Before I close this rather dull but very necessary chapter, I must tell you something about the two provinces which form the northern and part of the southern boundaries of Russian Poland. Let us look first at the country which lies between the Lower Vistula and the Lower Niemen, the region in which the Germans and Russians first came to blows. Along the coast, which is lined with sand dunes, you see two lagoons almost entirely cut off from the Baltic Sea by tongues of land. Into the westward of these the Vistula and the Pregel discharge themselves; by means of the other lagoon the river Memel finds its way to the sea. A large map would show you that these rivers form deltas at their mouths, and this clearly proves that the country is flat and low-lying. The rivers are sluggish, and the slightest obstacle causes them to change their beds. The deserted channels remain as stagnant pools and marshes, and in course of time have become filled with peat. A bird's-eye view of this region shows a maze of water-courses, swamps, lakes, peat bogs, dense forests, and green meadows. Farther south the country rises to a low plateau, which is literally pitted with lakes, amongst which is the Spirding See, forty-six square miles in extent, the largest inland lake in Prussia. Some of these lakes are wide and shallow, with hard gravel floors, but others are simply a film of water above yards of mud. Bogs abound, and it is very hard to tell where the meadows end and the swampy ground begins. On the map you will notice that the lake district is called the Masurian Lake Region; it receives this name from the Masures, a section of Poles who have long inhabited the country. Round about the lakes are thick, dark forests, in which wolves, lynxes, and elks are still found and hunted. In the valleys of the Pregel and Memel there is fertile soil, in which rye, oats, and potatoes are grown; but for the rest the country is largely sterile moor and bog. East Prussia is the headquarters of German horse-breeding, and there is a great Government establishment for this purpose a few miles to the east of Gumbinnen.[31] East Prussia has for many years past been a favourite hunting-ground of the Kaiser.