1918] 
BONNS—ETHERIZATION AND ENZYME ACTIVITY 237 
respect to intramolecular respiration. A minimum, optimum, 
and maximum stimulation were evident which were corre- 
lated with changes in the intensity of intramolecular respira- 
tion. It was found that under the stimulus plants could de- 
velop an anaérobic respiration equal to, or greater than, the 
normal respiration value. The ratio of anaérobie to normal 
respiration, however, was not found in general to change 
under the effect of stimuli. 
Treboux (703) concluded that ether and chloroform in 
weak concentrations increased both growth and respiration 
of Elodea, but did not have a similar effect on assimilation; 
a suitable dose of chloroform caused assimilation to be tem- 
porarily inhibited. Kegel (705) found reduction or complete 
inhibition of carbon dioxide evolution in Elodea canadensis 
with chloroform of varying concentrations. Solutions of 
4-.7 per cent accelerated assimilation, even where the iodine 
test showed little or no stareh present. Ether gave similar 
results. The presence of varying amounts of starch in the 
leaves appeared to have no effect on the response, but varia- 
tions in different seasons were noted. Schroeder ('07), in 
determining whether the retardation of respiration by hydro- 
cyanie acid was a primary or secondary effect, used ether for 
purposes of comparison, and found that with the latter the 
reduction of respiration was gradual with small doses. With 
long exposure there was no recovery, as was the case with the 
acid. The conclusion was reached that the respiratory re- 
sponse to ether was of a secondary nature and resulted from 
injury as the primary cause. 
Palladin (710), in а study of the effect of toxins on the 
respiration of living and dead plant tissues, determined the 
carbon dioxide evolved by corms of Gladiolus Lemoine, G. 
Calvilli, bulbs of Allium Cepa, and seedlings of wheat and 
Vicia Faba. Various chemical agents were employed, among 
them ether. In general the results showed carbon dioxide 
stimulation by toxins, the effect of which disappeared when 
the plants were subjected to lethal conditions. The other 
phase of Palladin's work will be considered later. 
