122 FUNCTIONAL INERTIA 



Automatic and spontaneous activities and rhyth- 

 mical phenomena are said to be due to " internal 

 stimuli." Now what are these stimuli if they are 

 not the metabolic transformations of the molecules 

 which physico-chemically underlie the phenomena ? 

 Molecules we know, their two-phased metabolism 

 we know, their properties we know, their external 

 stimuli we know, but what are " internal stimuli " 

 over and above all these ? 



I expect that what is often meant by the expression 

 !l internal stimuli ' : is that certain molecules in a 

 state of agitation (katabolism ?) act on or induce 

 other neighbouring molecules to become similarly 

 agitated. In other words, vibrations are propagated 

 through groups of molecules possessing not too 

 much inertia. 



Molecular vibrations in one portion of an affectable 

 mass may in this way be regarded as the stimuli for 

 other less agitated portions, and this is the essence 

 of Hering's view of metabolism, viz., that anabolism 

 induces katabolism in space and in time and vice 

 versa : but the question has still to be answered what 

 was the stimulus responsible for the original vibra- 

 tions of the molecules first agitated ? What agency 

 produced the initial disturbance ? Their own meta- 

 bolism : this is tautology : they are found to be in 

 a state of metabolic activity induced by their own 

 metabolic activity this is neither logically correct nor 

 biologically common sense : it is, however, precisely 

 what some authors affirm, although, of course, in 

 other words. It is particularly automatisms and 



