1918] Yocuni: The Neuromotor Apparatus of Eiiplotes Patella 357 



fiber the function of contractility. ]\Iaier (1903) in commenting on the 

 fibers found in ciliates, suggests that they have a supporting function. 

 HoM^ever, none of the above mentioned investigators has described 

 these fibers as joining to any such structure as the motorium of 

 Euplotes patella, neither have they given credence to the idea that the 

 fibers may be nervous in function. 



Joining the right end of the motorium is another fiber which also 

 connects with certain motor parts of the animal, the membranelles, 

 thus forming an unbroken fibrillar complex between the heavy anal 

 cirri which are chiefly used in locomotion and the membranelles of 

 the adoral zone which function as organs of food getting, organs of 

 locomotion and as tactile structures. This membranelle fiber (mb.f., 

 fig. A), which has the same granular structure as the motorium and 

 fibers to the anal cirri, extends from the motorium along the base of 

 the anterior lip around the anterior end of the cytostome where it 

 connects with the anterior cytostomal membranelles, and the lattice- 

 work sensory structure of the lip, along the entire left edge of the 

 cytostome in connection with the lateral cytostomal membranelles. In 

 the pharyngeal region this fiber is indistinct and difficult to see as it is 

 hidden by closely massed cilia of the pharynx. When stained the 

 membranelle fiber shows the same staining reaction as the other parts 

 of the neuromotor apparatus, thus indicating that all parts of this 

 structure are in some way related to one another, at least to the extent 

 of having the same chemical composition. 



In the anterior lip is another structure in connection with this 

 associated neuromotor apparatus, which although it has not been 

 heretofore described for any other species of Euplotes, is of especial 

 interest and significance. Along the membranelle fiber in the anterior 

 lip, at the points where the anterior cytostomal membranelles join the 

 fiber, enlargements occur from which short rodlike projections grow 

 out into the lip almost at right angles to the rows of basal granules of 

 the anterior membranelle (s.a.l., fig. A). Each of these processes is 

 connected with its neighbors by bifurcating projections which meet it 

 at an angle of about 120 degrees. These second projections meet in 

 such a way as to form Vs with the apices pointing anteriorly. From 

 the apices of these Fs, short projections extend still farther forward 

 into the lip, forming the lattice-work structure, occupying from one- 

 half to two-thirds of the width of the lip. Thus the lip is provided with 

 a structure having a series of points extending well out toward its 

 anterior edge, directly connected with the fiber of the membranelles. 



