64 Col. Sir D. Bruce and others. Glossina palpalis as a [Nov. 27, 



August 8. Keturned from Lake-shore to Mpumu. 



August 11. Trypanosoma vivax present in the blood of this calf. 



Remarks. — If the incubation period of this disease is assumed to be 

 eight days, then this calf remained 19 days at the Lake-shore before it 

 became infected. The proof that the trypanosome found in this calf's blood 

 was Trypanosoma vivax and not Trypanosoma gambiense was the shape and 

 appearance of the parasite, the fact that the calf's blood injected under the 

 skin of two monkeys gave negative results, and, lastly, that 50 laboratory- 

 bred flies fed on this calf afterwards infected a goat with Trypanosoma 

 vivax. 



Experiment 431.— Cow. (Mother of Calf, 1318.) 



July 12, 1909. This cow accompanied her calf to Kibanga, and remained 

 with it during the experiment. 

 August 8. Eeturned to Mpumu. 

 August 19. Trypanosoma vivax discovered in blood. 

 The following table shows the dates of examination : — 



Date. 



Parasites in blood. 



Piroplasma. 



Trypanosoma. 



1909. 

 January 9 



„ 20 

 21 

 28 



February 2 

 9 

 26 



August 9 



Remarks. — It is possible that this cow became infected from her calf, but it 

 is more jjrobaljle that she became infected in the same way and about the 

 same time as her calf. 



The remaining experiments were carried out by bringing freshly-caught 

 Glossina palpalis from the Lake-shore to the laboratory at Mpumu and 

 placing them on healthy oxen. 



