These ventures were followed by similar undertakings on the part of Colines and Badius. The former issued editions of _Sophocles, Aristophanes, Demosthenes_, and _Lucian_, while from the press of the latter came the great _Commentary_ of Budæus on the Greek language, and the _Areopagiticus_ of Isocrates. Another Greek printer of enterprise was Christianus Wechel, who was a friend of Erasmus. He issued, in 1529, a further edition of the frequently printed Greek _Grammar_ of Gaza, and, later, many of the _Opuscula_ of Galen, the latter printed in the original Greek with Latin versions. Wechel came into trouble in 1534 for having sold the treatise of Erasmus _De esu interdicto Carnium_, which had been censured by the Theological Faculty. In the year 1530, the production of Greek books in Paris was taken up energetically by Gerardus Morrhius Campensis, who dates his impressions from the College of the Sorbonne. His list includes a _Lexicon Græco-Latinum_, the _Rhetorica_ and _Poetica_ of Aristotle, the _Ajax_ of Sophocles, and a number of the essays of Galen. The titles of the works selected by these earlier Parisian printers have interest as indicating the direction of the studies pursued at the time in the University, or which were taken up in connection with special scholarly undertakings outside of the routine university curriculum. While these printer-publishers were usually able to secure, in preparing their editions for the press, the services of scholarly editors (or, as they were more frequently called, correctors), it is evident that no little original learning as well as scholarly judgment was required on the part of the publishers themselves in the selection of the texts and in the supervision of the correctors, while in the majority of cases the publishers added to their volumes original work of their own. Thus to the _Lexicon Græco-Latinum_, Morrhius had contributed an elaborate Latin preface, while to the _Interpretatio Didymi in Odysseam_, he prefixed an analytical introduction in Greek.