University of Padua in 1541 to replace Vesalius while he traveled to Basel in order to supervise the printing of De humani corporis fabrica. It is often thought that Colombo was a student of Vesalius, but this may not have been the case. Regardless, they had become bitter rivals by 1555. While teaching Vesalius' classes in 1543, Colombo pointed out several errors Vesalius made, most notably attributing properties of cows' eyes to the eyes of humans as well as claiming to have discovered a vein in the human body, the existence of which Vesalius had previously denied. Although Vesalius has been much maligned for correcting Galen, Colombo was the one to criticize him for his own mistakes. When Vesalius returned, he was outraged. He publicly ridiculed Colombo, calling him an "Ignoramus" and stating that "what meager knowledge [Colombo] has of anatomy he learned from me" on a number of occasions. Despite Vesalius's claims, it is likely that Colombo was a proper colleague of Vesalius rather than a student. For one thing, Vesalius attributes many of his discoveries in De Fabrica to Colombo who is referred to as a, "very good friend." Vesalius and Colombo were also from very different academic backgrounds. Vesalius was a Galenic expert, trained in Leuven, whereas Colombo began his study of anatomy as a surgeon. Finally, Colombo refers frequently to Lonigo as his teacher of surgery and anatomy, never mentioning Vesalius. While both Colombo and Vesalius were in favor of returning to the anatomical practice of vivisection, as the Alexandrians did, Colombo was the only one to actually do so. This is one of the main reasons as to why Colombo criticized Vesalius. Vesalius criticized Galen while he himself continued to show the anatomy of animals, instead of humans, in his book. Colombo and Falloppio Colombo's only published text, De Re Anatomica, was released shortly after his death in 1559. His sons, Lazarus and Phoebus, were responsible for overseeing the final stages of the publishing process of his book after Colombo’s death interrupted it. Many of the contributions made in De Re Anatomica overlapped the discoveries of another anatomist, Gabriele Falloppio, most notably in that both Colombo and Falloppio claimed to have discovered the clitoris. Although both Colombo and Falloppio gave claim to what was actually the re-discovery of the clitoris, it is Colombo who is credited as having been the anatomist who correctly identified the