AOA 100. 
408 PROF. J. C. BOSE ON THE 
or summer. But I had no difficulty in obtaining very well- 
marked effects, even at this season of the year. I have, 
however, postponed some further and more delicate experiments 
for a more favourable season. 
The movement of the leaflet, in some instances, takes place 
by jerks; in others it is more uniform. The period for a 
complete up-and-down movement was on an average about 
3°5 minutes. From the normal or highest position the leaflet 
sinks somewhat rapidly ; having reached its maximum depressed 
position, it rests for a while; there is then produced a rather 
1 2 3 4 5 6 7 g8 9 0 WwW 2 min. 
Electric response in Desmodium gyrans. The electric response corresponding 
to one complete mechanical vibration consists of a principal wave (a) 
shown in continuous line, and a subsidiary wave (2) shown in dotted line. 
slow rise to its original position. The up-and-down motion 
18 In Some cases approximately straight, the curve described 
being a very elongated ellipse. In other cases the petiolule 
of the leaflet is slightly twisted after its descent, and the 
corresponding curve described becomes more circular. 
The numerous varieties of these mechanical responses give 
rise to corresponding modifications of the curves of electric 
Tesponse. It will, however, be best to take the records of some 
typically simple cases, on consideration of which it will be easy 
to understand what happens under more complex conditions. 
