On the lately demonstrated Blood-contamination and Infective
Disease of the Rat and of Equines in India.

BY
H. VANDYKE CARTER, M.D., LOND.,

BRIGADE SURGEON, BOMBAY.

(With Plate V. )

     In July 1877 the late lamented T. R. Lewis, soon after visiting Bombay to
see the then newly-found relapsing fever organism of man—Obermeier's blood
spirillum—made the observation, also novel here, that the blood of seemingly
healthy rats often contains a ' flagellate organism' which at first sight was not
dissimilar to a spirillum. Towards the close of 1880 Dr. Griffith Evans, A.V.D.,
whilst investigating in the Punjab frontier the equine disease known as 'surra'
(a wasting disorder), made the further discovery that the blood of affected
horses contained a specific parasite, which Dr. Lewis then identified as being
very closely allied to the flagellated parasite of the rat; and by experiment
Dr. Evans showed that the 'surra' contamination and disease were both com-
municable through inoculation to healthy horses and also to the dog. In
January 1885, Mr. J. H. Steel, A.V.D., when investigating a hitherto unrecog-
nised disease amongst the transport mules in British Burma, found it to be the
same as the 'surra' of the N.-W. Provinces, and was further led to regard the
specific organism as a 'spirilloid' and the malady as a fever of relapsing type.
Mr. Steel also showed that the monkey was susceptible of this infection, and
at Dr. Evans' suggestion having applied to me for some technical information,
he was good enough to send from Burma to Bombay several specimens of the
tainted blood of mule, dog, and monkey, through means of which, by direct com-
parison, I too was enabled to identify the hæmatozoon of 'surra' with that of
healthy-looking rats; and the subject being an interesting one, I continued to
pursue it at leisure during 1885. My notes at that time were generally confir-
mative of prior morphological observations, including Lewis' latest published
memorandum in the Quarterly Journal of Microscopical Science, July 1884 (which
I had not then seen in India); and they also contain figures anticipating some
quite recently given by Dr. E. M. Crookshank (Journal of the R. Microscopical
Society, under date November 1886), who, in England, having examined Dr.
Evans' specimens of the equine 'surra' blood, and of the tainted rat's blood
procured in London, considers the hæmatozoon in both to be identical in character,

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