1904] DARWIN: MOVEMENTS OF STOMATA 95 
The temperature difference recorded is about 36™™ or 1.5°C. 
It must be noted that at 11:46 A.M. or 12:38 P.M. when the 
plant was placed in dry air the effect of such change, if the 
stomata were immovable openings, would be to cool the attached 
a |_| | 
| Lt 
TJ 
| 
| | 
| 
a2a 
|_| 
|_| 
bli 
| 
| 
| 
aha | 
N 
R.CooL. 
<— 
Lit | 
a | 
| 
Bee [ 
al La ue 
Be es 
a I 
| 
iH 
bid os te] 
” a a oo 
oe ~ a 
f ee 
et 
Fic. 8.— See Experiment 206, p. 96. 
leaf R still more. The stomata, therefore, must have closed at 
once. 
It may be suspected that, the damp house being some : 
Cooler than the dry one, the rises of temperature at 12 18 and 
12:38 were due to leaf R assuming the temperature of the air in 
the dry house more quickly than B. But if this were the case, 
the temperature curve between 1:18 P. Mand 2:4 P. M. when both 
