vi PREFACE 



Professor J. M. Cowan ; Professor V. Dahlgren ; Professor W. E. 

 Dixon, F.R.S.; Dr. Robert Hutchison; Professor A. Keith, F.R.S.; 

 Professor J. N. Langley, F.R.S.; Dr. Thomas Lewis, F.R.S. ; Dr. 

 F. W. Mott, F.R.S. ; Professor F. G. Parsons and Professor William 

 Wright; Dr. M. S. Pembrey; Sir E. A. Sharpey Schafer, F.R.S.; 

 Professqj C. S. Sherrington. F.R.S. ; Sir J. Purves Stewart, K.C.M.G.^ 

 Professor* Swale Vincent; and Dr. A. D. W r aller, F.R.S. Also to the 

 Editors of the Journal of Physiology, the Quarterly Journal of Experi- 

 mental Physiology, and Brain ; to the Secretary of the Roj'al Society: 

 and to the following publishers for permission to use such illustrations : 

 Messrs. Longmans, Green and Co. ; J. and A. Churchill ; Constable 

 and Co., Ltd.; Macmillan and Co., Ltd.; John Wright and Sons, Ltd.; 

 the Delegates of the Clarendon Press; the Syndics of the Cambridge 

 University Press ; Yale University Press ; Oxford Medical Publications ; 

 Shaw and Sons. 



MARTIN FLACK. 



LEONARD HILL. 



