622 Professor Jagadis Chunder Bose [May 10, 



If a piece of muscle be taken, and simultaneous records of its 

 response be made by tbe mechanical and electrical recorders, it will 

 be found that the one is practically a duplicate of the other. This is 

 well shown in a pair of records taken by Dr. Waller, and here re- 

 produced (Fig. 4). It will be seen that the peculiarities of either 

 curve are re-exhibited in the other. The muscle acted on grew 

 fatigued, and both sets of response-curves show this effect by their 

 gradual diminution of amplitude.* 



I find that the electric response seen in animal 

 Besponse tissues is also strongly exhibited by the tissues of 



in Plants. plants. For experimental illustration we may 



take the leaf-stalk of horse-chestnut. f 



1. Let us take such a stalk, and securely tying two strips 

 moistened cloth to A and B to prevent shifting of contact, con" • jt 



these with two leading non- 

 polarisable electrodes, E and 

 E 1 (see Fig. 5). From what 

 has been said before, it will 

 be seen that these two points 

 being practically iso-electric, 

 little or no current will flow 

 through the galvanometer. 

 If, now, we apply a mechan- 

 ical stimulus to the whole 

 stalk either (1) by tapping 

 or (2) by holding it at its 

 two ends, and giving it a 

 rapid torsional vibration, we 

 shall have similar disturb- 

 ances produced both at A 

 and B, and there will be 

 practically no resultant current of response. 



2. We may now use the block method (Fig. 6). That is to say, 

 the stalk is held securely in tbe middle by a clamp C, so that a dis- 

 turbance made at one end will not reach the other. The electric 

 contact is made with the uninjured, therefore iso-electric, points A and 

 B, by securely tying tbe stalk with strips of moistened cloth at those 

 points, as in the experiment just described. If now the A half be sub- 

 jected to taps, or to torsional vibration, there will be a current of response 

 through the stalk from tbe excited to the unexcited end. If the B end 

 be next excited, a current in the reverse direction will be observed, 

 in this case also from the excited to the unexcited end (a, Fig. 6). 



Fig. 5. — Kesponse in plants. There 

 being no block, effects at A and B are 

 equal and opposite; hence no resultant 

 effect. 



* Waller, ' Animal Electricity,' p. 13. 



t Various parts of plants — leaves, stems, stalks, and roots — will give electric 

 response. In some there is rapid fatigue, whereas in others there is little fatigue. 

 I intend to publish at a future date a more detailed account of these responses 

 and their modifications by anesthetics, poisons, and other agencies. 



