79 
Permeability of the Pulvinus of Mimosa pudica. 
Bose describes in Mimosa a multiple electrical response as the result of 
one strong stimulation ; our results, however, show that under appropriate 
conditions Mimosa may, like Biophytum , exhibit temporarily a series of 
movements which can be closely compared with those of Desmodium gyrans. 
The high degree of sensitiveness brought about by a bright light and 
high temperature is no doubt related to this striking phenomenon. 
Details of an experiment in which autonomous contractions appeared 
are given in Table III. It is to be noted that the increase in the rate of 
exosmosis is visible after each response in spite of the absence of either 
cooling or of mechanical stimulation. 
Table III. 
Effect of Autogenic Contraction on Exosmosis from the Pulvinus 
of Mimosa. 
October 6, 1913. Pulvinus with sides sliced. Temp. 35-0° C. Illumi¬ 
nated by 4 Lilliput * arc lamp focused on pulvinus by lens. Stimulation by 
cooling was followed by three autogenic responses during the first seventy 
minutes. The liquid was then changed and a sequence of eight more 
autogenic responses followed the initial stimulation by cooling. 
Time. 
Gemhos. 
Diff. 
Diff. 
Min. 
i mm. 
3 min. 
0 
Leaf cut 
_ 
- - 
__ 
73 
75 
Pulvinus raised ; the liquid changed 
18-5 
_ 
78 
24-4 
— 
5*9 
79*5 
81 
Autogenic response 
30-1 
_ 
5*7 
84 
34 - 2 
4 -r 
85 
87 
Autogenic response 
39-7 
_ 
5*5 
90 
42-4 
— 
2‘? 
9 1 
93 
Autogenic response 
46-8 
__ 
4*4 
95 r 
96 
Autogenic response 
50-8 
_ 
4-0 
97 
5 i -7 
0.9 
— 
98 
5 2 -3 
c-6 
— 
98-75 
99 
Autogenic response 
53-4 
i-i 
_ 
100 
54-9 
3-5 
— 
IOI 
55-8 
0.9 
— 
102 
56-6 
o-8 
— 
102.75 
103 
Autogenic response 
58.2 
i-6 
_ 
104 
59 - 1 
0-9 
— 
105 
6o-o 
0-9 
— 
106 
6o-8 
o-8 
_ 
106-75 
107 
Autogenic response 
62-3 
1 *5 
108 
63-3 
1-0 
— 
109 
640 
o -7 
— 
no 
64-6 
o-6 
— 
iio-75 
in 
Autogenic response 
65-8 
1-2 
112 
66-8 
1-0 
— 
113 
67-5 
0-7 
— 
