The purpose of this paper is twofold: (1) to review the reproductive systems of the pulmonates in order to determine the inherent trends displayed by this system in these animals. The different elements composing this system, especially those of the pallial region, are homologised and the functional aspects (s. 1.) of the components described, including the origin and evolutionary development of the various prostatic elements of the pulmonates; and (2) to review ideas on and discuss the origin of the hermaphroditism of the pulmonate reproductive systems.