INFECTIOUS DISEASES AND MICROBES, ETC. 183 



axis cylinder and its medullary sheath. This 

 microbe (Fig. 40 A) occurs in groups and as 

 diplococci, but never in chains. According to Fol, 

 if a cultivation (in bouillon) be made of part of the 

 brain, there is a deposit which, on inoculation into 

 healthy animals, produces all the features of rabies. 

 If, however, the cultivation be more than six days 

 old there are no marked toxic effects. Fol says 

 that nothing can be distinctly made out by merely 

 reducing the nervous tissue of a rabid animal to a 

 pulp and examining it microscopically, as recom- 

 mended by Gibier. 



Babes states that he has found micrococci in the 

 brain and spinal cord of rabid animals. These 

 measure from 0'6 to 0*8 p in diameter, i.e. from three 

 to four times as great as the microbe described by 

 Fol. These micrococci are stained in situ by Loffler's 

 alkaline methylene blue solution. They are culti- 

 vated on blood serum or agar-agar (at 37 C.), and 

 on bouillon made with the brain of a rabbit. The 

 micrococci grow slowly and give rise to grey spots. 

 ' A pure culture of the second, or even of the third 

 generation, when inoculated into animals occasion- 

 ally produces hydrophobia, but in most cases the 

 cultures have no pathogenic properties, and it must, 

 therefore, be concluded that the microbe has either 

 lost its virulence or that it is not the actual cause of 

 the disease.' 



The late Mr. G. F. Dowdeswell observed a 

 microbe, measuring about the same diameter as 

 Babes' micrococcus, in the central canal of the 



1 Comptes Rendus, 1883, p. 1701 ; 1884, pp. 55 and 531. 



