Repeated attempts tto demonstrate the virus of poliomyelitis in the spinal fluid of human poliomyelitis both by cultures and by animal inoculation have all proved negative. Flexner and Lewis1have demonstrated its presence in the spinal fluid from an infected monkey drawn three days after the time of the intracerebral injection of virus. This fact suggests that it may be present in the fluid at some stage of the incubation period. If it is present, it is prrobable that it diminishes rapidly with onset of the symptoms, but may not wholly disappear. It is possible that the virus is present in the later stages in such minute quantities that it cannot be demonstrated by animal inoculation. Nuzum and Herzog2have recently reported the finding of a gram-positive coccus in 90 per cent. of the spinal fluids from positive cases of acute poliomyelitis. This organism was isolated with apparent