Three large thalli of the saxicolous lichenParmelia cumberlandia(Gyeln.) Hale were subdivided. Portions were relocated to new sites within southern Ontario where they were left for a period of 1 year. At the end of the transplant period lichen substances in young tissue at the transplant sites were compared quantitatively with those produced at the original collection site. Changes were observed with respect to one minor unknown substance, but the depsidones and usnic acid were unaffected either qualitatively or quantitatively. Environmental differences of the magnitude tested were insufficient to cause major changes in lichen chemistry.