Leonardo da Vinci (1452-1519) spent over twenty-five years investigating the workings of the human body. While his paintings were widely known in his day, only a few friends and associates had any intimation of the extent of his medical research. Leonardo's Anatomical Manuscript A, created over the winter of 1510-11, is the only group of such drawings in which he approached complete coverage of the human form, and it represents his finest work in this area. This fascinating book presents a complete discussion of all the drawings in Manuscript A, not only as evidence of Leonardo's artistic genius, but also as the product of the sophisticated scientific investigations they represent. Each drawing records a meticulous human dissection and is extensively annotated with Leonardo's notes, questions, and memoranda to himself in mirror-writing, (backward writing legible only when held up to a mirror, the motivations for which have been the subject of much speculation). Each drawing is reproduced twice: once in its original form and once with a new English translation in place of Leonardo's original notes. The authors comment on the accuracy of the anatomical renderings and the conclusions Leonardo draws from them.