Infectious NDV particles produce extensive pulmonary consolidation in the mouse in the absence of demonstrable virus multiplication. The lesions are indistinguishable from those of influenza A virus infection. This effect of NDV was blocked by intranasal injection of RDE or immune serum before virus inoculation, but not by immune serum injected 5 minutes or more after NDV. Influenza A virus infection did not diminish fixation of NDV in excised lungs but did interfere with the injurious action of this agent in the living mouse. The analogy between these reactions and those which take place in a progressive virus infection is pointed out, and the mechanism of production of lesions in virus pneumonias discussed.

This content is only available as a PDF.