“…The development of malignant lymphoma in stumptail monkeys (Macaca arctoides), following injection of human leukaemic blood has been described in previous publications (Lapin & Yakovleva 1970, Lapin et al 1967, Lapin, Yakovleva, Indzhiia et al 1973, Lapin, Yakovleva, Bukaeva et al 1973, Yakovleva 1970. The present report describes the extension of this work in which both whole blood and plasma filtrate were used; the experiments have also included injections of baboons, Papio hamadryas, which reacted similarly to the stumptails and showed cross-infection.…”