238 E, A. MINCHIN. 
length which gave the impression of slenderness). Their 
cytoplasm was not granular or vacuolated, and they appeared 
perfectly healthy and normal; the free flagellum was relatively 
short ; 1 relatively large, sometimes rod-shaped. No dividing 
forms were seen. 
The second fly (male, seventy-one hours after infection, re- 
fed Oct. 21st) showed exactly the same condition as the last, 
and in this case also no trypanosomes were found in the red © 
blood, but in the black blood they were numerous; some 
more slender in appearance and active in movement, progres- 
sing rapidly en fléche; others stouter, slower in movement. 
Smears were made of the black blood; unfortunately the 
preparations were not very successful, but they showed 
trypanosomes similar to those seen in the first fly (figs. 
89-92), some very slender. 
The third fly (female, seventy-two hours after infection, re- 
fed Oct. 21st) showed the same condition as the two already 
mentioned. In the black blood a few trypanosomes were 
seen, both slender and stout, but less active than those seen in 
the other two flies. The smears made were defective, but in 
one of them two trypanosomes of rather stout build were seen. 
Oct. 23rd (ninety-four to ninety-eight hours after infection, 
re-fed Oct. 21st). The five remaining flies were dissected ; 
in all of them both red and black blood was present in the 
digestive tract ; the black blood contained numerous crystals. 
No trypanosomes were found in the red or black blood, nor 
in the proventriculus nor proctodeum. Smears were made of 
the blood, but prolonged searching failed to reveal any 
trypanosomes. 
The remaining eleven flies of this batch were examined 
at intervals up to Nov. Ist, on which date the last seven were 
examined ; in no case were any trypanosomes found. 
Batch of Nov. lst, 1905.—Some freshly-caught 
Entebbe flies were fed on Monkey 405, which, however, was 
showing very few trypanosomes in its blood. . 
Noy. 2nd.—Some of the flies were dissected ; no trypano- 
somes were found in them with the exception of one, which 
