386 RABIES 
in the state of Maryland; in 1785 it was prevalent throughout the 
Northern States and soon after it spread to the South. It has caused 
heavy losses among farm animals throughout Europe and America. 
It has called forth careful study from many of the ablest men in the 
medical professions. Among them may be mentioned John Hunter 
in England, Viborg in Copenhagen, Waldinger in Vienna, Hertwig in 
Germany and Pasteur in France. Without detracting in the least 
from the great work of other investigators, we may say that to Pasteur 
and his co-laborers, Nocard and Roux, we owe much of the knowledge 
of the nature of rabies which we possess at the present time. 
Fic. 89. NEGRI BODIES IN NERVE CELLS: (a) NUCLEI OF CELLS; (b) NEGRI BODIES 
(after Frothingham). 
Geographical distribution. Rabies is known to exist or at some 
time to have existed in almost every country on the globe. Australia 
is the largest area which is said to be absolutely free from it. This 
exemption is the gratifying result of a rigid quarantine enforced 
against dogs imported on that island. It is wide spread in the United 
States. 
Etiology. In 1903, Negri described small bodies or cell inclu- 
sions, since called Negri bodies, which he found in the Purkingie 
cells of the cerebellum and in the large ganglion cells of the 
Ammons horn. Negri believed these bodies to be the etiological 
factor of the disease and classified them among the protozoa. 
