Abstract
1. A child is described in whom an acute osteitis was produced by some organism which could neither be identified nor cultured in vitro, and which provoked a violent general reaction but which also showed a distinct affinity for the central nervous system.
2. This organism survived in a cavity in the femur for four months; it preserved its pathogenic properties, and could only be cultured in living tissue.
3. A twice repeated passage through animals increased the toxicity of this organism and proved its affinity for the central nervous system.
4. This organism may have been a virus similar to those producing encephalitis. A final answer may be obtained by further attempts to provoke experimental osteitis with live cultures of viruses in animals.
