156 THE ACTION OF THE LIVING CELL 



is identical with cytost, we should expect to find histo- 

 logical changes similar to those observed in other 

 tissues when induced to discharge cytost by any means. 

 Such is actually the case, for microscopic examina- 

 tion of bits of muscle taken from the cardiac and py- 

 loric ends of the fatigued stomachs showed some stasis, 

 congestion, and distention of the capillaries. These 

 changes appeared much more marked in the pyloric 

 end of the stomach than in the cardiac end, a diflfer- 

 ence of some interest, inasmuch, as demonstrated by 

 numerous observers, only the pyloric end of the stom- 

 ach shows definite peristaltic movements. 



Under higher magnification it was observed that 

 the cytoplasm of the cells stained poorly and appeared 

 to be less granular than that of normal muscle cells. 

 Similarly, the nuclei did not stain well with methylene 

 blue, as is the case in normal tissues. (Turck, 1903.) 

 These observed histological changes are distinctly 

 analogous to those observed in other instances of 

 beginning cellular autolysis, which we have shown to 

 be prerequisite for the liberation of cytost. 



These observations are substantiated by the obser- 

 vations of Oilman (1903) on the nuclear changes 

 incident to the fatigue of striated muscle. 



From the above discussion it will be seen that mus- 

 cular fatigue involves the production of cytost which 

 in turn tends to inhibit the action of the muscle. This 

 conclusion must not be interpreted as meaning that 

 muscular fatigue is caused solely by the accumulation 

 of cytost resulting from muscular activity. The re- 

 cent remarkable advance in our knowledge of the 

 chemistry of muscular contraction would nullify any 

 such interpretation of the facts; for quite obviously 



