BACILLUS DYSENTERL^. 443 



there is a general invasion of the body by the bacilli ; 

 at others they are only to be found at the local site of 

 inoculation. Sometimes they can be detected in the 

 intestinal contents after both subcutaneous and intra- 

 peritoneal inoculation ; at other times they cannot. 



If the stomach contents be neutralized and large doses 

 of the bacilli be administered per os, death may occur. 

 Under these conditions the small intestine is liypersemic 

 and contains blood-stained mae(jid matter, from wliich 

 the bacilli may usually be culti\'ated. 



If cultures be fed to cats after administration of 

 croton oil, a fatal diarrhoea may ensue. The mucous 

 membrane of the large intestine is injected, its surface 

 covered with mucus, and its contents mucoid. From the 

 latter the bacilli may be recovered in culture. 



A fatal diarrhoea may follow the simple feeding of 

 cultures to dogs. This occurs in somewhat less than 

 six days. The condition of the contents and walls of 

 the large intestine is essentially similar to that seen in 

 the cat. 



In view of the fact that marked evidences of intoxi- 

 cation may follow upon the injection of suspensions of 

 dead cultures of this organism (solid cultures killed by 

 exposure to 60° C), it is probable that the pathogen- 

 icity of this organism is referable to the poisonous nature 

 of the proteid making up the bodies of the bacilli, rather 

 than to a soluble intoxicant secreted or manufactured by 

 them in the course of their growth. 



Protective Inoculation. — By the repeated inocu- 

 lation of animals with cultures of this organism, killed 

 either by heat or by chemicals, it has been found possi- 

 ble to protect them against otherwise fatal doses of the 

 living virulent organism. When treated in this way, 



