Girolamo Fabrici, better known under the Latinized form of his name, Fabricius ab Aquapendente (from the name of his home town, near Orvieto in Italy), studied medicine under Fallopius at Padua, and eventually succeeded him as Professor of Anatomy in 1562, a position he held for more than fifty years until his retirement in 1613. An outstanding teacher, he counted Harvey, Bauhin, Paaw, Spieghel and Caspar Bartholin among his pupils. He was, moreover, responsible for the construction of an anatomical theatre at Padua in 1594. In addition he taught privately, and was a practicing physician and surgeon (Galileo and Paolo Sarpi were among his patients). Fabricius laboured many years over a projected textbook of anatomy, to be entitled Totius animalis fabricæ theatrum, that would reflect the advances made since Vesalius, Eustachi and others. The project as a whole, however, was only partially realized. It was not until 1603, when he was in his mid-sixties, that the first part appeared - De locutione et eius instrumentis liber. Other monographs followed, notably: De venarum osteolis (1603); De formatu foetu (1604); and, posthumously, De formatione ovi (1621). De venarum osteolis, first published at Patavia in 1603, was Fabricius's most important work. Although the presence of valves in the veins had been known since at least the mid-sixteenth century, Fabricius was the first to give a systematic and accurate description of them. He discusses the role of the valves in slowing down the normal flow of blood in order to maintain an even distribution of the blood to the various parts of the body. The work had a great influence on Harvey in his landmark discovery of the circulation of the blood. Fabricius's work is illustrated with twenty-three plates, one of which, showing the veins at the inner surface of the forearm, was adapted by Harvey in reduced size in De motu cordis. The plates were widely borrowed and frequently appear in anatomical textbooks. Fabricius's treatise on embryology, De formatu foetu, first published at Venice in 1604, is beautifully illustrated by unknown artists. The thirty-four plates show the uterus, placenta, membranes and fetus in humans and thirteen animals.