236 EH. A. MINCHIN. 
sucking stomach. The two smears made showed trypano- 
somes for the most part long and moderately stout (fig. 87), 
others more slender (fig. 86), and others again stouter (fig. 
88), all of them very granular and very different in form and 
appearance from the two types found at twenty-four hours. 
The third fly (female, seventy-two hours, re-fed at fifty-one 
-hours after infection) had the digestive tract gorged with 
blood, red in the stomach, black in the intestine. No 
trypanosomes were found in the red blood, but in the black 
blood as many as three or four in a field (3 mm. apochr. 
immersion) ; at first very active, they soon became sluggish 
under observation. A stout one was seen with very distinct 
undulating membrane, aud with n and N apparently dividing 
(fig. 109). Another rather smaller one had the undulating 
membrane distinct, and the cytoplasm containing refringent 
eranules (fig. 107). A third was long and slender, with 
eroups of refringent granules (fig. 108). Of the red blood 
five smears were made, and, after much searching, two 
trypanosomes were found in one of them; one of these was 
damaged, the other (fig. 82a) was of extremely large size, 
very granular and vacuolated, and in process of division. 
My two smears of the black blood show fairly numerous 
trypanosomes (figs. 83-85), most of them remarkable for 
their length and large size, varying in type from slender to 
stout; they are nearly always very granular and frequently © 
vacuolated. Dividing forms were also seen. 
Oct. 19th (ninety-four to ninety-eight hours after infection). 
—Three flies dissected, two male and one female; the two 
first had been re-fed Oct. 17th, the last re-fed Oct. 18th. All 
three flies appeared healthy and full of blood, red and black, 
but no trypanosomes were found in any of them. Numerous 
smears were made of each and carefully searched, but no 
trypanosomes could be found. 
Oct. 20th (118-119 hours after infection).—The last two 
remaining flies (both males) were dissected and examined. 
No trypanosomes could be found in the digestive tract, 
neither in the fresh condition nor in smears, _ 
