The mechanisms of meiosis induction in Paramecium were analyzed in this publication, mainly based on the author's researches. The clonal cycle begins with fertilization preceded by meiosis. The conditionings of meiosis induction were precisely studied in cells entering autogamy, a self-fertilization process, occurring in P. aurelia species. In clones of cells, meiosis appears during starvation after passing a number of vegetative divisions (cell generations), starting from the last fertilization. Investigations concerning the number of generations between two successive autogamies in Paramecium were performed. Genetic as well as the exogenous and endogenous factors were studied and discussed in order to elucidate their effects on induction of meiosis.