Mondino was just past fifty when he finished his little book and permitted copies of it to be made. Though the book occurs so early in the history of modern book-making the author offers his excuses to the public for writing it, and quotes the authority of Galen, to whom he turns in other difficult situations, for justification. As prefaces go, Mondino's is so like that of many an author of more recent date that his words have a bibliographic, as well as a personal, interest. He said: "A work upon any science or art--as saith Galen--is issued for three reasons: first, that one may satisfy his friends. Second, that he may exercise his best mental powers. Third, that he may be saved from the oblivion incident to old age. Therefore, moved by these three causes, I have proposed to my pupils to compose a certain work on medicine. "And because a knowledge of the parts to be subjected to medicine (which is the human body, and the names of its various divisions) is a part of medical science, as saith Averrhoes in his first chapter, in the section on the definition of medicine, for this reason among others, I have set out to lay before you the knowledge of the parts of the human body which is derived from anatomy, not attempting to use a lofty style, but the rather that which is suitable to a manual of procedure." Some of the early editions of Mondinus' book are said, according to old writers, to have contained illustrations. None of these copies have come down to us, but the assertion is made so definitely that it seems likely to have been the case. The editions that we have contain wood engravings of the method of making a dissection as frontispiece, so that it would not be difficult to think of further such illustrations having been employed in the book itself. As we note in the chapter on "Great Surgeons of the Medieval Universities," Mondeville, according to Guy de Chauliac, had pictures of anatomical preparations which he used for teaching purposes. It is easy to understand that the value of such aids would be recognized at a time when the difficulty of preserving bodies made it necessary to do dissections hurriedly so as to get the rapidly decomposing material out of the way.