206 University of California Publications in Zoology [Vol. 20 



while a second junction is effected between the intracytoplasmic parts 

 of the anterolateral flagella in the anterior node (ant. node). 



The centrosome {cent., fig. A) is a minute granule at the anterior 

 pole of the nucleus and is found with difficulty, especially in the cysts. 

 Duplication of the neuromotor system proceeds from it through the 

 blepharoplast at mitosis, and the paradesmose (pi. 23, fig. 7 ; fig. A, 

 par. ) is spun out between the daughter centrosomes prior to the meta- 

 phase and lies on the nuclear membrane as a dark meridional thread. 



The intranuclear (intranuc. rhiz., fig. B) and extranuclear (rhiz.) 

 rhizoplasts are found with difficulty in both free and encysted stages 

 since they destain quickly. The intranuclear rhizoplast passes to the 

 central karyosome in the resting stage of the nucleus, and forms the 

 line along which the longitudinal spireme forms at mitosis (pi. 23, 

 fig. 5), as Boeck (1919) has shown in G. microti. The extranuclear 

 rhizoplast passes obliquely antero-laterally to the head of the axostyle 

 or blepharoplast. 



The blepharoplast (bleph., fig. B) in G. enterica is obscured more 

 than in G. muris and G. microti by the fact that it has nearly the same 

 diameter as the axostyle and, unless deeolorization is carried on until 

 the latter organ destains, the small blepharoplast buried in its head 

 is not distinguishable from the contiguous axostyle. When destaining 

 is adequate (fig. B; pi. 23, fig. 4), and especially in the prophase, the 

 blepharoplast is seen as a small ellipsoidal body with its longer longi- 

 tudinal axis buried in the head of the axostyle. To it converge all of 

 the elements of the neuromotor system, though the parabasal rhizoplast 

 par. b. rhiz., fig. A), the ventral and posterolateral flagella. and the 

 posterior peristomal fiber are generally so obscured by the axostyle 

 that they cannot be followed separately to any junction with the 

 blepharoplast. Their trend is toward the blepharoplast as far as they 

 can be followed. From it passes the rhizoplast (rhiz.) to the centrosome. 

 We have been unable to find the tivo granules figured diagrammatically 

 by Hartmann (1910) in G. muris and by Rodenwaldt (1911) in [?]G. 

 enterica. It is possible that they were prophetic of the prophase of 

 mitosis (see our text-figures F-K). 



The transverse commissure {trans, comm., fig. B) is a heavy fibrous 

 band joining the two blepharoplasts. 



The four pairs of flagella (/?., fig. A) all appear to arise from, or 

 near, the blepharoplasts, in a bilateral arrangement. They all stroke 

 posteriorly and are typically found in living and fixed material trailing 

 more or less posteriorly. 



