the Respiratory Exchanges of Leaves . 
701 
The 0 2 intake and the C 0 2 output show a similar increase, the curves 
for both corresponding with type B of Miss Irving’s schema } in which, after 
the initial stimulation, the respiration diminishes as starvation proceeds. 
Seventy hours after removal from the chloroforming vessel the respiration 
had still further diminished, the 0 2 intake being 0-16 c.c., and the C 0 2 output 
0-14 c.c. per hour per leaf. The leaves were then still green. 
Experiment II. July 11,1911. Dose, 0.3 c.c. per litre for 15 minutes. 
Temperature, 19-2 2° C. Six leaves of the current season, weighing 
9-6 grammes, starved for four days in the dark. 
Owing to starvation the leaves used in this experiment were respiring 
at a very low rate. In Fig. 3 are plotted the results obtained during the 
first thirty-four hours, after treatment with chloroform exactly as in 
Experiment I. 
0-4 
0 - 3 . 
02 . 
0 I 
1 
— — 
4 - 
-4 
<^2 
C0 2 
8 12 /6 20 
HOURS AFTER CHLOROFORM 
Fig. 3. 
24 
28 
32 
The respiration was in this case greatly augmented, and remained at 
the high level for a considerable time. The leaves were kept under 
observation for fifteen days, and their rate of respiration determined at 
intervals. Comparison with results obtained with other lots of leaves of 
similar age which had been in the dark for the same time but had not been 
chloroformed, shows that the respiration of the chloroformed leaves had 
fallen to the normal level on the sixth, but not on the third day. The 
parallel results in c.c. per gramme of fresh weight , and reduced to 22° C., 
are given in the following table : 
Chloroformed leaves 
c.c. per hr. per grm.fr esh weight. 
Leaves 710 1 chloroformed 
c.c . per hr. per grm. fresh weight. 
Day. 
co 2 
0 2 
co 2 
3 
j 0.083 
0.105 ) 
0.068 
0.082 
( 0.086 
0*109 i 
5 
0.049 
0.075 
6 
0.059 
0.080 
7 
0*066 
0-082 
In these two experiments the stimulatory effect of chloroform is plainly 
visible, and the augmentation affects the absorption of oxygen and pro- 
duction of C 0 2 nearly equally. The recovery which follows is apparently 
1 Loc. cit., p. 1083. 
