42 



Immunity 



Tokishlge states that in Japan the popular Idea 

 amongst farmers and quacks is that one attack reduces 

 the predisposition of the animal to the disease, but he 

 himself says that this is questionable and requires 

 further investigation. 



Peuch, in writing of African farcy and, no 

 doubt, referring to this disease, states that the predis- 

 position is diminished after one attack, but most other 

 writers on the subject have seldom omitted to point 

 out the likelihood of the disease recurring. 



I have personal experience of several cases break- 

 ing out again after they had been apparen tly cured, but 

 must point out that, in all these cases, the disease 

 developed at the same place in which the original 

 lesions were present, and in these cases 1 was of the 

 opinion that the organisms had simply become inert for 

 the time being, as a result of so many of them being 

 removed or destroyed by the treatment, and that gradually 

 they began to increase and became active again. 1 do not 

 think that reinfection from external sources was the 

 cause of their recrudescence, but that simply the cure, 

 in the first instance, was incomplete, i.e.y all the organisms 

 were not either removed or destroyed, and Nocard and 

 Leclainche point out that a relapse is to be feared, for 

 a long time, from small abscesses containing the 

 organisms, remaining in the cicatrized tissues, which, 

 breaking out, become a fresh source of infection. 



Predisposing Causes 



On this point opinions seem to differ. 

 Tokishige states that the most cases occur in 

 animals between the age of three and four years, and 



