58 PROTOZOOLOGY 



and Lwoff, Gelci, Jirovec, Lynch, Jacobson, Kidder, Lund, and 

 others, applied the silver-impregnation methods to many other 

 ciliates and confirmed Klein's observations. Chatton and Lwoff 

 (1935) found in Apostomea, the system remains even after the 

 embryonic cilia have entirely disappeared and, therefore, named 

 it infraciliature. 



The question whether the neuromotor apparatus and the silver- 

 line system are independent structures or different aspects of 

 the same structure has been raised frequently. Turner (1933) 

 found that in Euplotes patella the silverline system is a regular 

 latticework on the dorsal surface and a more irregular network 

 on the ventral surface. These lines are associated with rows of 

 rosettes from which bristles extend. These bristles are held to be 

 sensory in function and the network, a sensory conductor system, 

 which is connected with the neuromotor system. Turner main- 

 tains that the neuromotor apparatus in Euplotes patella is 

 augmented by a distinct but connected external network of 

 sensory fibrils. 



Lund (1933) also made a comparative study of the two systems 

 in Paramecium multimicronucleata, and observed that the silver- 

 line system of this ciliate consists of two parts. One portion is 

 made up of a series of closely-set polygons, usually hexagons, but 

 flattened into rhomboids or other quadrilaterals in the regions of 

 the cytostome, cytopyge, and sutures. This system of lines stains 

 if the organisms are well dried. Usually the lines appear solid, 

 but frequently they are interrupted to appear double at the ver- 

 tices of the polygons which Klein called "indirectly connected" 

 (pellicular) conductile system. In the middle of the anterior and 

 posterior sides of the hexagons is found one granule or a cluster 

 of 2-4 granules, which marks the outer end of the trichocyst. The 

 second part which Klein called "directly connected" (subpel- 

 licular) conductile system consists essentially of the longitudinal 

 lines connecting all basal granules in a longitudinal row of hexa- 

 gons and of delicate transverse fibrils connecting granules of 

 adjacent rows especially in the cytostomal region (Fig. 19). 



By using Sharp's technique, Lund found the neuromotor sys- 

 tem of Paramecium multimicronucleata 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 cir- 

 cuits (the circular cytosomal fibrils) (Fig. 20). The postoral 



