communities of various socioeconomic levels in Erie County and Series A samples, sewage from stages of treatment in Albany and environs. The samples were collected by suspending cheesecloth swabs 3 in flowing sewage for two days (Series A) or for seven days (Series B). The expressed liquid of the swabs was adsorbed onto and eluted from ion exchange resin,4 treated with antibiotics, and stored in a dry ice chest at -450 C until tested. Etherization 5 and centrifugation of the thawed eluates before inoculation into tissue cultures were helpful in reducing toxicity. The eluates were inoculated into newborn mice and into tissue culture tubes. Eight one-day-old mice were inoculated subcutaneously with 0.03 ml of eluate and eight intraperitoneally with 0.05 ml. Mice paralyzed or spastic during the 14-day observation period were killed and their tissues harvested for confirmatory passage. Pathologic examination and serologic identification were carried out on confirmatory passage material. Three fourto seven-day-old tissue cultures containing 0.5 ml maintenance 1 or 199H 8 solution were inoculated with 0.1 ml amounts of the eluates and were incubated at 320 or 370 C. Before inoculation cultures were rinsed at least twice to remove traces of serum. Fluids from cultures which showed signs of degeneration during the sixto 10-day observation period were subcultured. Serologic typing was carried out with secondor third-passage fluids.