In August, 1581, the Jesuit Peter Canisius wrote to Duke William, referring with approval to the Index then in preparation, and adds the recommendation that a _Censor Librorum_, to be appointed by the Duke and the bishops, should be sent to Munich, Ingolstadt, Straubing, Burghausen, and other places where annual fairs were held, to examine the books offered for sale, and particularly those imported, and to inspect all libraries, both public and private. They were to have authority to confiscate and to destroy all copies of books condemned or likely to prove pernicious.[154] He suggests further the desirability of an Index published as a serial from year to year. This idea of Canisius was, some twenty years later, carried out, though not in Bavaria. From 1606 to about 1619 was published in Mayence a yearly list, prepared for the use of booksellers in Catholic States, and presenting titles selected from the annual catalogue of the Frankfort Fair. The title was: _Index novus librorum imprimis Catholicorum theologorum aliorumque celebrium auctorum quarumcunque facultatum et linguarum, causas religionis tamen non tractantium ... pro Italia ceterisque nationibus confectus_. The first issue includes a preface from Leuchtius, _Sedis Apost. librorum revisor_, an authorisation from Paul V, and a privilege from the emperor. The Index is devoted to the titles of books the reading of which is permitted.[155] 3. Censorship under Pius V and Gregory XIII, 1570–1585. _1570._ _Pius_ gives instructions for the preparation of a new _Index expurgatorius_, but the plan was not carried out. _1572._ _Gregory XIII_ issues a Bull directing the production of an _Index expurgatorius_ on the lines of that published in Antwerp. The work was, however, delayed so that it was not until 1590, five years after Gregory’s death, that this Roman Index appeared. During the reigns of both Pius and Gregory, however, attention was given to the production of expurgated editions of the works of a number of authors, such as Erasmus, Boccaccio, Polydorus, Vergilius, Zasius, Harphius, etc. Under Pius, condemnation was ordered for the teachings of Bajus, but this did not bring any new titles into the Index. In 1569, Guido Zanetti de Fano was put under arrest for heretical teaching. The Senate of Venice demanded that the trial should take place in Venice. The Pope Pius replied that the civil authorities had no proper concern with matters of heresy, except to carry out in due course the verdicts or judgments given by the Church.[156]