220 CILIATE FIBRILLAR SYSTEMS 



knowledge of their contractile function probably also that of conducting. 

 But for the other fibrils of this ciliate, evidence regarding their actual 

 function or functions is mostly wanting. Interpretations based on mor- 

 phological evidence concern chiefly the relations of these fibrils (neuro- 

 phanes or neuroids) to other organelles. 



Neresheimer's observation on the parallel course of the neurophanes 

 with the myonemes and the differential stainability of these two kinds of 

 fibrils, suggested for the neurophanes a conductive function. By means 

 of a drop-weight apparatus (Fallmachine) he tested the responses of 

 Stentor to a variety of narcotics: morphine, strychnine, atropine, caffein, 

 and so forth, and to other chemicals which are known to affect the nerves 

 of higher animals. On the basis of an assumed selective action of these 

 reagents, he derived evidence which seemed to favor assigning a nervous 

 function to the neurophanes. The technique for these tests was ingeni- 

 ously devised and might prove useful also for others. But owing to lack 

 of adequate controls and because of other possible interpretations, his 

 results do not seem very convincing. 



Schroder (I906) considered Neresheimer's interpretation of the 

 neurophanes invalid. He believed that Neresheimer had mistaken a struc- 

 tural feature of the "mid-stripes" for his neurophanes, as indicated upon 

 comparing the latter's Figures 7 and 8 with Schroder's Figures 1-5. 



From Dierks' more extensive and detailed studies, however, there can 

 be no doubt about the identity of another fibril coursing with each of 

 the myonemes. The occurrence of these was consistent and their relation- 

 ship with the myonemes apparently significant. As formerly noted, 

 Dierks found that in good preparations branches were given off from 

 the neuroids to the myonemes which they evidently joined. He considered 

 several possible functions which this connection between neuroids and 

 myonemes might indicate, and finally, as a plausible hypothesis, sug- 

 gested for them a conductive function. 



Von Gelei (1926c) rejects this interpretation. From his own previous 

 studies (1925) on Stentor, he concludes that Neresheimer's neurophanes 

 and Dierks's neuroids are real and are identical structures. But, according 

 to von Gelei, these neuroids are not fibers but bands composed of fibrils, 

 which are quite wide, especially in the aboral region. They are not a 

 structural feature of the pellicle (Schroder, 1906), but are sub pellicular 

 and fused to the pellicle. This was indicated in contracted Stentors by 



