INTERKELATIONS AMONG COMPONENTS 419 



secures maximal randomness. Many physiologists consider any 

 such formal plan a discouragement to their sentiments and pleasure 

 in work. At the same time it may be realized that ' ' as the art of 

 experimentation advances the principles should become clear by 

 virtue of which this planning and designing achieve their purpose" 

 (Fisher, '37, p. 9). The design of experiments now looms large in 

 physiology as in other sciences. 



It may be said that the analysis of simultaneous interrelations 

 among components exposes quantitative competitions during re- 

 coveries. The load of each component modifies exchanges of itself 

 more than exchanges of other components. Components are found 

 combined in multiple ways, each combination constituting an 

 entity that may still be represented as a single component. All 

 components and combinations may be compared in terms of their 

 effect upon some common index of "value." All enter into an 

 account of the actual physiological state of the living unit. 



§ 150. Meanings of interrelations 



So far it might be supposed that the study of related components 

 is simply a matter of trying to represent a number of events that 

 "by chance" are simultaneous. But it was noted early (<§ 80) that 

 any change in one component inevitably leads to changes in other 

 components. It may now be inferred that this extensive associa- 

 tion is a basis of recovery and of physiological organization. 



Numerous are the instances in which one component does not 

 change without modification of others. If water is removed from 

 the organism, either solutes are removed too or osmotic pressure is 

 increased. If the heart beats more frequently, either the cardiac 

 output increases or the stroke output decreases. It might be pos- 

 sible to dissociate any two given components in the organism, but 

 I infer that during life one given component is rarely if ever dis- 

 sociated from all others. I draw the induction that many com- 

 ponents are interrelated or tied to one another. This mutiplicity 

 of connections has the effect of anchoring each component ; when- 

 ever the component is disturbed (loaded) the resistance to change 

 of the other components is met. 



A conception reached is that of a large stress-strain system. 

 Displacement of any content puts under strain not only the com- 

 ponent itself but all the components that are associated with it. 

 In addition, other components serve to locate the zero load of the 



