In his Ars grammatica Fl. Sosipater Charisius quotes long portions of text which he has taken over from books of other grammarians. One of these quotations starts at 246.18 (‘C. Iulius Romanus ita refert de adverbio sub titulo ϕορμν’) and continues up to 289.17. At 246.19–252.31 we find a long argument in which Romanus offers a sort of introduction to the theory of the adverb. This introduction is a surprise to modern readers because it is written in a very rhetorical manner. I mention this because otherwise one cannot understand why at 251.22ff. the author of a Latin treatise on grammar should quote from a Greek work on Aristotle's Categories by a certain Aquila.