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that an insect showing such developmental stages in its gut is the true 
carrier of the disease, for there is no question of the possibility of the 
bed bug being the carrier of the sore in Bagdad. This development is 
then merely a partial imitation of what would actually take place in the 
true intermediate host. 
Mosquitoes. During the earlier part of my stay in Bagdad and 
before the commencement of the hottest season, various species of Oulex 
(including C. fatigans) were very common, and numbers of experiments 
were made with these. It was exceedingly difficult to induce them to 
feed upon the sore and it was only rarely that one would feed more than 
twice. In all thirty-one mosquitoes other than Stegoviyia fasciata 
chiefly C. fatigans, were fed on the sore. Some of these fed twice and 
one three times, but the majority fed but once. These were dissected 
twenty-four, forty-eight and seventy-two hours after feeding. No trace 
of the sore parasites or developmental forms could be discovered. Five 
mosquitoes were induced to take up exudate from the sore but the 
parasites could not be traced. 
Owing to the difficulty of inducing these mosquitoes to feed on the 
sore, the experiment was tried of turning loose mosquitoes into a net 
under which a boy with a sore on his face was sleeping. Those 
mosquitoes which had fed were collected in the morning and dissected 
after varying intervals. Of course in such an experiment only a small 
percentage of mosquitoes would have fed on the sore and taken up 
parasites, unless we assume that parasites are taken up from the 
peripheral blood in support of which assumption we have seen above 
there is little evidence. Close on one hundred mosquitoes were 
examined after feeding in this manner, but with negative results. 
Much difficulty was experienced in keeping the Gulex alive in 
captivity, as frequently whole batches would be found dead though they 
had appeared healthy a short time before. In these cases it was found 
that the intestine and even the other organs of the body were teeming 
with a bacillus which had evidently destroyed them. 
With Stegomyia fasciata which first began to make its appearance 
in June, experimental work was much more readily carried out. These 
mosquitoes feed greedily in broad daylight, and are quite willing to 
feed from the sore every twenty-four hours. It was easy to make them 
feed on any spot on the sore by gently guiding the proboscis to this 
spot. So eager were they to feed that they were not unduly disturbed 
by this interruption. While feeding the proboscis was generally 
plunged in to its base, and if the blood did not flow readily, the 
