494 



FAMILY: TRYPANOSOMID^ 



dominant type present in the intestinal infection, which was still found 

 to persist five months after the feed on infected blood. The fseces of the 

 infected bug contain numerous metacyclic trypanosomes, and are infective 

 to animals (Fig. 205). The infectivity of the fgeces commences with the 

 appearance of the trypanosome forms. Chagas (1909), as noted above, 

 described flagellates of the trypanosome type in the body cavity fluid 



of the bugs, and stated that 

 he had also seen them in the 

 smears of the salivary glands. 

 This infection is supposed to 

 spread from the gut by way 

 of the Malpighian tubes. 

 According to Brumpt, this 

 phase cannot be of constant 

 occurrence, as he was unable 

 to demonstrate it, even 

 when he examined bugs with 

 a heavy intestinal infection. 

 Torres (1915) failed to de- 

 monstrate flagellates in the 

 body cavity fluid of infected 

 reduviids {T. megista), though. 

 he succeeded in infecting 

 animals by allowing the bugs 

 to bite through gauze, which 

 prevented fsecal contamina- 

 tion of the skin. Extending 

 his observations, Brumpt 

 (1912) was able to demon- 

 strate that, in addition to 

 T. megista, other allied species 

 are easily infected — T. infes- 

 tans, T. chagasi, and T. sordida 

 — while Brumpt and Gon- 

 zales-Lugo (1913) proved this 

 Brumpt also obtained develop- 

 C. rotundatus, and C. boueti, 

 Mayer and Eocha Lima 

 of T. 7negista, which was 



Fig. 208. — Triatoma megista ( $ ), One of the 

 Transmitting Hosts of Trypanosoma cruzi 

 ( X 3). (After Chagas, 1909.) 



Dorsal view and side view of head, showing recurved 

 proboscis. 



for Rhodnius prolixus, another reduviid. 

 ment in the bed bugs, Cimex lectularius 

 and even in the tick, Ornithodorus moubata. 

 (1914) found that infection of the intestine 



associated with a penetration of the epithelial cells by the trypano- 

 somes, persisted for at least two years. They also showed that 

 T. cruzi would undergo development in the bed bug, C. lectularius, and the 



