214 ELECTRON-MICROSCOPIC STRUCTURE OF PROTOZOA 



The dorsal bristles of Euplotes are cilia arising singly or in pairs 

 from conical depressions of the body surface. Glium and 

 kinetosome structure are typical, but no associated fibrous 

 structures are discernible. In light-microscope preparations, six 

 or more rod-shaped granules appear, surrounding each bristle. 

 Electron micrographs reveal these to be vacuoles bounded by a 

 single membrane and containing a homogeneous material of low 

 density. Similar vacuoles are observed singly or in small clusters 

 near the bases of the cirri and membranelles. The dorsal bristles 

 are supposed to be non-motile and have been suspected of serving 

 a sensory function. 



No structures were observed that would account for the 

 silverline system. 



