150 University of California Publications in Zoology [VOL. 1! 



a sacklike structure from the region of the blepharoplast. Unlike th< 

 suspensory apparatus of C. leptocoridis , C. euryophthalmi does no 

 show a fan-shaped mass of contractile cytoplasmic fibrils covering this 

 axial portion, which is of blepharoplastic origin (figs. A, 1, 2 ; figs. B 

 1-5). The outline of this cytoplasmic envelope in C. euryophthalmi i: 

 definite, slightly opaque, and continuous with the cytoplasmic sheatl 

 of the flagellum. 



The parabasal body of the trypanosomes (figs. A, 3, 4, 5) is simi 

 larly a bar-shaped structure, which stains deeply, located to on< 

 side of the nuclear rhizoplast and blepharoplast. In T. leivisi (fig 

 A, 3) the parabasal body is relatively small while the blepharoplast ii 

 correspondingly large. As previously noted, no parabasal rhizoplas 

 has been figured by Minchin and Thomson in T. Lewisi. Here am 

 there suggestions of a connection might be pointed out in their figures 

 While it is possible that T. lewisi is exceptional in this respect, yet 

 since the structure is found in other flagellates of this group, we ma] 

 infer that a critical study of the preparations with a binocular micro 

 scope will reveal the presence of such a connection in the crithidia 

 stages of this flagellate. 



Trypanosoma lewisi (fig. A, 3) is likewise the only flagellate her< 

 figured in the crithidial stages without a nuclear rhizoplast. Her< 

 again T. leivisi is either exceptional or the structure has perhaps beer 

 overlooked, since it is usually discerned with difficulty. Chagas (1909] 

 has figured a nuclear rhizoplast in Schizotrypanum cruzi and we hav< 

 found it also in T. triatomae. Therefore we may expect that it wil 

 be found in T. lewisi. 



The parabasal body in Trypanosoma triatomae (fig. A) is a rela 

 tively large structure, its width approximately equal to one-half of it! 

 length. It is located a short distance anterior to the nucleus, and is sus 

 pended from the blepharoplast by a fan-shaped parabasal rhizoplas 

 like that of Crithidia leptocoridis, i.e., a suspensory apparatus with j 

 fibrous appearance. In the crithidial stage of T. triatomae a nucleai 

 rhizoplast was observed connecting the blepharoplast with the centriol< 

 of the karyosome, but such a connection was not found in the trypani 

 form individuals. If a nuclear rhizoplast be present in the trypaniforn 

 stage, in which we did not find it, it is possible that we may have beer 

 prevented from observing it because of the density of the cytoplasn 

 in this stage and a tendency in this delicate thread in the trypano 

 somes to stain lightly. In the crithidial stages of this trypanosome, or 

 the other hand, the cytoplasm is more or less vacuolated in appear 

 ance thus making the nuclear rhizoplast more evident. When a try 



