t .1 .1 wr used small gauze cages and found it difficult to 
. i . :/m pal pahs) alive for more than a few days 
\i Li >|)oldvillc we attempted to keep them longer by 
r 'ai > I i mg their natural habitat in their cages. Cubical 
.mi n ug 18 inches along each side and containing water 
. njj ',\cre placed in a sheltered position out of doors. 
■ ' •• ; mental animals were simply turned loose in these 
i f , - '.ere found to feed much better on them if they 
. t nder these circumstances flies often lived in 
" 11 ! of months. 1 he method, however, had distinct 
•, ,t ' as difficult to feed the flies on large animals and, 
1 'i r 11id contents of the cages, it was almost impossible 
idler of living flies they contained. 5 For this reason. 
. •, ii ' done at Kasongo the smaller cages were again 
f ;«■, ted ii the experimental animals daily. 
r ' animals or men, whose blood contained many 
.. . . were chosen for the infecting feeds. In the latter 
., .. : . , lt Kasongo, when it was found that so few of the 
enta bad been successful, the flies were fed on 
.-.r ... of sleeping sickness, in whose blood there were very 
i - ntly no parasites, in order that flies should be 
■r wiih V. inch had fed on persons at each stage of the 
u,ic, ting hosts have been further described in the 
of the successful experiments. 
' n . neerning the infectivity of the parasites at various 
T X rJ ' • disease can be drawn from an examination of t ie 
Ml, Hies used in successful experiments, because 
Md uninfected after having been fed upon by the 
identical conditions. 
, <1|l( l,t,ons permitted, tlie flies were used for several 
, example, many of the ^ies use 1 
• i infect a healthy animal by Hu es 0 
ns previously on an animal tnfected wrth 
^FMmu gambienae) had been used before in other e*per— 
mjf u then bad therefore fed several times, u i 
n pe on infected animals. As far as we ’ 
•i If ... vs ( s used in the experiments made at eop 
