BACILLUS DYSENTERIC 141 



infected food and drink, and pass through the ali- 

 mentary tract to their organ of predilection, the 

 colon. Here they penetrate the mucous lining to its 

 deeper layers, causing violent irritation. They may 

 get deeper into the wall or even to the glands draining 

 the colon, but not into the blood. The inflammation 

 gives rise to diarrhea which passes from feculent to 

 mucus, to bloody mucus, and may be almost wholly 

 blood. These effects are due to the effort of the 

 colonic wall to rid itself of the poisons, and the body 

 seems to choose this method to free itself of the 

 intruder. This fact is further shown when we inject 

 susceptible small animals with the poisons, for a con- 

 gestion of the colon and diarrhea result, although no 

 living organisms are present. The poisons of the dysen- 

 tery bacilli are probably both extra- and intracellular, 

 the latter being more abundant. The toxic effect, 

 therefore, is exerted by the existence of the germs in 

 the mucous membrane giving off poisonous products 

 of their life, and to a greater degree, by the poisons 

 liberated upon their disintegration. The poisons are 

 absorbed into the blood, giving rise to an irregular 

 fever in which sudden drops are common. This sud- 

 den fall of temperature may be observed in animals 

 receiving doses of the poison. 



Dysentery is transmitted like other diarrheal dis- 

 orders, that is, by the pollution of food and drink by 

 discharges of patients, since the germs leave the body 

 only by the feces. Disinfection of excreta, clothes, 

 utensils, and hands should be done as for cholera. 

 After an attack persons may be carriers, and disinfec- 

 tion of stools should not cease upon clinical recovery. 



