THE KINETIC SYSTEM 171 



cells in the brains of hibernating woodchucks ; but the 

 percentage of exhausted cells was increased also. 



Having noted the effect of exhaustion by insomnia 

 upon the brain, the adrenals and the liver, we repeated 

 the investigation in other typical cases of exhaustion 



A. B. 



Section of normal liver of cat. Section of liver of cat showing effect 



of extreme physical exertion. 



FIG. 29. PHOTOMICROGRAPHS SHOWING THE EFFECT OF EXERTION ON 

 THE LIVER OF A CAT. 



In B, note the vacuolated spaces and the disappearance of many nuclei. 

 (From photomicrographs, X 1640.) 



by physical and chemical stimuli. We examined the 

 organs of animals exhausted by the muscular work of 

 running and fighting (Figs. 27, 28, 29) ; the organs of 

 foxes chased by hounds ; of dogs and woodchucks ex- 



