FINE STRUCTURE 55 



in Stentor by identifying nerve structures. Following him closely 

 and yet insisting on the uniqueness of what he had found, Dierks 

 (1926a) also sought a nervous system because he thought that the 

 coordinated behavior of Stentor implied its existence. 



Neresheimer called his fibers "neurophanes" to contrast them 

 with *' myophanes ", the term used by Haeckel for the myonemes. 

 In retrospect Neresheimer seems to have stained and been 

 examining the ribbon bundles, which may indeed have a nervous 

 function if they serve to coordinate the body cilia. But in whole 

 mounts he could follow these bands only from the posterior end 

 to the middle of the cell. Along this course the fibers branched and 

 some of them ended in minute bulbs or boutons which he regarded 

 as sensory but which Dierks and Gelei (1926) thought to be mere 

 optical artifacts. Most of the study was on pieces of ectoplasm 

 loosed from the animal by treatment with methylene blue, and 

 Schroder (1907) criticized the results as artifacts from injury and 

 distortion. In reply, Neresheimer (1907) admitted that he could 

 not find his neurophanes in all preparations but insisted that they 

 were evident in some. Apparently he saw something of the ribbon 

 bundles but could not divine their intimate structure and actual 

 extent. To demonstrate that his fibers were nervous in function 

 he treated stentors with drugs which act as nervous excitants and 

 depressants in metazoa and found they had a similar effect on 

 stentors but not on other ciliates in which "neurophanes" are 

 lacking. 



The fibers described by Dierks were called "neuroids". He 

 pictured them as running close to but above the myonemes 

 (ribbon bundles) and present throughout their entire extent, 

 either ending in these bands or sending side branches to them. 

 The " neuroids " may very well have been kinetodesmata or strips 

 torn loose from the ribbon bundles, as Villeneuve-Brachon sug- 

 gested. In any event, nothing like them has so far been found with 

 the superior resolution of the electron microscope. 



Although Dierks (1926a) himself questioned why stentors 

 should need ''nerves" when the myonemes are so intimately in 

 contact with other parts of the cell, he nevertheless considered the 

 "neuroids" nervous in function. This assumption was based on 

 the response of stentors to the potassium ion which causes them to 

 relax in the extended state as if the "neuroids" were anaesthetized; 



