AUTHOR'S PREFACE 



This book has been written with the object of bringing together 

 the more important facts bearing upon the internal secretions 

 of the ovary. This subject now forms a vigorous growing-point 

 of physiology, and its innate complexity, combined with the 

 present activity of research workers, makes the presentation of 

 a coherent picture difficult. Nevertheless, while many aspects 

 must as yet be dealt with tentatively, my aim has been to 

 bring forward in their natural relevance and in due proportion, 

 the observational and experimental data which comprise our 

 knowledge of the ovary as an endocrine organ. 



The more general sections of the book, notably the chapter on 

 the morphology of the female reproductive organs, are merely 

 introductory. No useful purpose could be served by reproducing 

 in detail what is found in numerous anatomical and histological 

 text-books. The morphological aspect of the oestrous cycle is of 

 necessity dealt with fairly fully, but only those species are 

 considered which have been studied in some detail. The re- 

 maining chapters on the endocrine control of the female 

 reproductive organs are intended, however, to be tolerably 

 complete, both as regards fact and hypothesis. The biblio- 

 graphy has been designed to include as much as possible of the 

 literature up to the end of 1928. 



My obligation to workers in this and similar fields is un- 

 bounded. The development of my own research has largely 

 been directed by the critical interest of Dr. F. H. A. Marshall, 

 F.R.S., whose writings form the groundwork of the subject, and 

 who has most kindly read the proofs and allowed me to use 

 certain illustrations from his Physiology of Reproduction. I am 

 deeply conscious, also, of my debt to Prof. C. Lovatt Evans, 

 F.R.S., and Prof. J. P. Hill, F.R.S., for their continued advice 

 and encouragement. The work on X-ray sterilization has been 



