The thirteenth century was a time of immense development in art; what Niccolò and Giovanni di Pisa did for sculpture, Jacopo Tedesco and Arnolfo did for architecture. Jacopo was the first to introduce the pointed arch into Central Italy, at Assisi; Arnolfo further developed it in his cathedral at Florence, where the arches of the nave are round, and the windows pointed. After this era we have no more Romanesque--the reign of Italian Gothic has begun. The Basilican form, too, has vanished; we have now the nave and transepts of the Latin cross. No longer the small double-arched window, but long pointed arches filled with beautiful tracery. The old symbolic animals linger on, but in the subordinate form of grotesques in ornamentation. That distinctive mark of the guild, the lion of Judah, takes a new position in the Italian Gothic. It is no longer between the pillar and the arch, but beneath the column, as Niccolò and Guido da Como first placed it in their pulpits. You see it under the pillars of the north door of the Florentine Duomo, where the transition into Renaissance is indicated by a particularly classic figure of a child standing by the lion; and under the central column of the windows of the Spanish chapel in the cloister of S. Maria Novella, where it serves to mark the fact that the architects Fra Sisto and Fra Ristoro (who in the documents of the time are styled Magister Fra Sisto and Magister Fra Ristoro) were members of the Masonic Guild. Jacopo, the inaugurator of Italian Gothic, spent all his later years in Florence, having left Colle many years before, when he had finished the castle there. Jacopo's work in Florence consisted of the building of the Bargello, which is a perfect specimen of the late Comacine style, built in _modo gallico_ with large smoothly-hewn stones. The connection of the Masters of the guild with the south of Italy is shown here as well as at Pisa, for it is said that King Manfred commissioned Jacopo Tedesco to design the sepulchre of the Emperor Frederic in the abbey church of Monreale in Sicily. (Manfred died in 1266.) Jacopo also introduced a reform into Florence. In the time when Messer Rubaconte of Como was Podestà of Florence (1236, 1237), his compatriot, Jacopo Tedesco of Campione, near Como, proposed to him that the streets should be paved with stones instead of bricks, to which Messer Rubaconte agreed, and the same method of paving still continues in Florence. The second Lapo, Arnolfo's fellow-pupil, and perhaps brother, was the author of several buildings in the end of the thirteenth century, which Vasari falsely attributes to Jacopo the elder. He also continued Jacopo Tedesco's fortifications at Colle.[243]