554 Proceedings of the Royal Society of Edinburgh. [Sess. 
each, but no specific agglutinins were demonstrable in the blood. The only 
noteworthy feature of the post-mortems was the appearance of the spleen 
(enormously hypertrophied, and dark red or even black in colour ; and the 
pulp very friable) and the general glandular enlargement. With the culture 
derived from the spleen of the last rat of the series other rats were inoculated 
intraperitoneally and subcutaneously. 
Rats 5 and 5a each received intraperitoneally 0‘2 loop of a twenty-four- 
hour-old aofar culture emulsified in normal saline solution. Death occurred 
■O’ 
in twenty-four hours in each case. Post-mortem, the heart blood and spleen 
were crowded with M. melitensis. Serum reaction nil. 
Rat 5b received 02 loop subcutaneously over abdomen from the same 
culture emulsified in normal saline solution. Four days later an abscess 
had formed at the seat of inoculation, containing pus, which was full of 
M. melitensis. Death ensued in twenty-one days. Post-mortem showed the 
presence of a pocket of pus in right thorax, suppurative peritonitis and 
vaginalitis, and in each situation the pus was crowded with M. melitensis. 
The blood, spleen, axillary glands, and vas (left) were also crowded with 
the micrococcus. Serum reaction again nil. 
These experiments were repeated and confirmed during 1907 and 1908, 
and the same method of exalting the virulence of M. melitensis was applied 
to the mouse with equally successful results. Thus white and black mice 
inoculated intracerebrally with OT of a loop of twenty-four-hour-old agar 
culture of the rat strain of M. melitensis died within three days in the 
earlier experiments; but after three intracerebral passages death ensued 
with the standard dose within twenty-four hours. 
When this point was reached, intraperitoneal inoculation of a like dose 
caused death also within twenty-four hours, and subcutaneous inoculation 
was followed by pus formation and death in from seven to twenty-one days. 
CARNIVORA. 
Dog. 
Having dealt at some length with the results of the various experimental 
infections of the commoner laboratory animals, the dog can be very shortly 
dismissed, more especially as I have not carried out any observations 
relating to the exaltation of virulence of M. melitensis in dogs by means of 
intracerebral passages, and the subsequent injection of the highly virulent 
strains thus obtained into other tissues ; but I have no doubt that, judging 
from the results of my experiments upon other species of mammals, effects 
similar to those already described should be obtained. 
