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35.7°C., a sudden rise taking place on the twenty-second day following the inoculation. At the time
of the hæmatozoon being first discovered the temperature was 38°C., but attained a maximum of
38.7°C. on the following morning. Death took place on the evening of the third day of the disease.
Autopsy.—Body fairly well nourished. Lungs.—Localized emphysema at the apices and along the
free borders of the organs, numerous sub-pleural ecchymoses. No fluid in the pericardial sac. Heart.—The
base of the organ is surrounded by a light-yellow-coloured exudation, numerous small sub-pericardial
extravasations, large masses of almost black-coloured blood lying beneath the endocardial lining of the
four cavities, most marked on the right side of the organ; the left auriculo-ventricular valves are also
petechiated on their inner surfaces. Spleen.—Three times the size of normal, small sub-capsular petechiæ
and the superficial vessels of the capsule are injected. Liver small, otherwise healthy in appearance.
Kidneys—numerous cysts filled with green-coloured fluid involving the cortical portion. Stomach.—Cuti-
cular portion healthy, villous portion presents several congested patches, one is devoid of the mucous
membrane covering it and is surrounded by a zone of congestion. Small Intestines.—The internal
surface of the mucous membrane is dotted over with dark red coloured petechiæ which are found to lie
at considerable distances apart. Large Intestines present a healthy appearance. Nasal fossæ.—Mucous
membrane was considerably thickened and of a dark purple colour, but there was no ulceration. Brain-
membranes pale, superficial veins deeply congested, the lateral ventricles distended with a clear-colour-
ed fluid, containing a few hæmatozoa.
Horse No. XLII.—Chestnut Country-Bred, aged. Inoculated subcutaneously on the 21st Septem-
ber 1891, at 4 P.M., with 2.0 c.c. of blood, containing numerous hæmatozoa, taken from the heart and great
vessels of two rats (Mus decumanus) immediately after death. The latent period was thirteen days.
Some swelling was present at the seats of inoculation on the day following the injection, but their size
remained unaltered up to the 1st October, when the one on the right side of the neck presented a tumour
two inches in diameter, and on the evening of the 3rd October it was surrounded by an œdematous
zone which disappeared on the appearance of the hæmatozoon in the blood on the following day.
Death occurred fifty-two hours after the organism was discovered in the blood of the general circulation.
The temperature during the incubative period was normal and subnormal until the day before the dis-
ease manifested itself, when it rose at midday to 39.2°C., but fell again the same evening. On the first
day of the disease it attained a maximum of 40°C., four hours after the first appearance of the hæma-
tozoon, and then the temperature gradually fell until the morning on which death occurred.
Autopsy.—Body fairly well nourished, there was a raised swelling at the seat of inoculation about
2½ inches in diameter. On reflexion of the skin a small amount of yellow-coloured exudation was
found occupying the subcutaneous-tissue Lungs.—Apices the seat of a localized emphysema. Peri-
cardial sac contained several ounces of fluid. Heart.—Base of the organ, surrounded by yellow jelly-
like exudation ; sub-pericardial extravasations ; extensive anteriorly. On section sub-endocardial extra-
vasations involving the right auricle, and more especially the right ventricle, but they are absent from
the cavities on the left side of the organ. Liver small, old signs of perihepatitis. Spleen enlarged,
sub-capsular petechiæ present. Tissues on section appear healthy. Kidneys.—Pale in colour, dotted
over with numerous small extravasations, dipping into the cortical portions of the organs. Stomach.
Cuticular portion tinged a yellow colour, villous portion, patches of congestion but no ulceration.
Small Intestines present a number of small sub-peritoneal extravasations; and on section several
patches of extravasation lying beneath the mucous coat of the gut. There is no ulceration and there
are no parasites.
Horse No. LXII.—Brown Country-Bred pony, aged. Inoculated subcutaneously on the morning
of the 14th May 1891, with 2.0 c.c. of blood containing numerous hæmatozoa taken from the heart and
large vessels of a rat (Mus decumanus) immediately after death. The latent period was sixty-three
days. On the day following the injection of blood, a small raised tumour, one inch in diameter, was
apparent at the seat of inoculation. On the morning of the third day it had still further increased in
size and was tender on manipulation. It continued to increase in extent until the 18th, after remaining
stationary in size for a few days, reduction took place on the 24th, and finally disappeared, only leaving
a slight thickening of the integument at the site of the tumour. During the whole of this time the
blood presented a healthy condition. No symptoms of any kind referable to the disease were observed
until the morning of the 16th July 1891, when an urticaria, general in character, broke out, involving
the skin of the body, together with the ordinary symptoms of Surra. On microscopical examination
the blood was found to be swarming with what appeared to be the ordinary 'Surra' hæmatozoon, and
the slightly blood-stained mucus from the inner canthi of the eyelids contained the organism also. The
temperature during the latent period oscillated between 39.8°C. and 36°C., but after the appearance of the
hæmatozoon it rose rapidly and attained a maximum of 40.6°C. four hours later. The subsequent
readings of the thermometer were marked by extreme variations between the evening and morning
records. The animal survived the presence of the hæmatozoon by a little over five days.
Autopsy.—Body emaciated, considerable swelling and œdema of the extremities. Lungs.—Localized
emphysema at the apices and localized infiltration over both bases ; consolidation of both bases, indivi-
dual lobules clearly defined and separated from each other by a layer of yellow exudation. Pericardial
sac contained two ounces of fluid. Heart.—Yellow-coloured exudation round the base dotted over with
separate and, in some places, with petechiæ aggregated together. On section the endocardial lining in
the four cavities was tinged yellow in colour, but there were only a few sub-endocardial extravasations
in the left ventricle. Spleen.— Enlarged, presented a peculiar lumpy appearance on both surfaces.