The composite forms that have arisen since commerce and civilization have brought the ends of the world together, increase the complication. There have been marriages and intermarriages, some good matches and some bad ones, some with vigorous and some with sickly offspring, and some hybrids of such monstrous malformation as almost to make us fear that a new style can be invented. But the effect is impossible without the cause. Save the mysterious Pyramids, every structure extant acknowledges its ancestry. If physiologists are fond of claiming the history of the race as one of their own chapters, architecture has at least an equal claim. But all this does not mean that we are mere passive agents in the matter. _We_ are, in a great measure, the 'external influences' that modify art. The motion exists, but it devolves upon us to give direction. We have already alluded to Venetian architecture as being parallel in origin and tendency to our own, and much can be gained, we believe, by a careful examination of what it accomplished. Not that we ought to copy, line for line, the doge's palace or the Casa d'Oro--the arabesque arcade, or the Gothic balcony--that would only be following the well-worn rut of imitation. We are not to study the result, but the cause. For the causes that produced the style in question were not unlike what we find at home to-day. A commercial republic, there was the same liberty of expression--the same preponderance of the individual over the national; and there, as here, are we attracted rather by the elegance of independent units than by any general unity of design. But the growth of art in Venice (we ask special attention) was due to her central situation, and the simultaneous influx of foreign elements. It was her commerce that made Venice great: her glory came and departed with it. Witnessing, as she did, the development of all the mediaeval styles, she became--geographically and historically--the metropolis of architecture. 'The Greeks,' says Ruskin, 'gave the shaft, Rome gave the arch, the Arabs pointed and foliated the arch.... Opposite in their character and mission, alike in their magnificence of energy, they came from the North and from the South--the glacier torrent and the lava stream, they met and contended over the wreck of the Roman Empire; and the very centre of the struggle, the point of pause of both, the dead water of the opposite eddies, charged with embayed fragments of the Roman wreck, is _Venice_. 'The ducal palace of Venice contains the three elements in exactly equal proportions, the Roman, Lombard, and Arab. It is the central building of the world.' Truly, it was a glorious success that art achieved in the Italian republic, Whether the old precedents were violated or not, the result is unquestionably pleasing, and the pleasure-seeking tourist lingers there as long as the critic.