Abstract
A simplified procedure is descr. for isolating the cysts either from cultures or from feces; their successful chemical sterilization; and the initiation of pure cultures with single bacterial associates. Escherichia coli and Chromo-bacterium prodigiosum were the bacteria used in such cultures. Enormous growths[long dash]up to 8 million per ml. of culture[long dash]were obtained with E. coli as the associate.