420 PHYSIOLOGICAL. EEGULATIONS 



first one, for, the fact is that the original zero load is again pre- 

 cisely located after recovery. I infer it is only the quantities 

 (contents) that are not changed that are able to 'inform" the 

 processes of recovery how much to return. If any component were 

 independent of all others, probably no means would be left the 

 living unit of ''knowing" where balance lies. 



Undulations of diverse components similar in time are also evi- 

 dence of interdependences. Such rhythms may be "spontaneous" 

 or induced. The interrelations are made known by the demonstra- 

 tion of what components take part in the one rhythm. When first 

 observed the undulations are usually regarded as random, later 

 they are said to be physiological. Often, I believe, rhythmical 

 changes are stabilizing something; perhaps even concerned in 

 maintaining constant a function that itself shows no periodicity, 

 as in the uniform flow of blood with intermittent heart beats or 

 uniform flow of heat with fluctuations in peripheral blood flow of 

 man in every minute (Burton and Taylor, '40). 



The facts lead to the general proposition that probably no one 

 physiological function can be different from what it is without 

 many others being different. Each change involves a ''network" 

 of many unforeseen changes. To find a new equilibration or bal- 

 ance for one component means securing some arrangement for 

 bringing all the others to new balances too. The shift of Co might 

 be sudden and complete, as in some components at birth; or pro- 

 gressive, as during ontogeny or acclimatization. 



A living unit may be viewed as such a system of unexceptionally 

 related quantities. The components are each subject to certain 

 ties and relationships in space and time. The existence of inter- 

 dependencies among them is a matter of fact ; that all components 

 have interrelations can never be demonstrated except with ex- 

 trapolation; that, further, these interrelations are the visible ele- 

 ments of recovery and of stability probably remains a hypothesis. 



Such a view may be compared with the implicit supposition of 

 many physiologists that an organism is a conglomerate of chiefly 

 uncorrelated happenings. For each function it is assumed there 

 is a regulator or key or master lever. All or any components 

 might then be at designated loads, at one time or separately or in 

 any combination. This supposition could be supported by finding 

 some load of a component that shows high constancy unaccom- 

 panied by changes of other compounds (after exhaustive search). 



