83
No swelling or œdema followed, but there was only a slight thickening of the tissues on the 4th
day at the seat of the injected blood. Three paroxysms occurred, viz., on the 1st, 111th and 233rd days
lasting 1, 2 and 3 days, with two intermissions occupying 109 and 120 days respectively.
The animal contracted rinderpest on the 26th September 1893, although isolated with several other
bovines in an enclosed area, surrounded by a wall 7 feet, in height, and succumbed on the 28th Sep-
tember.
Bull No. IV, was inoculated on July 27 th, 1892, with 2.0 c.c. of blood containing the hæma-
tozoon, taken from the rat (Mus decumanus) immediately after death. A considerable amount of
swelling and œdema followed at the seat of the injection which gradually decreased in extent and
finally disappeared about the 10th August 1892. From the 27th July until October 10th, 1892, the
blood remained free from the hæmatozoon, on the evening of the 9th September an urticarial eruption
broke out on both sides of the neck, chest and scapular regions, but had disappeared entirely by the
following morning. On the. morning of the 3rd October a similar eruption to the former made its ap-
pearance and again faded the same day. On microscopical examination of the blood on the 11th
October, the 76th day after inoculation, a long and active Trypanosoma was discovered, the dorsal mem-
brane being particularly well developed, From the latter date up to the 9th February 1893, the 21st
day of the disease, no further hæmatozoa were observed, although several specimens of the blood were
subjected to careful microscopical examination daily. The temperature on the morning of the 8th day
following inoculation attained a maximum of 41° C., but by the following morning had fallen 2° C.,
and although it subsequently on numerous occasions reached 40° C., it has only risen to 40.3° C. Since
November 16th the pyrexia was characterized by marked morning remissions and evening exacerba-
tions, especially on the 55th, 56th and 59th day of the disease, when the morning and evening tempe-
ratures varied from 2.5°C. to 3° C. (4.5 to 5.4° F.). The animal lost flesh during the months of August,
September, October and November, but in January 1893 began to put on flesh.
On February 9th, 1893, 197 days after the inoculation with rat's blood and 121 days after the first
and last appearance of the hæmatozoon in the blood, it was decided to inoculate the animal with Horse
Surra blood in order to test whether any protection had been acquired from the previous inoculation.
Consequently, the animal was subcutaneously inoculated with 2.0 c.c. of blood, containing numerous
hæmatozoa drawn from the jugular vein of Horse LXXXIV immediately after death. No swelling
followed at the seat of the injection, but on February 14th the muzzle became hot and dry, and there
was considerable fever,* lasting several days, but the hæmatozoon was not discovered, although the
blood of the animal was collected and examined microscopically three times daily during the period the
fever lasted. On the 30th of April, 80 days after the re-inoculation, the hæmatozoon was observed in
small numbers and remained in the blood for 48 hours, after which it disappeared and was absent until
the 18th July, a period of 78 days, when it was again present in small numbers for one day. From this
date until the 29th January 1894, a period of 195 days, the hæmatozoon was never found, although daily
examinations of the blood were made. The animal unfortunately met with an accident, broke its leg and
consequently had to be destroyed.
The chief points of interest in this case are that,
(i) This is the first case recorded of any animal of the bovine species having been successfully
inoculated with the hæmatozoon of the rat (Mus decumanus).
(ii) The amount of swelling and œdema which followed inoculation, at and around the seat of the
injection, which finally disappeared on the 14th day after the operation, also the temperature 41°C.
105.°8 F.) registered on the morning of the 8th day.
(iii) The protracted period of incubation of the disease whether we take it as terminating on the
first appearance of the urticarial eruption on the 44th day—as previous experience points to the
hæmatozoon being the cause of the manifestation in the skin or on the 75th day when the organism was
found for the first time in the blood. In either case the length of the latent period, 63 days, has only once
been exceeded, viz., in Horse LXII, which was inoculated with soiled rat's blood.
(iv) The discovery of the Trypanosoma in the blood on the 76th day after inoculation, when
a long and active specimen of the organism was alone observed ; the dorsal membrane in which was
particularly well developed. The absence of further specimens from the blood during a prolonged
period of 121 days.
(v) The marked evening exacerbations and morning remissions of temperature which occurred on
the 55th, 56th and 59th days of the disease-.
(vi) The loss of flesh during the month which immediately followed inoculation.
(vii) Re-inoculation of the animal with Horse Surra, 197 days after the former injection of soiled
rat's blood, followed by high fever, but a total absence of swelling at the seat of inoculation.
(viii) The appearance of the Surra organism in the blood for a period of 48 hours, 80 days later,
and re-appearance for 24 hours on the 158th day, but total absence during a further period of 195 days.
Cow No. I.—The experiment determined upon had for its objects—
(i) If Surra is communicated to the cow subcutaneously, does the hæmatozoon or its imma-
ture form pass from the general circulation into the milk.
* It is possible that the hæmatozoon was present in very limited number, during the presence of the fever between the 13th
and 16th February 1893.
† Two Guinea Pigs inoculated on the 21st September 1892 with blood from this animal in which no hæmatozoon could be
discovered, failed to contract the disense.