The art work put into the manuscripts produced in the Low Countries, particularly in Belgium, was more highly developed and was a more important part of the industry than was the case in any other portion of the world. In the earlier German universities, the _stationarii_ also found place and found work, but this work seems to have been of less importance and the scribes appear to have secured for themselves a less definite university recognition than in Italy or in France. The explanation given by Wattenbach is that the German students, being better informed and more industrious, did for themselves a larger portion of the transcribing required and were, therefore, freed from the necessity of hiring their hefts. The statutes of the universities of Prague and of Vienna permitted the masters and the baccalaureates to secure from the university archives, under certain pledges, the loan of the books authorised as text-books or of works of reference, for the purpose of making trustworthy copies of the same. The copyists were enjoined as follows: _Fideliter et correcte, tractim et distincte, assignando paragraphos, capitales literas, virgulas et puncta, prout sententia requirit._[305] The practice also obtained in these universities of having texts dictated to the students by the _magisters_ or the Bachelors of Arts. This was described as _librum pronuntiare_, and also as _ad pennam dare_. In this phrase, Karoch sent word to Erfurt that _ad pennam dabit_ his treatise _Arenga_.[306] The text-books utilised in the German universities in the thirteenth and fourteenth centuries were as limited in range and in number as those of Bologna and of Padua. The instruction in the medical departments of Prague and Vienna was based in the main on the works of Hippocrates and Galen, with some of the later commentaries, principally from Arabian writers. In philosophy the chief authority was Aristotle, in mathematics Euclid, and in astronomy Ptolemy. A few works of later date were utilised, such as the _Summula_ of Petrus Hispanus and the _De Sphæra Mundi_ of Johannes de Sacro Bosco. Bosco is otherwise known as John Holywood or Halifax. He held the chair of mathematics in the University of Paris about the middle of the thirteenth century. The use of his treatise for classes in Prague is evidence of a certain interchange between the universities of books in manuscript. An important reason for the very large membership of the universities of the Middle Ages as compared with their successors of to-day, is to be found in the fact that they undertook to supply not only the higher education which belongs to the present university curriculum, but also the training now furnished by the _gymnasia_ or High Schools, which were at that time not in existence. We find, therefore, in their membership, thousands of students who were little more than boys either in their years or in their mental development.