C. M. Wenyon 
299 
of feeding in the two cases would account for this. It was impossible to 
determine what percentage of Stomoxys took up parasites from the sore 
without feeding very large numbers on the sore, and dissecting im¬ 
mediately. However, in some cases large numbers of parasites were 
taken up and even the large mononuclear cells full of parasites, and a 
short examination of the stomach contents sufficed to demonstrate their 
presence, so that it is possible that in those cases where the parasites 
were not found they were present in small numbers only. The experi¬ 
ments with Stomoxys were conducted on the same lines as those made 
with house-flies, with the difference that the Stomoxys were not fed on 
scrapings from the sore. The greatest number of feeds given a Stomoxys 
was ten, and the flies wmre dissected twenty-four hours after the last feed. 
This time generally sufficed for the complete disappearance of the blood 
taken up twenty-four hours before. As in the case of the house-flies the 
parasites very quickly disappeared from the gut and on no occasion was 
any trace of a development discovered. The presence of a Herpetomonas 
in the Stomoxys tended to obscure the result, but the flagellate was only 
found once in a fly fed on the sore, though several times in flies 
dissected immediately after capture in the stable. The Herpetomonas 
is either a flagellate peculiar to the fly, or represents some trypanosome 
of the horse or other animal. 
Dog Flies (Hippoboscidae). I w'as not successful is inducing these 
flies to feed on the sore, and they very quickly died if kept in confine¬ 
ment away from a dog. 
Fleas and Pediculi. Experiments with fleas and body lice were not 
made though numbers of these were dissected wdthout result. 
In view of the expei’iments on the transmission of canine leish- 
maniosis recently recorded by Basile, the possibility of fleas transmitting 
the sore must not be forgotten. 
Canine leishmaniosis of this type is however a general infection, 
while the sore is a local skin disease. In the latter one can safely 
assume that the sore develops at the site of the inoculation whether this 
be carried out naturally or artificially. In such a case the flea can 
hardly be responsible for a lesion appearing exclusively upon exposed 
surfaces of the body. 
Bed Bugs. Experiments were carried out by allowing the bed bugs 
obtained from the prison to feed on the sore. Only a small percentage 
of bugs would feed under these circumstances, even after prolonged 
starvation, so that it was a laborious process inducing the bugs to feed. 
When they did feed they became gorged with blood. Bugs which had 
