VIRULENCE OF BLOOD AND MUSCLES IN TUBERCULOSIS. 233 
that the bacilli here shown formed an infiinitesimal fraction of 
those present in the cover-glass film, and that 5 cc. of a liquid 
equally rich in bacilli were injected into each horse, it will 
Tuberole Bacilli from Horse (x 1000). The larger spots represent solid' 
masses of bacilli in which the outlines of the single rods were not 
clearly distinguishable (see text). 
readily be admitted that such an enormous number of these 
organisms can seldom or never in the course of nature be 
thrown into the blood-stream of a tuberculous animal. That 
the bacilli were fully virulent was abundantly proved by the 
enormous number of miliary tubercles found in the lungs of 
these horses when they were afterwards killed. 
Experiment III.—Each of two guinea-pigs received into 
the peritoneal cavity 5 cc. of defibrinated blood withdrawn 
from the jugular of a horse 24 hours after it had been inocu¬ 
lated intravenously, as already described, with a liquid rich 
in tubercle bacilli. 
One guinea-pig was killed on the 27th, and the other on 
the 28th day after inoculation ; in both the peritoneum was 
absolutely healthy, and no trace of tuberculosis was dis¬ 
coverable in any organ of the body. 
