'1'iii/lnr: .\i iir/nii/iliir Ai'/Kii-nh/x in Kni>l<>lis 40!) 



whirl) is lint the r;lsr. Furthermore. the organelles with which the 

 strands are associated arc never translated in "the direction of the 

 strands leaving the motorinm. hut rather in a direction at right angles 

 to the course of the tihers. thus inilitat ing against a contractile func- 

 tion for the tihers" (Sharp. 1!14. p. 81 



The perfect coordination in the activity of mobile parts, all of 

 which are supplied liy strands from the centrally placed inotoriuin. 

 and the advantageous location of the system to function "as a center 

 nf motor coordination in an animal which is exceedingly active, exceed- 

 ingly responsive to external stimuli and one, moreover, which exhibits 

 a high decree of selective feeding." are phenomena which could In- 

 most satisfactorily explained on the hypothesis that this apparatus 

 functions as a primitive type of nervous system whose coordination 

 is i fl'ected through the central motor mass, the motorium. Accord- 

 ingly, Sharp gave to this system the name " neuromotor apparatus." 



fii a fresh-water ciliate. K>ii>li>l<x /m/i/ln, a fibrillar system rom- 

 paralile with that of Diplodinium < rni/ilnl 11 in has recently hern worked 

 out and descrihed liy Yocom (1918). Tt is noteworthy that these two 

 forms are of different orders and habitats as well, the latter an Oligo- 

 trichan parasite common in the stomach of ruminants, while the former 

 is free-living and a member of the order Ilypotricha. The presence of 

 these homologous systems in ciliates so varied in mode of life and kin- 

 ship indicates the possible widespread occurrence of comparable 

 systems in numerous other forms of this exceedingly interesting and 

 important group of protozoans. 



Let us now consider the nature of this "neuromotor apparatus" in 

 K n liln /-\ /m/illii. as found and described by Dr. Yocom. 1'ivfacing 

 this consideration, if will be convenient to offer a very brief account 

 of the external form of the animal and the relative positions of its 

 ectoplasmic oi-Lranelles. The body in general contour roughly resembles 

 the bowl of a tablespoon, the convex surface of which represents the 

 dorsal side of the oriranism. and the concave surface its ventral side. 

 For the anterior end. to complete the figure, one should picture a mere 

 stub of a very broad handle still attached and well rounded to suit the 

 contour of the bowl. The stub would then represent the oral lip of the 

 animal. This lip forms an anterior projection of the dorsal side over 

 a wide triangular cytostome at whose posterior apex is the pharynx 

 situated on the left about halfway down the body. A series of mem- 

 branelles borders the dorso-posterior margin of the oral lip and on the 

 left turns ventrad to continue along the left side of the cytostome into 



