RADIOLOGICAL TERMINOLOGY

human. This embodies a concise review of our present knowledge of the functions of the spermatozoon and ovum and of the parts played by the ovarian (foll1cular) and corpus luteum hormones. Time spent in the study of this section of the book will prove valuable to any gynrecologist desiring a thorough understanding of what is commonly regarded as an obscure field. . With the foregoing as a basis Professor Knaus describes in detail an original and impressive method of experimental biology in the human female. Any criticism of his methods used in obtaining data regarding ovulation in the human can be disregarded as the results obtained furnish us with knowledge previously quite unknown. In the latter half of the book the author applies his fresh knowledge to defining a period of conception control depending on the date of ovulation, the life of the ovum and of the spermatozoon. In this way he evolves a natural method of birth control by temporary abstinence during the fertile period of the women. He puts forward a convincing case; and whether one reads the book from the point of view of gaining knowledge as to contraception or the investigation of sterility, the result cannot be anything but beneficial. Well printed on good paper with copious illustrations and tables, the English translation by D. H. Kitchin and K. Kitchin provides something which must be regarded as of the highest order.