DERIVED ORGANIZATION 



111 



and a residual kinetic element in the form of a chromatoid mass. 

 To this residual chromatoid mass the name parabasal body is applied, 

 the term originating with Janicki (1915). Kofoid (1916) interprets 

 its function as a storage or feeding reservoir for the kinetic elements, 

 its substance in turn being derived from the nucleus. 



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/.;/ 



*%> 



D 



Fig. 61. — Relation of parabasal to nucleus. A, Crithidia euryophthalmi endosome 

 of nucleus and parabasal connected by rhizoplast; B, origin of parabasal from endo- 

 some of nucleus; C and D, differentiation of parabasal and rhizoplasts; E, Trypano- 

 soma cruzi, and F, Crithidia leptocoridis, for comparison. (After MeCulloch.) 



It is in connection with the parabasal body that most of the 

 difficulties have arisen concerning the interpretation of cytoplasmic 

 kinetic elements. It is still in the stage of polemics and contro- 

 versies continue over the chemical nature of its substance. The 

 difficulties began with Schaudinn's work (1904) on the trypanosome 



