"Vorticella. A, B, living specimens in different positions; C, optical section; D1, D2, diagrams illustrating coiling of stalk; E1, E2, two stages in binary fission; E3, free zooid; F1, F2, division into mega- and microzooids; G1, G2, conjugation; H1, multiple fission of encysted form; H2, H3, development of spores; ax. f, axial fibre; cort, cortex; cu, cuticle; c. vac, contractile vacuole; d, disc; gull, gullet; m, microzooid; mth, mouth; nu, meganucleus; per, peristome." -Parker, 1900

Vorticella

"Vorticella. A, B, living specimens in different positions; C, optical section; D1, D2, diagrams illustrating…