A fact that another has once discovered and substantiated seems so obvious to those who come after, that they can hardly understand how it could so long have remained unrecognised. To Morelli belongs the credit of having swept away the tradition that in Signorelli and Perugino were to be found the authors of the two frescoes, "The Journey of Moses" and "The Baptism," on either side of the altar-piece in the Sixtine Chapel. After four hundred years of gathering oblivion came one who looked with open eyes, disregarding all mere tradition, and who saw the handwriting of Pintoricchio writ large upon the walls, waiting there, full within sight, yet overlooked, till, after centuries, the truth is acknowledged, unmistakable, supported not only by internal evidence but by drawings and studies--direct testimony affording conclusive proof of their authorship. It is perhaps owing to Melozzo da Forli being court painter to the Vatican in 1480 that we may attribute the preference shown in the first instance to Umbrians in the choice of decorators for Sixtus IV.'s new chapel. To Perugino the direction seems to have been given in the first place, he and his assistants arriving in Rome in October 1482. Here they would have had a great deal to prepare, the spaces to plan, the Pope's directions to consider, the ornamentation of the windows and the niches for the martyred Popes to decide upon. The scheme of the type and anti-type which balances the opposite walls, is very probably due to the Pope and his advisers. Pope Sixtus was a writer on theology, was esteemed a man of profound scholarship, and had in the years immediately preceding written several books on important points of doctrine. Perugino was at that time the undisputed head of the school of Umbria, and his religious spirit and conventional treatment of sacred subjects was likely to be much more acceptable to the Holy See than the new spirit of scientific inquiry. The contract between him and the Pope makes it probable that at first he and his assistants were to be entrusted with the entire work. Whether the Pope got impatient and wished to see his chapel more speedily completed, or for what other reason, is uncertain; but when Giuliano della Rovere went to Florence in December, he agreed with a number of Florentines to resort to Rome, and the whole company of artists was gathered there by the year 1483. Foremost among these was Sandro Botticelli, and from documents which have recently come to light we gather that the superintendence of the entire scheme was finally entrusted to him and not to Perugino.