70 University of California Publications in- Zoology [Vol. 20 



in the process, so far as Foa lias described them, are identical with 

 those of Trichonympha campanula. She does not, however, give 

 further details of the process, the formation of the chromosomes or 

 their number. She did not record division of the chromosomes in 

 the small form but figures longitudinal splitting in those of the larger 

 species. 



In the nearly allied form, Holomastigotes {Trichonympha hert- 

 wigi) Hartmann (1910, pi. 28, figs. 23-29) has- figured certain stages 

 of the prophase nucleus, leading up to the formation of the chromo- 

 somes, which are nearly identical with phases found in our own 

 material (pi. 6, figs. 14r-16, 20-22). He also figures division of the 

 structure which we call the centroblepharoplast and the anterior tip 

 of the body, processes which also closely parallel those found in our 

 own material. Further details of the mitotic phenomena he did not 

 record. 



The work of earlier investigators of these flagellates, such as Leidy 

 (1881) and Porter (1897), also fails to give any clue to tlie details 

 of the division processes. 



The abundance of division stages in our own material has given 

 us an unusual opportunity of determining the flagellate type of 

 mitosis in Trichonympha and to follow out the details of the mitotic 

 phenomena. The relatively large size of the nucleus of Trichonympha 

 and the structures connected with its division, renders it a favorable 

 object for study. In the foregoing outline of these various processes, 

 certain points have been omitted or briefly touched upon, which will 

 be discussed more fully in the following paragraphs, along with an 

 explanation of some of the terms used in this paper. 



The union of blepharoplast and centrosome in one structure which 

 may or may not become separated at the time of division, is a 

 condition quite common throughout the flagellates generally. The 

 occasional separation of these in trichomonad flagellates (Kofoid and 

 Swezy, 1915), becomes a permanent condition in the mitosis of 

 Trichomitus temiitidis (Kofoid and Swezy, 1919b). This relation- 

 ship makes the term centroblepharoplast an appropriate one for 

 this structure. The application of it to the more complex organelle 

 of Trichanympha is also based on these same relations. The enormous 

 increase in the number of flagella in this organism necessitates a 

 coordinating mechanism related to each flagellum individually. This 

 is found in the intricate system of fibrils radiating from the central 

 mass at the anterior cone-shaped portion of the body, which thus 



