V. R. RAJAGOPALAN and V. R. GOPALAKRISHNAN        231

It will be seen that the foal pneumonia organism fixes complement in
the presence of the buffalo-diphtheroid-serum at about the same titre as in
the presence of its homologous serum and vice versa.

                                    PATHOGENICITY

The organism was found to be non-pathogenic to rabbits and guinea-pigs.
With a view to ascertain the pathogenicity of the organism for young equines,
Foal No. 417, aged fourteen days was swabbed inside both nostrils with an
emulsion of the buffalo strain of diphtheroid. The animal behaved exactly
like a foal infected with C . equi (Text-fig. 1). It showed a distinct rise in
temperature on the evening of the sixth day. The animal was dull and
lacking in appetite. It had an occasional cough and became progressively
weak. The respiration was distressed and gurgling noises could be heard on
auscultation of the lungs. The temperature continued to be high until just
before death when there was a slight fall. The foal died on the sixteenth
day after infection. A post mortem examination, the anterior portion of
both the main lobes of the lungs were found studded with characteristic
abscesses (Plate XV). An organism indistinguishable from C. equi was
re-isolated from the lung abscesses in pure culture.

Whether the organism is capable of causing abortion or purulent metritis
in she-buffaloes under experimental conditions could not be determined owing
to lack of pregnant she-buffaloes. In the hope that a pregnant cow might
react in a similar way, Cow No. 5, nine months pregnant, was instilled intra-
vaginally with five c.c. of a saline emulsion of the organism made from four
48-hrs. old agar slants, combined with an oral administration of an equal
quantity of a similar emulsion. Twelve days later the cow gave birth to
a calf which died soon after birth. The organism could not be recovered
from the uterine discharges of the cow, nor from, any of the internal organs
of the dead calf.

Another experiment was conducted to find whether this organism could
cause pneumonia or joint-ill in bull-calves, in the same way as C . equi does in
young equines. Two calves, aged two to three months, were swabbed in both
nostrils with an emulsion of the organism. No lesions attributable to in-
fection with C. equi developed in either of them.