208 ELECTRON-MICROSCOPIC STRUCTURE OF PROTOZOA 



The adoral ciliature consists of a long spiral band in which 

 cilia occur in short oblique rows, each row arising from a basal 

 rod visible in the light microscope (Text-fig. 16). Electron 

 micrographs of sections through the level of the kinetosomes 

 show that the rows are uniformly aligned, and not separated into 

 groups corresponding to discrete membranelles. Each kineto- 



Mymr 



Text-figure 16. Diagrammatic reconstruction of part of the 

 adoral ciliary zone of an ophryoscolecid ciliate. Two syncilia are 

 shown at the rear, labeled Ma and Mi. In front of these are shown, 

 on the right, the stubs of cilia making up another syncilium and, 

 on the left, microvilli labeled Mi, that protrude from the cell 

 membrane between cilia. In front of this are the apices of kineto- 

 somes (Ki) on the left and the outlines of basal rods on the right. 

 Noirot-Timothee has shown that in at least some species the basal 

 rods pass obliquely across the band rather than longitudinally as 

 shown here. Commissural fibers (Ko) are shown connecting the 

 kinetosomes laterally. On the cut faces of the stereogram are seen 

 various fibrous structures considered by Bretschneider to be 

 myonemes. My I, II, and III are retrociliary fibers passing in 

 different directions. My IV and Ld together are the fibrillar sheets 

 subtending the peristomial disc (D). From Bretschneider, 1960. 



