DEATH-SPASM IN PLANTS 105 



found that there is induced an electric-spasm at the onset 

 of death. When the temperature is rising, a given point 

 of the plant-tissue exhibits increasing galvanometric posi- 

 tivity, till at the critical temperature there is a sudden 

 electric inversion into galvanometric negativity. The 



Fig. 61. — ^Thermo-mechanical inversion indicating 

 death-point at 60° C. in leaf of bean plant. 



electric-curve of death is of the same type as the thermo- 

 mechanical curve. With specimens of Musa and Amaranth 

 the death-point was found to be 59*5° C.^ 



As the death-spasm is a form of physiological response 

 we should expect the curve of death to undergo modi- 

 fication under physiological variation. One such modifica- 

 tion would lie in the translocation of the point of inversion, 

 or the displacement of the death-point. Thus age has 

 some influence, the death-point of very young specimens 

 being lower than that of mature ones. I shall demonstrate 



^ Bose : Comparative Electro-Physiology , p. 202. Longmans, London, 

 1907. 



