8O JUSTIN M. ANDREWS. 



chromatic basal rod published by Kofoid and Swezy ('15), pre- 

 sumably in support of this view, differ from figures published by 

 the other authors purporting to show parabasal bodies, both in 

 size, shape, and spacial relationships. 



The parabasal body is an elusive organelle, and is apparently 

 dissolved out by some fixatives, leaving nothing to suggest its 

 shape or position. It is very sensitive to decolorization, and is 

 seldom seen in those preparations which are decolorized suf- 

 ficiently to permit analysis of mitotic phenomena. But in prepa- 

 rations fixed with chromic acid, osmic acid vapor, or Flemming's 

 fluid and perhaps others that are not too strongly decolorized, 

 the parabasal body is a very conspicuous feature of Trichomonas 

 termopsidis. If the parabasal is not carefully decolorized, it 

 appears as a stout, club-shaped, serpentine organelle which takes 

 its origin from the centroblepharoplast. After more critical 

 destaining, a darker line appears, that is not always in the center, 

 but which weaves from side to side, suggesting the probability 

 that it does not lie within the parabasal body as is indicated by 

 the previous writers, but is on the outside of it. This line the 

 chromatic filament (Chrom. fil. Fig. 2) is undoubtedly the 

 "parabasal thread" of Janicki. The body appears to have little 

 rigidity of its own, as it sometimes loops itself back and forth on 

 the axostyle (Fig. I, A), and occasionly surrounds it. The 

 parabasal is about the same length as the axostyle, and about the 

 same breadth, but is otherwise readily distinguishable from it. 



MITOSIS. 



Mitotic phenomena in Trichomonas termopsidis are strikingly 

 different from any of the types described by Kofoid and Swezy 

 ('15) for Trichomonas, but are identical with the type described 

 for Trichomitus termitidis Kofoid and Swezy ('19). Briefly these 

 are as follows: the nucleus darkens, and shortly thereafter the 

 surrounding cytoplasm becomes charged with chromidia (Fig. 4, 

 B] which soon disappear. Then the centroblepharoplast releases 

 the centrosome (Fig. 3, A], and the remaining blepharoplast 

 splits into two daughter blepharoplasts. Simultaneously the 

 nuclear rhizoplast and the parabasal body split (Fig. 3, C). The 

 centrosome maintains its connection with the two new blepharo- 



