lotka: discontinuous evolution 73 



the carrying out of the "purpose" in view, i. e., in impressing 

 upon the external world the form corresponding to the modified 

 representation just referred to. 



Now the efficiency of the "receptor-effector system" depends 

 on the perfection with which each of the steps of the sense- 

 motor circuit is carried out. The investigation of the function 

 r in its relation to the physical properties of an organism such 

 as man for example therefore resolves itself into the discussion 

 of the several sources of "error" in the working of the receptor- 

 effector system, and the influence of such errors upon the rate 

 of increase of the group. No attempt shall be made here to 

 attack this problem, or even to put it in mathematical setting, 

 tho this latter offers no difficulty, and might prove instructive. 

 We will rest content on this occasion with a tabular synopsis of 

 the principal sources thru which errors enter into the functioning 

 of the receptor-effector system. Such a table appears as follows: 



Synopsis of the Steps in the Sensory-Motor Circuit, with the 

 Corresponding Sources of Error. 



1. Representation of the external world in the individual 



A. Sense perceptions Observational error 



B. Reasoning (as a step in the further 



development of the image formed Logical error 

 by the senses) 



2. Determination of the "Modified Representation" 



A. Unconscious (Reflex) Deviation from the "best adapted" 



modified representation 6 



B. Conscious: "Valuation" of several 



possible "modified represent a- Error of the "judgment of value" 7 



tions" and selection of one of 



them 



3. Action 



A. Actuation of limbs, etc. Operational error 



B. Reasoning (as a step in the realisa- 



tion of the "modified represent a- Logical error 

 tion") 



G It is presumably by such a "false reflex" that a moth is drawn into the 

 destroying flame. 



7 Flagrant errors of this kind are seen for example in the case of the drunkard, 

 the gambler and so forth. 



