604 



RABIES AND THE NEGRI BODIES 



lation. A more important observation, which for a time gained great 

 importance in the microscopic diagnosis of rabies, was made by Van 

 Gehuchten and Nelis. They found in the cerebrospinal and sym- 

 pathetic ganglia, particularly in the plexus nodosus of the pneumo- 

 gastric nerve and in the upper cervical ganglia of the sympathetic nerve, 

 a proliferation of the endothelial cells of the capsules of the ganglia. 

 These proliferating cells invade the nerve cells of the ganglion, destroy 

 them more or less, and may take their place entirely. The prolifer- 

 ating cells also infiltrate the periganglionic region. The observations 

 of Van Gehuchten and Nelis were soon confirmed by a number of 

 observers, among others by Frothingham, w r ho considers these 

 findings as fairly accurate means to the diagnosis of rabies. He 

 always found them present in cases of rabies and also in one case, 

 that of a dog, where inoculations of emulsified central nervous material 

 failed to produce rabies in the injected animals. 



FIG. 212 



FIG. 213 



'Negri bodies in nerve cells." 

 (After Wolbach.) 



X 2000. 



"Negri bodies in nerve cells." X 1000. 

 (After Wolbach.) 



Today the microscopic diagnosis of rabies is made upon the finding 

 of the so-called 



Negri Bodies. Negri, in 1903, described certain inclusions in 

 the ganglion cells of the central nervous system. He claimed that 

 they were protozoa and the cause of rabies and the most reliable 

 means of diagnosticating this disease in dogs, other animals, and man. 

 These cell inclusions, now universally known as the Negri bodies, 

 are contained in the protoplasm, particularly of the large ganglion 

 cells of certain regions of the brain. They vary from minute dots to 

 large bodies of 25 micra in diameter. Negri's observations were 

 soon confirmed by numerous observers, and it can be stated today 

 that these bodies are found almost without exception in all cases of 

 natural rabies infection, so-called street rabies. However, after the 

 virus has been passed a number of times through rabbits by subdural 



