3

except for a few small perforations, remains intact almost to the termination
of the disease. It is in this type of sore that the periodical swellings caused
by the marginal extension of the parasites are observed, and it is in these
cases alone that the parasite can be found with any certainty in the circulating
blood. Any one who has once seen this variety of sore, will not fail to recog-
nise it again; I had the good fortune to see several during my stay in Cambay.

      Having definitely settled that the parasite is frequently liberated into the
circulating blood, and finding that the case under observation often exhibited
this phenomenon, I utilised it for my feeding experiments. Dr. Row, who has
on several occasions visited Cambay, has come to the conclusion that the house
fly is the most probable transmitter. It was therefore important to settle this
question once and for all. That house flies may transmit the parasite of
Oriental Sore is no new hypothesis, for Seriziat and Laveran have long ago
suggested this possibility. Laveran states, that from September to October at
Biskra the slightest wounds tend to become transformed into true Oriental Sores
and he adds that he has seen it grafted on to acne, impertigo, and vaccine pus-
tules, as well as on wounds following burns, he therefore does not doubt that
the virus is carried on the feet and proboscides of flies.

      In this connection it should be remembered that these statements were
made long before the parasite of Oriental Sore was discovered, and that many
of the older observers have undoubtedly included, in their descriptions, sores
other than the true specific lesion, such as are extremely common on the skins
of the inhabitants of Eastern countries. When I was in the Aden Hinterland,
and particularly at Sheik Othman, I examined many such sores thinking
they were true Oriental boils, but never once found the characteristic parasite
though many of these sores were exactly similar to the true "Bouton d' Orient."
These ulcers and sores almost always contained spirochætes. Precisely the
same state of affairs was seen in Cambay, for during the rainy season, from
June to September, I found that the vast majority of skin lesions were not the
true " Cambay Boil." As I was working in a room in the Hospital, I daily
saw all the people who came for treatment, and sores and ulcers were invaria-
bly shewn to me. In this way I had the opportunity of examining a great
many cases, but in the majority I failed to find any parasites.

      On comparing the stained films made from these sores, with some made
from the late stage of the true Oriental Boil, I was able to say at once whether
these sores were ordinary ulcers, or whether they were the true lesion from
which the parasite had disappeared. I will describe the characteristics of the
latter in the complete account of my investigations. In Cambay I saw a few
sores caused by blister beetles (Cantharinæ), several species of which were
extremely prevalent during the rainy season. These insects being attracted by

c