viii AUTHOR'S PREFACE 



made possible by the kindness of Prof. G. Elliot Smith, F.R.S., 

 in allowing me facilities in his Department, and by the interest 

 of Dr. H. A. Harris. 



Mr. J. Hammond, in addition to allowing me to reproduce 

 Figs. 10 and 17, has also given me the benefit of his wide 

 experience. To Dr. J. H. Burn I am indebted for permission 

 to reproduce Figs. 68 and 69, while Mr. W. Shaw has kindly 

 supplied me with the human material shown in Figs. 4, 5 and 35. 



Table 3 and Figs. 14, 18 and 63 respectively have been 

 included by the courtesy of Prof. H. M. Evans, Prof. Carl 

 Hartman, Prof. G. W. Corner, and Prof. B. Zondek, while I am 

 particularly grateful to Dr. P. E. Smith and Dr. E. T. Engle for 

 the illustrations in Figs. 59, 60 and 61. To all of these I would 

 offer my best thanks. 



Finally, I would take this opportunity of thanking most 

 sincerely my friends and collaborators, Dr. F. W. R. Brambell, 

 Mr. G. F. Marrian, Mr. C. W. Bellerby, Miss U. Fielding, Dr. 

 A. R. Fee, and Mr. S. Zuckermann, who have taken a large 

 part in the research upon which this monograph is based, and 

 who have assisted me with the preparation of the book. 



I have been fortunate in obtaining permission from the Council 

 of the Royal Society, from the Cambridge University Press, 

 and from the Editors of the Quarterly Journal of Experimental 

 Physiology and of the Lancet, to reproduce various illustrations 

 and figures. 



The new illustrations are the work of Mr. F. J. Pittock. 



A. S. Parkes. 

 University College, 

 London, 

 1929. 



