416 BIOLOGY OF THE PROTOZOA 



extend anteriorly or laterally while the longer ones extend posteriorly, 

 covering the entire hinder end of the organism. 



With these enormously-developed external locomotor organs we 

 would expect to find more or less complicated internal structures 

 for attachment and support. In uniflagellate forms these are rela- 

 tively simple, the single flagellum originating from and attached to 

 a kinetic element in the nucleus or on its membrane (Salpingoeca, 

 J. Clark); or from a kinetic element (blepharoplast) in the cyto- 

 plasm (e. g., Oicomonas, Kent; Trypanosoma, Gruby, etc.). Com- 

 plications appear with the development of the parabasal body 

 (Herpetomonas, Crithidia, etc., see p. Ill) and with the axostyle 

 while parastyles and epistyles support the undulating membrane 

 and other motile organs. The nucleus is supported by axial threads 

 from the blepharoplasts in Lophomonas, by the axostyle in Tricho- 

 monas, Joenia and Parajoenia and Metadevescovina and by special 

 strands or membranes in Trichonymphidae. 



Basal bodies are frequently united into apparently solid bars as 

 in the head organ of Triclionympha or plates as in Staurojoenia 

 assimilis, Kirby, the former acting as a complicated centrosphere 

 (centroblepharoplast, Kofoid) during division (Fig. 54, p. 100). In 

 Joenopsis polytricha, Cutler, this becomes a horseshoe-shape struc- 

 ture which bears the basal bodies for the anterior flagella. 



With these intestinal forms bacteria are frequently found attached 

 to the body wall and may be mistaken for additional flagella. In 

 some cases they become a part of the organism, forming a fairly 

 complete armature (e. g., Lophomonas striata, Biitschli). 



The protoplasmic body in all types of flagellates contains the usual 

 cytoplasmic substances. Mitochondria are probably universally 

 present (see p. 73), and volutin (see p. 72) is widely distributed, 

 if not universal. ( nromidia are only rarely present (Rhizomas- 

 tigidae). 



The presence of Golgi bodies (see p. 77) is not demonstrated in 

 many forms, and some difference of opinion has arisen concerning 

 the chemical identity of certain characteristic structures, particu- 

 larly the parabasal body. Kofoid (1916) believed it to be of 

 chromatin (nucleic acid) nature, acting as a reservoir of substance 

 to maintain the activity of the kinetic elements. The chromatin 

 make up of the blepharoplast in Trypanosoma supports this view. 

 A similar purpose of the parabasal is advocated by Janicki (1915) 

 and by Duboscq and Grasse (1925), but they argue against its 

 chromatin nature and regard it as the homologue of the metazoan 

 Golgi apparatus and the product of the vacuome (Parat). This is 

 based on the fact that the colorable substance is often immediately 

 adjacent to a colorless vesicle. Janicki holds that the parabasals 

 present in large number in the Polymastigida and Ilypermastigidae 

 secrete substances of high potential energy which are used by the 



