Bologna had become the most important school in Europe for the study of Roman and Canonical law, and it was in Bologna that the undertakings of the university bookseller first became important. The booksellers were not only subject to the supervision of the university, but were also brought under the regulations of the town, and the town authorities undertook to prescribe prices as well for the renting as for the selling of the manuscripts, and also to prescribe penalties for the renting or selling of incorrect or incomplete texts. The university regulations specified that there must be on the part of the booksellers no modification of the text under which new readings or glosses should be inserted to replace those accepted as authoritative, and a penalty was attached to the selling or renting of the texts in any other form than that in which they were prescribed by the instructors of the Faculty to which the study belonged. In 1289, the penalty for the contravention of this regulation, previously fixed at ten lire, was raised to one hundred lire.[265] A few years later, a university regulation specified that the _stationarii peciarum_ who undertook to rent out the authoritative texts, must keep in stock sufficient supplies of 117 specified works. In the year 1300, there were in the university six official _stationarii_, of whom three were Italians and three, foreigners. They had to be appointed each year, but it seems probable that when their work proved satisfactory they were re-appointed from year to year. The responsibility for the general supervision of the texts and for their correctness and completeness rested with the _bidellus generalis_. Any reader who should discover blemishes or omissions in the _peciæ_ was under obligation to report the same to the _bidellus generalis_, and the _stationarius_ who was responsible for the preparation of the defective text was fined five solidos, one half of the fine going to the university chest, one quarter to the _bidellus_, and one quarter to the informant. The _stationarii_ were ordered to post up in a conspicuous place in their shops all the regulations having to do with their trade, in order that all buyers could know what they were entitled to receive. They were not at liberty to decline to rent to university members any _peciæ_ on the official list. On the other hand, if they rented out _peciæ_ to students who had been expelled or who were under suspension, they were themselves liable to fine. The usual rental at this time, that is to say, the beginning of the thirteenth century, was four _denarii_ for a _quaterne_ (four sheets) and two _denarii_ for a _pecia_. The _denarius_ was the equivalent of about ten cents.