The traveller who enters Italy by any of the Alpine passes will not fail to note the contrast between the northern streams and the more torrential water-ways of the south, which, however, being soon checked by the deposit they bring, grow slack and fray out into many and varying channels, through which the waters find their way with small, at times almost imperceptible, flow into the sea. So lazily do the rivers discharge that the north-east shores of the Adriatic are formed of sandbanks, shoals and islets, which for nigh a hundred miles from Cavarzere to Grado constituted the _dogado_ of Venice. The famous Venetian lagoon is confined to some thirty miles north of Chioggia, and is divided into the _Laguna morta_, where the tide is scarcely felt, and the _Laguna viva_, where the sea is studded with numerous islands and islets protected by the _lidi_, a long line of remarkable breakwaters formed by the prevailing set of the current to the west, with narrow openings or _Porti_ through which the shallow tide ebbs and flows. This natural barrier has made the existence of Venice possible, for the islands on which the city is built afforded a refuge safe alike from attack by sea or land. The colonisation, development and defence of these lagoons and islands by settlers from the mainland make up the early history of Venice. Some misapprehension exists as to the nature of these settlements. The picture of terror-stricken and despoiled fugitives from the cities of Venetia escaping from hordes of pursuing Huns or Lombards to seek a refuge in the barren and uncertain soil of mud-banks and storm-swept islands is true in part only. In many cases the movement was a deliberately organised migration of urban communities, with their officers, their craftsmen, their tools, their sacred vessels, even the very stones of their churches, to towns and villages already known to them. Among the settlers were men of all classes--patrician and plebeian, rich and poor. “But they would receive no man of servile condition, or a murderer, or of wicked life.” [Illustration: ON THE LAGOONS]