VARIOUS AGENCIES ON DEATH-RESPONSE 1 8 1 



the physiological condition of the tissue. The rigor of 

 spasmodic contraction at death is, therefore, not to be 

 regarded as due to any coagulative action. And, indeed, the 

 theory of a connection between rigor and coagulation is now 

 generally discredited. 1 



By the methods described, then, it is possible to study the 

 effect of various agencies in the modification of death-response : 

 in the case of anisotropic organs, by observation of their 

 lateral responsive movements, and in that of radial organs, 

 by the translocation of the point of inversion. I was next 

 desirous of discovering some still simpler means of determin- 

 ing the effects of various conditions in a qualitative manner. 

 This might be accomplished if we had a number of organs 

 exactly similar to one another, which would give some 

 unmistakable sign of death-response, at the point of occur- 

 rence, either immediately, or at some definite interval after- 

 wards. A certain number of these organs might then be 

 taken as standard, and the others subjected to the action 

 of various modifying influences. Any differences between 

 the temperatures concomitant with post-mortem symptoms 

 would now indicate the modifications produced by these 

 agents. 



In a certain sense, such an experiment may be carried 

 out with a number of leaves on the same plant of Mimosa. 

 But in such a case the organs to be compared are not very 

 numerous, and different leaves of exactly the same age 

 cannot be secured. 



Death-response in flowers. — This led me to investigate 

 whether, amongst flowers, specimens could be obtained which 

 would exhibit a death-movement at the critical temperature. 



1 ' The causes which determine the varying resistance of different plants to 

 heat are quite unknown. The fact that a temperature of from 20° C. to 40° C. 

 kills certain plants, shows that in their case death is not the result of coagulation 

 of the plant-albumin. Further, some plants grow at 75 C, i.e. above the 

 temperature at which egg-albumin coagulates. Coagulation need not always 

 occur, for we must remember that the acid and alkali albumins are not coagulated 

 by heat.' — Pfeffer, Physiology of Plants, English edition, 1903, vol. ii. p. 230, 



