TYPHOID FEVER. 375 



intestine, exists there in typhoid fever, and adds no little 

 complication to the bacteriological diagnosis by respond- 

 ing in exactly the same manner as the typhoid bacillus 

 to the action of carbolic acid, by having colonies almost 

 exactly like those of typhoid, by growing in exactly the 

 same manner upon gelatin, agar-agar, and blood-serum, 

 by clouding bouillon in the same way, by being of almost 

 exactly the same shape and size, by having flagella, by 

 being motile, and, in fact, by so many pronounced simi- 

 larities as almost to warrant the assertion of some that it 

 and the typhoid bacillus are identical. 



Not the least significant fact about the colon bacillus 

 is that it is also pathogenic and capable of exciting acute 

 inflammatory processes which are not infrequent, and 

 which sometimes serve to increase the seriousness of 

 typhoid fever. 



At the present time we are in more or less of a quan- 

 dary about this extraordinary resemblance, but base our 

 differentiation of the species upon certain constant, slight, 

 but distinct differences. 



The typhoid bacillus does not produce indol. 



The open lymphatics and vessels of the intestinal ulcers 

 of typhoid favor the absorption of the bacteria in the diges- 

 tive tract, and the colon bacillus enters the blood no 

 longer to be a saprophyte, but now to be a virulent pus- 

 producer, and in many cases of typhoid we find suppura- 

 tions and other milder inflammations due to this microbe. 

 This is also a stumbling-block, for the typhoid bacillus 

 when distributed through the blood may act in exactly 

 the same manner. 



The typhoid bacillus may enter the body, at times, 

 through dust (Klemperer and Levy), but no doubt, in the 

 great majority of cases, enters the digestive tract at once 

 through the mouth. It may possibly enter through the 

 rectum at times, as illustrated by the mention which 

 Eichhorst makes of the infection of soldiers in military 

 barracks through the wearing of drawers previously worn 

 by comrades who had suffered from typhoid. 



