Scale 1 : 290,000.] Amongst the ancient industries of the country not yet extinct, the fisheries of the lagoons of Comacchio occupy a foremost place. The Canal of Magnavacca, now hardly navigable, admits the waters of the sea into the Canal Palotta, which may be described as the great artery of these lagoons. It was constructed in 1631–34, and, by an ingeniously designed system of ramifying canals, carries the vivifying floods to the most remote parts of the lagoons. The various basins, or _valli_, of the lagoons are thus filled with sea-water, and constitute as many breeding beds, where the fish come from the sea multiply abundantly. A labyrinth of canals provided with flood-gates cuts off their retreat to the sea, and they are caught in immense numbers when the fishing season arrives. Spallanzani has seen 60,000 pounds of fish taken in a single bed, or _valle_, within an hour; but sometimes the draught is even more considerable, and the fish are actually used as manure. The fishing population of Comacchio numbers about 5,000 individuals, most of them distinguished by tall stature, great strength, and suppleness. Coste, the fish-breeder, mentions it as a curious fact that this secluded colony of fishermen {221} should have retained these characteristic features for centuries, though sustained exclusively by fishing, and living upon mullets, eels, and _acquadelle_. Unfortunately these fishermen are not the proprietors of the ponds, for they belong to the State or to rich private individuals. The workmen live in large barracks away from the town, to which they return only at stated intervals, and even their wives and relatives are not permitted to visit them in their places of exile. [Illustration: Fig. 73.—THE FISHERIES OF COMACCHIO. Scale 1 : 78,000.] The enormous population of the valley of the Po, which almost equals that of the remainder of continental Italy, is very unequally distributed; but, except in the high and cold Alpine valleys, the inhabitants live in towns, dozens of which may be seen peeping out amidst the verdure if we ascend a high tower. There are scarcely any villages or hamlets. The farmers alone live in the country, completely isolated from each other, whilst the numerous landed proprietors throng the towns, and impart to them an aspect of wealth which similar places in other {222} parts of Europe cannot boast of. No other country in the world is as densely populated, and in Lombardy the number of towns is relatively larger than anywhere else.[70]