86 
responsible for the spread of the disease, in the light of our prfsent 
knowledge. 
In parts of the Congo Free State visited by the Expedition 
this School to the Congo, the disease was found to be widdr 
disseminated, although Gl. palpalis was found only vcr>- scantih- 
Since, therefore, the numbers of this fly did not ap|>car toaccoontfo 
the number of cases, experiments" were made with various othe 
biting Arthropods—the larva of Auchmeromyia /nifo/a (Congo Fltw 
Maggot), Ornithodoros mouhnta, Simu/hfw and Anoplielmes -t' 
transmit Trypanosoma gnmhiensc. All these resulted negatirdr 
The experiments to transmit hy means of tsetse flies were alsp 
unsatisfactory, and although positive results were obtained, the 
number of flies required was so great that it was felt the solution had 
iii Ljgdnaa,* me results were Similar Uigf 
numbers of flies were required for success, and this only foUowfd 
when the interval between the ' infecting ‘ and the ' transmitting ’ fed 
did not exceed 48 hours. No satisfactory evidence of a devdopmentai 
cycle of the trypanosome in tsetse flies has yet Ix-en obtained, and 
It can now be accepted as proved that transmission by mechanical 
means is possible. The importance of this is self-evident 
Mechanical transmission does not explain satisfactorily the rapid 
nevtXl t in many instances 
do ™ss r"' T “ ^hn^-n that the trypanosomes 
of thi ' P-ctical impof 
of the eenus r ' Tv,"' ’ nicclianical, transmission by other spccifs 
or me genus cannot be overlooked. 
in 1906 BrNobl^ 'u'' ^‘^"’'"'^‘'■“‘ion of North-East Rhodesia 
him that tL™ ‘he Congo service, told 
to he inc™":re7r::ra:i^ 
from the work on cattle trynanoso — ^''2“'"^ '’y 
expected. As is well I-„ somiasis, this is what would be 
»>orsitans (and probabl) “‘'•'nntily spread by « 
experiments have been ^ ^ ^ successful transmission 
‘~somes, natura;\™ r “ 
genus Glo,,i„a, have been carried f 
rom animal to animal by distinct 
