PREFACE vii 



The reader will find in these pages a comparative and 

 connected account of the endocrine functions of the gonads, 

 so far as these are known, in all groups of multicellular animals. 

 The importance of such knowledge has now become generally 

 recognised, and the subjects treated are of profound interest 

 for zoologists and physiologists alike, as well as for medical 

 men, psychologists and students of eugenics. As a guide to the 

 literature of a branch of endocrinology that has grown rapidly 

 in recent years the work should be of great value. 



The manuscript has been written by the author in EngUsh, 

 and in my capacity as editor I have confined myself for the 

 most part to making such alterations as seemed to render 

 Prof. Lipschiitz's meaning more clearly. For the views ex- 

 pressed (with which I am not always necessarily in complete 

 agreement) the author is solely responsible, and to him alone 

 the credit is due. 



F, H. A. MARSHALL. 



Christ's College, 



Cambridge. 

 April, 1924. 



