ACKNOWLEDGEMENTS 



I AM pleased to record my thanks to Professor J. E. Harris and 

 Dr. J. A. Kitching of the University of Bristol, both for introducing 

 me to the study of ciliary activity and for valuable comments on 

 parts of the text of this book. I am also grateful for the advice 

 and criticism of Professor J. O. Corliss of the University of 

 Illinois, who, while visiting Professor of Zoology at the University 

 of Exeter, has read the whole text and spent much time in fruitful 

 discussions. My wife Peggy has given invaluable help in correcting 

 manuscripts and proofs and in innumerable other ways. The 

 help of these kind people has improved this book considerably, 

 but the author must bear the responsibility for the shortcomings 

 that remain. 



The book was written at the suggestion of Dr. G. A. Kerkut, 

 to whom I am sincerely indebted. My thanks are also due to Dr 

 R. Barton, Professor J. T. Randall and Dr. K. Vickerman who 

 have passed on valuable information for this book in discussions 

 of their unpublished work. 



It is a pleasure to acknowledge the assistance of Mr. N. Barratt 

 in preparing photographs of some of the illustrations, and of 

 Miss B. Mortimer in typing parts of the script. 



The generosity of the following workers who have lent or 

 given copies of electron micrographs is acknowledged with 

 gratitude: Dr. B. A. Afzelius, Dr. W. Bernhard, Dr. E. De 

 Robertis, Professor D. W. Fawcett, Dr. J. G. Gall, Dr. I. R. 

 Gibbons, Dr. E. G. Gray, Dr. A. V. Grimstone, Dr. D. R. 

 Pitelka, Professor J. T. Randall, Dr. L. E. Roth, Dr. J. E. 

 Shapiro, Dr. K. Vickerman and Dr. E. Yamada. Professor 

 P. P. Grasse, Professor I. Manton and Lord Rothschild have 

 kindly given permission for electron micrographs to be copied 

 from pubUshed work. 



Permission to reproduce material from books and periodicals 

 has been given by Publishers and Journals as follows: 



Academic Press for Plate VIIc (from the Proceedings of the 



viii 



