42. Thus it is in the promontories of serpentine which meet with their polished and gloomy green the sweep of the Gulf of Genoa, that we find the first cause of the peculiar spirit of the Tuscan and Ligurian Gothic--carried out in the Florentine duomo to the highest pitch of colored finish--adorned in the upper story of the Campanile by a transformation, peculiarly rich and exquisite, of the narrowly-pierced heading of window already described, into a veil of tracery--and aided throughout by an accomplished precision of design in its moldings which we believe to be unique. In St. Petronio of Bologna, another and a barbarous type occurs; the hollow niche of Northern Gothic wrought out with diamond-shaped penetrations inclosed in squares; at Bergamo another, remarkable for the same square penetrations of its rich and daring foliation;--while at Monza and Carrara the square is adopted as the leading form of decoration on the west fronts, and a grotesque expression results--barbarous still;--which, however, in the latter duomo is associated with the arcade of slender niches--the translation of the Romanesque arcade into pointed work, which forms the second perfect order of Italian Gothic, entirely ecclesiastical, and well developed in the churches of Santa Caterina and Santa Maria della Spina at Pisa. The Veronese Gothic, distinguished by the extreme purity and severity of its ruling lines, owing to the distance of the centers of circles from which its cusps are struck, forms another, and yet a more noble school--and passes through the richer decoration of Padua and Vicenza to the full magnificence of the Venetian--distinguished by the introduction of the ogee curve without pruriency or effeminacy, and by the breadth and decision of moldings as severely determined in all examples of the style as those of any one of the Greek orders.