308 ; The Botanical Gazette. 
tigations in the article mentioned in the first page of this pa- 
per it will be seen that this relation, even under the mot 
favorable conditions is far too general and fluctuating to be 
of any value whatever as an exact measure of evaporation! 
This difficulty alone is sufficient to make Mr. Schneider's e 
sults practically valueless as far as transpiration is concerned. 
Further, M. Jumelle took special pains to ascertain the 
amount of anesthetic that was required to stop assimilation 
without killing the plant, and always tested the plant alter 
the experiment in order to be certain that it had not been killed 
Mr. Schneider took no such precaution in his experiments 
but says that he took ‘‘no special notice of the amount of a 
zsthetic used;” and further says that after a time the plant 
exposed were killed. He is thus dealing with plants under 
entirely different conditions from those maintained by Mt J® 
melle; hence, even had Mr. Schneider's measure of transpit 
ation been reliable, his results could have no direct bearing. 
on M. Jumelle’s results or conclusions. Me 
In part Iv, ‘Experiments on transpiration of leaflets, 
Schneider estimates the transpiration by hee? 
and noting the loss. The slight objection to ae 
fore Séationed and will let it pass. The second objection : 
that the leaflets were not supplied with water and the amo A 
of Jumelle’s experiments. The fact that the leav 
supplied with water is alone sufficient to ma 
least extremely doubtful. It is unnecessary to inly quite 
Schneider’s article further at this time. It 1s oT ae 
evident that his results do not affect M. Jumelle’s per do 
“transpiration” as left by M. Jumelle. First, the tag bas 
absence of the usual amount of carbon dioxid - plants ¢i : 
no effect on the transpiration of chlorophyll-less Pvt oh 
in light or dark. Here certainly ‘‘transpiratiol. | 4 slag 
tion to assimilation. We know further - oe in the date 
lose water much more rapidly in strong light th ( 
Darkness, Diffused light ago = 
106 15% a 
97 a ae 
s subject pate ae 
Plant, 
?°Zea Mais (etiolated). . . 
Zea Mais (green)... . . 
Snes also Dr. Alfred rik geen leat = thi 
article referred to on first page of this papet. 
279 of Goodale’s Phys. Bot.—Also Vines’ Phys. Bote oy i 
10Experiments by Wiesner, page 110, Vines’ Phys. 
