[Vor. $ 
258 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
crease in the permeability, induced by the solvent action of 
an anaesthetic on the membrane lipoids, produces stimula- 
tion; an inereased amount of such lipoid solvent makes a 
change in membrane permeability diffieult, with resulting in- 
hibition or narcosis. A still greater amount injures the mem- 
brane, causing irreversible cell changes and consequent death. 
THEORY OF ANAESTHETIC ACTION ON ENZYMES 
A consideration of the possible mode of action of anaes- 
thetie substanees upon enzymes seems desirable, inasmuch as 
such action involves the effect upon the catalytic agents of 
cell metabolism, as distinct from the direct effect upon plasma 
permeability. Palladin (710), in a paper already noted, 
pointed out four possibilities in his study of respiratory 
enzymes. Regarding this group of catalysts these possibilities 
are: 
1. Direct effect on one or all respiratory enzymes. 
a. Stimulation as a catalyser. 
b. Inhibition as an anti-ferment or toxin. 
2. Effect on reactions which precede enzyme formation. 
a. Stimulation by conversion of zymogens to enzymes. 
b. Inhibition by killing of zymogens. 
3. Effect on reactions which furnish material for respira- 
tion (i. e., for cleavage and oxidation). 
a. Stimulation as catalysers for proteolytic and glu- 
cosidie enzymes. 
b. Inhibition as an anti-ferment or toxin. 
4. Effect on the environment of the enzyme, with resulting 
inerease or decrease of enzyme activity. 
Palladin's experiments led him to the general conclusion that 
respiratory stimulation depended on the inereased conversion 
of zymogens to enzymes. Such inerease, however, he consid- 
ered, was accompanied by increased enzyme destruction, by 
which explanation he accounted for the equal amounts of 
enzyme in control and in dead plants. 
Armstrong and Armstrong (710) reported studies on 
hydrolysis of the glucoside prulaurasin in the cherry laurel, 
which were inspired by the earlier reports of Mirande (’09) 
