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to make daily observations for a few days, if the first examination is
not satisfactory. The history of the case, the condition of the animal,
the presence of the œdema, and state of the membranes, lead us to
suspect the nature of the disease.

Prognosis.—Invariably fatal, no equine ever having been known to
recover.

Post-mortem appearances.—There are no specific lesions character-
istic of the disease. A general anæmic condition of all organs will be
noted. Some observers have noticed peculiar ulcers in the stomach in
Burma, but we have never met with them, nor have other observers
(Gunn, Evans). The heart generally presents some abnormal appear-
ance, the most common being very extensive sub-endocardial ecchymoses.
The kidneys often appear congested and ecchymosed, but not always.

Etiology.—Everything points to the infusorian (Trypanosoma Eransi)
as the vera causa of surra, although absolute proof is still wanting,
owing to the fact that it has not been obtained free from the blood,
etc. (pure), although numerous attempts have been made, so that we
have been unable to use pure cultivations of it for inoculation, and
the production of the disease. The following facts go to show the inti-
mate connection which exists between the organism and the disease:—

     1.  No case of "Surra" naturally contracted has been observed in
                which the Trypanosoma Evansi has been absent, and all
               previous authenticated cases investigated by such observers
               as Evans, Steel, Pottinger, Gunn, and Rimington tend to
               confirm this.

     2.   In all cases of the inoculated disease, the organism has been
                present, and has comported itself in a similar manner to
               that which has been observed in naturally-acquired cases.

     3.   By passing the infusorian through the organism of various
                animals, and after it has been passed through a large number,
               again bringing it back to the horse, fatal surra, with all its
               distinctive characters, has again been induced, and the
               infusorian has always been present.

     4.  The serum of blood swarming with the infusorian, when
                passed through a porcelain filter, and thus deprived of the
               infusorian, fails to produce surra on inoculation, and the
               infusorian is never found in the blood of the inoculated
               animal in these circumstances.

     5.  In addition to this, we have the undoubted influence which the
                presence or absence of the infusorian has upon the course