358 KOFOID AND SWEZY. 



(in T. muris) having a particular location in the nucleus in the late 

 prophase, and lagging on the spindle in the metaphase. 



4. The chromosomes appear to be split longitudinally prior to 

 their arrangement in the equatorial plate, and seem to slip into an 

 end-to-end position in this plate, or to be parted by a transverse con- 

 striction. 



5. The extranuclear organelles all share in the process of mitosis. 

 The blepharoplast from which flagella, rhizoplast, chromatic margin 

 and basal rod, and axostyle all take their origin, contains the division 

 center. It parts into two bodies which go to the two poles of the fusi- 

 form mitotic nucleus spinning out the deeply staining always extra- 

 nuclear paradesmose between them. 



6. The daughter l)lepharoplasts may each divide in the polar 

 position into an axial centrosome and an adjacent basal granule to 

 which flagella, paradesmose, and parabasal are attached. These two 

 granules subsequently reunite. 



7. In its divisions the blepharoplast shows no independent mitotic 

 phenomena. It is not a "kinetonucleus," and its behavior does not 

 support the binuclearity hypothesis. 



8. The anterior flagella are shared, two and one respectively by 

 the daughter blepharoplasts and new outgrowths, complete the com- 

 plement of each daughter organism. 



9. The chromatic margin of the undulating membrane represents 

 an intracytoplasmic posteriorly directed flagellum. It splits longi- 

 tudinally to the tip of its projecting end. The undulating membratie 

 below it also splits. 



10. The chromatic basal rod is the homologue of the parabasal 

 body of Parajooiia and the Trichonymphida as established by Janicki. 

 His so-called parabasal in Trichomonas is in reality only the early 

 stage in the outgrowth of a new parabasal or chromatic basal rod at 

 mitosis, hence its rarity and transitory nature. At mitosis a new 

 parabasal or chromatic basal rod grows out in the base of one of the 

 new undulating membranes while the old parabasal lies in the other 

 membrane. 



11. The new axostyles of the daughter organisms are formed by 

 the longitudinal splitting of the old axostyle from the anterior end 

 posteriorly. They are not formed from the paradesmose (central 

 spindle) as maintained by Dobell nor anew as claimed by Kuczynski. 



12. The axostyle is not primarily a skeletal structure as usually 

 supposed, nor an organ of fixation as described by Kunstler and 

 Kuczynski but a locomotor organ used vigorously during the amoeboid 

 stage in the mucous substrate. 



