240 
Worm ova in Flies 
The more frequent triple infection is: 
A. duodenale, A. lumbricoides and T. dispar. 
Examination of Flies. 
Shortly after war was declared a large number of porters came to 
Mombasa in connection with the Expeditionary Forces. Several cases 
from amongst these were admitted to the Native Hospital. One ward 
(No. 3) was set aside for them. Innumerable flies were attracted to 
this ward. Later, as more room was required for Indians in the two 
remaining wards, African cases, including fractures, were also put into 
ward No. 3. They, after varying intervals, also contracted bowel 
troubles, which were found to be due to intestinal parasites. The flies 
frequenting these wards lay under suspicion and an investigation was 
undertaken. 
On 6. xi. 1914 an initial experiment was conducted with 50 flies taken about 
mid-day from ward No. 3. They were killed and placed in a \ oz. bottle with ether. 
After being shaken, some water was added and the flies were subjected to a thorough 
washing. The wash-water, on being centrifuged, yielded a very slight deposit 
which gave negative results on examination. All the flies were now well mashed 
up in ether, water was added, and the whole thoroughly mixed. The larger fly frag¬ 
ments which remained were carried up to the top of the fluid by the ether. The 
fluid below the level of the fly fragments was pipetted off and centrifuged. Washings 
with fresh water were repeated until enough fluid was obtained to fill the centrifuge 
tube. The tube was then centrifuged for two minutes. The deposit thus obtained 
was a deep blackish brown colour and was composed of finer debris from the flies. 
The deposit was drawn up in a pipette, the centrifuge being used after each pipetting, 
and 50 preparations were made of which 13 contained 29 ova. 
The ova seen were those of T. dispar .. .. 6 
T. saginata .. .. 15 
A. duodenale .. 4 
A. lumbricoides .. 4 
As obviously one or two flies may have contained all of these ova 
it was decided to examine flies individually. 
The tables give the results obtained from preparations made of the 
abdominal contents of each fly of a series of three hundred. 
