THE ETIOLOGY OF BURSATI.                               221

the surface. When the surface is shed, the sore is smooth, but as granulations
start, an irregular worm-eaten picture is presented. The degenerative lesion is
seen to be active at more than one focus, the healing of the first sore being followed
by the appearance of fresh ones at the same site or elsewhere. It seems obvious
from this that the supply of the infective agent is continuously maintained
throughout the Bursati season and this has been repeatedly confirmed in micros-
copic sections. In an equine already affected or showing what has been called a
Bursati diathesis [ Collins, 1874 ], an accidental wound may assume the typical
clinical features, but it is very doubtful if ordinary wounds on non-infected cases
ever develop into the genuine sores of Bursati. Pruritus may be intense at the com-
mencement, but if the sores are protected from flies, the affected animal does not
show much evidence of discomfort, once the disease has become established.

The clinical features of Bursati sores are typical, but the most distinctive of
all is the presence of what have been called kunkurs. These are yellowish bodies,
globular and of the size of a millet seed or a pea, or elongated and about the size
of a rice grain, found in varying numbers embedded in little pockets or fistulae in
the limited patches of the diseased tissues. The kunkurs are soft and contain
granular flesh coloured material when young but are hard and fibrous or even
calcareous when old. Deposition of calcareous salts is generally inappreciable but
occasionally it may be very pronounced. When pressed between glass slides, well-
formed kunkurs behave as a hard elastic body. They have a smooth surface and
can be easily shelled out on pressure, leaving pockets of variable dimensions in the
mother tissue. If an incision be made into the tumefied tumour, the underlying
disease process is found to extend well beyond the limits of the superficial sore and
more numerous kunkurs are seen in the subcutaneous tissue. Most writers have
described caseous and calcareous degeneration in kunkurs but there seems to be no
resemblance of these to tuberculous changes. The commonest predilection seats
of the lesions are provided by the angles of the mouth, the fetlock and pasterns,
the prepuce and the face just below the eyes, but occasionally the lesions may occur
in any other situation liable to persistent and mild abrasions.

The occurrence of Bursati kunkurs in internal organs such as the liver, lung,
kidney, etc., has been reported by several workers [ Burke, Meyrick, Steel, 1881,
Lingard 1905, and others ]; but it has been shown in another article by Datta
[1933] that the conditions of '' perihepatitis and small filarial nodules" of
Lingard [ 1905 ], "calcific diathesis " of Meyrick [ 1878 ], and " Calcareous de-
generations in the horse " of Smith [ 1885 ], are due to infection with Schistosoma
indicum. It has to be conceded, however, that at least one internal organ—the
lung—is sometimes affected with genuine lesions of Bursati. Meyrick [ 1878 ]