1918] Yocum: The Neuromotor Apparatus of Euplotes Patella 379 



In this light it seems quite apropos to suggest that probably a 

 reversal of the terms would better indicate the function of these two 

 sets of fibers in Stentor. Should we ascribe a nervous function to the 

 myophanes as described by Neresheimer (1903) we might account for 

 the rhythmical contraction of the cilia, for the contraction takes place 

 not in the fiber but in the cilium itself, due to the central contractile 

 axis. Likewise a contractile function might be ascribed to the so- 

 called neurophanes. It would seem that were these contractile the 

 contraction of the body would be explained fully as well, even though 

 they do not extend the full length of the body. To say that they are 

 of nervous character would seem rather improbable, since a nervous 

 structure would naturally be expected to be found near the part of 

 the body which is the most exposed to stimuli and most sensitive. 

 These neurophanes are not closely associated with the large anterior 

 cilia w^hich in all probability are more sensitive than the small cilia 

 covering the body. The other set of fibers is closely associated with 

 these cilia and the undulating membrane, and it seems from their 

 relation to these that it is far more likely that they have the nervous 

 character rather than the so-called neurophanes. 



This brings us to the more recent work of Sharp (1913). He 

 undoubtedly found a structure in Diplodinium ecaudatum which is 

 , comparable to that found in Euplotes patella and described as the 

 neuromotor apparatus. There is no reason to think that this structure, 

 composed of fibers going to the motor parts and the so-called motorium 

 to which the fibers are joined, has a function other than that given 

 to it by Sharp, namely a neuromotor apparatus with special emphasis 

 on the neural function. However, it seems in the light of the above 

 criticism of the work on Stentor that Sharp made a wrong comparison, 

 for instead of this system of fibers in Diplodinium being "probably 

 comparable to the simple fibers of Stentor figured by Neresheimer 

 (1903) and regarded by him as 'neurophanes,' " they are comparable 

 to the myophanes. Especially is this true if we can base such a com- 

 parison on staining reactions and anatomical relationship, for the 

 fibers of Diplodinium are in connection with the basal parts of the 

 cilia composing the membranelles, a condition very similar to that of 

 the myophanes of Stentor. 



Besides the above mentioned examples there are many indications 

 that a structure may be found in many ciliates comparable to the 

 neuromotor apparatus of Euplotes patella and Diplodinium. In 

 looking over the literature several instances are shown in which there 



