One of these two new books is a comprehensive textbook and the other a heavily edited record of a symposium. Their appearance is justified by the rapid advances in our understanding of the origins of thyroid disease and by recent progress in diagnostic technology and the use of laboratory data in patient care.The first book here, by Burrow, Oppenheimer, and Volpé, has a gratifying uniformity of style, is comprehensive, and avoids the duplication that so often mars multiauthored textbooks. The chapter on hormone biosynthesis is outstanding, as are the two chapters on the metabolism and effects of thyroid hormones. . . .