This is a splendidly written and beautifully illustrated book with a number of able contributors. A brief glance through the book will show how valuable it is. Impressive is Dr. George W. Corner's enthusiastic and very thought-producing foreword, which refers to an authoritative volume, Sex and Internal Secretion, edited by Edgar Allen in 1932. This presented a great mass of biological information which pointed the way to further research and became a landmark in our knowledge of reproduction in animals and man. Dr. Corner thinks that now, in 1964, Dr. Lloyd and 15 collaborators have written a work which will become another landmark, "this time for those who are working with patients rather than in the laboratory." As Corner says, "the book is unique in getting together, in one volume, summaries of what is known today about all the functional elements of sex behavior and reproduction—endocrine, neurological, psychological and psychiatric."