of One Cell 



first lie writes "That the above deseribed structure functions 

 a- a true skelatal (supporting) structure, not only for the 

 retractile oesophagus, |, u f a ] so f or the entire body, seems al- 

 together certain." Tire illustration shows something as 

 to its composition (fin-tire 1 .v/, - . l(un.., indicating skeletal la- 

 mina' ). It is composed of plates or laminae, running length- 

 wise of the organ, and placed edgewise relative to the sur- 

 face of the creature. This organ is said to be the most rigid 

 and brittle of any in the animal, and is conjectured to con- 

 tain silicic acid. One dots well to note the section headings 

 of Sharp's description: '"Organs of Locomotion," 13 "Organs 

 of Food-taking," M "Organs of Defecation," 15 "Organs of 

 Erection.** 16 An examination of figure 1 by the aid of let- 

 terings accompanying it, will give the reader some idea about 

 each of these sets of organs. 



One of these organ systems must In- attended to more 

 specifically. It is called by Sharp the ncnrojnotor appara- 

 tus (labelled in the figure m.m. and circ. oes. ring). The 

 discovery of this remarkable svstein mav well be regarded 

 as epochal in the history of knowledge of the protozoa, for 



stems to indicate the presence of a nervous system in 

 higher members of this great subdivision of the animal 



igdom no whit less well different iat< d and elaborate than 



some of the meta/oa and that by no means the lowest of 

 "This apparatus." says Sharp, "consists of a cen- 



il motor mass or motorium, from which definite strands 

 liate: one to the roots of the dorsal membranelles (dorsal 



)tor strand): one to the roots of the adoral membranelles 

 (ventral motor strand); one to the circumoespohagea] ring 



(circumoesophageal ring strand ): and several pass out into 

 the ectoplasm of the operculum (opercular fibers). Kach of 

 these strands may send off one or more branches. In the 

 walls of the oesophagus, both nervous and contractile fibers 

 may be distinguished." 17 



