Volume V 
JANUAKY, 1913 No. 4 
-b 
THE FIXATION OF RABIES VIRUS IN THE 
MONKEY {MACACUS RHESUS) WITH A 
STUDY OF THE APPEARANCE OF NEGRI 
BODIES IN THE DIFFERENT PASSAGES. 
By Captain HUGH W. ACTON, I.M.S., 
A ssistant Director, 
AND Majok W. F. HARVEY, I.M.S., 
Director, Pasteur Institute of India, Kasaidi. 
(With Plate X.) 
Pasteur, in May 1884, showed that if the rabies virus of the dog 
was passed from rabbit to rabbit, or guinea-pig to guinea-pig, it 
gradually became exalted in virulence and fixed in incubation period 
for these rodents. This fixed virus remained exalted in virulence when 
inoculated subdurally into other animals. Magendie held the opinion 
that the rabies virus, when transmitted by bites from dog to dog, lost 
its virulence by about the fifth passage. 
Celli and Marino-Zucco (1892) held identical views, and considered 
them confirmed by their experiments on dogs. They found that from 
the 6th to the 10th passage (employing the subdural or intra-ocular 
mode of infection) their dogs no longer showed furious rabies, but died 
from the dumb or paralytic form. As they continued these passages, 
their dogs now began to die of a curious consumptive or cachectic type 
of rabies which developed after a very long incubation period. The 
brains of these dogs suffering from this chronic type of rabies were no 
longer capable of transmitting the disease to rabbits— i.e. had lost all 
virulence. 
Marie (1907) and Lamb and McKendrick (1909) showed, however, 
that this was not the case for dogs, but that street virus became fixed 
in this animal, just as it did in the rabbit. In a recent experiment, 
on the passagfe of fixed virus of the rabbit through the dog, we found 
Parasitology v 15 
