ROLE OF STOMOXYS CALCITRANS. 



485 



moment they were used to supply the infected blood. The 

 number of trypanosomes per field is not given in the table. 



Guinea pig 45, which had been infected by an inoculation of 

 blood from carabao 3252, underwent an incubation period of five 

 days, and died of surra twenty-six days after inoculation. 



Monkey R was inoculated with blood from monkey A, drawn 

 while the latter was dying of the disease. 



The infection in monkey A was very light, trypanosomes in 

 the blood being scanty. Monkey R reacted with the presence 

 of surra organisms within four days, showing the usual febrile 

 changes, followed in a few days by other characteristic symp- 

 toms. This monkey lived for twenty-two days after inoculation, 

 showing a moderate number of trypanosomes in blood from its 

 heart. The lesions showed characteristic changes of surra. 



Monkey F was inoculated with a carabao strain of surra from 

 bull 3148. Seven days after inoculation trypanosomes were 

 recovered from the monkey's blood. It died fifteen days after 

 inoculation, showing all the appearances of trypanosomiasis with 

 characteristic lesions and a moderate number of flagellates in 

 the heart's blood. 



Monkey A, as has been previously noted, reacted to an injec- 

 tion of the blood of horse 49. In the present experiment 

 it was used shortly before the death at a time when the blood 

 showed only a moderate number of trypanosomes. The blood 

 was used, while the animal was dying, to infect monkey R, which 

 reacted with a heavy infection. 



Table II. — Mechanical transmission by Stomoxys on guinea pigs and 

 monkeys, after com,pleted feeding. 



No. of 

 ex- 

 peri- 

 ment. 



Infected animal 

 used. 



Healthy animal 

 used. 



Num- 

 ber of 

 flies 

 fed 

 on 

 first 

 host. 



Length of 



time fed on 



infected host. 



Interval 

 between 

 feedings. 



Flies 

 feeding 

 at time 



of 

 trans- 

 fer. 



Num- 

 ber of 

 flies 

 fed 

 on 

 sec- 

 ond 

 host. 



Length 

 of time 

 fed on 

 second 

 host. 



1 

 2 

 3 

 4 

 6 

 6 

 7 

 8 



Guinea pig 45-- 

 do 



Guinea pig 18-- 

 Guinea pig 53— 



Monkey 3M 



Monkey 2M 



Monkey 2L 



Monkey 3L 



Monkey 2G 



MonkeyC 



2 

 11 



150 

 12 

 29 

 12 

 25 



300 



Hrs. mins. 



11 



1 32 



1 

 20 

 35 

 30 

 28 



2 



Hrs. mins. 

 20 

 6 



24 

 10 

 12 

 20 

 16 



20 



None - 

 None - 

 None - 

 None - 

 None - 

 None - 

 None- 

 None. 



2 

 11 

 43 

 12 

 23 



7 

 10 

 182 



Minutes. 

 12 

 41 

 75 

 30 

 20 

 25 

 40 

 50 



Monkey R 



do 



do 



do 



Monkey F 



Monkey A 



