1911.] Antelope Infected with Trypanosoma gambiense. 



48 5 



mucous membrane of the fourth stomach also showed many petechise. 

 Microscopical examination of smears made from the various organs was 

 negative. It is, therefore, impossible to say what the cause of death was in 

 the ease of this buck. 



With the view of ascertaining how long the antelope remained infected, 

 investigations were carried out on the following lines : — 



1. Feeding laboratory-bred Glossina palpalis for several days on the 

 antelope and subsequently endeavouring to infect a healthy susceptible 

 animal. 



2. Dissecting these flies and examining them for flagellates. 



3. Injecting blood of the buck into animals susceptible to T. gamhiense 

 infection. 



Table I gives the detailed results obtained by the first of these methods 

 The number of days which elapsed from the date on which the buck was 

 infected until the commencement of the experiment is given. 



" Hereditary transmission " flies indicates that the flies before being put 

 upon the antelope had been fed for 30 days upon healthy monkeys to 

 ascertain if laboratory-bred flies which had never fed upon an infected 

 animal could give rise to an infection. As it has been suggested that flies 

 were most readily infected when their first feed was upon an infected 

 animal, these flies were used with the view of obtaining evidence on this 

 point, control experiments being at the same time made with laboratory- 

 bred flies which had not fed before they were put upon the antelope. 

 Although it will be noted that no infection occurred among the 

 •" hereditary transmission " flies, whereas the control flies sometimes became 

 infected, the numbers of the flies used are too small to allow of any 

 conclusions being arrived at. 



It will be noted that flies which were fed on Bushbuck 2372, 315 days 

 after it had been infected with a human strain of T. gambiense, became 

 infected and successfully transmitted the disease to a healthy monkey. 



Table II gives the results of the dissections of laboratory-bred Glossina 

 jxdpalis which had fed on the infected antelope. 



The experiments recorded in Tables I and II are summarised and grouped 

 according to the length of time the antelope had been infected in Table III. 



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