Originally published in 1979. A review of the broad subject of the ecology of fungi. Fungi, are progressive, ever changing and evolving rapidly in their own way, so that they are capable of becoming adapted to every condition of life. We may rest assured that as green plants and animals disappear one by one from the face of the earth, some of the fungi will always be present to dispose of the last remains. Ecology has been defined by Daubenmire as the study of the reciprocal relations between organisms and their environment. Fungi are heterotrophic organisms which cannot manufacture their basic food requirements and so are dependent on food materials produced by other organisms either as saprobes or parasites.