96 BOTANICAL GAZETTE [FEBRUARY 
leaves were left on the recorder bulbs would have fallen to what 
it was at 12:38, as the leaves became equal in temperature. 
Inequality in assuming a given temperature is a genuine source 
of error, as appears at p. 85, but in the present case it cannot 
be admitted. 
EXPERIMENT 26, fig. 8. March 21, 1899. CAMPANULA. 
A. M. ' 
10:34-11:21 T. at 10:34 13.7°, Psy. 88%. Zero line drawn; nothing on 
b 
either bulb. 
11:21 T. 15.0°, Psy. 75%. Attached leaf on bulb R. Withered leaf 
P.M. on bulb B. 
12:16 T. 21.2°, Psy. 47%. Plant removed to dry greenhouse. The 
first effect of the dry air is a considerable fall in temperature 
(R-cool). 
12:42-2:25 TT. 24.5-21°, Psy. 43-48%. An irregular rise indicating 4 
partial closure of stomata. 
a2°9 (T. at 2.40 21°, Psy. at 2.40 58%.) A further closure of 
stomata, owing probably to the darkening effect of a snow- 
storm. 
11a 
ae 
a ane we 
tH Ht 1 J tt oy 
B | Hae pe a tes oe aa | 
ee at SS a oe oe is ptt tt oe. a Ee a 
(Sk oh Ks Heat oe 
+} aa se 
mai 2ugne = 
= /—2' St Geen ae oo — =—_e.. Va. 
SE Ae ee SN S2eane 
| ae Se he om ee 
Bate Be ee ee 
cae aaa BEASSag «h 
PCH HH 
SRE WE a Cee 
ag IS OR Se 
|_| 
co oa Pt 
Ret Be ee 
a —o saa 
al Se 2 ah See ee a 
= BR Be we = 
I Coo 
" EH 
— ++ a 
=i ae 
“o 
= 
a 
B-41 
FIG. 9.— See Experiment 15, p. 
