Septa of bordering alveoli when lying in the plane of section exhibit pores at their outer margins closest to the plasma membrane. This shows that there is physical continuity between the lumens of al...

Detail of the junction between the ribbed wall and the right side of the cytopharynx area. The ribbed wall is covered by alveoli and the ribs are produced by small narrow ridges similar to the larger ...

The three ciliary membranelles in the buccal cavity from which this class of ciliates gets its name, Oligohymenophorea, are each composed of four rows of basal body/cilium complexes. The quadrulus has...

A grazing section through the cell’s surface shows segments of six rows of cilia running across the figure sectioned superfically at the top and deeper into the cell as one progresses down the figur...

Detail of the origin of the cytopharyngeal microtubules along the left side of the cytopharynx that arise within the filamentous reticulum in contact with its electron-opaque nodes. This system does n...

Single microtubules extend into the cytoplasm from the tips of the cytoproct ridge. These are thought to come to lie along the surface of the approaching DV-IV and to pull the ridge down against the D...

The cytosol of Paramecium contains many vesicles of various sizes, shapes and contents as well as complex particles such as ribosomes and glycogen granules. The rough endoplasmic reticulum exists as m...

Details of the origins of the cytopharyngeal ribbons and the quadrulus associated ribbons. At first view the cytopharyngeal ribbons look like they might arise next to basal bodies but it is clear that...

The collapsed cytopharyngeal membrane extends from the open cytopharynx into the cytosol. This membrane is associated with many docked acidosomes, vesicles that contain V-type proton translocating ATP...

The micronucleus of Paramecium caudatum is distinctive from other closely related Paramecium such as P. multimicronucleatum and P. tetraurela. P. caudatum has only one micronucleus of a type in which ...