1. The transmission of heartwater to three blesbuck and a black wildebeest is discussed.
2. The virulence of the heartwater “virus” did not change by passage through the antelopes.
3. The antelopes did not show any clinical symptoms that could be ascribed to heartwater. In case of the splenectomised blesbuck however heartwater lesions were observed at autopsy and Rickettsia ruminantium was demonstrated in the intima smears prepared from the jugular vein.
4. Heartwater “virus” could be demonstrated by blood sub-inoculations into susceptible sheep on the 16th and 28th day in two blesbuck and from the 13th to the 30th day in case of the black wildebeest.
5. The fact that heartwater “virus” could be demonstrated in the blood of one animal for 9 days and in another for 18 days gives one good reason to believe that antelopes can act as reservoirs themselves by feeding on these animals.