276 PROF. J. C. BOSE ON ELECTRIC RESPONSE IN 
In connection with this, Kunkel made the very interesting 
observation that an electrical disturbance was produced in stems 
by injury or by flexion, the point in the neighbourhood of injury 
becoming negative. 
My own attempt has been directed not towards the obtaining 
of mere qualitative response, but rather to the determination 
if throughout the whole range of response phenomena a 
parallelism between animal and vegetable could not be detected. 
That is to say, I desired to know, with regard to plants, what 
was the relation between the intensity of stimulus and the 
corresponding response, what were the effects of superposition 
of stimuli; whether fatigue was present, and in what manner it 
affected the response; what were the effects of extremes of 
temperature on the response; whether chemical reagents could 
exercise any influence on the plant-response, as anesthetics 
and poisonous drugs have been found to do with nerve and 
muscle. 
Finally: if it could be proved that the electric response 
served as a faithful index of the physiological activity of plants, 
it would then be-possible successfully to attack problems the 
solution of which at present offers many experimental difficulties. 
But before obtaining satisfactory and conclusive results 
regarding plant-response, many difficulties had to be surmounted. 
It is obvious that if we wish to find out the influence of various 
external agencies on the modification of response, we must first 
of all succeed in devising experimental arrangements by which 
uniform responses may be obtained and recorded with unfailing 
certainty. I shall presently describe how this has been 
accomplished. 
Conditions for obtaining Electric Response. 
If we take a piece of uninjured living tissue, and two contacts 
be made on its surface by means of non-polarizable electrodes at 
A and B, connection being made with a galvanometer, 00 
current will be observed, as both A and B are in the same 
physico-chemical condition: the two points, that is to say, are 
1so-electric, If now the tissue be excited by stimulus, similar 
disturbances will be evoked at both A and B. If, further, these 
disturbances, reaching A and B almost simultaneously, cause 
any electrical change, then, similar changes taking place at both 
