2 72 THEORETICAL BIOLOGY 



of the nucleus, from which the framework portion of the cell 

 proceeded, and may at any time again proceed. 



Every organism, therefore, represents not merely a 

 machine, which has nothing but a framework ; but it con- 

 sists of framework + protoplasm, which itself has the power to 

 form fresh framework. Whereas in a machine all wear and 

 tear of its parts through use must be repaired from without 

 by the director of the action, in the organism this is done 

 by the framework-forming protoplasm, which, by means 

 of this faculty, takes the place of the external direction. 



Hitherto we might have written the formula for a reflex 

 action R — MO — AO — E (Receptor — Mark - organ — Action - 

 organ — Effector), because we were concerned only with the 

 rule of working of the finished framework. If we wish to com- 

 bine with this the power to direct the working, we must write 



the formula t ~ j "" j "" j > thereby indicating that every 



part of the framework occasionally comes under the influence 

 of the super-mechanical factor active in the protoplasm. 

 The formula R — MO — AO — E, accordingly, stands for the 

 known rule, while I — I — I — I indicates the unknown rule of 

 direction. It is only by taking the two together that we get 

 reproduced the function-rule of the reflex action. 



Now the reflex action is by no means the only action of 

 which animals are capable ; but, in the reflex, all the parts 

 of the framework are ready prepared from the beginning, 

 and so it is only in reflexes that the action completely repro- 

 duces the rule of working. In all other actions, framework- 

 forming comes in, and this necessitates the entry of the 

 super-mechanical factor of direction. In this case, therefore, 

 the " I " must be included along with the main formula. 

 According to the points at which the " I " comes in, it 

 is possible to institute a classification of actions which 

 agrees in the main with the one that is in general 

 use. 



