[Vor. 5 
234 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
experimental method by forcing solutions of ether under 
pressure into the cut ends of twigs. The lower concentrations 
used aeted as stimulants, causing bud development if treat- 
ment occurred during the normal rest period of the plant; 
otherwise action was injurious. 
EFFECT ON TRANSPIRATION 
In the field of transpiration studies Jumelle (790, ’90*) 
found that the effect of ether in darkness was to decrease the 
action, while the same dosage had an accelerating influence 
in the light. He concluded that the anaesthetic acted on the 
chlorophyll and increased transpiration by converting all the 
energy in that direction, while assimilation was inhibited. 
His findings appear to be confirmed by Lommen in a brief 
note by MacMillan (’91), the former having measured the 
loss in weight of Selaginella following etherization. Schneider 
(93) explained the increased water loss observed in his ex- 
periments as evaporation from tissues killed by the anaes- 
thetic. Woods (’93), however, points out the error in these 
deductions, and on the basis of his investigations on Canna 
indica and Mnium sp. confirmed Jumelle’s findings and ex- 
plained the increased water loss in light as compared with 
plants in darkness purely on the physical basis of increased 
evaporation in daylight from the living tissues. 
Darwin (’98) in an extensive study of stomatal response 
found that both chloroform and ether vapors caused a partial 
closing of stomata without subsequent injury. А careful 
study of anaesthetic effects with reference to water loss as 
related to plant activity was made by Dixon (’98), who gave 
special attention to the physical factors involved. Dixon 
found that ether and chloroform produced inhibition in both 
rate and amount of transpiration of cuttings, in contrast to 
an acceleration effected by oxygen. When, however, the 
specific transpiration in various atmospheres, based on air as 
standard, was compared with the specific evaporation of 
water in atmospheric currents of the same substances it ap- 
peared that, with the exception of oxygen, there were no 
marked differences within limits not lethal to the plants. The 
