This slide shows a number of stained specimens of Paramecium engaged in various stages of a type of sexual reproduction called conjugation. During this process, two individuals of different mating types come together and form a cytoplasmic bridge between them. This is followed by a complex set of divisions and degenerations of the macronuclei and micronuclei that ultimately results in an exchange in genetic material between the conjugants analogous to the sexual reproduction seen in multicellular organisms.