Permeability of the Pulvinus of Mimosa pndica. 
81 
Table IV. 
Effect of Light and Darkness on the Rate of Exosmosis from the 
Pulvinus of Mimosa. 
March 24, 1913. Pulvinus slit down axis in the anterior-posterior 
plane, washed well with water and placed in darkness. Experiment started 
12.7 p.m. Temp. 26-1° C. 
Time . 
Gemhos corr . 
Diff . 
Time . 
Gemhos corr . 
Diff . 
15 mm . 
p . m . 
to 26-4° C . 
15 mm . 
p . m . 
to 26-4° C . 
Darkness 
Daylight and Nernst lamp 
h . m . 
h . m . 
12 10 
24-8 
— 
3 40 
i 5 6 * 8 
2-8 
12 25 
44-2 
T 9‘4 
3 55 
161-3 
4*5 
12 40 
54-9 
10-7 
4 10 
165-2 
3*9 
12 55 
63*5 
8-6 
4 25 
167-9 
2-7 
r 10 
7°*3 
6-8 
4 40 
170-0 
2-1 
Daylight and Nernst lamp 
Darkness 
173-6 
1 25 
8i-6 
n -3 
4 55 
3-6 
1 40 
96*0 
14-4 
5 10 
176-2 
2-6 
1 55 
i° 8*3 
12-3 
5 25 
178-3 
2-1 
2 10 
119-3 
11.0 
5 4 ° 
179-7 
T *4 
Darkness 
5 55 
181-2 
2 25 
131-2 
ii-9 
2 40 
140-0 
8; 8 
2 55 
147-2 
7-2 
3 10 
152-2 
5*0 
3 25 
154-0 
i-8 
This and other experiments brought out very clearly: (x) That light 
has a marked effect in increasing permeability to electrolytes ; (2) that the 
effect takes some time to reach a maximum, and then, after a varying period 
of time, begins to fall off; (3) that the sudden change from light to darkness 
also increases the permeability. 
G 
