A method for isolation culture of Paramecium aurelia, P. caudatum, P. multimicro-nucleatum, and for Blepharisma undulans is described. The culture tubes and transfer pipettes are easily made of glass tubing. The method has the advantages of making easy and accurate determinations of division rate. The effects of variations in temp., conc. of nutrient, buffer type and conc. pH, and type of inoculum are recorded in graphs.