SOME SPECULATIONS CONCERNING REGULATIONS 455 



of effort to rediscover the existence of such rules in connection with 

 every component of metabolism and with every organ. The exis- 

 tence of self -recovery after displacement from balance seems to me 

 to be one such generalization, and coordinate with the other rules 

 mentioned. 



One very special feature of regulations seems to make the gen- 

 eralization about their prevalence in all organisms and all compo- 

 nents unusually probable. The geneticist often uses animals in 

 which certain genes for study are linked to "lethal genes"; then 

 all surviving individuals will be automatically free of the linked 

 genes. I feel a similar assurance that physiological components 

 present in an organism are regulated. Organisms without a cer- 

 tain number of regulations would not survive, and survival per se 

 is a measure of the efficiency of regulations. This view yields the 

 prediction that regulations exist in every organism, for every 

 organism has some constant physiological properties. 



Biologists have fears of deductive work, of specific prediction 

 from a generalization, based probably on the experience of numer- 

 ous failures. With the increase of quantitative biological knowl- 

 edge, relations become more nearly adequate for certain sorts of 

 deductions, and in particular (1) interpolation may usually be 

 trusted in quantitative correlations, and (2) it is allowable to cor- 

 relate A and C, when each is known under identical conditions to 

 be correlated with B. The abuse of these limitations has led to 

 disappointment; the method is none the less valid. Deduction is 

 useful when it recognizes that it is provisional and statistical until 

 the tests are made by which it will become historical. 



So induction leads to general rules among similar phenomena. 

 And deduction leads to predictions that can be applied to new tests 

 of the rules. Free play of imagination also creeps into every set 

 of relations examined; this is "seduction." Certain of those 

 speculations and theories are now set down. 



§ 166. Maxima and minima 



(1) Minima. Rates of exchange might be thought to be ideally 

 zero. The organism would conserve what it has and waste no en- 

 ergy in acquiring more. That would be maintenance by isolation. 

 The organism perhaps makes "sacrifices" to its non-isolation; 

 perhaps it leaks ; perhaps it is cheaper to find new than to save old. 

 So there are nitrogen minima, water minima, energy minima, heat 



