A high resolution view of a dividing Didinium nasutum. This large ciliate is capable of engulfing Paramecium. It has a thick ectoplasm containing numerous mucocysts embedded in its extensive epiplasm....

Lamellae of cytopharynx in the opisthe of a dividing cell. This cytopharynx is not yet functional and lacks most of the medium dense vesicles that accumulate between the lamellae. Toxicysts are presen...

Freeze fracture of the plasma membrane and outer alveolar membrane of the pellicle of V. microstoma. The surface of Vorticella is encircled by rings which follow the septa of underlying alveoli. In th...

A high resolution tangential view of the surface of a non-dividing cell shows several ribbons of microtubules between the alveolar sac and the epiplasm. The thick fibrous layer associated with the epi...

Detail of cell surface structures. The cell is covered by the plasma membrane and outer alveolar sac membrane which is separated from the inner alveolar sac membrane by an extensive alveolar space. Ci...

The early days of electron microscopy provided the first views of cell ultrastructure. This electron micrograph shows the plasma membranes of two closely apposed glial cells from the central nervous ...

This electron micrograph shows the E-fracture face (above) and P-fracture face (below) of the membrane of adjacent epithelial cells from the ciliary epithelium of the monkey eye. Intramembranous part...

This image, produced by the freeze-fracture technique, shows regional specialization in the structure of mammalian sperm. The P-face of the plasma membrane of a guinea pig sperm tail can be divided i...

This electron micrograph shows the P-face of a small region of membrane from the midpiece of guinea pig sperm. The changing distribution of intramembranous particles (IMPs)in this image provided some...

Transitional epithelial cells of the bladder. Upper panel is an electron micrograph from thin sectioned superficial cells of the uroepithelium in the rat; lower panel shows a scanning electron microg...