9
the one which received 0.2 c. c. exhibited an incubation period of three and a half
days and succumbed on the third day of the malady with over one hundred try-
panosomata in each field of the microscope (Leitz. Oc. 4 Obj. VII), maximum
temperature 39.9°C., only 0.9°C. above the normal of health. The second animal
pricked once only with the finest needle of a Pravatz syringe (detached from
the body of the instrument) containing a trace of a drop of Surra blood
(hæmatozoa 17 in a field of the microscope) succumbed to an acute Septi-
cæmia, the blood at the time of death containing an enormous number of
Bipolar staining Cocco-bacilli. The third animal was also once pricked with
a small needle detached from the Pravatz syringe in the skin of the back.
In this instance, the contained Surra blood presented seven trypanosomata in
a field of the microscope. The incubation period occupied four and a half days.
Two paroxysms occurred lasting 12 and 15 days respectively and two inter-
missions of 3 and 10 days, death taking place on the first day of the third
paroxysm with one flagellate in 25 fields of the microscope. Course of disease
41 days.
From the above experiments one may draw certain deductions—(i) That
all black bucks do not exhibit the same degree of susceptibility to T. Evansi.
(ii) That toxin is not readily elaborated, for the trypanosomata swarmed
between 60 and 100 in each field for six consecutive days in No. III buck,
without making any appreciable difference on the number of flagellates in the
peripheral circulation. (iii) That the black-buck is not capable of carrying
over the trypanosoma from the end of one Surra season to another. (iv) That
this species of deer is very susceptible to wildseuche.
Camel Trypanosomiasis.
35. Attenuation of the trypanosoma by passing through the body of ani-
mals, before testing on Equines.—An article appeared in the Journal of Tropi-
cal Veterinary Science dealing largely with this question embodying some of
the most important results, hitherto arrived at. This subject will be further
dealt with in the Report on Camel Trypanosomiasis mentioned later in this
communication. It was noted in my last year's report that two country-bred
ponies each received 20 c. c. of blood, containing 20 flagellates in a field,
subcutaneously, on the 24th November 1904, from a camel, the subject of
spontaneous Trypanosomiasis, with a view to being further tested when the
"causal factor " of the disease finally disappeared from the blood of the
peripheral circulation in each case respectively. One animal, however, suc-
cumbed to complications, partial consolidation of both lungs and hydatid cysts,
etc. The second, however, after a period of incubation, lasting four and a half
days, has exhibited 44 paroxysms and is now on the 28th day of the 44th inter-
mission, or the 570th day since the appearance of the flagellate in the blood.
Consequently, the final tests with the injection of camel blood and later, if
satisfactory, with Equine Surra blood, cannot yet be carried out.
36. By the administration of certain chemicals.—Although, as early as
1893,I recommended arsenic in the form of Liquor Arsenicalis to be adminis-
tered to camels, the subjects of Trypanosomiasis, mixed with their food, and
this system of treatment proved to be of value in some cases, no knowledge
of any kind was forthcoming with regard to the tolerance of camels to the
subcutaneous or intravenous injection of arsenical solution alone or in combina-
tion with trypan-rot. Therefore, our first care was to make experimental
researches for the elucidation of these problems.
The doses of arsenic and trypan-rot well tolerated by equines in this
country, when injected intravenously, in combination, have been proved to
be lethal to camels in the course of a few hours. Camels appear to be very
susceptible to the action of arsenic and trypan-rot in combination, as colic
followed small doses intravenously. Two-thirds of the doses administered to
equines was tolerated by camels, and produced no severe symptoms ; never-
theless, such doses only kept the flagellates in check for varying short periods,
when they again appeared in the peripheral blood in increased numbers and
death followed.
A fairly comprehensive report on Camel Trypanosomiasis, the collected
results of experiments which have now been in course of investigation during
B