Observations on T. pecorum [Bruce) and T. uniforme [Bruce). 555 



Table I. 



Expt. 

 No. 



Period for which flies 

 fed on Bushbuck 55. 



Number of flies. 



Length 



of 

 experi- 

 ment in 



Result 



of 

 feeding 



clean 

 monkey. 



Remarks. 



1st 



30th 



Dissected 

 during 

 experi- 



Con- 

 taining 

 flagel- 



112 



June 6 — 13, 1911 ... 



42 



32 



39 



1 









129 



June 9—13, „ ... 



37 



34 



37 



1 



63 







135 



June 12— 14, „ ... 



34 



33 



34 







80 







247 



Aug. 5—12, „ ... 



93 



85 



90 



8 



141 







253 



Aug. 7— 12, „ ... 



105 



86 



91 



1 



66 





Fed on Monkey 359, 

















which developed T. 



















pecorum. Of. infra. 



541 



Dec. 1—8, „ ... 



109 



56 



109 







61 





542 



Dec. 4—8, „ ... 



94 



39 



94 







58 







The following cycle experiments were carried out in which animals other 

 than Bushbuck 55 supplied the infecting feeds : — 

 Table II. 



Expt. 

 No. 



Period for which flies fed on 

 infected animal. 



Number of flies. 



Length 



of 

 experi- 



in 



Result 



of 

 feeding 



1st 



30th 

 day. 



Dissected 

 during 

 experi- 



Con- 



96 



1911, May 31— June 5, on Monkey 



















46 



44 



46 



1 



49 





212 



1911, July 19—21, on Calf 33 ... 



83 



80 



82 



2 



104 







1911, Sept. 6—9, on Monkey 321 



136 



124 



133 



1 



108 





716 



1912, April 18—27, on Calf 688 



46 



42 



45 



2 



82 





717 



1912, April 18—27, on Calf 688 



59 



53 



59 



2 



82 





It is unfortunate that in the case of the only (apparently) successful trans- 

 mission experiment (253) a possible alternative source for the trypanosome in 

 the monkey was introduced. Owing to a temporary shortage of monkeys 

 monkey Experiment 359, whose blood had been negative for 10 days after the 

 last feeding of Experiment 253 upon it, was taken to the Lake. Box 253 had 

 been dissected, and as no fly was found with flagellates in the proboscis, it 

 was thought that the experiment would necessarily be negative. It happened 

 that three bushbuck, A, B and C, were shot, and the citrated blood of two 

 of them, A and B, was inoculated into the monkey, 3 c.c. from each animal. 

 At the same time, 6 c.c, 5 c.c. and 3 c.c, citrated blood of Bushbuck A, B and C, 

 respectively were inoculated into Goat 484. This goat remained healthy, 



