[Vor. 5 
238 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Müller-Thurgau and Schneider-Orelli (710) recorded both 
carbon dioxide data and sugar content of etherized potatoes 
previously stored at 0° C. They concluded that etherization,— 
at least in comparison with the effect produced by heat,—had 
little effect upon the metabolie processes concerned in the 
conversion of sugar with which carbon dioxide evolution is 
associated. "These results are open to criticism in view of 
the fact that in all cases where the effect of ether was studied 
the tubers were halved, which introduced the important addi- 
tional wound factor with respect to respiration processes. 
Irving (711) has noted the difference in the effect on respira- 
tion of single doses of chloroform versus continuous treat- 
ment, as well as the effect of this anaesthetic on assimilation, 
using barley shoots or leaves of the cherry laurel. With 
respect to respiration she found that the effect depended upon 
the dosage, with a regular progression in the respiration 
curve between the augmentative effect of minute doses and 
the inhibitory action of large ones. The increased respiration 
effected by small amounts of vapor could be maintained if 
such amounts were continuous, and normal respiration was 
restored with its withdrawal. Medium dosage resulted in an 
initial outburst of earbon dioxide followed by a decline much 
below normal, the rate and extent of decline inereasing with 
the dosage. With stronger doses the initial stimulus fell 
rapidly to zero. The early period of application was found 
to be the most effective time, as the same respiration curve 
was found to hold thereafter when chloroform was withdrawn 
or continued. The destruction of chlorophyll in barley leaves, 
with exudation of water from the stomata, and the browning 
of the cherry laurel tissues and decomposition of the cyano- 
genetic glucoside were indices of the lethal action of the 
anaesthetic. Interesting effects on assimilation were also 
noted. Minute doses which had no detectable effect in dark- 
ness arrested assimilation in the leaf in light. Recovery of 
assimilative powers could be noted following a short exposure 
to a low concentration. Quite moderate doses abolished all 
traces of assimilation, while larger ones acted so rapidly that 
