When some century and a half later the Venetians began freely to decorate their glass with enamels, we note an entire change both in the colours and in the nature of the fluxes used. To this point I shall return later on, but I may call attention here to the almost total absence of Oriental influence in the designs found on the Venetian enamelled glass of the fifteenth century. This is the more remarkable when we remember that at this time as regards other arts—their inlaid metal-ware and the stamped leather of their bookbindings, to give but two instances—not only is this influence strong, but we know that Oriental craftsmen were at work at Venice. I think that one simple explanation may be given of this apparent anomaly, namely, that by the time the Italians took to the practice of enamelling their glass, that art was practically extinct in the East. It was during the course of the fourteenth century apparently that the glass-workers organised themselves into separate guilds or _arti_, governed by the rules set out on the _Matricola_ or _Mariegola_. It is from these _matricole_ that the little we know of the Venetian glass of this time is derived.[133] The glass-workers now obtained many important privileges, and the town of Murano was granted a considerable measure of self-government; but it was not till the year 1445 that these rights were fully established. Each _arte_ was governed by an elected _guastoldo_, assisted by three superintendents, to whom it fell among other duties to bring the petitions and complaints of the glass-workers before the Great and the Lesser Council at Venice. Not the least important duty of the _guastoldo_ and his lieutenants or _compagni_ was the periodical selection of the proof-pieces—the _prove_—to be made by the apprentices of the various _arti_ before they could claim rank as masters. These tasks were inscribed in the _Mariegole_, and from them Signor Cecchetti, in his often-quoted paper, has extracted many examples. To give an instance: the _Maestri di Rulli_ (_Rui_, small window-panes) had among other things to make ‘_due occhi di bo_,’ an early instance of the term ‘bull’s eyes.’ But the technical terms employed in most cases render the interpretation very difficult. Some of the strange-shaped vases in our collections may not improbably be examples of such proof-pieces. After this time the working year—the period during which the furnaces were kept constantly alight—was confined to nine months; this was afterwards prolonged to forty-four weeks. There was, however, plenty of work to do during the summer vacation, which ended on October 1, for the furnaces had now to be repaired if not rebuilt.