68 



PROTOZOOLOGY 



of Paramecium multimicronucleatum constructed as follows: The 

 subpellicular portion of the system is the longitudinal fibrils which 

 connect the kinetosomes. In the cytostomal region, the fibrils of 

 right and left sides curve inward forming complete circuits (the 

 circular cytostomal fibrils) (Fig. 20). The postoral suture is separated 

 at the point where the cytopyge is situated. Usually 40-50 fibrils 



Fig. 19. Diagram of the cortical region of Paramecium multimicronu- 

 cleatum, showing various organellae (Lund), c, cilia; et, tip of trichocyst; 

 k, kinetosome; If, longitudinal fibril; p, pellicle; t, trichocyst; tf, transverse 

 fibril. 



radiate outward from the cytostome (the radial cytostomal fibrils). 

 The pharyngeal portion is more complex and consists of (1) the 

 oesophageal network, (2) the motorium and associated fibrils, (3) 

 penniculus which is composed of 8 rows of kinetosomes, thus form- 

 ing a heavy band of cilia in the cytopharynx, (4) oesophageal process, 

 (5) paraoesophageal fibrils, (6) posterior neuromotor chain, and (7) 

 postoesophageal fibrils. Lund concludes that the so-called silverline 

 system includes three structures: namely, the peculiarly ridged 

 pellicle; trichocysts which have no fibrillar connections among 

 them or with fibrils, hence not conductile; and the subpellicular sys- 

 tem, the last of which is that part of the neuromotor system that 

 concerns with the body cilia, ten Kate (1927) suggested that senso- 

 motor apparatus is a better term than the neuromotor apparatus. 

 Silverline system (Klein, 1926-1942; Gelei, 1932); fibrils in ciliates 



