RABIES. 153 



found in seven cases that were later proven not rabies by- 

 animal inoculation tests. 



In 1903 Professor Negri, of Pavia, described small cell 

 inclusions in the nerve cells of the nervous system of animals 

 dead of rabies, known as Negri bodies, which he not only 

 regards of the highest diagnostic value, but as protozoa and 

 the cause of rabies. The bodies are easily demonstrated in 

 sections of the nervous system in the nerve cells. The size 

 varies, some being 20 microns in diameter. Larger forms are 

 frequently seen. The shape is generally round, frequently 

 oval, but other forms are occasionally seen. They possess a 

 distinct structure, show dark staining granules in the centre of 

 the round forms or ends of the oval or other forms, and are 

 surrounded l)y a rosette like structure, which Negri describes 

 as a membrane composed of two layers. 



A total of 576 cases has been gathered, in which Negri 

 bodies were found, and to this may be added 350 examined in 

 the laboratory of the State Live Stock Sanitary Board, in 

 which the bodies were also found. Negri bodies are not 

 found, although rabies exists, in one to three per cent, of the 

 brains examined. As yet the bodies have never been found 

 in the saliva or other secretions of the body, nor have the}' 

 been found in the peripheral nerves. It must be yet reported 

 that the Negri bodies were found in any other disease. Much 

 work is being done upon the relation these bodies have to the 

 cause of rabies. Many views are held, but none have as yet 

 been proven. Negri bodies cannot be regarded as the cause 

 of rabies, but this by no means reduces their value in the 

 diagnosis of the disease. More than nine years ago it required 

 on an average 21 days to confirm a positive diagnosis by the 

 use of the animal inoculation test. With the discovery of the 

 proliferation changes described by Van Oehucten and Nelis, 

 in 1900, it was possible to make a diagnosis in a few hours. 

 Although this method had its weak points, it was used and relied 

 upon until the discovery by Negri of the so called Negri bodies. 



