1921] Kofoid-Swczy: Cmnicilmania hifcuri 177 



The eight-uucleate encysted stage is preceded by the unimicleate, 

 binucleate, and quadrinucleate stages, which are less abundant than 

 those with eight nuclei in most stools, but may be found in larger 

 numbers in liquid stools or in mucus strands on formed stools. Three 

 successive divisions occur, resulting in two, four, and eight nuclei. 

 These divisions are approximately synchronous in the one, two, and 

 four nuclei at the successive mitoses, though slight irregularities in 

 division rate or even an abnormal or moribund nucleus may occasion- 

 ally be found. Occasionally a fourth mitosis in the cyst which would 

 result in sixteen nuclei is indicated by the prophase conditou of the 

 eight nuclei. In one instance a cyst with eleven nuclei was found. 

 This last mitosis proceeds sometimes during budding. 



In the uninucleate stage (pi. 20, fig. 11) the nucleus is pushed to 

 the wall by the central vacuole, as are also the nuclei of the binucleate 

 (pi. 20, fig. 12), and sometimes in the quadrinucleate (pi. 20, fig. 14) 

 stages, while in the cyst with eight nuclei, and sometimes in the quadri- 

 nucleate ones, the vacuole has vanished and the nuclei are distributed 

 through the cytoplasm (pi. 20, fig. 15). The nuclei in these early 

 stages are much larger than in the later ones; The prevalence of 

 mitotic phases and the nuclear conditions generally in the stages prior 

 to the cyst with eight nuclei indicate that the three mitoses follow 

 rapidly one after the other, though the predominance of the binucleate 

 phase suggests that this is more prolonged than the quadrinucleate. 

 Not all stools, even liquid ones, contain these stages, as a consequence, 

 probably, of recurrent periods of multiplication in the bowel in the 

 intervals between which such stages are rare or wanting. 



There are eight chromosomes in Councilmania lafieuri clearly dem- 

 onstrable at the metaphase, while Endamocia coli has but six. An 

 intradesmose connecting distinct chromatic polar masses is prominent 

 in the prophase-metaphase period of mitosis, in the first and second 

 mitoses especially, in Councilmania. It lies in contact with the nuclear 

 membrane. 



The term intradesmose is proposed for the chromophile strand be- 

 tween two polar eentrosomes of the spindle, which lies on the inner 

 face of the nuclear membrane, in contradistinction to the paradesmose 

 of flagellates on the outer side of the nuclear membrane. 



In the precystic stage neither glycogen vacuole nor chromatoidal 

 bodies are present, but both develop shortly after encystment. The 

 glycogen vacuole develops first. Many uninucleate cysts have this 

 vacuole but no chromatoidal bodies, which appear later and usually 



