230 BE. A. MINCHIN. 
Sept. 10th (forty-eight hours after infection).—Three flies 
were dissected; the most successful preparation showed long, 
moderately stout or slender forms (see P. R.8., Pl. XII, fig. 
15); the slender clear forms of the previous day wanting. 
Sept. 12th (ninety-six hours after infection).—Three flies 
were dissected, and smears made of the blood. In the first 
two flies no trypanosomes were found ; in smears of the third 
trypanosomes were found scantily in the red blood, but 
fairly abundant in the black. They were, for the most part, 
remarkable for their large size (p. 183, and Pl. X, figs. 97-101). 
Batch of Oct. Ist, 1905.—This batch consisted of 
ten flies bred from pupe. They were put on to Monkey 
478, which was showing a fair number of T. gambiense in- 
its blood, some smears being made from the monkey at the 
same time. Seven of the flies fed, three refused. 
The smears of the monkey’s blood showed trypanosomes 
chiefly of an indifferent type (figs. 1-5). None of the typical 
stumpy forms were found, but after some searching a few 
slender forms (fig. 5) were found. In all 83 indifferent forms, 
10 slender, and | dividing form were counted in a smear. 
Of the seven flies that fed one died before being examined ; 
the remaining six were dissected on Oct. 2nd, 3rd, 4th, 
Sth, 6th, and 8th respectively. All their organs were 
examined very carefully, namely the pericardial fluid, Mal- 
pighian tubules, salivary glands, proventriculus, stomach, 
intestine, proctodeeum, and in some cases the genitalia. In 
no case were trypanosomes found of any sort. Some of the 
flies were full of bacteria. 
The negative result obtained in this batch was remarkable 
and difficult to explain. ‘lwo points call for notice—the very 
shght amount of differentiation in the trypanosomes of the 
monkey’s blood, and the fact that the flies were bred in 
captivity and probably rather sickly and delicate; but 
whether the result is to be explained by either of these data 
cannot be asserted definitely. 
Batch of Oct. 3rd.—this consisted of a few flies caught 
the day previously in the vicinity of Entebbe, and fed on 
