TRYPANOSOMA CRUZI 



495 



tick, 0. moubata, but that infection was not transmitted by their bites. 

 Mayer (1918) found that specimens of 0. moubata still contained infective 

 flagellates in the intestine five years after feeding on an infected animal. 



Neiva (1913a), experimenting on the transmission of canine piro- 

 plasmosis by means of Rhipicephalus sanguineus, infected dogs with Try- 

 panosoma cruzi. In the bed bug Brumpt found that the infection persisted 

 for over two months, and that the same forms occurred as in the true host, 

 Triatoma ^negista. Moreover, the faeces of the bed bug were infective to 

 animals. In one instance, Blacklock (1914) was able to transmit T. cruzi 

 by allowing infected Cimex lectularius to feed on an animal. Yamasaki 

 (1924) experimented with the dog flea, but found that in this insect a 

 rapid degeneration of the trypanosomes took place. Brumpt (1914) 



Fig. 209. — Development of Trypanosoma cruzi in Gut of Bhodnius prolixus 

 (x 2,000) from a Film of the Intestinal Contents. (Original from 

 Preparation made by Dr. Tejera). 



1-3. Trypanosomes of the blood type which are ingested by the bug. 

 4-9. Various crithidia forms. 10-\'I. Dividing crithidia forms. 



13-16. Metacyclic trypanosomes which escape in the fseces of the bug. 



noted that reduviid bugs had the habit of attacking each other, and also 

 of ingesting the liquid fseces passed by themselves or other bugs. That 

 infection may be acquired in this manner was proved by feeding bed bugs 

 on diluted fseces containing crithidia forms of T. cruzi. Some of the 

 bugs became infected, and the flagellates persisted in them for over two 

 months. Though admitting the cannibalistic habits of the reduviid bugs, 

 Torres (1915) does not think they can infect one another, as they only suck 

 the clear body cavity fluid, in which he could find no evidence of trypano- 

 somes. Though he found that bugs feed on one another's faeces when in 

 captivity, he believes that under natural conditions this does not occur. 



