7

most convincing arguments against the fly transmission hypothesis, is the fact
that although flies were most abundant during the rainy season in Cambay, I
never saw a single early case which I could say was definitely infected during
this time. From October to January I regularly examined some eight hundred
children in three of the local schools, and although a number of them had not
yet contracted the disease, I failed to find a single early lesion. The skin of
each child was thoroughly searched, and any suspicious pimple or nodule was
punctured and the contents microscopically examined. Further, if the trans-
mission is regularly carried out by the fly, as suggested by Row, surely I would
myself have become infected, for all the factors mentioned by him were cer-
tainly present in my case, with the exception that the flies did not ingest the
parasites along with blood, which he states is essential for them to live and
develop in. I find it difficult to understand how a non-bloodsucking fly, such
as Musca nebulo, can obtain blood from a sore, for the only medium in which
I found the parasites discharging from the sore, was a whitish fluid containing
leucocytes. Lastly, the fact that the disease never spreads in a house during
the fly season, even when several people with sores in a suitable condition are
present, is I think very strong evidence against the fly transmision hypothesis.
In Cambay the disease is most frequently contracted during the cold weather,
which is very severe, the thermometer frequently registering a few degrees
above 0°C, and at this time of the year house flies are very scarce.

      Cardamatis and Melissidis state that the parasite of Oriental Sore in
Greece (?) lives as long as six days in the alimentary tract of the house fly
(species not stated), but they do not say whether they used bred flies in their
experiments. From the fact that wild house flies are commonly infected with
several species of herpetomonads, such experiments as they record are of little
or no value.

EXPERIMENT III.

IS THE PARASITE TRANSMITTED BY LICE,—PEDICULUS VESTIMENTI
AND PEDICULUS CAPITIS L. ?

      It may be thought that lice are the most suitable carriers of the parasite,
more particularly the species found on the body, as they may crawl over a sore,
and thus become infected. Later they may be transferred to a susceptible person
and infect him. A large number of body and head lice were obtained, the
former with great difficulty, they were then kept on small pieces of cloth, in
glass tubes, and regularly fed on the case mentioned above; others were allowed
to crawl over the surface of the sore, and to suck up blood from the margin.