POPULAR interest has been aroused in the 'swollen shoot' disease of cacao ; but it is only one of many virus troubles which are being investigated. The annual report for 1947–48 of the West African Cacao Research Institute at Tafo, Gold Coast (Crown Agensts for the Colonies 4 Millbank, London, S.W.I. 1949. 5s.), revears extremely complex relations between numerous viruses, particularly in the Western Province.