Clinical and anatomo-histopathological features of experimental infection by DF-2 in rabbits are described. Hyperthermy, sensory reduction, diarrhoea, weight loss and catarrhal nasal discharge are reported. PTT and PT are shown to increase and number of platelets diminish markedly. Considerable haemorrhagic diathesis is reported for several organs. Several clots (especially in pulmonary vessels), serious alterations in kidney glomeruli, degeneration of hepatocytes and disseminated necrosis foci are also reported. Lesions are stated as being very similar to those observed in man.