212 LIFE AND WORK OF SIR JAGADIS C. BOSE 



impulse, which is the basis of sensation. He begins with 

 the simplest type of nervous tissue in plants like Mimosa. 

 He uses his Resonant Recorder for determination of speed 

 of nervous impulse and its variation the Automatic 

 Recorder enabling him to measure accurately to the 

 thousandth part of a second. He shows that there is no 

 physiological characteristic of the animal nerve which is 

 not also to be found in the plant nerve. The various 

 physiological ' blocks ' which arrest the nervous impulse in 

 the animal are shown to arrest the corresponding impulse 

 in the "plant. Agents which accelerate the nervous impulse 

 in the animal are shown to exalt the impulse in the plant. 

 Thus within the normal range, a rise of temperature of 

 about 9 C. doubles the speed in animal nerve ; this is also 

 found to be the case in the plant. 



He next determines the latent period or the perception- 

 time of contractile tissue in Mimosa. This latent period 

 in Mimosa, as previously stated, is 0-076 sec., or one-eighth 

 the value in an energetic frog. We are of course prepared 

 for slower reaction in plants, the difference between the 

 plant and animal being one of degree and not of kind. Our 

 perception-time is slowed down under fatigue ; exactly 

 parallel is the effect on plants. 



Bose's further investigations give again very significant 

 results as regards the power of stimulus to fashion its 

 own conducting path. Thus a plant carefully protected 

 under glass from the stimulating buffets of the elements 

 looks sleek and flourishing, yet in 'reality it is flabby. Its 

 conducting power is found to be in abeyance. But when a 

 succession of blows rain on this effete and bloated specimen, 

 the shocks themselves create nervous channels and arouse 

 anew its deteriorated nature. ' And is it not shocks of 

 adversity, and not cotton-wool protection, that evolve 

 true manhood ? Thus we see how organism is modified by 

 its environment, and how an organ is, as it were, created 

 by the cumulative effect of stimulus/ These discoveries 



