THE KINETIC SYSTEM 169 



of the prolonged consciousness. (Figs. 24, 25, 26.) In 

 the animals which were allowed eight hours of sleep at 

 the close of the period of insomnia these organs were 



A. 



Section of normal cerebellum of cat. Section of cerebellum of cat showing 



effect of extreme physical exertion. 



FIG. 27. PHOTOMICROGRAPHS SHOWING THE EFFECT OF EXERTION ON 



THE BRAIN-CELLS OF A CAT. 



Note the general disintegration of the Purkinje cells in B. 

 (From photomicrographs, X 310.) 



restored to their normal histologic condition with the 

 exception of some cells in the brain and the liver which 

 had been irreparably damaged. 



