SOME EFFECTS OF ELECTRICALLY STIMU- 

 LATIXG GANGLION CELLS.' 



C. F. IIOnGE. 



The experiments about to be described were made in 

 the Psycho-physical Laboratory of the Johns Hopkins 

 University during the winter of 1887-8 and fall and 

 winter of 1888. I desire at the outset to make the 

 fullest acknowledgment of my indebtedness to Dr. 

 H. H. Donaldson, under whose guidance the work has 

 been carried on, and to whom much of its success is 

 due. 



Thkory and Purpose of the Investigation. 

 The theory that underlies physiology is that all func- 

 tion is due to chemical changes taking place within 

 the living organism ; and, further, that the functional 

 activity of a specialized tissue depends primarily upon 

 these changes in its individual cells. That these 

 changes may reach a magnitude easily demonstrable 

 with the microscope has been proved, as every one 

 knows, for the cells of certain glands. My present 

 purpose is to ascertain to what extent and by what 

 methods changes due to the functional activity of 

 ganglion cells may be in like manner demonstrated. 



' Dissertation submitted to the Board of University Studies, Johns 

 Hopkins University, for the degree of Doctor of Philosophy, April, 



A preliminary communication upon this work appeared in the 

 A.MERICA.V Journal op Psychology for May, 1888. 



