Mitlimetres. 
ELECTRIC PULSATION IN DESMODIUM GYRANS. 419 
response, with its recovery, was executed in this time. After a 
pause, the movement upwards now commenced, and the sub- 
sidiary electric response is seen to commence at the same 
moment as the upward movement. The upward movement of 
the leaflet ceased in a little more than two minutes, and the 
period of the secondary wave occupied the same time. (The 
secondary wave is therefore broader than the primary wave.) 
Thus we have the period of the principal wave coinciding with that 
of the downward mechanical movement of the leaflet, and tho 
secondary wave with that of the upward movement, 
Fig. 11. 
8 ——— 
“A 
NN 
NN 
NX 
s 
X 
6 a 
N 
N 
N 
\ 
N 
‘ 
\ 
4 X 
y \ 
\ 
N 
N 
N 
\ 
N 
2 N 
N 
XN 
. 
N 
\ 
N 
N 
NN 
LON 
O 5 / 1S 2 ad 3 J 
Minutes 
Mechanical response curve. Here the rising portion of the curve, shown in 
continuous line, is traced by the leaflet during its descent, and the falling 
portion during its ascent. 
We have still to account for the greater intensity of the 
principal electric response, which was shown to accompany 
the downward movement of the leaflet. I have already explained 
that it is the rate of mechanical movement which determines this 
intensity. In the present case, the greater amplitude of the 
principal wave would be accounted for if it can be shown that 
the downward motion of the leaflet is quicker than its motion 
upward. In the simultaneous record (fig. 10) a careful 
LINN. JOURN.—BOTANY, VOL XXXV. 2K 
D 
