tlie Domestic Animals in Nyasaland. 53 



Table I — continued. 



Date. 



No. of 

 expt. 



Source of virus. 



Period of 

 incubation, 

 in days. 



Duration 

 of disease, 

 in days.* 



Remarks. 







Guinea-pigs. 







1912. 













.April 24 . . . 











Never showed trypanosomes. 



Oct. 29... 



1524 



From Goat 1483 





z 





Nov. 5... 



1546 



From Monkev 1541 ... 









„ 5... 



1547 



„ 1541 ... 





— 





1913. 













Jan. 4... 



1731 



Transmission expt. . . . 





— 



;) 33 









Rats. 







1912. 













April 24... 



484 



From Monkey 405 



_ 





Never showed trypanosomes. 



„ 27... 



491 



449 







Oct. 29... 



1521 



From Goat 1483 







) j i) 



Nov. 5... 



1548 



From Monkey 1541 ... 







3) 3) 



„ 5... 



1549 



1541 ... 







3) 3) 



* Duration includes the days of incubation ; it dates from day of infection. 



Action of T. simise on Horses, Oxen, and Antelope. — There has been no 

 opportunity of testing the action of T. siwiice on equines. Four oxen were 

 inoculated, two from an infected monkey and two from a goat, but all four 

 remained in good health. Five antelope in confinement were also inoculated 

 without result, and it would seem that these animals are really refractory, 

 since in no instance has T. simice ever been found in the blood of antelope. 



Disease set up in Goats and Sheep by T. simia?. — Thirty-one goats and one 

 sheep were infected by this parasite, as the result of various experiments. 

 Fifteen of these were used in wild G. morsitans feeding experiments, three 

 had warthog blood injected into them, and 14 were inoculated with the 

 blood of infected experimental animals. It has already been remarked that 

 this species of trypanosome varies rapidly in its virulence or . power of setting 

 up disease in animals. Its virulence would appear to be exalted by passage 

 through the " fly," or, at least, to have reached its highest virulence after 

 passage through the " fly," and lowered by passage through certain animals. 

 For example, of the 15 goats infected by the bite of the " fly," 13 died, on an 

 average, in 46 days, and only two recovered. The three goats which were 

 infected by the direct injection of warthog blood all recovered ; this is curious 

 when it is remembered that in all probability the " fly " must get its infection 

 solely from this animal. Six goats were injected with the blood of " fly "- 

 infected monkeys ; only one died, four recovered, and one proved refractory. 



