VIII, B, 3 Mitzmain: Transmission of Surra 225 



The three positive experiments are described in detail as 

 follows : 



The experiment in which monkey L became infected was 

 conducted with flies bred from eggs. The source of this strain 

 of surra was carabao 3182 which had been infected with 

 surra for nearly one year previous to this experiment. Blood 

 of this animal was inoculated into guinea pig 119 which showed 

 infection in eight days, and was used for the present experi- 

 ment, December 28, when its blood showed numerous trypano- 

 somes. Three flies were applied individually in tubes to guinea 

 pig 119 and allowed to feed from forty-five seconds to one minute 

 and thirty seconds. They were then transferred to monkey L, 

 after intervals of from twenty seconds to three minutes, and 

 allowed to feed until satisfied. The flies fed on the latter animal 

 five, sixteen, and twenty-one minutes, respectively. 



From December 28 to January 8 no reaction was noted. The 

 first high temperature, 40°. 1, occurred on the evening of Jan- 

 uary 8, accompanied by a few trypanosomes in the peripheral 

 circulation. The presence of trypanosomes continued daily, 

 moderate to swarming in numbers, with several febrile periods 

 until the animal's death on December 22, 1912, 



Blood from the heart of monkey L was inoculated into horse 

 343 and guinea pigs 101 and 102. The latter showed infection 

 upon the eighth and ninth days, respectively. Horse 343 had 

 an abnormal temperature and a moderate number of trypano- 

 somes in its blood upon the seventh day. The animal died 

 March 1 with surra. At autopsy there was observed a general 

 emaciated condition and enlargement of the spleen. The splenic 

 pulp contained enormous quantities of trypanosomes as did the 

 heart blood. 



Horse 343 was also used as the blood donor in transmission 

 experiments in which tabanids infected two other horses, namely, 

 50 and 342. The latter experiments were made in order to 

 verify the previous one, in which a monkey contracted the 

 disease. In only the first of the latter experiments were bred 

 flies used. Two flies were permitted to bite horse 343 at a time 

 when its blood was swarming with trypanosomes. The flies were 

 interrupted in their biting in from forty to forty-five seconds 

 and transferred to healthy horse 50. The infected flies bit after 

 intervals of from five to fifteen seconds and were permitted to 

 complete the feeding on horse 50. The latter was replaced in 

 the fly-screened stable and examined daily. The initial rise of 

 temperature was noted upon the eighth day, February 10, when 

 a few surra organisms were found in the animal's blood. On 



