 He afterwards continued it in Rome.It is compiled out of an "Adversaria", or commonplace book, in which he had jotted down everything of unusual interest that he heard in conversation or read in books, and it comprises notes on grammar, geometry, philosophy, history and many other subjects.One story is the fable of Androcles, which is often included in compilations of Aesop's fables, but was not originally from that source.