1. The virus of psittacosis is present in the nasal secretions, feces, blood, spleen, and liver of an infected parrot.
2. Parrots are susceptible to intraoral, intranasal, or intramuscular inoculations of the virus.
3. The most constant pathological changes produced by psittacosis in parrots occur in the spleen and liver. The lesions exhibited in the latter organ consist of areas of necrotic liver cells and damage to bile ducts. In no instance, in our experience, were lesions observed in a parrot's lungs comparable to those found in the lungs of men.
4. "Minute bodies" similar to those described by Levinthal and others were found in many, but not in all of the infected birds.
5. Parrots that have recovered from one attack of psittacosis exhibit an active immunity against reinfection.