On the whole, we may say that the arctic and boreal faunas of Europe extend over Siberia, with a few additional species in the Ural and Baraba region - a number of new species also appearing in East Siberia, some spreading along the high plateau and others along the lower plateau from the steppes of the Gobi.
There the Volga, the Ural, the Syr-darya and the Amu-darya discharge their waters without reaching the ocean, but they bring life to the rapidly desiccating Transcaspian steppes, and link together the most remote parts of Russia.
The steppes along the bottom of the principal valley are for the most part too dry to be cultivated without irrigation.
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.
A further gentle rise in the high steppes leads to the mountains of the West Australian coast, and another strip of low-lying coastal land to the sea.