CILIATE FIBRILLAR SYSTEMS 



251 



memb. 



KA_,,b.pf. 



b.i. 



Figure 90. Spirostoiiium 

 ambiguum. Diagram of 

 membranelles and their 

 intracytoplasmic structures. 

 (Bishop, 1927.) 

 b. fib. — basal fibril 

 b. 1. — basal lamella 

 b. pi. — basal plate 

 e. thr. — end thread 

 memb. — membranelle 



-_e. thr. 

 ^ b. fib. 



C. OLIGOTRICHA 



Diplodinlum ecaudatum (Sharp, 1914). — The motorium is located 

 in the ectoplasm above the base of the left skeletal area and between the 

 left extremities of the dorsal and the adoral membranelle zones. Dorsally 

 it is connected with the bases of the dorsal membranelles by a dorsal 

 motor strand, which also sends a branch along the base of the inner 

 dorsal lip. A ventral motor strand connects the motorium with the bases 

 of the adoral membranelles and its branch and passes along the base 

 of the inner adoral lip. Numerous fibers from the motorium follow the 

 contour of the operculum and disappear near the base of the right skeletal 

 structure. A circumesophageal ring surrounds the esophagus at the level 

 of the outer adoral furrow, from which a fibril connects with the mo- 

 torium. Certain fibrils in the wall of the esophagus appear to unite with 

 the circumesophageal ring; others are attached to skeletal structures and 

 are considered contractile fibrils. Rootlets from the oral cilia end in, or 

 close to, the ring. A coordinating (conductive) function was ascribed 

 to this fibrillar system of D. ecaudatum, because of its initimate relation- 

 ships with the motor organelles and its complete structural integration 

 through the motorium. 



Methods 



Fixatives: Schaudinn's (alcoholic, hot), Zenker's, Flemming's, Worcester's, 

 Bouin's, formalin 4 percent, osmic acid one percent (formalin 36° C.) 

 Stains: Heidenhain's haematoxylin and Mallory's triple. 



