CMV was obtained from 5 stunted plants with leaves showing yellow blotching and line pattern symptoms but not from 7 symptomless ones. The virus was readily transmitted to other wineberry plants by grafting but not to several cvs. of R. idaeus, either by grafting, mechanical inoculation with purified preparations, or by aphids (Macrosiphum euphorbiae). The isolate was indistinguishable serologically and in its behaviour in vitro from str. W, originally obtained from lettuce in England.