1922] Rees: The Neuromotor Ai^paralus of Paramaecium 335 



dilute solutions of narcotics, e.g., morphine, strj'chnine, caffein, 

 curare, and nicotine, and found Stentor to be easily narcotized, while 

 Paramaecium remained apparently normal. 



Khainsky (1910) made a contribution to the morphology of 

 Paramaecium, the importance of which he did not realize. He fixed 

 the animals with concentrated bromine water and found that none 

 of the trichocysts was discharged, whereas they are frequently dis- 

 charged in other fixatives. In his plate 1, figures 6 to 8, he shows 

 distinct fibers connected to the basal granules of the cilia. He 

 comments as follows : ' ' Die Gleichartigkeit der Pibrillen mit dem 

 iibrigen Cilienteile begeist dass ihre Hauptrolle in der Ernahrung 

 und dem Wachstum der Cilie besteht." 



Most of the recent work on contractile and eonductile eleinents of 

 protozoans has been done by the University of California Zoological 

 Laboratory. The name neuromotor apparatus was given by Kofoid 

 (1915) to the integrating fibrillar complex in Giardia associated with 

 the blepharoplasts, parabasal bodies, and other active organelles of 

 locomotion.' The literature is already extensive, comprising 473 

 printed pages and 42 plates in fifteen special research papers. 



A neuromotor apparatus was described by Sharp (1915) in 

 Diplodinium ecaudatum, a very complex member of the order Oligo- 

 tricha. Parts of this system had been prcviouslj' described (Braun, 

 1914), but either a supporting or contractile function had been 

 ascribed to it. Yocom (1918) described a similar system in the 

 hypotrichan Euplotes. These two ciliates, the one a parasite, the 

 other a free-living form, possess neuromotor systems easily com- 

 parable. In each the system consists of a motorium from which 

 fibers extend to the motor organelles and also to the membranelles 

 surrounding the cytostome. The motorium is in no way connected 

 with the nucleus. Taylor (1920), by the method of micro-dissection, 

 demonstrated that the system in Euplotes possesses eonductile func- 

 tions. His conclusions are based on three hundred and fifteen experi- 

 ments on which extensive notes Avere taken. His conclusions were as 

 follows : 



These experimental evidences do not support the assumption that the fibrillar 

 system in Euplotes is either contractile or supporting in function, but they 

 indicate that this complex system of fibers does possess conductive properties 

 functioning in the coordination of the movements of the locomotor organelles 

 with which it is intimately associated (Taylor, 1920). 



