Pellicle(redirected from brown pellicle)
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a condensed layer of cytoplasm on the body surface of many protozoans, such as flagellates and infusorians. It is sometimes thin and elastic and does not inhibit change in body shape. In other cases, it is solid and defines a constant body shape. The exterior of the pellicle is often sculptured, with denticles, papillae, ridges, or other formations. Study of the pellicle’s ultrastructure in the electron microscope shows that the pellicle is usually composed of two separated layers. Each layer, in turn, consists of two membranes, with a less dense, narrow fissure between them.