92 BIOLOGY OF THE PROTOZOA 



into the cell as in Chilomonos jMramecinm, (or in Rhizomastix 

 Mackinnon) , or a number of such rhizoplasts may be formed as in 

 Mastigella vitrea (Fig. 46) . In these cases the blepharoplast divides 

 independently of the nucleus at periods of cell division (Fig. 46, B). 



2. Parabasal Body and Blepharoylast. — As a centriole may be 

 contained in an endobasal body which consists largely of chromatoid 

 substance, so may a basal body be enclosed in chromatoid substance 

 of a blepharoplast, as shown by Goodey (1916) in the flagellate 

 Prowazekia (Bodo) saltans, or by Kofoid and Swezy (1915) in 

 Trichomonas aiignsta. Again, just as a centriole may be freed 

 from its enclosing chromatoid substance in an endosome, so may 

 the basal body be freed from the blepharoplast. In a similar way 

 the blepharoplast may be contained in an embedding chromatoid 

 mass of a cytoplasmic kinetic element, or it may be free from such 

 a mass. We may then have in the same cell a kinetic complex 

 consisting of one or more basal bodies, one or more blepharoplasts, 

 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. 



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

 difficulties have arisen concerning the interpretation of cytoplasmic 

 kinetic elements. The difficulties began with Schaudinn's work 

 (1904) on the trypanosome of the little owl {Glancidium [Athene] 

 noctvce). Schaudinn's description and figures of the history of the 

 kinetic elements at the base of the flagellum have been cited and 

 copied in practically every text-book dealing with the Protozoa 

 and have had a wide influence in theoretical protozoology. Other 

 keen observers, however, have sought in vain for evidence corrobo- 

 rating this history. In the absence of such confirmation and in view 

 of the multitude of different observers who find a simpler explanation 

 in many different types of trypanosomes, including that of the 

 little owl (see Minchin, Robertson, Sergent, et al.), Schaudinn's 

 interpretation and conclusions can be accepted only with many 

 reservations. 



The essential point in Schaudinn's description was the origin by 

 heteropolar mitotic division of the nucleus of a recently fertilized 

 cell (?), of a larger nucleus which becomes the nucleus of the cell, 

 and a smaller nucleus which forms the kinetic complex. This 

 smaller nucleus divides again by mitosis, also heteropolar, the 

 smaller portion becoming the basal granule which forms the flagellum 

 and the "myonemes" of the undulating membrane, while the larger 

 portion remains intact as a homogeneous deepl.^'-staining granule. 

 The contested points in regard to this phase of Schaudinn's work 

 are, first, the "fertilized cell" of the trypanosome, which is now 



