ZOOFLAGELLATES 155 



as a parabasal apparatus is shown by Beams and colleagues to 

 consist of an extraordinary system of radiating tubules. According 

 to the authors' reconstruction, these originate at or possibly 

 within the nucleus, extend outward, with some anastomoses, 

 through the calyx, become highly convoluted, and end in enlarged 

 bulbs filled with dense material. Their significance is unknown 

 and they resemble no other known organelle, least of all a 

 conventional parabasal or Golgi apparatus. Golgi bodies 

 (apparently without parabasal filaments) and mitochondria are 

 described in the cytoplasm of L. blattarum outside the calyx. 



The formidable complexity of the trichonymphid flagellates 

 almost defies description in a limited space. Trichonympha is 

 typically bell-shaped, with thousands of flagella arising in longi- 

 tudinal rows on the anterior part of the body. At the anterior end, 

 a hyaline apical cap surmounts the rigid, flagellated rostrum, which 

 is partly separated from the remaining flagellum-bearing zone by 

 a deep circular fissure. Pitelka and Schooley (1958) were able to 

 describe the chief architectural features of the flagellated portion 

 of the cell, and their results are summarized in Text-fig. 10. The 

 body is limited by a unit membrane which, on the apical cap only, 

 is underlain by three parallel sheets of fine fibrils. The axis of the 

 rostrum is occupied by an elongate, cone-shaped rostral tube, 

 whose wall consists of radially arranged, striated, longitudinal 

 ribbons enclosed in a membrane (Figs. 63, 65, PL XVII). At the 

 flaring posterior end of the tube, this membrane disappears and 

 the freed bands become slightly sinuous and pass posteriad to 

 make contact with the cord-shaped parabasal bodies clustered 

 about the nucleus. The rostral tube thus is composed of packed, 

 striated parabasal fibrils similar to the single parabasal fibrils of 

 trichomonads. Their striations have a period ranging from about 

 30 m/x in the rostral tube to 60 m/x posteriorly. 



It is characteristic of the trichonymphids that the flagella and 

 associated structures are divided into two (or four) symmetrically 

 placed sets that separate preceding cell division and are retained 

 in the daughter cells, which elaborate new sets to make up the 

 adult complement. This bilaterality is apparent in cross-sections 

 of the Trichonympha rostrum, where the rostral tube wall is seen 

 as two opposed crescents, with a delicate striated or fibrillar 

 lamella passing radially from one tip of each crescent. At the 



