the Respiratory Exchanges of Leaves . 
717 - 
SUMMARY. 
In conclusion, the following facts appear to be established : 
1 . In all the leaves examined, treatment with a small dose of chloroform 
results in stimulation of the respiration, the absorption of oxygen and 
production of C0 2 increasing in like proportion, and therefore probably 
remaining co-ordinated. 
In starved leaves the effect of stimulation was usually prolonged. 
2 . When the concentration of chloroform vapour was large enough to 
initiate visible disorganization, the production of C0 2 after treatment was 
always diminished, the outburst of C0 2 demonstrated by Miss Irving having 
already occurred, and it quickly fell to a very low level. At the same time 
the absorption of oxygen was no longer closely correlated with the pro- 
duction of C0 2 . 
In leaves of Tropaeolum , which contain no tannin, the absorption of 
oxygen was depressed still more than the production of C0 2 . 
On the contrary, in leaves of Cherry (and Portugal) Laurel, and 
Helianthus , which contain tannins, the oxidation of which imparts a brown 
or black colour to the disorganized leaves, the absorption of oxygen was 
very rapid for a short time, and, though quickly falling, remained at a much 
-higher level than the production of C0 2 . 
