P. G. PANDE 49
but was killed when heating was prolonged to 30 minutes. Broth culture
kept in the incubator (37°C.) for a week was found virulent for laboratory
animals and the natural host. Twenty-four hours old bouillon culture tubes
kept in April sun (outside temperature, 95°F.) in direct exposure for six
hours and for six successive days remained viable. The organism survives
for a long period under low temperature. The bacilli have repeatedly been
isolated from lung pieces and pleural fluid kept in refrigerator at freezing
temperature for a month; and even after this prolonged cold storage, the
above materials have also proved infective to goats when injected by the
intra-tracheal route.
Distribution in the organs. In every case of pleuropneumonia, the bacil-
lus has been isolated from the consolidated lung and observed in smears pre-
pared therefrom. From healthy parts of the lung the organism could not be
isolated. The same organism may be cultivable from the pleural effusion,
mediastinal and bronchial lymph glands, nasal discharge and pericardial
fluid. Inoculation of culture media from heart blood of animals which died
of the disease or were destroyed in extremis always resulted in good growths
of the organism. Blood from the jugular vein of two cases failed to give any
growth. The bacillus may be cultivated from the liver and the spleen, but not
always in a state of purity.
Pathogenicity in laboratory animals. The infective materials used in
pathogenicity tests were the pleural and the pericardial fluids, 24 hours old
culture in broth and an emulsion of 24 hours old culture on blood-agar media.
Rabbits inoculated intravenoulsy or intraperitoneally with 0.5 c.c. of these
materials succumbed within 6 to 12 hours after inoculation. Guinea pigs
and pigeons inoculated with the same materials in the same doses, by in-
traperitoneal or subcutaneous routes, succumbed two and three days after
inoculation, respectively. White mice inoculated with these materials by
the subcutaneous route in 0.5 c.c. dose died 24 hours after inoculation.
The organism could be isolated in pure culture from the heart blood of all
these laboratory animals.
In large animals. The typical disease in goats, sheep and buffalo
calves could be reproduced by intratracheal inoculation of infective materials,
and the goats thus infected showed symptoms of the natural disease, i. e.,
the lungs, the pleura and the pericardium were the principal organs involved.
The organism isolated from the artificially infected goats corresponded in
morphological and cultural characters and biochemical reactions to that
isolated from the natural cases of the disease.
Sheep were found equally susceptible when inoculated subcutaneously or
intratracheally, the symptoms and the lesions in these animals being those of
pleuropneumonia, as in goats.
In buffalo calves the inoculation of infective materials produced a
syndrome of generalized septicaemia, resembling those of haemorrhagic
septicaemia. The calves infected by the intratracheal route with 4 c. c. of
24 hours old bouillon culture of the organism showed about 48 hours after
inoculation high fever, trembling and inflammatory oedema in the region
of the throat and died on the following day, exactly 72 hours after injection.
Post-mortem examination of these animals revealed lesions of pleuropneu¬