pee] 
ELECTRIC PULSATION IN DESMODIUM GYRANS. 407 
made at two points; one of which undergoes periodic excitation, 
the other remaining quiescent. From the results of my previous 
experiments, I was led to expect that there would be periodic 
electric pulsations accompanying the periodic mechanical move- 
ments of the leaflets. From the experiments now to be 
described it will be seen that my anticipations have been fully 
justified. 
Arrangement for exhibiting electric response in Desmodium gyrans. Electric 
connections are made with the galvanometer by means of non-polarisable 
electrodes, one point of contact being made with the excitable tissue at A 
and the other with the resting-point B. G is the galvanometer and R 
the response-recorder. ‘The current of response in the plant is from the 
excitable A to the resting B. 
The habitat of these plants is the Gangetic plain, and I was 
able to secure several specimens from their natural surroundings. 
The plants could not be at their best condition at this time 
of year—the beginning of winter (November); besides, they 
have already commenced flowering. The vital activity, on which 
depends the intensity of the electric response which I sought 
to detect, is not therefore so great now as it would be in spring 
