Decorated letters from Vesalius' De Humani Coporis Fabrica (1543). A. The act of removing the head of cadavers prior to dissection can be seen, as cherubs set to the head of a man with a bone saw. B. Once decapitated, the subjects (human or beast) were hung to drain the blood from the body. This enabled a much 'cleaner' visualisation of the internal organs. C/D. At the same time as public dissections of human subjects were occurring, the dissections of beasts was also conducted. This increased the availability of subjects, but also allowed a better comparison to the works of the ancients who worked mostly on animals. In C, the cherubs can be seen dissecting a boar, while another looks on, reading from a book (possibly Galen's). E/F. The difficulty in obtaining human subjects was such that at the time of Vesalius' bodies were often obtained via grave robbing (E) or by taking the bodies of executed criminals (F). All images are reproduced by gracious permission of Her Majesty The Queen, from the Royal Collection © 2010, Her Majesty Queen Elizabeth II.