240 BE. A. MINCHIN. 
they were found, however, in the smears of both red and 
black blood. ‘The trypanosomes showed pronounced differen- 
tiation into slender and stout types (figs. 48-50), the latter 
greatly preponderating in number. A small number were 
seen to be dividing, in nearly all cases stout forms. Hxamina- 
tion of seven slides gave the following results : 
Slender. Stout. Dividing. 
lst fy, red blood . : 0 : it : 0 
Ist fly, red blood. me lS 64 1 
Ist fly, black blood . ‘ 0 é 23 0 
2nd fly, red blood . : 1 ; 29 0 
2nd fly, black blood 10 : 3 6 
3rd fly, red biood . ; 2 : 7 0 
ord fly, black blood : 9 a 4OY 4 
Total ; : Say . 436 iL 
This gives roughly twelve stout to one slender form. 
Nov. 6th (seventy-two hours after infection).—One fly was 
dissected ; the red blood examined fresh showed no trypano- 
somes, but in the black blood some active trypanosomes were 
found, chiefly of slender type; one large stout form, however, 
was seen. Three smears of the black blood were made, but 
put aside and fixed and stained in Hngland; only on one of 
them were two trypanosomes found after much searching ; 
both, unfortunately, were badly preserved. 
Nov. 7th (ninety-six hours after infection).—Three flies 
were dissected and all their organs carefully examined 
for trypanosomes. The flies were apparentiy healthy and 
contained both red and black blood. In the first fly (male) 
a few scarce trypanosomes were noted (by my colleague 
EF. M. Tulloch) in both the red and black blood, but in four 
smears made (two of each kind of blood) none could be found 
after prolonged searching. In the second fly (female) one 
active trypanosome was seen in the black blood, after much 
searching, but in the smear that was made none could be 
found. In the third fly (female) no trypanosomes were 
found. 
