72 THE NATURE AND ORIGIN OF LIFE 



must come back to observation of phenomena during a 

 certain time. We do not study how the being lives that is 

 beyond our present means of investigation but we do seek 

 how the living being continues living. And in this search 

 we hope to find a general law characterizing life. 



Organ and Function 



If our definition of function is accepted there will result 

 from it a corresponding definition of organ. The word 

 organ has been abused in current language ; and certain 

 authors have not feared to express by the word any anatomi- 

 cally described part in the animal body, to say, for example, 

 that the hand is an organ. In spite of all this, it is clear 

 that the definition of organ must be physiological and the 

 only possible definition is the following : an organ is the 

 sum of the parts of an individual working together in the 

 execution of a function. Those who believe in the existence 

 of partial functions, of local phenomena having no rebound 

 on the whole of the individual, may also believe in the 

 existence of partial organs comprising only a part of the 

 tissues of the animal. But if we go to the bottom of things, 

 we verify the correlation uniting among themselves every 

 instant all the regions of the living body. We are forced 

 to say on the one hand any organ whatsoever comprises 

 the whole organism ; and on the other hand the role of 

 this and that part of the individual has most importance 

 in the constitution of a given organ. 



Moreover, if our definition of functions considered as 

 the total successive activities of one and the same living 

 being is accepted, we ought to define an organ as the succes- 

 sive states of the organism corresponding to each function. 

 And so life is a succession of functions ; the living being is a 

 succession of organs. 



