176 HE. A. MINCHIN. 
“ stumpy ” forms (figs. 9, 10, 17, 20, 21, 33-35), in which the 
body is short and stout, usually rounded off abruptly at the 
posterior end, and witha very short flagellum. These stumpy 
forms are not always to be found, but when present are un- 
mistakable. I found the greatest contrast in the trypanosomes 
from cerebro-spinal fluid (figs. 30-35), in which the slender 
and the stumpy forms recall the two types of Try panosoma 
dimorphon, and very few intermediate forms were to be 
found. A count made from four smears of cerebro-spinal 
fluid gave twenty long and slender forms (43°47 per cent.), 
eighteen short and stumpy forms (39°12 per cent.), of which 
one was dividing, and eight intermediate forms (17°39 per 
cent.). In two preparations, made from the blood of the 
same monkey (478) on two successive days (pp. 230, 231), I find 
on one day (figs. 1-5) no stumpy forms, though they were 
present in smears made the next day (figs. 6-10); and it is 
noteworthy that in flies fed on this monkey on the first day I 
obtained no development of the trypanosomes, while the batch 
of flies fed two days later showed a normal type of infection 
(p. 231). My best infection of T. gambiense in the tsetse- 
fly was from a batch of flies fed on monkey 478 on a day 
(Oct. 19th, p. 237) when it was showing trypanosomes, few in 
number, but sharply differentiated in form (figs. 11-13). 
Castellani (18) has stated that T. gambiense, i.e. the 
trypanosome of Gambia fever, moves with the flagellum 
forwards, that of the sleeping sickness with the blunt end 
forwards. I find that the trypanosomes I have observed 
push their way through blood-corpuscles with the blunt end 
forwards, but when moving freely they tend to travel with 
the flagellum forwards. 
With due allowance for variations in form and size, I find 
the structure of T. gambiense very uniform. The nucleus 
is large and lodged near the middle of the body ; it appears 
to be a compact mass of chromatic granules, without any 
definite limiting membrane. Near the nucleus a few coarse 
granulations are commonly seen, which may, however, be few 
in number or absent. The kinetonucleus is usually close to 
