432 HENRY H. DONALDSON 



for action. Thus the integration of the incoming impulses is 

 continually in process at each level and impulses from above 

 act in a large measure to release mechanisms partially prepared. 

 It has been one purpose of this review to show that Herrick's 

 book is an introduction to a more significant neurology than is 

 usually presented to us, for starting as it does with the reflex 

 circuit as the unit of function and keeping the physiological rela- 

 tions in the foreground it illuminates the structural arrangements 

 within the nervous system in a way that is both unusual and 

 stimulating. 



