Among the assistants brought by Perugino, were "Rocco Zoppo and Bernardino Betti, called il Pintoricchio." The operations of the first were limited to certain portraits of the Rovere family in the altar-piece, which at that time represented the "Assumption," by Perugino, with the "Finding of Moses" and the "Nativity of Christ" as the beginning of the two sacred histories. Pintoricchio's place, in his master's estimation, was a very different one. We have no reason to doubt that he was Perugino's right-hand man. From the degree to which he has imbibed his style, he must have been working with him for some time before, and the drawings in the Venetian sketch-book, as it is generally called, so long erroneously attributed to Raphael, make it clear that he supplied Perugino with designs for several of his principal figures, which the master altered slightly to suit his taste when he came to transfer them to the plaster. Vasari[17] tells us that Pintoricchio worked with Perugino in the Sixtine Chapel, and took a third of the profits, but this testimony afforded no clue to former critics, and for some centuries "The Journey of Moses" was attributed to Luca Signorelli. Burckhardt was the first to dispute this claim, and to ascribe the fresco with more _vraisemblance_ to Perugino.[18] Crowe and Cavalcaselle[19] repudiate the attribution to Signorelli. They see in both this and "The Baptism" the work of Perugino, but in parts, in the young man stripping, and in the youth by his side, they recognise a likeness to Pintoricchio, though in the children of "The Journey" they profess to see plainly the hand of Bartolommeo della Gatta. [17] Manni. _Raccolta Milanese di vari opuscoli_, vol. i. f. 29. [18] Vol. iii. [19] _History of Painting in Italy_, iii. 1783. The attribution of these two great frescoes to the younger master has made a great difference to his place in art. In some ways they are the finest and truest works he has left us; it is curious that they are the first that can with certainty be ascribed to him.