Polo. | Reservoir of the Virus of Sleeping Sickness. 327 
Trypanosoma ganbiense, careful and continued examinations over prolonged 
periods may fail to reveal the presence of the parasite in the blood. 
4, The incubation of the disease (Sleeping Sickness) in antelope is probably 
seven days. 
5. Antelope of the water-buck, bush-buck, and reed-buck species, when 
infected with the virus of Sleeping Sickness, can transmit the infection to 
clean laboratory-bred Glossina palpalis. 
6. This transmission of the infection to clean laboratory-bred flies may 
occur at least 81 days after the last feed of the infected flies on a buck. 
7. Glossina palpalis, when infected with the virus of Sleeping Sickness 
obtained from the blood of infected antelope, are capable of transmitting the 
virus to susceptible animals. 
8. An appreciable percentage of Glossina palpalis will become infected with 
the virus of Sleeping Sickness should these flies feed on antelope suffering 
from this disease. 
9. It follows, from the above conclusions, that antelope living in the fly- 
areas are “ potential” reservoirs of the virus of Sleeping Sickness. 
10. No antelope up to the present has been found naturally infected with 
Trypanosoma ganbiense, 
