PREFACE ix 



Clyde E. Ford, Dr. H. P. Cole, Dr. D. A. Prendergast, 

 Dr. A. B. Eisenbrey, Miss 0. M. Lewis, Dr. A. M. 

 Tweedie, Dr. Lawrence Pomeroy. 



To Dr. David H. Dolley, Dr. F. W. Hitchings, and 

 Dr. J. B. Austin I wish particularly to express my 

 deep appreciation of their long, painstaking, and en- 

 thusiastic service in the laboratory ; and for bearing 

 the burden of the major portion of the experimental 

 details. I ana indebted to Dr. Dolley for making 

 for me the histologic studies of the brain in shock 

 and emotion; to Dr. Hitchings for prolonged and 

 extensive work in every branch of the research, par- 

 ticularly for his work on the adrenals ; for a critical 

 review of the literature ; for devising a method of 

 making actual Pnrkinje cell counts ; and for compil- 

 ing, analyzing, and tabulating the large mass of ex- 

 perimental data ; to Dr. Austin for painstaking work 

 on the histologic changes in the organs and tissues 

 of man and animals, and especially for his extensive 

 histologic study of the brain, which has included the 

 counting and classifying of over one hundred thou- 

 sand brain-cells; to Dr. H. G. Sloan for assuming 

 many of the operative details; for the physiological 

 investigation of the adrenals, and for other clinical 

 and research work ; to Dr. Maud L. Menten for her 

 researches upon the adrenals, the electric fish, and 

 the H-ion concentration of the blood, in its relation 

 to the factors causing exhaustion and death. 



My thanks are due to Dr. Austin and Mr. John 

 E. Olivenbaum for making the photomicrographs ; to 

 Mr. W. J. Brownlow for original drawings and pho- 

 tographic studies; to Miss Amy F. Rowland for 



