It is not positively certain whether the present façade was the one originally designed by Giovanni or not. We find that in November 1310, a commission of ten Master builders was formed, to superintend the work of the mosaic, already commenced, and to guard against useless expenses. Milanesi supposes this to refer to some mosaics destined for the façade, especially as in 1358 a Maestro Michele di Ser Memmo was paid six gold florins for his work, "per la sua fadigha (fatica) e magistero di Santo Michele agnolo, a musaica (_sic_) che fecie a la facciata di duomo nel canto."[223] The front, as it is at present, has no mosaics; probably Giovanni Pisano's plan was modified in later days. It is certain that after Giovanni's death in 1299 great changes of design were made. The interior has the same mixture as the façade; there are round arches below in the nave, and pointed windows above in the clerestory. The black and white marble, significant of the times though it be, detracts much from the effect of the really fine architecture by cutting it up in slices. Fergusson recognized the purely Italian pedigree of Siena cathedral.[224] "That at Siena," he says, "illustrates forcibly the tendency exhibited by the Italian architects to adhere to the domical forms of the old Etruscans, which the Byzantines made peculiarly their own. It is much to be regretted that the Italians only, of all the Western mediæval builders, showed any predilection for this form of roof. On this side of the Alps it would have been made the most beautiful of architectural forms." We cannot, however, endorse Mr. Fergusson's next assertion--"in Italy there is no instance of more than moderate success--nothing, indeed, to encourage imitation." In the face of the domes of St. Peter's at Rome, S. Marco at Venice, the cathedrals of Florence, Parma, Padua, Siena, and Monreale, this is rather a hard saying.