Diseases of Domestic Animals in Nyasaland. 19 



Blood taken from a wild animal and injected at the same time and under 

 exactly the same conditions into a healthy goat, monkey, and dog, will 

 often infect the first and last and fail to infect the monkey. In 10 

 experiments in which all the goats became infected, 8 of the 10 monkeys 

 remained healthy. The disease is also much more chronic in the monkey 

 than in the goat, the average duration of the disease in the former being 

 142 days, whereas in the latter it is only 56 days. 



Dogs. — In comparison with the goat, the dog is also somewhat refractory 

 to the Wild-game strain. In nine experiments all the goats became 

 infected, while their companion dogs, injected with the same blood, remained 

 healthy. 



Guinea-pigs. — The one guinea-pig inoculated remained unaffected. 



White Rats.— This strain is irregular in its action towards white rats. In 

 nine experiments four remained healthy, although the five which did become 

 infected died, on an average, in 30 days, which is moderately rapid for 

 T. pecorum. 



III. The Wild Glossina morsitans Strain. 

 Table XVI. 



Date. 



No. of 

 expt. 



Source of virus. 



Period of 

 incubation, 

 in days. 



Duration 

 of disease, 

 in days.* 



Keniarks. 









Cattle. 







1912. 













Feb. 3... 



108 





? 



140 



Mixed infection. 









Goats. 







Jan. 25... 



89 



Wild flies 



15 



60 



Died of T. pecorum. 



Feb. 3... 



125 





7 



36 



Mixed infection. 



„ 8... 



175 





20 



88 



Never showed T. pecorum. 



„ 13... 



200 









„ 19... 



247 





21 



30 



Mixed infection. 



„ 22... 



281 





10 



59 





Mar. 6... 



273 





6 



47 





„ 9... 



270 









Never showed T. pecorum. 



„ 18... 



343 





11 



34 



Died of T. pecorum. 



„ 23... 



363 





12 



43 



Mixed infection. 



„ 28... 



369 



From Goat 109 



21 





Still alive after 315 days. 



April 1... 



397 



Wild flies 



10 



60 



Mixed infection. 



„ 3... 



408 





11 



40 



Died of T. pecorum. 



„ io... 



410 









Never showed T. pecorum. 



„ 15... 



414 





10 



36 



Mixed infection. 



„ 18... 



428 









Never showed T. pecorum. 



„ 19... 



422 





7 



69 



Mixed infection. 



„ 23... 



420 









Never showed T. pecorum. 



„ 24... 



415 





16 



49 



Mixed infection. 



„ 29... 



429 





12 



43 





„ 29... 



430 





10 



45 





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



c 2 



