RABIES 387 
He believed the bodies were specific microérganisms characteristic 
of the disease, found only in animals affected with rabies. They 
appear early in the course. They occur in larger numbers and are of 
greater size as the disease progresses. They are most numerous and 
largest at the time of death. Smears or sections of the brain are 
stained in saturated alcoholic solution of eosin for from 10 to 30 min- 
utes after which they are counter-stained in alkaline methylene blue. 
No special technique is necessary to demonstrate these bodies. Their 
constant appearance in cases of rabies forms a basis for a positive 
diagnosis and they are affected very little by beginning decomposition 
of the surrounding nervous tissue. 
Williams and Lowden state concerning the channels of infection 
that “in whatever way the virus enters the body, so far as we know, 
there is no development of the organism, or none, to any appreciable 
extent, until it reaches the central nervous system, and not until after 
a certain amount of development there does it infect the peripheral 
organs. Before the disease was well studied it was thought that the 
salivary glands were the chief site of the infection. But it has been 
shown that these glands are not always infective, and when they are, 
not until comparatively late in the disease and that when the virus is 
inoculated into them, the animal seldom comes down with the disease 
and probably never if the centripetal nerves are cut (Bertarelli). 
This means that the parasite does not grow in the salivary glands, 
that it is only carried there incidentally by its spread from the central 
nervous system along the nerve branches. That the organisms escape 
into the blood and are carried in this way in small numbers is shown by 
the fact that the blood in large quantities has been found infective 
(Marie). Principally by the nerve channels, secondarily by the blood 
and lymph channels, the organisms are carried in small numbers to 
all parts of the body. With other investigators, we have found the 
suprarenal capsules infective.” Their conclusions relative to the 
nature and diagnostic value of the Negri bodies are as follows: 
‘The smear method of examining the Negri bodies is superior to any 
other method so far published for the following reasons: (a) it is 
simpler, shorter and less expensive; (b) the Negri bodies appear 
mugh more distinct and characteristic. For this reason and the 
preceding one, its value in diagnostic work is great; (c) the minute 
structure of the Negri bodies can be demonstrated more clearly; (d) 
and characteristic staining reactions are brought out. 
