The best known and the most extensive of these lagoons is that in which Venice is situated, which extends from Torcello in the north to Chioggia and Brondolo in the south, a distance of above 40 m.; but they were formerly much more extensive, and afforded a continuous means of internal navigation, by what were called "the Seven Seas" (Septem Maria), from Ravenna to Altinum, a few miles north of Torcello.
The Roman district, the largest of the four, extends from the hills of Albano to the frontier of Tuscany, and from the lower slopes of the Apennines to the Tyrrhenian Sea.
Groningen is connected with the Drente plateau by the sandy tongue of the Hondsrug which extends almost up to the capital.
Here we find open plant associations of Haifa or Esparto Grass (Stipa lenacissima) alternating with steppes of Chih (Artemisia herba-alba); and each plant association extends for several scores of miles.
The cells not only fuse together in longitudinal and transverse rows, but put out transverse projections, which fuse with others of a similar nature, and thus form an anastomosing network of tubes which extends to all parts of the plant.
