CHAPTER XLVI 



REVIEW OF RESPONSE OF ISOTROPIC ORGANS 



Laws of response Opposite responsive expressions of true excitation and 

 increase of internal energy Separation of the positive and negative waves 

 Position in molecular cycle determines character of response Abnormal 

 sub- tonic positive and reversed fatigue positive Effect of tetanisation 

 Similar effects in the inorganic Phasic alternations Multiple and auto- 

 nomous response Unmasking of antagonistic element by overshooting 

 Different expressions of a single fundamental molecular change Response 

 by change of form, by secretion or absorption, by variation of electric 

 resistivity, or by electro-motive change For the last, induction of anisotropy 

 necessary Perfect modes of stimulation : (a) Torsional vibration ; (/;) Rotary 

 mechanical stimulation ; (c) Thermal shocks ; (d) Equi-alternating electric 

 shocks Accurate determination of the death-point by mechanical and 

 electrical spasms Current of injury due to after-effect of stimulus 

 Explanation of characteristic electric distribution in plant and muscle 

 cylinders Relative positivity of dead tissue Reversal of current of injury 

 so-called Unreliability of response by negative variation. 



IT has been shown, in the foregoing chapters, that all the 

 diverse phenomena of response may be summarised in the 

 two following formulae : 



1. Excitatory response takes place by contraction and 

 galvanometric negativity. 



2, Increase of internal energy induces the opposite effect, 

 of expansion and galvanometric positivity. 



The first of these effects is simply demonstrated by direct 

 excitation of an excitable tissue. In order to demonstrate 

 the second, stimulus is applied at a distance from the 

 responding point. In consequence iof sudden local con- 

 traction at the receptive area, a wave of increased hydrostatic 

 tension is transmitted with great rapidity. Energy is thus 

 conveyed hydraulically, and at the distant responsive point 

 the transmitted effect induces expansion and galvanometric 



