10 PROTOPLASMIC ACTION AND NERVOUS ACTION 



they may be of an active kind; such are classed as 

 regulations. In this case the activity of the organism 

 or of its parts changes in such a way as to resist or 

 compensate departure from the normal; i.e., from the 

 physiological or other conditions required for continued 

 life. The automatic regulation of food-intake, gaseous 

 exchange or temperature, the protective and other 

 self-conserving reactions or instincts, and the phenomena 

 of form-regulation are examples. Since in all such cases 

 the persistence of the organism in the environment is 

 the condition promoted or secured, and since persistence 

 in external nature implies equilibrium, we may character- 

 ize regulations as reactions of an equilibrating type; 

 i.e., regulation corresponds essentially to equilibration. 

 In a sense it is obvious that the structure and activities 

 of an organic species must be such as to secure persistence 

 in the environment, since the alternative is extinction; 

 nevertheless the universal presence of regulative modes 

 of activity is a peculiar and highly remarkable feature 

 of living as distinguished from non-Hving systems, and 

 requires special consideration. Regulations or automatic 

 equilibrations are also met with in many non-living 

 systems (regulators in machines or other artificial 

 systems), but for the most part these are of a relatively 

 simple type. 



The conception of organic integration is closely 

 related to that of regulation; the maintenance of a 

 definite and unified structure and activity in any complex 

 system consisting of many parts requires the mutual 

 interaction and control of the different parts in such a 

 manner that the activity of each is subordinated to that 

 of the whole. This integration presupposes the trans- 



