Marx is considered to be the last representative of the so-called Bonn school of classical philology, a scholastic entity that was initiated by Friedrich Wilhelm Ritschl (1806-1876) in the 1840s. He was the author of numerous scholarly works, including editions of: Plautus' play "Rudens" (1928), writings by the encyclopaedistAulus Cornelius Celsus (1915), Filastrius' "Diversarum hereseon liber" (1898), fragments from the satirist Gaius Lucilius (1894-95) and a critical examination of "Rhetorica ad Herennium" (1894); the latter work being published over several editions up to the year 1993.
From 1925 to 1934 he was editor of the journal Rheinisches Museum für Philologie ("Rhenish Museum for Philology").
References
This article is based on a translation of an equivalent article at the German Wikipedia.