234 TABANID^ AND DISEASE [CH. 



having shaved and damped a patch of skin on the trypanosome 

 infected subject, one end of such a tube was then appUed to 

 the latter. As soon as it was seen that a number of flies had 

 commenced to feed on this animal, the tube was removed and 

 without delay applied to the skin of a healthy animal, the flies 

 being allowed to finish their meal on the latter. At the con- 

 clusion of the experiment the flies in most instances were 

 killed. Occasionally they were dissected. Only on two or 

 three occasions were they kept and used for feeding a second 

 time during the following days. The experiment therefore, 

 permitted only of mechanical transmission." 



Only one positive result was obtained out of five experiments. 

 In this case 122 Stomoxys were fed in the course of 14 days on 

 an infected sheep and afterwards on a healthy sheep. After 

 an interval of six days three Hmmatopota, of which one was seen 

 to bite, fed similarly. Trypanosomes were found in the blood 

 of the sheep 13 days later, and it died after another 10 days. 

 The experiment shews that this trypanosome can be conveyed 

 mechanically by one of these species, and Jowett thinks that the 

 HcBmatopota were responsible. 



Hart records an experiment in North-Eastern Rhodesia 

 supporting the view that Pangonia and Stomoxys may transmit 

 trypanosome infections. 



An outbreak of trypanosomiasis {T. dimorphon, or pecaudi) 

 occurred on a farm fifty miles from Fort Jameson. The 

 owner stated that tsetse-fly had never been seen, but Pangonia 

 had been numerous. Two bullocks infected with trypanosomes 

 were kept at the farm and the remainder sent away. Then 

 three healthy cows were brought from Fort Jameson and 

 kraaled with the two bullocks, and to ehminate the chance of 

 their being bitten by a stray tsetse-fly, the animals were fed 

 close to the house. The experiment began on April nth and 

 the animals were at once bitten by Pangonia and Stomoxys nigra. 

 On May 27th trypanosomes were seen in one of the cows, and 

 the remaining two died of trypanosomiasis at the beginning of 

 July. It is impossible to decide whether the infection was due 

 to Pangonia or Stomoxys, or both, and the possibility of stray 

 tsetse-flies having bitten the animals is also not excluded. 



