314 
Oriental Sore 
found in the sores could do so. It is possible, as Dr Eow suggests, that 
the parasite undergoes some development in the house-fly, and is then 
deposited upon the skin probably in the faecal matter, and that a sore 
arises in this way. Dr Kow is conducting experiments with the object 
of elucidating this matter, but the quick disappearance of the parasites 
in the house-fly and their failure to develop into Herpetomonas forms, 
afford a strong argument against the view advanced by Row. The 
fact that the parasite develops into flagellate forms in the culture tube 
and also in the bed bug and in Stegomyia is almost conclusive evidence 
that a similar development will take place m the true host. From 
this point of view the house-fly cannot be suspected. However, in 
the light of the experiments of Hindle on the passage of Trypano¬ 
soma gambiense through the normal uninjured skin of the rat, it is 
a possibility to be considered that the parasite of the sore is taken up 
by the house-fly, that it develops into flagellates in its gut, probably 
minute forms like those described as occurring in the culture tube and 
not easily to be detected, and that in this condition it is passed on to 
the skin and is able to penetrate and produce a sore. My experiments 
lend no support to such a view, and should the house-fly be the normal 
carrier it still has to be explained why the disease is limited in its 
distribution, though the house-fly occurs everywhere. 
Of the biting flies in Bagdad the Stomoxys as the carrier of the 
disease, is not to be suspected, as it is not only limited in its distribution, 
but also fails to give any development of the parasite in its gut, even 
after as many as ten feeds from the sore. The Hippohoscidae, the ticks, 
fleas and body lice, will not explain the disease. The two former on 
account of their seldom attacking man, and the two latter because they 
would give rise to sores on the unexposed rather than the exposed 
surfaces of the body. The bed bug on account of the development of 
the Kala azar parasite which takes place in its gut, and its supposed 
responsibility for the spread of this disease, was at first looked upon 
with suspicion. It was soon found that its distribution in Bagdad w^as 
not wide enough for this hypothesis to be correct, and further it would 
not explain the occurrence of sores only upon the exposed surfaces of 
the body. In spite of the impossibility of the bed bug being the host of 
the sore parasite, it has been pointed out above that a certain develop¬ 
ment of the parasite takes place in its gut. This observation is of great 
importance, for it shows that the development of the Kala azar parasite, 
which w'as found by Patton to take place in the same host, may be of 
a similar nature. The evidence afforded by the occurrence of such a 
