LICHEN PHYSIOLOGY

Abstract

The pattern of 14 C fixation and release by algae after isolation from lichens was studied using Nostoc from Peltigera canina, Hyalococcus from Dermatocarpon miniatum. Coccomyxa from Peltigera aphthosa and Trebouxia from Xanthoria aureola ; cultured strains of these algae were also investigated. In all cases, the following changes occur as soon as the algae are isolated: (a) release of fixed 14 C to the medium declines sharply; (b) the proportion of released 14 C incorporated into simple carbohydrates also falls rapidly; and (c) incorporation into ethanol‐insoluble material in the cell rises substantially. The direction of these changes is towards the behaviour of cultured algae. It is concluded the lichen algae begin to show substantial changes from their behaviour in symbiosis as soon as they are separated from the fungus.