1920] Taylor: Nt uronwtor Apparatus in Euplotes 4'27 



that show basal granules distinctly, while later there appear along the 

 cilia minute, coagulated globules comparable with those described for 

 the cirri. Also, excellent views of the shape and arrangement of the 

 entire series of membranelles may be had upon transferring an 

 organism to a hanging drop of 0.1 per cent solution of tannic acid. The 

 animal usually dies within a few minutes but in the meantime the 

 membranelles become stained and their movements are slowed so as 

 to afford a splendid study of each membranelle of the entire series. 



The primary function of the membranelles of the cytostomal and 

 pharyngeal region is food-taking. Yoeom (1918) has discussed the 

 manner of the intake of food, but he does not refer to the expulsion 

 of particles from the pharynx after they have been "sampled" and 

 refused. This ejection may be sometimes rather violent and is effected 

 by a reversal of the membranelles which may involve only those of 

 the pharynx, or also the cytostomal membranelles. or occasionally 

 even the entire series. The chief function of the adoral membranelles 

 is their indispensable service in swimming. An acount of this im- 

 portant feature is given in later paragraphs. 



Neuromotor Apparatus 



The system of fibers connecting the series of membranelles, the 

 lattice-work structure of the oral lip and the five anal cirri to a small 

 bilobed body lying in the extreme anterior right of the animal, together 

 with other fibers radiating from the base of the remaining thirteen 

 cirri were found and described by Yocom (1918) as the neuromotor 

 apparatus of Euplotes patella. In preceding paragraphs I have given a 

 brief but fairly complete review of Dr. Tocom's account of this appa- 

 ratus. It is my purpose here to reconsider certain parts of his account 

 and in following paragraphs (see "Experimental") offer a few minor 

 modifications and additions (fig. 13). 



Following Yocom 's figures and descriptions, I have been able to 

 identify in the living organism all the structures of this interesting 

 and complex mechanism. The anal cirri fibers are usually distinctly 

 visible throughout most of their length. The presence of food vacuoles 

 dorsal to the frontal cirri frequently interferes with the tracing of 

 these fibers to their junction with the motorium, but this interference 

 may be obviated by keeping the animals in well-filtered water for 

 several hours, at the end of which time most of the food vacuoles will 

 have disappeared. It is then possible to observe not only all five fibers 



