206 CILIATE FIBRILLAR SYSTEMS 



Yocom (I9I8), working in Kofoid's laboratory, found and described 

 in E. patella a fibrillar system much more extensive than that delineated 

 in other Enplotes by Maupas, Prowazek, and Griffin, as noted above. 

 In addition to the anal cirri fibers, such as they had found, Yocom 

 discovered in E. patella "a fiber connecting the inner ends of the 

 cytostomal membranelles" ("anterior cytostomal fiber"), and a "ino- 

 tor'ium" (after Sharp, 1914) which united the membranelle fiber with 

 those from the anal cirri. A structural integration was traced, therefore, 

 between the cytostomal membranelles and the anal cirri. Similar fibers, 

 radiating from the bases of the other cirri, were also described, but no 

 connection was found between them and the others above mentioned. 

 In the "anterior lip" of this species, Yocom depicted a fibrillar lattice- 

 work which was united by "short rodlike projections" to the mem- 

 branelle fiber. 



The intimate contiguity between this fibrillar system of E. patella 

 and its motor organelles was clearly detailed by Yocom. Certain minor 

 modifications and additions to his account were made by Taylor (1920), 

 from studies especially of dissected and slowly disintegrating organisms. 

 Following Sharp's (1914) terminology for a comparable fibrillar system 

 which he had found and elaborately described in Diplodinium ecauda- 

 tum, Yocom designated this system in E. patella a "neuromotor ap- 

 paratus." 



The neuromotor apparatus discovered by Yocom is to be distinguished 

 from an additional fibrillar system in this same species, which was 

 carefully worked out by Turner (1933) by means of his modification 

 of Klein's (1926) and von Gelei and Horvath's (1931) methods. His 

 technical procedure is here worthy of note. After fixing the organisms 

 in osmic acid vapor for about three seconds, and before the material 

 was quite dry, Turner added two or three drops of 2-percent silver 

 nitrate. Within four to eight minutes the nitrate was poured off and the 

 slide placed in distilled water, barely covering the preparation. Over a 

 white background, the slide was then exposed to the sun until the 

 reduction of the nitrate had progressed as desired, according to occa- 

 sional microscopic examinations. The preparation was then thoroughly 

 washed in distilled water, dehydrated, and mounted. "The method gives 

 strikingly clear-cut results." For this study, various other techniques 

 were also employed, on both whole mounts and sections. 



