66 PROTOZOOLOGY 



fibers have nothing to do with the maintenance of the body form, 

 since there results no deformity when Euplotes is cut fully two- 

 thirds its width, thus cutting the fibers, and that when the motorium 

 is destroyed or its attached fibers are cut, there is no coordination 

 in the movements of the adoral membranellae and anal cirri. Ham- 

 mond (1937) and Hammond and Kofoid (1937) find the neuromotor 

 system continuous throughout the stages during asexual reproduc- 

 tion and conjugation so that functional activity is maintained at all 

 times. 



A striking feature common to all neuromotor systems, is that 

 there seems to be a central motorium from which radiate fibers to 

 different ciliary structures and that, at the bases of such motor or- 

 ganellae, are found the kinetosomes or basal plates to which the 

 "nerve" fibers from the motorium are attached. 



Independent of the studies on the neuromotor system of American 

 investigators, Klein (1926) introduced the silver-impregnation 

 method which had first been used by Golgi in 1873 to demonstrate 

 various fibrillar structures of metazoan cells, to Protozoa in order 

 to demonstrate the cortical fibers present in ciliates, by dry-fixation 

 and impregnating with silver nitrate. Klein (1926-1942) subjected 

 ciliates of numerous genera and species to this method, and observed 

 that there was a fibrillar system in the ectoplasm at the level of the 

 kinetosomes which could not be demonstrated by other methods. 

 Klein (1927) named the fibers silver lines and the whole complex, 

 the silverline system, which vary among different species (Figs. 18- 

 20). Gelei, Chatton and Lwoff, Jlrovec, Lynch, Jacobson, Kidder. 

 Lund, Burt, and others, applied the silver-impregnation method 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 considered it in- 

 fraciliature. 



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 (E. eurystomus) 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 maintains that the 

 neuromotor apparatus in Euplotes is augmented by a distinct but 

 connected external network of sensory fibrils. He however finds no 

 motorium in this protozoan. 



