THE GENESIS OF FUNCTIONAL INERTIA 123 



rhythmical activities that are supposed to be due 

 to " internal stimuli/' e.g., rhythms of Medusae. 

 When Professor Ribot * speaks of " reactions . . . 

 coming from within not from without " he means 

 much the same as do those w r ho use the term " in- 

 ternal stimuli." The phrase is objectionable because 

 all reactions (responses) are from within, though 

 stimuli are from without. 



All " reactions " are from within ; but whereas 

 some are known to be definitely and strictly related 

 to some change in external conditions (stimuli) and 

 are, therefore, responses related to the property of 

 affectability, others are as clearly not definitely or 

 directly related to such conditions and are, therefore, 

 to be regarded as related to anabolic or katabolic 

 inertia. As a term, " internal stimuli " is super- 

 fluous ; if they are not really external stimuli, then 

 internal stimuli are either, (i) one or other of the 

 properties of the living molecules or else, (2) they are 

 the molecules themselves in the condition of pre- 

 dominent Anabolism or Katabolism respectively. 



If the former is meant, then stimuli are confused 

 with properties of living matter ; if the latter, stimuli 

 are identified with molecules in activity. Now most 

 certainly there are such things as stimuli which are 

 molecules in activity, e.g., the nerve-impulses as they 

 impinge on muscle or gland, but these, as related 

 to muscle or gland, are as external to the affectable 

 tissues as is an electric discharge or a mechanical 

 shock. 



* Ribot, Psychology of the Emotions, p. 399. 



