304 



Dr. H. L. Duke. Antelope as a [Apr. 20, 



It will be seen that this buck still harboured T. gamiiense 15 months after 

 its original infection. For the last seven months, however, no positive 

 evidence has been forthcoming. Experiments to try and re-infect this 

 antelope will be now undertaken. 



Bushbuck 2371. 



Original infection April, 1910. Latest evidence of infectivity obtained in 

 December, 1910, when it infected laboratory-bred G. palpalis. 



Fly Experiments. 



Expt. 

 No. 



Period for which 

 flies fed on 2371. 



Number of flies. 



Length 

 of 



ment in 



Eesult 



of 

 feeding 

 on clean 

 monkey. 



Remarks. 



1st 

 day. 



30th 

 day. 



Dissected 

 during 

 experi- 



Con- 

 taining 

 flagel- 



80 

 220 



May 22— 27, 1911 

 July 24—29, „ 



59 

 110 



50 

 76 



57 

 110 



1 







53 

 48 



+ 



Monkey died of the disease 

 after 130 days. 



Fed on monkey through- 

 out the experiment. 





Totals 



169 



126 



167 



1 









Experiment 80 was nourished on a fowl during the earlier days. The 

 positive fly showed a characteristic infection of salivary glands and gut, while 

 the proboscis was negative. It was dissected on the 53rd day of the 

 experiment and infected the monkey on the 50th day. 



Injection Experiments. 



Date. 



Expt. No. 



Quantity of blood injected. 



Result. 



Animal used for 



Pure. 



Citrated. 



injection. 



31.5.11 



29.11.11 

 23.1.12 



536 

 628 



c.p. 

 5 



? 



3 





Monkey. 





653 





















From the above experiment it will be seen that this antelope proved 

 infective with T. gambiense 22 months after its original infection with 

 laboratory-bred G. palpalis. The incubation period in the monkey was 

 10 days. 



