In 1539 he spoke out on the process of bloodletting, agreeing with the famous Greek physician Galen (which would evidently prove quite a rare occurrence) who claimed that blood should be taken from the infected sector of the body, and not a distant area for effective remedy. In 1541, Vesalius came to discover that the physician he had based much of his scientific inquiry on, Galen, had performed the majority of his experimental dissections on primates due to the criminal nature of the dissection of cadavers at the time. This meant that all of the information Vesalius had taken from Galen was now in question due to the differences between the species of ape that Galen had used, Barbary Macaques, and humans. As Galen’s research came into question, Vesalius set out to disprove many of his theories and discoveries. The first being that arteries were responsible for carrying rich, pure blood to the higher order organs like the brain and lungs from the left ventricle and that veins transport blood from the right ventricle of the heat to the lesser organs like the stomach. The second discovery was that the mandible was actually only one bone, contrary to the original thought of it being composed of two separate pieces. Finally, Vesalius found that against Galen’s research, there was no large, complex network of blood vessels at the