THE ELECTRICAL SPASM OF DEATH 197 



of Mimosa was lowered from the normal 60 C. to about 

 53 C. This latter value, it will be remembered, was ap- 

 proximately the same as that obtained with radish, in winter, 

 by the method of electrical response. Again, I find fatigue 

 to induce a lowering of the death-point, the extent of which 

 depends upon the degree of fatigue. When this was moderate, 

 I have found the death-point of Mimosa to be lowered to 

 56 C. 



This spasmodic contraction, indicative of the initiation of 

 death, may express itself in diverse ways. For example, 

 if the tubular peduncle of A Ilium be filled with water, and 

 raised gradually in temperature, there comes a moment at 

 which a sudden expulsion of the contained water occurs. A 

 spiral tendril of Passiflora, under the same circumstances, 

 exhibits a sudden uncurling. The florets of the ray, in certain 

 Composite?, show characteristic movements, either up or down. 

 In all these cases alike, under normal circumstances, the 

 death-point is found to be at or near 60 C. 



Turning next to the radial organs of ordinary plants, 

 these also exhibit a sudden longitudinal contraction at the 

 onset of death. I have shown elsewhere how, by means 

 of the Morograph, an instrument which I devised for this 

 purpose, a thermo-mechanical curve is recorded by the 

 specimen, while it is being subjected to the continuous rise of 

 temperature, culminating in the death-point. The ordinate 

 of this curve represents the induced variation of length, and 

 the abscissa the temperature. The expansion described in 

 the case of Mimosa is seen here in the form of a gradual 

 elongation, up to the moment of reaching the death-point. 

 When this point is reached, however, a sudden contraction 

 takes place, giving rise to an inversion of the curve. This 

 turning point is very abrupt. The curve as a whole is 

 thus one of life-and- death, in which the point of inversion 

 separates the two. I give below a photographic record of 

 this thermo-mechanical curve, obtained with the coronal 

 filament of Passiflora. The death-point occurred here at 

 59'6 C. (fig. 129). The thermo-mechanical curve is very 



