STOMATAL MOVEMENT. 41 
TaBLe 16.—Relative transpiration and stomatal openings. Experiment XIV. 
Date, March 29, 1911. 
Time. | I w | Viw z | 
shade 8.8 1.4 3.5 
oe 0a sii, co 8.8 116 3.7 |f 0-181 
11 05 a.m.......cc. 4.4 6 1.6 079 
V2: LO: petite sats 2 ages 6.0 8 2.2 124 
3 00 p.m............ 8.8 1.5 BEG oho pekars 
EXPERIMENT XV. 
Leaves and tangential surface sections of young twigs from tree A were 
taken simultaneously with leaves from plant No. 1, subjected to the picric 
acid treatment, and stomatal measurements were made. As a control, 
stomatal measurements were also made on No. 1 by Lloyd’s method, 
through the 1 o’clock reading. The potted plant was placed in the open, 
about 50 feet distant from the tree. It will be seen that the agreement of 
the alcohol method with the picric acid method here is not as good as in the 
test experiments; however, the lack of agreement is one of actual size only, 
for the two curves have practically the same shape. The guard cells of the 
stomata of the tree were always smaller than those of the potted plant. The 
stomata of the twigs very evidently are not movable to any extent. A few 
days after this experiment measurements of the stomata of twigs were tried 
and no evidence of any motion of the stomata was gained fromsome 20trials. 
Tasie 17.—Stomatal measurements from leaves and twigs of an adult tree and from leaves 
of a potted plant. Experiment XV. Date, August 11, 1911. 
No. 1 leaves. AA 
A leaves, picric acid. | .1 twigs, picric acid. 
Time. Picric acid. : Absolute aleohol. 
1 w Viw l w Viw L w Viw 1 w Viw 
4b 30™ a.m. 4.2] 0.6 1.4 4,2 0.6 1.6 5.6 1.0 Ps. Se eeeaneirees ebregeeieee 
6 00 am.j 11.6} 4.6 7.2 8.8 sushi 6.0 6.4 1.3 Pa a [eee 0 0 
9 00 am 10.8} 3.8 6.4 8.8 2.5 4.7 6.4 3.4 4.7 |14.8(2)) 1.4(2) 0 
11 00 a.m. 8.8) 2.4 4.5 8.8 1.5 3.6 7.6 1.1 2.9 (?) (2) (?) 
100 pm. | 12.0} 2.1 5.0 7.6 1.6 3.4 7.6 9 2.7 2) (G (?) 
2 00 pm. | 10.8] 3.5 6.1 mt a ee 6.4 1,5 3.1 |14.8(4)) 1.4(4) 3 
4 00 p.m. | 10.8] 4.4 6.9 7.2 2.5 4.2 2) (2) (2) 
10 00 p.m. 6.4] 1.0 2.7 6.4 6 1.9 |312.0 3.8 
1All the rest shut. 2All shut. 3A verage of 6; all the rest: shut. 
‘s_ No, 1 Pierie 
. 
oe 
. 
~s._ A Pierie  *s 
Pam x 
1 1 rn 
5 a 9 11 1 2 4 10 
n n 
Fic. 21.—Stomatal measurements from leaves of potted plant and from adult tree by 
the picric-acid method, with absolute-aleohol method check on potted plant. Exp. XV. 
