
such as albumin, casein, and legumin. No tests were made to 
determine the transformation of these bodies into proteoses or 
peptones, but the formaldehyde method of determining amino 
acids was employed, and in no case had any transformation of 
these substances proceeded to the amino acid stage. 
Glucose, levulose, and galactose were used in two series of 
experiments designed to determine the presence of zymase in 
the aleohol-acetone Fucus powder. No sufficient evidence, 
however, of the occurrence of this enzyme was obtained even 
when the most delicate tests were employed to determine the 
liberation of СО. The action of Fucus extract from the 
alcohol-acetone preparation upon tannin was tested by means of 
quadruplicate experiments. Two concentrations of tannin 
were used, 1 per cent and 2.5 per cent. The determinations 
were made by means of Jean’s iodine method, but in no case did 
the flasks receiving the Fucus extract exhibit hydrolysis greater 
than that shown by the controls. Neither prepared nor fresh 
Fucus material gave sufficient evidence of oxidase or peroxidase 
action to be considered positive. Negative results were obtained 
both by the direct method with gum guaiacum, and by the in- 
direct method, in which the reagent mentioned is used with 
hydrogen peroxide, and apparently acidity is not a determin- 
ing factor. The use of benzidine seemed to indicate oxidase 
activity, but it has been clearly shown that the ease with 
which this reagent undergoes ‘‘spontaneous”’ oxidation in boiled 
solutions necessitates caution in using it as a test of oxidase 
activity. Tests for catalase by the usual method, evolution of 
oxygen on the addition of hydrogen peroxide, have clearly in- 
dicated that this enzyme is widespread in Fucus. It should be 
noted that the findings with respect to oxidase and catalase 
activity are in agreement with those of Atkins (714). Catalase 
was very generally identified by him in the alge, but evidence 
of oxidase in the Fucacee was obtained only with benzidine as a 
reagent. 
The unexpectedly negative character of the experimental 
work here briefly outlined prompted us to make many repeti- 
E NE^ 
