1. A viral agent, Powers, causing myocarditis, adipositis, pancreatitis, hepatitis, and encephalomyelitis but not myositis in suckling mice 1 to 2 days old has been isolated from the stool of a patient in whom the clinical diagnosis was "non-paralytic poliomyelitis."
2. Serological evidence linking the virus to the clinical disease observed was clear only in the case of "non-paralytic poliomyelitis" from which it was isolated.
3. The possible relation of this agent to the Coxsackie group of viruses is discussed. No serological relationship with the Connecticut 5, Ohio R, and High Point strains was demonstrated.
4. A second virus, Matulaitis, has been isolated from a concurrent case of "non-paralytic poliomyelitis" in the same area. Lesions produced in infant mice by the two agents show certain differences.