216 The Botanical Gazette. [June, 
In the true or upper pulvinus, which shall receive the bulk 
of attention in this paper, the upper end may be said to form 
a portion of the upper surface of the lamina of the leaf, while 
the leaf veins, seven in number, of which the central one is 
probably twice the size of either of the others, are given off 
from its margin. An upper view of the mature pulvinus is 
given in plate xx, fig. 3. When a mature pulvinus presents 
a series of transverse markings or wrinkles it may be takenas 
an indication that the leaf is capable of very great movement. 
This is found to be quite true in the case of the plant under 
study. In a series of observations made on a number of 
leaves at different times during the day it was found that the 
angle between the petiole and the lamina varied nearly 100 
degrees. With slight modifications due to variations in tem- 
perature and light the daily movement of the leaf may be said 
to be as follows: The rise, beginning approximately at 3 4 
M. is continued quite rapidly untilg a. M. A slight decline 
then occurs, the lamina again rising to near its forenoon p& — 
sition at about 2 Pp. M. After this time rapid falling takes 
place, the full sleep position being reached at about 10 P, M. 
1. MOVEMENT OF UPPER PULVINUS. | FIRST DAY. 
A 
ANGLE OF LEAF-BLADE WITH PETIOLE IN DEGREES.| tEM- | AVERAGE 
TIME PERA- Move 
OF DAY. a era 
LEAF 1.|LEAF 2.|LEAF 3./LEAF 4.|LEAF 5.\LEAF 6.| °F. ya 
ee 
6 
2:30a.M.| 41 41 21 30 32 18 80 52.1 
5 eee Gee Bed Sale ce 75. | 3B te 0.3 
6 104 113 78 102 100 13: 
7 118 127 88 117 111 113 76 me 
8 112 127 82 118 105 111 76 a6 “e 
9 92 129 78 104 97 107 6 5, . 
10 gr | 125 | -79 | go | 96 | 108 | 3 Qi 
II 85 118 67 75 72 g! : sit a 
I2M 83 112 56 60 67 77 8 4 
I P.M 88 104 60 61 68 $3 *s 
2 95 Iil 63 73 71 9! 5 : 
3 105 125 73 81 84 gt 8 "7. 
4 114 128 80 gI go 94 re 5 10 
5 127 I 92 113 116 | 112 a es 2 
vd 152} 131 og. |-233--| 403: | 55 | ee 
7 101 1{4 85 87 86 és Bs 
8 84 | 91 74 70 71 Ue pie eS 
9 71 77 58 58 57 5 66 
10 60 61 43 60 46 a 
