8 PHYSIOLOGICAL REGULATIONS 



are varied in content, uniformities of pattern are evident. These 

 general features form quantitative pictures of the manner of regu- 

 lations. Instead of having a different basic scheme for handling 

 each component, the organism apparently assigns to some portion 

 of itself the fulfilling of the specific operations, consistent with the 

 general pattern that it has for other components. While the spe- 

 cific physical machines for liandling excesses of water, heat, oxy- 

 gen, and glucose might be infinite in variety, the kinetics of 

 restoring content is practically singular. That general fact calls 

 for intensive study. 



In brief, diverse sorts of living units and of a variety of proper- 

 ties, may be examined in the light of relations of compensation, 

 preference, and variability. Studies of stages in development of 

 the individual, comparisons among species and tissues, and exami- 

 nations of simultaneous disturbances of many properties, are indi- 

 cated. The task is to discover those features that are common to 

 numerous kinds of regulated properties. 



•^ 4. Mode of treatment 



Every investigation appears to start from vague notions about 

 the relations among observable phenomena. Having supposed that 

 certain quantities might inform me about regulations, and tested 

 the suppositions, I find scarcely worth mentioning what the work- 

 ing hypotheses were and what vicissitudes they have undergone. 

 Then how shall I proceed to record the results, contributing order 

 to the concrete observations'? 



(1) Description. There are often said to be two kinds of scien- 

 tific ordering, causal and mathematical. In physiology the causal 

 has frequently been essayed, and has not, I believe, revealed all that 

 can be discovered with respect to regulations. I propose to try the 

 other procedure, indicating descriptive relations among processes 

 that seem concerned in maintenances of organisms. I will ask how, 

 and not the unanswerable why. It is often supposed that mathe- 

 matical descriptions do not satisfy the desires for understanding 

 in the way that causal orderings do. That seems to depend on the 

 individual scientific appetite. For I find that mathematical rela- 

 tions in physiology, even as in modern physics, may prove just as 

 explanatory as any others that have been proposed. Of that no 

 one can judge who has not attempted to use them. 



Readers may feel the omission of the usual excuses, arguments, 



