MORPHOLOGY 



59 



which marks the outer end of the trichocyst. The second part which 

 Klein called "directly connected" (subpellicular) conductile system 

 consists essentially of the longitudinal lines connecting all basal 

 granules in a longitudinal row of hexagons and of delicate transverse 

 fibrils connecting granules of adjacent rows especially in the cyto- 

 stomal region CFig. 19). 



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

 cleatum, showing various organellas, X7300 (Lund), bg, basal granule; 

 c, cilia; et, tip of trichocyst; If, longitudinal fibril; p, pellicle; t, trichocyst; 

 tf, transverse fibril. 



By using Sharp's technique, Lund found the neuromotor system 

 of Paramecium multimicronucleatum constructed as follows: The 

 subpellicular portion of the system is the longitudinal fibrils which 

 connect the basal granules. In the cytostomal region, the fibrils of 

 right and left sides curve inward forming complete circuits (the 

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

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

 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 basal granules, 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 



