ACKNOWLEDGEMENTS 



OF 



INDEBTEDNESS 



THOSE who have assisted me in the preparation of this work are so 

 numerous that it is impossible to mention them all by name. Its 

 original impetus was derived from a discussion with Professor Sir 

 F. G. Hopkins in 1923 on the observation of Klein that inositol, though 

 absent from the undeveloped hen's egg, was present in considerable 

 quantity at hatching; and throughout the period of preparation his 

 encouragement, help, and advice were never-failing. I have derived great 

 benefit from the discussion of various points with Miss Marjory Stephenson, 

 M. Louis Rapkine, Dr R. A. Fisher, and my wife. Professor J. T. Wilson 

 has been repeatedly helpful to me on anatomical points, and in the 

 Zoological Laboratory I was always sure of obtaining expert advice from 

 Mr James Gray, Mr J. T. Saunders, Mr C. F. A. Pantin and Dr Eastham. 

 I have relied much upon the kindness and wide biological knowledge of 

 Dr D. Keilin and Dr F. H. A. Marshall. As regards the historical chapters, 

 I am most grateful to Dr Charles Singer, who annotated them with 

 valuable comments, and to Professor R. C. Punnett who placed un- 

 reservedly at my disposal his knowledge of the history of generation, and 

 his library of old and rare biological books. To Dr Arthur Peck I am 

 indebted for the correction of my Greek, and it was Professor A. B. Cook 

 who guided me to the embryology of the ancients. Without the assiduous 

 backing of Mr Powell, the Librarian of the Royal Society of Medicine, and 

 his assistants, I should have dealt much more inadequately than I have 

 with the papers which cannot be consulted in Cambridge. I have also to 

 thank the administrators of the Thruston Fund of Gonville and Caius 

 College for a grant which was devoted to incidental expenses. For the 

 indexes I wish to thank Miss Helen Moyle, and for other services which 

 have made the book possible, Mrs V. Townsend. My thanks are also 

 due to the Editors of the following journals: Biochemical Journal, Journal 



