872 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



Although sections are most satisfactory for diagnostic purposes and especially 

 to show the relation of the Negri bodies to the ganglion cells, it is usually possible 

 to recognize the Negri bodies in smears, after a little experience. For this purpose 

 a portion of the gray matter of the Ammon's horn is crushed by gentle pressure 

 between two perfectly clean flamed slides and spread upon them by carefully slip- 

 ping the slides apart. The moist smears are at once fixed in methyl alcohol for 

 one minute, then washed in absolute ethyl alcohol, whereupon they are ready to be 

 stained by the procedure outlined above. 



FIG. 182. Section through the cornu ammonis of brain of a rabid dog; stained by 

 the method of Lentz. Five Negri bodies of different sizes are shown, enclosed within 

 the ganglion cells. The smallest contains only three minute granules. (After 

 Lentz, Centralbl.f. Bakt. 1907, Abt. I, Vol. XLIV, p. 378.) 



The Negri bodies (Fig. 182) appear as round or somewhat tri- 

 angular structures, for the most part inside the ganglion cells. Their 

 size varies considerably, from IJJL to 27/1 in diameter, the majority 

 measuring about 5^. In the interior of the Negri body, smaller 

 structures of variable size and number can be seen. These granules 



