1920] 'I'/ii/l/i/-: Neuromotor Apparatus in l''u/>l<>tix 



Sharp i 1!M-1 ' was the tirst to succeed in tliis endeavor. Working 

 upon a parasitic ciliate. l>ii>l<iilii<i'n,>i 'ni<!nhnn. common in the 

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

 necting all the niot.pi- orjanellex 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," hears all the organs of 1 miotion 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 e.xoskeleton. 

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



located tl ylostome. 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- 

 bi-anelles that function chiefly in locomotion. Encircling these mem- 

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

 prominent operculnm. The latter structure is continued dorsally into 

 the dorsal disk which is surrounded by the dorsal membranelles. 

 These, like the adoral membranelles. are locomotor organdies. 



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- 

 cnlar fibers. ((>) 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 



