Studies of germination and growth of asymbiotic and infected protocorms of Goodyera repons revealed that asymbiotic germination and growth to the aut.otrcfphic stage was favoured by high concentrations of glucose and •ootato extract, while infected, protocorms survived and grew best on cellulose media. Infected protocorms on any media were larger than their asymbiotic counterparts. Temperature and light were important factors controlling germination and growth of asymbiotic and infected protocorms. Asymbiotic protocorms grew slowly and accuired large amounts of starch on glucose media, while the reverse obtained in infected material. It was concluded that this was effected by the fungus through suppression of starch synthesis and the channelling of nutrients into growth. An attempt was ms.de to implicate increased invertase activity, 14 but this failed since very little C labelling appeared in hexoses in infected -olantlets. Accumulation of *. C (applied to the fungus) by infected protocormswas demonstrated and the infection process in Goodyera re~oens investigated. 'Khen protocorms were analysed for labelling in sugars during the pre-digestion phase of infection, only trehalose was labelled :in the soluble fraction: either trehalose was not released to the orchid before digestion, or the label in sucrose was too snail for detection. from orchid to fungus proved negative. After eroosure to the endophyte emerging from plantlets- plated on Pfeffer 14 agar or glass wool contained C only where rhisomes had been 14 exposed, indicating that this had originated, from C0o fixation by the endophyte in the rhizome. Cultures of the fungus itself fixed large' ouantities of ie endophyte 14. _ was capable or translocating .Large ouantities 01 c from killed plant material but not from the living host.