Skepticism may be expected with regard to any publication limited to aspects of the endocrine system. The field of endocrinology is new, confused still by many unknowns, masked by the reactions of hormonal balance and bewildered through numerous publications by as many investigations in the fields of botany, zoology, physiology, biochemistry, internal medicine, metabolism, urology, obstetrics and gynecology, and psychiatry. In this book there are ample drawings, illustrations, tables and graphs. The microscopic reproductions vary from satisfactory to poor. The bibliography is composed of 1,297 different references, only 67 of which are the author's own publications. The world literature appears to have been well surveyed and appropriate credit given generally. The book is unusual also in that the table of contents is in the back. The author arranged the book into twenty-four chapters and five sections. The presentation is systematic. The first section includes the development of the ovum to