I9I4.] CRILE— THE KINETIC SYSTEM. 277 



is also lessened or prevented by nitrous oxid. But morphin does not 

 prevent the action of adrenalin injected into the circulation, hence the 

 control of morphin over energy expenditure is exerted directly on 

 the brain-cells. Apparently morphin and nitrous oxid both act 

 through this interference with oxidation in the brain. We, therefore, 

 conclude that within a certain range of acidity of the blood adrenalin 

 can unite with the brain-cells only through the mediation of oxygen, 

 and that the combination of adrenalin, oxygen, and certain brain- 

 cell constituents causes the electric discharge that produces heat and 

 motion. In this interrelation of the brain and the suprarenals, we 

 have what is perhaps the master key to the automatic action of the 

 body. Through the special senses environmental stimuli reach the 

 brain and cause it to liberate energy which in turn activates certain 

 other organs and tissues, among which are the suprarenal glands. 

 The increased output of adrenalin activates the brain to still greater 

 activity, as a result of which again the entire sympathetic nervous 

 system is further activated, as is manifested by increased heart action, 

 more rapid respiration, raised blood-pressure, increased output of 

 glycogen, increased power of the muscles to metabolize glucose, etc. 

 If this conclusion is well founded, we should find corroborative 

 evidence in histologic changes in that great store-house of potential 

 energy, the liver, as a result of the application of each of the ade- 

 quate stimuli which produced brain-cell and suprarenal changes. 



The Liver. 



Prolonged insomnia, prolonged physical exertion, infections, in- 

 jections of toxins, and of strychnin, rage and fear, physical injury 

 under anesthesia, in fact all of the adequate stimuli which affected 

 the brain and the suprarenals, produced constant and identical histo- 

 logic changes in the liver — the cells stained poorly, the cytoplasm was 

 vacuolated, the nuclei were crenated, the cell membranes were irreg- 

 ular, the most marked changes occurring in the cells of the periphery 

 of the lobules. In prolonged insomnia the striking changes in the 

 liver were repaired by one seance of sleep. 



Are the histologic changes in the liver cells due to metabolism or 

 toxic products or are they " work " changes incident to the conversion 

 of latent into kinetic energy? Are the brain, suprarenals and liver 



