PREFACE TO FIRST EDITION 



It is the purpose of this book to survey 

 the most important recent researches in 

 problems of sex, especially those concerned 

 with internal secretions, in order that con- 

 cepts already established by experimental 

 evidence may be clearly stated and made 

 readily available. While general principles 

 can in many cases be stated concisely, the 

 recent data have accumulated so rapidly 

 that there has not yet been time for retesting 

 and evaluating much of the evidence. This 

 may account in some chapters for emphasis 

 upon certain work with which contributors 

 may have had personal contacts. Further- 

 more, sex and reproduction show such wide 

 ranges of variation in both the structures 

 and functions involved that major dif- 

 ferences, even among species of higher mam- 

 mals, make generalizations both difficult 

 and dangerous. This whole field has recently 

 undergone such rapid growth that many 

 new ciuestions have arisen to challenge the 

 investigator's curiosity. An attempt will be 

 made to indicate productive approaches to 

 some of these unsolved or only partially 

 solved problems. 



This book is intended for the reader with 

 a moderate biological background, to whom 

 the less involved technical terminology may 

 not prove a serious handicap. It is not our 

 intent that it should be a "popular book on 

 sex." Instead, it is designed for those in- 

 terested in the progress of research in 

 problems of sex, and those who may be 

 already engaged in investigations thereon 

 or casting about for promising problems for 

 investigation. Physicians who are interested 

 in fundamentals will find much valuable 

 recent material. In suppljnng a biological 

 foundation for education in matters of sex, 

 it should also attract the interest of serious 

 students of sex function in man. 



Specialization in research has reached the 

 point where any detailed authoritative sur- 

 vey requires a group effort. Conseciuently, 

 the editoi attempted to gather together a 

 group of investigators whose work has es- 

 tablished them in their respective fields. 



Each contributor has develop(>d his chapter 

 in his own way and assumes full respon- 

 sibility for the content of his section, in- 

 cluding his discussion of the work of othei' 

 investigators. 



Since it was inevitable that considerable 

 correspondence would be involved, intro- 

 ducing the time-transport factor, choice 

 of the group was restricted to American 

 investigators. Several prominent workers 

 in this field, whom we would have desired 

 as co-authors, have necessarily been omitted 

 because of absence abroad or press of 

 other work. 



As the Foreword indicates, this project 

 saw its inception in a proposal by Dr. E. V. 

 Cowdry, then Chairman of the Medical 

 Division of the National Research Council, 

 to the Committee for Research in the Prob- 

 lems of Sex. In the publication of many of 

 the contributors to this book, acknowledg- 

 ment will be found to this Committee for 

 support of investigations. In a sense the 

 book will serve as a summary of some of the 

 work accomplished under grants from this 

 Committee. Obviously, however, it was not 

 desirable to limit choice of contributors to 

 investigators who had received grants from 

 the Committee, and that consideration has 

 not determined their choice. Instead, it is 

 probable that the Committee in the first 

 place chose to make grants to these men 

 because of the promise of their work shown 

 by their previous investigations. 



The editor wishes to acknowledge the 

 support of the Committee for Research in 

 Problems of Sex, which has made provision 

 for the editorial expenses involved in the 

 preparation of the manuscript. He also 

 wishes to commend the cooperation between 

 investigators who, even though they may be 

 competitors in the same field, have col- 

 laborated so well. The cooperation has been 

 completely free from the secretive reserve 

 sometimes encountered among investigators 

 who may be leaders in their particular 

 fields. The editor wishes further to acknowl- 



