1920] Taylor: Neuromotor Apparatus in Euplotes 435 



only one end to the membranelle fiber. Explorations with the needle 

 show this connection to be fairly secure. Also, the relation of each 

 membranelle to its corresponding membranelle fiber plate has been 

 found to be the same as the relation of the anal cirrus to its anal fiber 

 plate. Of this one may be fully convinced upon observing the mem- 

 branelle peel from its plate, a process which occurs not infrequently 

 about one minute after the disruption of the ectoplasm. Thereupon, 

 the basal plate of the membranelle, in which the basal corpuscles of 

 the component cilia and the ciliary rootlets are imbedded, completely 

 separates from the membranelle fiber plate which, like the anal cirrus 

 plate, shows a smooth, clean surface, with no evidence of any ciliary 

 rootlets having been attached. 



The "dissociated fibers" described by Yocom (1918) as radiating 

 at the base of each of the thirteen cirri (i.e., excluding the anal cirri). 

 have been found to be definitely connected with a plate somewhal 

 similar to the anal cirri plate, although of a shape (fig. 21) correspond- 

 ing to that of the base of the cirrus. These were first observed upon 

 the disintegration of an animal likewise stained with a .0001 per cent 

 aqeuous solution of haematoxylin. Several radiating fibers were ilis- 

 tinetly seen to be united to each plate. As yet. I have not definitely 

 observed the separation of one of these plates from its cirrus. Indica-" 

 tions in two cases where the separation was almost complete point 

 toward a relation between cirrus and plate here that is similar to the 

 relation of an anal fiber plate to its corresponding cirrus. 1 shall 

 designate these plates the "dissociated fibers plates." Figures 21 and 

 21a show several such plates from the same organism which vary 

 slightly in size and shape. These variations are apparently common. 



Transections 



Between the "group of three" and "group of four" frontal cirri 

 (fig. 2). — The anterior part of the animal swims rapidly (cf. swim- 

 ming movement 3, p. 429 ) , the inner side, that with the three frontal 

 cirri, performing a small circle and the opposite side a correspondingly 

 larger one. This performance continues the same after more water is 

 added to the hanging drop. The part infrequently revolves, a.s on the 

 long axis of the normal animal, and it occasionally reverses the effective 

 stroke of the membranelles to drive itself a short distance backwards 

 (cf. swimming movement 6, p. 429). In either case the circus move- 

 ment to the right is soon resumed and continues with few such inter- 

 ruptions until the part apparently becomes fatigued and dies. Death 



