Kinetodesmal fibers arise from the proximal ends of the basal bodies and curve upward and to the cell’s right of the kinety. Together with kds arising from more posterior basal bodies they form a st...

A high magnification view of the paracrystalline structure of the trichocyst tip and the cortex and core of the resting trichocyst body. Details of the sheath around the tip spike are also shown. (For...

Detail of the filamentous reticulum along the left side of the cytopharynx from which cytopharyngeal ribbons arise next to its nodes. Quadrulus associated ribbons lie between the filamentous reticulum...

Nucleoli in a macronucleus of a cell undergoing micronuclear division. The nucleolus appears to have an organized surface layer composed of parallel threads of subunits. These may be developing riboso...

Ciliates such as Paramecium have specialized sites for endocytosis and exocytosis. Most of their surface is not available for internalization of membrane because of the underlying alveolar sac system....

Receptor mediated endocytosis is a process in which extracellular molecules are taken into the cell via coated vesicles that pinch from the plasma membrane. In Paramecium the resulting vesicles fuse w...

Dictyosomal elements of the Golgi complex consist of a layer of coated transition vesicles next to a specialized area of ER called the transition zone and two or three highly fenestrated layers of cis...

Sections show the origin of one cytopharyngeal ribbon of 12 microtubules from the nodes and show the tight curve the ribbon follows over the cytostomal cord. These ribbons move discoidal vesicles, aci...

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...

Stacks of 4 or 5 kinetodesmal fibers occupy the longitudinal ridges in a cross-sectioned cell. The kds lie along the right side of each ridge (cell’s left side), and as the kds are tapered, the smal...