6io Vines. — Proteolytic Enzymes in Plants (IP). 
juice, strong in the NaF bottle with diluted juice, marked in both the 
HCN bottles. 
From these experiments it is clear that the influence of 
such antiseptics as NaF and HCN on proteolysis depends, 
not upon the amount of the protease present, but upon 
the nature of the protease, probably upon its chemical 
constitution. 
The general conclusion to be drawn from all these experi- 
ments with various antiseptics is that these substances exert 
a considerable influence, greater than is usually supposed, 
upon proteolytic processes. It is, I think, made clear that 
in investigating the action of any protease, it is necessary 
that experiments should be conducted with more than one 
antiseptic before any conclusion as to the properties of the 
enzyme is arrived at. I am also justified in reasserting that 
all vegetable proteases, so far as they have been investigated, 
are essentially proteolytic ; and that no merely peptonizing 
protease has yet been discovered. 
I may incidentally mention here an experiment upon the 
action of Pine-apple juice at the ordinary temperature of the 
laboratory instead of in the incubator : that is, at about 17 0 C. 
instead of 40° C. The results show that proteolysis is 
effected under these conditions, but more slowly than at the 
higher temperature. 
50 cc. of Pine-apple juice were placed in each of two bottles, with 
1 grm. moist fibrin; to the one 0*5 grm. of NaF (= 1 %) was added, 
to the other 2-5 cc. of 4 % HCN (= 0-2 %). 
After 1 9 hours' digestion the fibrin was quite disintegrated in both : 
the NaF bottle gave distinct tryptophane-reaction, the HCN bottle 
gave no reaction. 
29 hours later, the NaF bottle gave strong tryptophane-reaction, 
the HCN bottle a distinct reaction. 
Dahlia variabilis. 
The tuberous roots of the Dahlia have long been the 
subject of investigation on account of their peculiar chemical 
contents. They have largely provided the material for the 
