79
and demonstrated at the Poona Laboratory in 1890. We have before pointed to the fact that when
once the disease exists, its further development in other animals is frequently due to the bite of flies,
which carry the soiled blood on their piercing organs.
The chief question which presented itself for solution was whether the trypanosoma is ever to be
found in the body fluids of flies and ticks, (i) during the hot season of the year, when it is very ex-
ceptional to find a case of the disease, (ii) during the early part of the rains before the disease has
manifested itself in animals. In order to elucidate the above problems it was necessary to visit the
localities known to be Surra centres, during the hot season, but just before the rains usually commence
at the end of May and beginning of June ; and a second time about the end of August and beginning
of September, the middle of the rains, on each occasion to systematically make a very large number of
microscopical observations of the different fluids to be examined. With this object in view (i) in the
hot season, numerous specimens of the thoracic and abdominal fluids of the following species of Diptera
were submitted to microscopical examination.
(a) Large green-headed fly.—Tabanus lineola.
(b) Large brown-headed fly.—Tabanus tropicus
(c) Horse and cattle fly.—Hippobosca maculata.
(d) Small variety infesting dogs.—Hippobosca.
(e) Local varieties of the—Muscidæ.
(f) Mosquitoes—Culicidæ.
Flies obtained from every available source were submitted to microscopical examination. During
a sojourn in a Surra locality we engaged coolies to supplement our own staff, consequently fresh supplies
of Diptera were brought in several times daily. These were carefully examined in the fresh state. In
different, districts one or more species of flies were generally found to predominate, but they varied also
in number and species according to the season of the year.
The microscopical examination of the water, mud, fresh water shell-fish, flies and ixodes collected
during the hot season observations, failed to reveal the presence of any form of Trypanosoma.
(ii) During the rainy-season tour, hundreds of flies belonging to some ten different species, together
with ticks from equines and canines, were collected and their body fluids submitted to microscopical
examination, but in all cases with negative results as regards the presence of the Trypanosoma.
Veterinary-Captain G. H. Evans, during his tours in Burmah, has been good enough to make a large
number of microscopical observations for this report, but has failed to detect anything like the Surra
hæmatozoon in the jungle diptera examined. He states that,a fly exists in Burmah, a little larger than
the common house-fly, with body yellowish in colour and with its legs bent on themselves. At the
point where this fly bites, a small extravasation of blood appears just under the skin, which shortly
after presents the appearance of a blood-bleb, such as follows a contused wound. These insect pests
are present in great numbers just before thunder-storms at the termination of the hot season, not only
in the plains, but also at Thandaung in the Karen and Binjyi in the Shan Hills. The Gaur (Indian
Bison) and Tsaing suffer from rinderpest, and foot-and-mouth disease, yet these animals have, up to the
present, never been observed with Surra, although careful search for the disease has been made. They
live in heavy jungle, where the flies are so annoying to them that they have to go in the open to escape
their attacks.
early in October they are obtained with difficulty. The fly bites horned cattle and donkeys, but they suffer no ill effects; it bites
men, and a painful swelling follows; it bites horses and camels, and gives them a fatal disease known by several names, such as
Khanhog, doaia and Surra, depending upon the several stages. Phipri is another name by which it is known among camels. I
know of no reason for saying that the fly causes the disease except the common tradition of my people."—G. Evans' Report on
' Surra ' 1880, Loc : cit.
"The author had the opportunity of seeing the fly (Glossina morsitans) several times in the jungle a few marches from
Nichugard, and when he found that nearly all the ponies and mules had died of debility or a gradual wasting away of the body,
he naturally associated the fly with the disease. The symptoms noted in equines were a gradual but persistent wasting of the
animals affected ; in fact they became so emaciated that one might be readily led to suppose that they were dying of starvation.
No cases, as far as I could learn after the fullest inquiry, had ever been known to recover. Comparing the above symptoms
with those described in Dr. Livingstone's work, and having personally seen the insect. I have not the slightest hesitation in
attributing the mortality amongst the transport animals on the Naga Hills to the Tse-tse fly."—Kay-Lees, 1888, Loc : cit.
In the forest region of Korea insect pests abound in the summer months. Mosquitoes, gnats, and gad-flies make the lives
of the settlers perfectly burdensome for two or three months of the year, and ponies and bulls quickly succumb to their attacks.
The houses are kept constantly filled with birch smoke to drive them off; cattle are protected by fires of green wood in the open,
and men working the clearings carry coils of rope made from dried artemesia, which burns slowly and emits a pungent odour,
for the same purpose—C. W. Campbell, 1892, Loc : cit.