[VoL. 2 
830 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
of the algae is also probably slower than that of the higher 
plants and one might expect, a priori, the enzymes also to be 
less rapid in their action. Although the algal enzymes may 
be inherently slow, it seems that there may also be substances 
set free on the death of the cell which either partially or en- 
tirely inhibit enzyme action. The writer has found evidence 
in some preliminary experiments, that the action of taka 
diastase upon starch is directly proportional to the amount 
of free tannin present. In connection with this, it was also 
found that Ascophyllum had a ‘‘tannoidal’’ content of 1.1 
per cent of the dry weight. It is possible that such tannoids, 
if in an uncombined state, may after the death of the cell unite 
with an enzyme to throw it out of the sphere of action. That 
diastases are demonstrable in tissues having a high tannin 
content may perhaps be explained on the basis that they are 
bound up in such a way as to render them incapable of uniting 
with the ferments. Still other organic inhibiting compounds 
may be present, and the point opens up a very interesting 
problem concerning inhibition, not only in algal tissues, but 
in those of many higher plants as well. 
SuMMARY 
1. Using standard methods of enzyme isolation and de- 
termination, the following enzymes have been found in fresh 
or dried algal tissue: 
a. Carbohydrases hydrolysing the polysaccharides, 
starch, dextrin, glycogen, and laminarin, but not those 
hydrolysing the several disaccharides employed as 
substrates. 
b. Lipases acting upon neutral fats but not upon the 
esters of the lower fatty acids. 
ce. Proteinases (tryptic and ereptic) acting best under 
neutral and alkaline conditions. 
d. Nucleases. 
e. Oxidases and peroxidases (in but two forms—Agard- 
hiella and Ulwa). 
f. Catalases. 
