American Trypanosomiasis 565 



cruzi. It proved upon experiment to be infective for Brazil- 

 ian monkeys, dogs, guinea-pigs, rabbits, and other small 

 animals. 



It has been successfully cultivated upon the special blood 

 agar-agar of Novy and McNeal. 



The developmental cycle of this trypanosome as worked 

 out by Chagas is peculiar, and not only takes place by the 

 usual asexual fission, but also is apparently in some way 

 associated with an intracorpuscular infection, in which fig- 

 ures resembling the merozoits of the malarial plasmodium 

 are formed. These subsequently grow into trypanosomes. 

 In the lungs, also, special forms are said to develop, con- 

 taining light bodies resembling the merozoits seen in the 

 peripheral circulation, and probably corresponding to the 

 bodies seen by Schaudinn in his studies of Trypanosoma 

 noctua, in the stomach of the mosquito. 



Transmission. The transmitting agent was found by 

 Chagas to be a rather large hemipterus insect, Conorhinus 

 megistus. A special cycle of development of the parasite 

 in the body of this bug was described, but has not been 

 confirmed. Chagas was able to transmit the parasites to 

 monkeys by permitting the infected bugs to bite them. 



