C. M. Wen YON 
315 
development is not sufficient to prove the bed bug to be the intermediate 
host. There is just the possibility in my experiments as well as in 
Patton’s that the flagellates seen in the bed bugs are parasites peculiar 
to these insects, but I consider this highly improbable since the dissection 
of numbers of bugs which have not fed from a sore has failed to reveal 
these flagellate forms. It seems therefore that the large quantity of 
blood taken up by these insects when they bite is able to act as a culture 
medium for the sore parasites, without this culture indicating in any 
way that the development is the true development in an intermediate 
host. 
The only other biting flies of any note in Bagdad are the mosquitoes 
and the so-called sand flies (Phlebotamus). Of the mosquitoes the 
Stegoniyia fasciata both on account of its voracity and numbers would 
be looked upon with greater suspicion than the various species of Culex. 
This suspicion is increased when we consider the development undergone 
by the sore parasite in its gut, a development which does not take place 
in the other mosquitoes. At one time I was inclined to regard the 
Stegomyia fasciata as the probable agent of transmission. It is 
essentially a house mosquito and is most persistent in its attempts to 
obtain a feed of human blood. When it has completed its fill it quickly 
digests this apparently enormous quantity and is ready on the next day 
for another feed. It bites as readily by day as by night, so that one is 
never free from its attacks. Allowing about two months as the incuba¬ 
tion period of the disease the time of maximum incidence of the 
Stegomyia corresponds with the time of maximum incidence of the sore. 
The result of the experiment upon myself with Stegomyia fasciata 
detailed above, appears to me to negative such a view, so that at 
present it is impossible to say whether the Stegomyia fasciata can or 
cannot act as the transmitting host of the sore parasite. It is still 
possible that some other mosquito less numerous and not so voracious 
as the Stegomyia fasciata will eventually be incriminated, but a more 
probable fly has yet to be excluded, in the sand fly (Phlebotamiis). 
Unfortunately, experimental work was not undertaken with these flies 
till later in the year. This was just commenced when the unfortunate 
accident to my assistant and the destruction of part of the laboi’atory 
completely put a stop to the work for some time. When this was again 
resumed, it was not found possible to secure Phlebotamus in sufficient 
numbers for experimental work, so that I am unable to give any 
experimental results in support of this fly being the agent by trans¬ 
mission. Its numbers and distribution both as regards place and season 
