Journal of Cell Science, Vol 10, 883-903, Copyright © 1972 by Company of Biologists

Submitted on September 23, 1971

Microtubule-Arms and Propulsion of Food Particles Inside a Large Feeding Organelle in the Ciliate Phascolodon Vorticella

¹ Department of Zoology, The University, St. Andrews, Fife, Scotland, and Department of Zoology, Cambridge, England

Attention is drawn to the apparently invariable presence of rows of arm-bearing microtubules lining the sucking mouthparts of ciliates. Their arrangement inside the cytopharyngeal basket of Phascolodon is described and compared with that in the tentacles of suctorians and the sucking tubes and baskets of other ciliates. It is suggested that arms are involved in the propulsion of materials alongside microtubules when these ciliates ingest food. Mechanisms by which arms may accomplish this are outlined. The different functions of links and other intertubular materials in the several microtubular basket components of Phascolodon are considered. The form and arrangement of microfilarnents and pointed, sharp-edged structures around the mouth are also described. The possibility that the pointed structures are used for biting is discussed.