4
5. The blood of raits obtained from certain localities was almost always
free from the hæmatozoon, while that of the majority of rats from other
localities was affected.
6. The hæmatozoon of the rat appears to disappear from the circulation
at irregular intervals, thus producing paroxysms and intermissions, as in the
case of Surra in the Horse.
7. The presence, in varying numbers, of the hæmatozoon in the circulation
of rats, does not appear to produce any noticeable symptoms in the great majo-
rity of them. But some few rats, whose blood swarmed with the hæmatozoon,
have succumbed to leucocytosis, with extravasations of blood, containing the
organism, into the anterior chamber and vitreous humours of the eye, opacity
of the cornea, enlarged spleens, and extravasations of blood, or in some cases
ulceration of the mucous membrane of the stomach.
8. It has been observed in a considerable number of cases that although
the hæmatozoon may be present in vast numbers in the blood of pregnant rats
(M, d.), in no case has the hæmatozoon been discovered in the circulation of
the foetus.
9. Parasites, Stomach.—Nematode worms, varying in number and
dimensions, were found in the stomach of rats in which the hæmatozoon was either
present or absent. In a total of 203 examined, nematodes were found in 40 or
19.75 per cent.
10. Saliva.—Microscopical examination of saliva proved the absence of the
Trypanosoma, when the hæmatozoon was swarming in the blood at the same time.
Immediately, however, a slight wound of the mucous membrane of the mouth
was made, the organisms were discovered in varying numbers according to the
amount of blood mixed with the saliva,
11. Urine.—The hæmatozoon was always absent from the urine of rats,
although swarming in the circulation at the time of examination.
12. Bandicoots [Mus (Nesokia) giganteus],—Previous observers have denied
the presence of the hæmatozoon in the bandicoot; but as early as 1892, I de-
monstrated the presence of the organism in the blood of young and half-grown
animals of this species, whether caught in Bombay and its surroundings, or on
the Deccan plateau; but it has been absent from all full-grown animals examined.
13. Musk-rat (Sorex cœrulescens) and Mice (Mus. species).—The hæma-
tozoon has not been found in the blood of these animals.
C.—Experiments on Animals with the Hæmatozoon of the Rat.
Proof was wanting that this hæmatozoon was capable of producing Surra,
when blood containing the organism was subcutaneously injected into horses,
and some other species of amimals. As early as November 1890,I commenced
a series of experiments for the purpose of deciding the above question, and
obtained positive results, but found that the periods of incubation were more
prolonged than in Horse-Surra, in one case being as much as 63 days. Notwith-
standing this, the virulence of the disease when once developed was intense, as
shown by the short period during which the animal survived, after the appear-
ance of the hæmatozoon in the blood; this being in three cases only 2 to 5
days.
(a).—Inoculation with the soiled blood of the Rat (Mus. d.).
Of twelve horses inoculated with soiled rat's blood, four animals con-
tracted Surra, or 33.3 per cent.
(i)
(ii)
(in)
(iv)
Period
„
„
„
of
„
„
„
incubation
„
„
„
lasted
„
„
„
18 days.
29 „
13 „
63 „
Animal
„
„
„
lived
„
„
„
19 days.
2 „
2 „
5 „