804 PROF. J. C. BOSE ON ELECTRIC RESPONSE IN PLANTS. 
of modification of response by high and low temperatures, and 
even in matters of occasional abnormal variations, such as 
positive response in a modified tissue, they are strictly corre- 
spondent to similar phenomena in muscle and nerve. Judged 
by the final criterion of the effect produced by anesthetics and 
poisons, these electric responses in plants fulfil with animal 
tissues the test of vital phenomenon. 
How are we to account for these remarkable similarities ? 
It may be that these resemblances are due to some chance 
coincidence. But do we know of any other instance where 
chance coincidence extended throughout the whole range of 
phenomena in all their details P 
There thus remains one other alternative, namely, that the 
underlying life-phenomenon is the same in both animals and 
plants, and that both animal and plant responses are its 
common physiological expression. 
The electro-physiological investigation on plants may thus 
be found to throw much light on the response phenomena 
inthe animal. With animal tissues, experiments have to be 
carried on under many great and unavoidable difficulties. The 
isolated tissue, for example, is subject to unknown changes 
inseparable from the approach of death. Plants, however, offer 
a great advantage in this respect, for they maintain their vitality 
unimpaired during a very great length of time. In animal 
tissues, again, the vital conditions themselves are highly complex. 
Those essential factors which modify response can, therefore, be 
better determined under the simpler conditions which obtain ia 
plant life.* 
In concluding I wish to mention the efficient help rendered 
me by my assistant, Mr. J. Bull, in the course of this investigation. 
* [The present work on Electric Response in Plants was undertaken to supply 
an important link between the responses observed in animal tissues and in 
morganic substances. A short preliminary account of results obtained with 
plants was given in my paper, “ On the Response of Inorganic Substances,” 
communicated to the Royal Society on the 7th of May, read June 6th, 1901, 
and also in my Friday Evening Discourse, ‘On the Response of Inorganic 
Matter to Stimulus,” at the Royal Institution, on May 10th, 1901. 
T am glad to find that Dr. Waller has subsequently been able to confirm the 
results which he heard me describe on the occasions referred to above. (Waller: 
“ Electric Response of Vegetable Protoplasm to Mechanical Excitation,” Nov. 9, 
1901, Proc. Physiological Society.) 
June 11, 1902. J.C. B.] 
