PREFACE Vll 



Some Latin names of organisms are abbreviated after they have 

 once been mentioned. If a reader is in doubt, reference to the 

 Index of Plants and Animals will provide the full name. Its prepar- 

 ation was made very much easier by the assistance of Sir Gavin de 

 Beer, F.R.S., and Dr H. W. Parker, of the Natural History 

 Museum, London. 



^Theories' of fertilization and activation. The desire to formulate 

 a new theory of fertilization seems almost to be an occupational 

 disease of the gametologist. Such theories have been connected, 

 at one time or another, with the names of Boveri, Bataillon, Dalcq, 

 Delage, Ileilbrunn, F. R. Lillie and Loeb. At the present time we 

 have gone too far — and yet not far enough — to formulate theories, 

 or even to make an 'Attempt at a Comprehensive View', as Runn- 

 strom tried to do in 1949. One function of a new theory is to pro- 

 voke further experiments and, although I have no new theory of 

 fertilization to offer, I hope that this end, at least, will be achieved. 



Acknowledgmetits. I am particularly indebted to Professor Sir 

 James Gray, F.R.S., who has been my mentor for twenty-five 

 years; to Dr George Beadle, Chairman of the Biology Division of 

 the California Institute of Technology, for his help and for his 

 hospitality at 'Caltech', where most of this book was written; to 

 Professor Albert Tyler for valuable advice and criticism, not all of 

 which has been taken; and to the Medical Research Council for 

 financial aid. In addition I am glad to record my thanks to the 

 following scientists and non-scientists for their help and advice: 

 Dr R. D. Allen; Dr C. R. Austin; Dr J. Beament; Miss G. Bend- 

 ing; Prof. J. Brachet; Miss M. Brewster; Dr R. R. A. Coombs; 

 Prof. E. G. Cox, F.R.S.; Dr G. Fankhauser; Prof. L. V. Heil- 

 brunn; Prof. A. L. Hodgkin, F.R.S.; Mr A. F. Huxley, F.R.S.; 

 Dr G. W. Kenner; Dr M. E. Krahl; Dr T. R. R. Mann, F.R.S.; 

 Dr R. Markham; Dr R. E. F. Matthews; Dr J. M. Mitchison; Dr 

 F. Moewus; Prof. A. Monroy ; Prof. C. Niemann; Prof. L. PauUng; 

 the Hon. Miriam Rothschild; George Rylands; Prof. E. C. Slater; 

 Prof. M. M. Swann; Dr E. Vasseur; and Prof. L. Zechmeister. 



