and finally south-westward along the lower river Don to Rostof and the Sea of Azof. Within this line, to south and west of it, are more than a hundred million Russian people. They, the main stock of Russia, inhabit the plain between the Volga and the Carpathians and between the Baltic and Black Seas, with an average density of perhaps 150 to the square mile, and this continuous sheet of population ends more or less abruptly along the line which has been indicated.
Northward of Petrograd and Kazan is North Russia, a vast sombre forest land with occasional marshes, more than half as large as all the region just defined as the Russian Homeland. North Russia has a population of less than two millions, or not three to the square mile. East of the Volga and Don, as far as the Ural Mountains and the Caspian Sea, lies East Russia, about as large as North Russia, and with a population also of about two millions. But in the Kama Valley, between North and East Russia, is a belt of settled country, extending eastward from Kazan and Samara to the Ural Range, and over that range, past the mines of Ekaterinburg, into Siberia, and right across Western Siberia to Irkutsk, just short of Lake Baikal. This belt of population beyond the Volga
