124 THE FISHERIES OF THE ADRIATIC, 



Grado, consisting- of a space of water partitioned off from the rest of lagoons, 

 in which they are situated, by reed-screens {valle a grigiuoli or grisiole), or by 

 dams and sluices {valle chiusa arginata) ; there are also valli semi-arginate. 



La valle chiusa ad arsrine is so constructed that the sea-water can flow in 

 at different points, the in-flow being regulated by means of sluices (cliiaviclie), 

 so that the water does not become stagnant. The bed must vary in its 

 quality and depth of water, so as to suit the requirements of the different 

 kinds offish as to food and temperature. In winter a stream of sweet water 

 is let in, in order to facilitate the freezing of the surface, and thus afford 

 greater protection to the fish from the cold. 



The valli a grigiuoli, and semi-arginate, are built on the same principle, 

 but they are liable to destruction by storms or floods, and require more 

 expense for keeping in repair. The people in charge are called vallicultori, 

 or valligiani, and the head man Par 011 {padron) da valle. The pond proper 

 is termed Lago, or Campo della valle, where the young fish {pesce novello) is 

 allowed three years to mature. The cogolera is a labyrinth of reed-screens 

 and Cogbli, similar to the serragli, into which fresh water is at times let, thus 

 alluring the fish into the nets ; the mature fish are taken out in the autumn 

 and winter. In the pond there are deeper basins and channels (Gorg/ii), to 

 enable the fish to seek refuge from the great heats and colds ; otherwise they 

 die off. 



The pond proper is separated from the cogolera by a dam {traghettd) 

 with an opening furnished with a sluice. The approach to the cogolera is 

 called Vegnua, or Venuta ; an obstruction to the passage of grey mullet and 

 gilt-head is the fermativa di cievoli e orade, by means of which they are 

 isolated ; further on is a similar obstruction for eels, the fermativa di bisatti, 

 and another called ckila, for catching the eels that escape from the former. 



On either side of the cogolera are ditches {depositi), partly roofed over, 

 affording protection to the young fry in hot or cold weather ; a trellis- work 

 separating the depositi from the rest of the cogolera, in order to afford 

 protection to the fry from the pursuit of the mature fish. 



The valli are opened in spring, allowing the free passage of the fish, 

 which accordingly enter of their own accord ; this is called the " montata" 



