(Paris, Gauthier-Villars), 1887. 4to. No wrappers. In: ""Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences"", Tome 105, No 7. Pp. (325--) 563. (Entire issue offered). Maupas' paper: pp. 356-359.
First appearance of this classic paper in whic Maupas determined that fertilization in protozoa is essential to the indefinite continuation of a cell strain. His discovery proved an importent stimulus to subsequent investigation not only upon protozoa but also in the area of parthenogenesis.""He found in Paramecium that after generations of division, the stock becomes infeebled. Ultimately the individuals die, unless they meet partners for conjugation. When two such enfeebled individuals meet, their bodies are approximated and they interchange nuclear elements. Next, division takes place. The stock has regained its vigour. No differentiation of sexes is evident in the conjugatory process, though such differentiation can be traced in other prorozoa.""(Singer ""The Story of Living Tings"", p. 531 ff.).Thomas Hall ""A Source Book in Animal Biology"", pp. 458-60.