li^'l'il h'ofoid-McCiiUocli : Trupanosoma iriaiomiu 123 



Chagas in ('diuirltiiius mcgi.sfits Bunii. from Brazil, whirli is the 

 etiological factor in South American human trypanosomiasis. 



4. Stages occur which are comparable to those described by Min- 

 chin and Thomson (1915) for Trypanosoma lewisi. We tind the early 

 stomach phase, or recently ingested trypanosome, the late stomach 

 phase, or merozoite, following a probable multiple fission in the epi- 

 thelial cells of the stomach, a crithidial phase of large size in the 

 stomach, with a "rolled-up" stage suggestive of intracellular multiple 

 fission in the crithidial stage, and a transition series leading to small, 

 stout crithidial forms. These small crithidial forms probably become 

 the smaller haptomonad types which we find undergoing binary fission 

 in the rectum. The final trypaniform stages are apparently different 

 from those of Scliizotrypanum in some minor details. They occur 

 in numbers in both transition and final stages in the rectiuii. 



5. The crithidial stage appears to be more extended in this species 

 than in Trypanosoma lewisi and to run a cycle of lai'ger forms in the 

 stomach than in the rectum. 



6. The structure of the so-called "kinetonueleus" supports the 

 interpretation that it is in reality the parabasal body. 



Traiismilled December 16, 1915. 

 Zoolof/ical Lahoratori/, 



Universily of Citlifoniia. 



VI. LITERATURE CITED 



(_'HAGA.S, (_'. 



1909. Ueber eine neue Trypanosomiasis des Menschen. Jleiii. Inst, Oswalilo 

 Cruz, 1, 1.59-218, pis. 9-13, 10 figs, in text. 



KOFOID, ('. A. 



1916. The biologifal anil nieilical significance of the life-history of intes- 

 tinal flagellates. Proc. Sec. Pan-Amer. Sci. Congress. Washington, 

 1915-16. (In press.) 

 Mcculloch, Irene. 



1915. An outline of the morphology and life-history of Critliidia leptocoridis. 

 sp. nov. Univ. Calif. Publ. Zool., 16, 1-22, pis. 1-4, 1 fig. in text. 

 MixcHix, E. A., and Thomson, J. D. 



1915. The rat-trypanosome, Trypanosoma lewisi, in its relation to the rat- 

 flea, CeratopliylJus faseiutns. Quart. Jour. Micr. Sci., 60, 46?l-692, 

 pis. 36-45, 24 figs, in text. 



