Vohcme VII. November, i8g2. Number 2, 



JOURNAL 



OF 



MORPHOLOGY. 



A MICROSCOPICAL STUDY OF CHANGES DUE TO 

 FUNCTIONAL ACTIVITY IN NERVE CELLS. 



C. F. HODGE, Ph.D. 



Experiments upon a series of animals, including the frog, cat, dog, birds (pigeon, 

 English sparrow, and swallow), and honey bee, with some observations upon 

 chased foxes and pathological human material. 



CONTENTS. 



PAGE 



I. Introductory 95 



II. Theory and Purpose 96 



III. History of Related Work 98 



IV. Effects of Electrical Stimulation 114 



V. Process of Recovery from Fatigue 130 



VI. Curves of Nerve Cell Fatigue and Recovery . . . .138 



VII. Effects of Normal Daily Fatigue 143 



VIII. Conclusions 158 



IX. Bibliography 160 



I. Introductory. 



Experiments for the purpose of studying changes in the cells 

 of spinal ganglia upon electrical stimulation of nerves going to 

 them, were begun in the biological laboratory of The Johns 

 Hopkins University in the winter of 1887-88, and were there 

 continued through the year 1888-89. During the two succeed- 

 ing years the work was prosecuted in the neurological labora- 

 tory of Clark University. First of all, I wish to express my 



95 



