Abstract
1. Dogfish, sea robin or tautog erythrocytes are agglutinable by all strains of influenza, mumps or Newcastle disease viruses employed. 2. Mackerel and turtle erythrocytes are agglutinable by mumps or Newcastle disease viruses as well as by some strains of influenza B virus. In the presence of these agents, agglutinable erythrocytes lose their capacity to be agglutinated by the same virus and spontaneous elution of the agent occurs. Elution of virus from erythrocytes and disagglutination appear to occur concurrently. 3. Among a number of other viruses tested, none was capable of agglutinating erythrocytes employed in this study.