The change of fungus communities parallels the successions of the higher plants. These successions are the bog-hydrarch, the river-hydrarch, the dune-xerarch, the forest-xerarch, the rock-xerarch, and the fen. The reason for the paucity of fungi in spring in contrast to their abundance in the autumn is discussed. A picture key to the genera of the larger fungi and one to the genera of the Agaricaceae are given.