1920] Taylor: Neuromotor Apparatus in Euplotes 407 



Sharp (1914) was the first to succeed in this endeavor. "Working 

 upon a parasitic ciliate, Diplodinium ecaudatum, coihraon in the 

 stomach of the ox, this investigator discovered a system of fibrils con- 

 necting all the motor organelles of the oral region. Owing to the 

 shape, position, relations, and staining properties of this system. Dr. 

 Sharp regarded it as having an unusual significance. 



The organism in several respects is one of the most complex among 

 all known Protozoa. The body, which resembles "a short, plump 

 banana," bears all the organs of locomotion and food-taking at the 

 anterior end. This region is more or less flexible and decidedly con- 

 tractile, while the remaining portion of the body is rigid, free from 

 appendages and, for the most part, firmly supported by an exoskeleton. 

 At the anterior extremity, toward the ventral side of the body, is 

 located the cytostome. This is an elliptical aperture surrounded by 

 an oval disk that bears on its inner border a circlet of oral cilia. The 

 cytostome opens directly into the oesophagus, a short tube which ends 

 blindly beside the anterior end of the macronucleus. Around the 

 outer border of the oral disk appears a row of heavy adoral mem- 

 branelles that function chiefly in locomotion. Encircling these mem- 

 branelles are an inner and an outer adoral lip dorsal to which lies a 

 prominent operculum. The latter structure is continued dorsally into 

 the dorsal disk which is surrounded by the dorsal membranelles. 

 These, like the adoral membranelles, are locomotor organelles. 



The relation of the above structures has been very briefly stated 

 only to facilitate a review of the excellent description Dr. Sharp has 

 given of the complex motor apparatus found in this ciliate. The 

 constituent parts of this mechanism embrace (1) a motorium lying 

 deep in the ectoplasm beneath the operculum, (2) a dorsal motor 

 strand, (3) a ventral motor strand. (4) a dorsal lip strand, (5) oper- 

 cular fibers, (6) oesophageal fibers, and (7) a circumoesophageal ring. 

 The relation of these parts to the organelles with which they are asso- 

 ciated is best described in Dr. Sharp's own words. In a specimen 

 stained with his modification of Mallory's connective tissue stain, the 

 so-called motorium was first observed as a mass "which had stained 

 rather intensely and showed by transmitted light the same bright red 

 color which was noted in the case of the micronucleus. Further in- 

 vestigation along this line revealed the fact that not only was this mass 

 constant but (1) that it was connected dorsally, by means of a delicate 

 strand, i.e.. dorsal motor strand, with the bases of the dorsal mem- 

 branelles, also a branch strand ran along the base of the inner dorsal 



