DYSETERY BACILLUS 159 



auto-digestion in bouillon, which leaves the latter highly toxic owing 

 to the liberation of the toxins. Laboratory animals quickly suc- 

 cumb to injection of this organism, injection producing a marked 

 reaction in the colon, a phenomenon suggesting that there is a 

 predilection for the organ and that the body uses it as an excretory 

 organ for the poison. Dysentery cannot be induced in animals by 

 feeding cultures. Poorly nourished subjects are easily infected 

 and quickly die. Digestive disorders favor infection. Death may 

 be due to toxaemia or exhaustion. As a causal agent in the produc- 

 tion of summer diarrhoeas of children, the dysentery bacillus plays 

 a part. It has been isolated from the stools of infants, with this 

 disease, and their sera have been found to agglutinate the bacilli. 

 Nevertheless it is known that other bacteria (streptococci, etc.) 

 cause this disease, and Weaver found that " clinically twenty-four 

 of our ninety-seven cases of ileocolitis in which dysentery bacilli 

 were discovered did not differ from cases in which dysentery bacilli 

 were not found. 



Immunity. The sera from convalescents from dysentery shows 

 a strong bactericidal action. Anti-bodies are developed by infection 

 and by artificial inoculation with killed cultures. Kruse obtained a 

 serum from horses which strongly protected a guinea pig against a 

 lethal injection of bacilli. The protective property of the serum is 

 due to its bactericidal action. Here the amboceptors act, but only 

 in the presence of a complement. Anti-toxic sera protected against 

 bacteria; and an anti-bacterial serum protected against toxin, 

 according to Rosenthal. 



Vaccination. Shiga tried to induce (i) passive and (2) active 

 immunity in many individuals by injecting both anti-toxic serum 

 and bacteria into them. This was not followed by a lowered 

 number of infections, but by a lowered mortality. A serum may 

 be produced by injecting horses with several dysentery strains, 

 called a polyvalent anti-serum. This has good therapeutic effects 

 but does not immunize prophylactically. 



Agglutination. The serum from a patient suffering from 



