302 Manual of Veterinary Microbiology, 



In the dog, iutra-crauial inoculation is always fol- 

 lowed by furious rabies; the period of incubation for 

 the virus of the streets is from fourteen to fifteen 

 days, on an average. 



The inoculation may also be made in the nerve 

 trunks, a previous lesion of the nerve fibers increas- 

 ing the chances of success; in this method the period 

 of incubation is not the same in all cases, and is 

 always longer than by trephining; the virus vege- 

 tates in the nerve and progresses from the periphery 

 toward the center, the disease being more tardy in 

 its appearance as the course to be traversed by the 

 virus is more extended. Inocula'tion in the posterior 

 nerve trunks is followed by paralytic rabies; in the 

 anterior trunks by furious rabies. 



The insertion of the virus into the anterior cham- 

 ber of the eye is invariably followed by rabies, the 

 incubation in this case being thirteen to sixteen days 

 for the natural virus of dogs. 



In the rabbit, intra-cranial inoculation enables us to 

 make some important observations : the incubation 

 is from fifteen to seventeen days, and death occurs in 

 the course of the next four days. The disease mani- 

 fests itself by paralytic phenomena with progressive 

 course ; rabies of the rabbit is, therefore, dumb rabies. 

 However, cases of furious rabies are also observed, 

 and Ferre has shown that symptoms of excitement 

 (accelerated respiration, etc.) precede the paralytic 

 symptoms. 



Passage of the virus of natural rabies from the first 

 rabbit to a second, from the second to a third, and so 

 on, exalts the activity of the rabic virus. This exal- 

 tation shows itself in the shortening of the period of 



