192 THEORETICAL DEDUCTIONS 



reechoed inversely by the same routes back again to the 

 "micelles." 



In order to understand in its entirety, the mechanism by 

 which the animal organism can live normally, become ill and 

 recover, we must also take into account the fact that the 

 individual reactions of " micelles" and of cells, determined 

 by specific chemotaxis are influenced also by the reactions 

 of the central nervous system which dominates the functions 

 of all the units of the organism, and can by itself disturb or 

 readjust the nutritive equilibrium of these units. 



It is always the central nervous system which, in the last 

 resort, reestablishes normal equilibrium; or, more accurately, 

 which establishes a new general equilibrium in an organism 

 which has been influenced more or less seriously by a hetero- 

 geneous substance; and the influence of the central nervous 

 system will be all the greater, as it will have attained a higher 

 degree of development. 



All these considerations lead us to conclude therefore that 

 an organism is absolutely incapable of assimilating colloid 

 particles wHich are specifically different from its own without 

 digesting them. This results not from a defensive biological 

 law, but simply from the physicochemical properties of its 

 structural and functional units. 



This having been stated, the theory of immunity and of 

 anaphylaxis may be formulated as follows : 



Every bacterium, every substance which penetrates in a 

 colloid state, into the blood or the tissues, or in other words, 

 into the interior of an animal organism must be transformed 

 into salts and crystalloids, that is, must be digested in order 

 to be assimilated or eliminated. 



Every organism, by its cells, glands or organs normally 

 produces a certain quantity of the substance, or more exactly 

 of a series of substances which carry on this digestion. 



When an organism has once been obliged to perform this 

 operation, it continues to produce digestive substances in 

 quantity greater than normal. It is then immunized and 

 anaphylactized. 



All the substances which the organism is obliged to digest 

 in its interior are antigens. 



