TRICHOMONAD FLAGELLATES. 339 



from the evidence from T. augusta represents the region of end-to-end 

 conjunction. 



The mitosis is promitotic, the nuclear membrane remaining intact, 

 constricting at the equator (Figs. 57, 58) and forming at once about 

 the severed daughter nuclei (Fig. 59). The chromosomes after part- 

 ing increase in length and in volume and become attached to the pole 

 of the nucleus next to the daughter blepharoplast (Fig. 58). 



The behavior of the extranuclear organelles in mitosis, is similar 

 to that in T. augusta. Their division is initiated by the longitudinal 

 splitting of the chromatic margin of the undulating membrane (PI. 5, 

 Figs. 49, 51-53) after which the blepharoplast divides into two (Fig. 

 54) and each migrates to a pole of the fusiform nucleus (Figs. 55, 56). 

 In one instance only (Fig. 56) did we find the division of a daughter 

 blepharoplasts into two granules which we interpreted in T. augusta 

 as l)asal grannie and centrosome. 



The new chromatic basal line forms at about the same stage in T. 

 muris as in T. augusta (cf. PL 2, Figs. 11-17 and PI. 5, Figs. 54, 55), 

 though we have not determined the precise method. Kuczynski's 

 (1914) figures also leave this in doubt. The undulating membrane 

 splits and the two membranes part after the formation of the new 

 chromatic basal rod (PI. 5, Fig. 57). At the division of the blepharo- 

 plast one daughter takes one anterior flagellum and axostyle and the 

 other the other two flagella (PI. 5, Fig. 57) and the full complement 

 of three from each blepharoplast is created by the outgrowth of two 

 and one new flagellum respectively from the blepharoplasts. 



The union of the distal ends of the daughter chromatic margins 

 (PI. 5, Fig. 52) here as in T. augusta, we regard as evidence of their 

 origin by splitting, and not by one new outgrowing one alongside the 

 old, as stated by Kuczynski (1914). It is possible that this difference 

 in method is without morphological significance. 



Between the migrating blepharoplasts is a slender deeply staining 

 paradesmose (PI. 5, Fig. 55-61) which does not disappear until after 

 the daughter axostyles are formed. 



The origin of the new axostyles occurs late in the telophase in T. 

 viuris as it does in T. augusta, by the longitudinal splitting of the 

 parent structure beginning at the anterior end and progressing to the 

 posterior tip (PI. 5, Fig. 60). The process is evidently a rapid one as 

 long search was necessary to find an axostyle in division. The in- 

 stance found is not one of superposition of posterior ends of two 

 daughter axostyles, for the two are plainly united, though the right 

 one lies somewhat higher than the left. 



