STUDIES ON PNEUMONIA VIRUS OF MICE (PVM) IN CELL CULTURE

Abstract
Pneumonia virus of mice (PVM) particles are spheres 80–120 mµ in diameter, or filaments of similar diameter with lengths up to 3 µ. The particles possess an outer spike-covered envelope and helical internal component 120–150 A in diameter. Virus particles acquire their envelope by a budding process at the cell membrane; mature particles are seen only extracellularly.