The history of anatomy is traditionally divided into two periods: pre-Vesalian and post-Vesalian. With the publication of De humani corporis fabrica in 1543, Vesalius lay the foundation for the scientific study of anatomy. Pre-Vesalian anatomy was characterised by its reliance on animal dissection - a tradition established by Galen, the Greek physician of the 2nd century A.D. who practised in Rome. Vesalius in De fabrica provided a complete anatomical and physiological study of every part of the human body, based on first-hand experience as public prosector in the Medical School at the University of Padua. His painstaking observations corrected many of the errors perpetrated by Galen and his followers. De fabrica not only revolutionised the science of anatomy, but also its teaching. Vesalius advocated that dissection should be performed by the lecturer, as it is only through direct first-hand experience that he could learn human anatomy in sufficient detail. The book is remarkable not only for its text, but also for its magnificent woodcut illustrations, which set the standard for future anatomical illustration. Indeed, Vesalius's illustrations were copied in many other medical works right up to the end of the eighteenth century. The blocks were commissioned by Vesalius, who supervised their production. They are thought to have been executed in Venice by an artist from the studio of Titian, possibly Jan van Calcar, who, like Vesalius, was a native of the Low Countries. The finished blocks were dispatched to Basel, where they were used by the printer-scholar Johannes Oporinus, to produce two editions of De fabrica. Amazingly the original woodblocks were discovered at the beginning of this century in Munich, and in a joint venture by the New York Academy of Medicine and the University of Munich the blocks were reimpressed and published in 1934 under the title Icones anatomicæ. Sadly, the blocks were destroyed in an Allied air raid during World War II. The 200-plus anatomical illustrations are divided into three categories: the skeleton men, of which there are three (p. 163-165) the muscle men, fourteen in number (p. 170, 174, 178, 181, 184, 187, 190, 192, 194, 197, 200, 203, 206, 208), and the individual parts of the body. The most striking are the flayed muscle men, arranged to display a progressive dissection, from the superficial muscles to the deep layers. The backdrops to the plates are also of interest, for when assembled in order, they represent a continuous panorama of the countryside around Padua [the Reading Room of the library of the Wellcome Institute in London is adorned with life-size facsimiles of the plates]. The illustrated title page to the work is also fascinating. The turbulent scene of a public dissection is full of symbolism, and has been the subject of full-length studies. In the centre of the scene is Vesalius himself, breaking with custom by descending from the lecturer's podium to conduct the surgical demonstration in person [contract with the lecturer in the Ketham illustration]. In addition to the anatomical illustrations, De fabrica is adorned by twenty-one pictorial woodcut initials, depicting puttis or cherubs engaged in various acts associated with dissection, such as removing a corpse from the gallows, preparing skeletons for study, dissecting a pig, etc. These initials add an element of macabre humour to the work. De fabrica was immediately recognized as a landmark in medical practice. It was reissued, translated, copied and plagiarized many times. A second authorized edition, containing Vesalius's revisions, was issued by Oporinus in 1555. An unauthorized edition was published in Lyon by Jean de Tournes in 1552 in two volumes duodecimo. Because of the greatly reduced format of this edition, only four of the original woodcuts were reproduced. No doubt the publishers were trying to cash in on the success of the original edition of De fabrica. Perhaps it was intended as a portable textbook for students, but without the illustrations it would have had very limited usefulness. Vesalius also published an abbreviated version, an 'epitome', which was reissued and translated several times. Further editions of De fabrica were published in Venice in 1568 and 1604.