Specific Agglutination of Murine Erythrocytes by a Pneumonitis Virus in Mice

a peumonitis virus has been isolated during the serial passage of human lung material through Swiss mice. This virus is closely related to the mouse pneumonia virus of Horsfall. The lungs of mice infected with this virus contain an agent capable of agglutinating murine erythrocytes. This agglutination is inhibited by specific anti-sera.