TRYPANOSOMA CRUZI 



487 



blood. The trypanosomes were found to be inoculable to dogs, guinea- 

 pigs, and rabbits. Extending his observations, Chagas ultimately found 

 the organism in a cat, and later in children who suffered from a wasting 

 disease which had long been known in the country. Chagas first placed 

 the trypanosome in the genus Trypanosoma, but later, on account of its 



Fig. 205. — Diagram of Trypanosoma cruzi in the Blood and Tissues of Man 

 AND IN THE BuG (Triatoma megista). (After Wen yon, 1922.) 



A. Leishraania forms in muscle fibre of heart. B. Trypanosome forms in muscle fibre. 



C. Trypanosome forms in blood. S. Trypanosomes in stomach of bug. 



R. Rectal phase of development. D. Multiplying crithidia forms in rectum of bug. 



E. Metacyclic trypanosome forms which produce infection. These forms usually have no flagella. 



peculiar intracellular mode of development as leishmania forms, created 

 the new genus, Schizotrypanutn, for its reception. This name was chosen 

 because it was believed that reproduction took place by schizogony, but it 

 is now known that multiplication, though occurring within cells in the 

 leishmania stage, is by the usual method of binary fission, so that it is 

 preferable to retain the trypanosome in the genus Trypanosoma. 



