60 David H. Dolley, Fatigue of Excitation and Fatigue of Depression etc. 



There are three reasons why this exhaustibility has not appeared 

 as a prominent factor in physiological experimentation: the resistance 

 of the less differentiated or primitive cells principally dealt with as 

 opposed to the lability of cortical cells; the existence of cells in 

 reserve; and, preeminently, the reserve power of cells. There is no 

 incompatibility with the relative difficulty of exhaustion. 



