CAUSING ACUTE INFECTIONS. 89 



the condition of the patient or by the appearance of 

 the throat, because it is possible and frequently is so 

 that although the patient is apparently well and the 

 throat clear, the bacilli of diphtheria are still there. 

 In order to tell when the bacilli have disappeared a 

 wiping of the throat is made just as described in 



Fig. 11. Organisms of Vincent's angina, showing spirillum 

 and fusiform bacillus. 



making the diagnosis, incubated and examined. Two 

 such cultures free from diphtheria bacilli are con- 

 sidered sufficient evidence that the patient is no longer 

 able to transmit the disease to others. Among healthy 

 persons, particularly attendants upon diphtheria pa- 

 tients, the bacilli may be carried in the throat for long 

 periods of time without causing any of the symptoms 

 of the disease. Such persons are called carriers, and 

 can transmit the disease to others. 



