... from the contractile vacuole seen immediately after changing the external osmolarity reduces an abrupt change in cell volume and thereby protects the cell from the disruption of the plasma membrane by excessive stretch or dehydration during shrinkage. ‡ Author for correspondence (e-mail: naitoh...

...Yutaka Naitoh; Takashi Tominaga; Masaki Ishida; Agnes K. Fok; Marilynn S. Aihara; Richard D. Allen ABSTRACT To examine the forces needed for discharge of the fluid contents from the contractile vacuole of Paramecium multimicronucleatum , the time course of the decrease in vacuole diameter during...

...Yutaka Naitoh; Takashi Tominaga; Richard D. Allen ABSTRACT The precise relationship between the rate of contractile vacuole fluid discharge and the vacuole diameter at the start of systole was determined in cells of Paramecium multimicronucleatum subjected to various external conditions. The rate...

... observed in intact colonies. Transmission electron micrographs reveal a unique organelle, with characteristics of a contractile vacuole, in the apical stolonal endoderm. The activity of this organelle, inferred from static observations, correlates with the observed pattern of stolonal contractions...