96 BOTANICAL GAZETTE [FEBRUARY 
inevitable dissociation when hydroxylation has progressed to a certain 
point. It seems, however, that there is generally—perhaps always— 
a hastening of this process, and that the highly unstable protoplasm 
is dissociated so rapidly that it liberates not only the energy imme- 
diately utilized in growth, movement, etc., but also an excess suffi- 
cient to be easily measured by so coarse an instrument as the ther- 
mometer. Catalytic agents like the enzymes are certainly (I think 
I may be permitted so strong an assertion) the usual accelerators. 
And it is highly probable that an enzyme identical with zymase oF 
at least analogous to it, is an active though secondary agent in this 
acceleration. It may very well be also that those changes outside 
the protoplast (whether without the organism or not) that are called 
stimuli accelerate still further the katabolism, even to an explosive | 
speed in some cases. 
This primary dissociation may plainly be independent of free 
oxygen, though it is hardly conceivable that there will not be some 
oxygen present unless the plant has grown under most unusual con- 
ditions, which one can scarcely realize experimentally. The products 
of this decomposition are not sufficiently known, nor is their precis€ 
character important for our discussion. Among them are certainly 
the more complex amido-acids, carbon dioxid, and alcohol. 
Third: Up to this point the respiratory processes are quite alike 
whether the plants grow in the air or apart from it. If sufficient 
oxygen be not present, the disruptive processes may reach an equilib- 
rium, just as an electrolyte practically ceases to pass a current of 
electricity unless a depolarizer be present. So in the hydroxylation 
of proteids, there is needed some substance to disturb constantly, 
in one direction or another, the equilibrium that tends to be reached. 
‘The common agent in this is oxygen. Of course, oxygen can ha 
_be the ne ‘depolarizer that can promote further action. Thus, 
ts characteristic “procs are carte 
