DIPHTHERIA 271 



the bacilli is proof positive of the diphtheritic nature of 

 the affection and its infective nature, their apparent absence 

 is not of so much value, as various circumstances modify 

 the result. For example, an unskilled person may not 

 happen to touch the right spot with the swab, or from 

 struggling, etc., on the part of the patient even a skilled 

 operator may fail to reach any but a small portion of the 

 mucous membrane, instead of obtaining a good mop from 

 all over, especially when there are no definite patches of 

 membrane. The use of antiseptic gargles or paints shortly 

 before the swabbing is taken will likewise prevent the 

 growth of the bacilli. It sometimes happens that a very 

 mixed growth is obtained in the cultures, and in such 

 cases the Klebs-Lofner bacillus may be missed. Bearing 

 such sources of fallacy in mind, and making due allowances 

 for them, the negative result of a bacteriological examina- 

 tion may have considerable value in those cases which 

 clinically are doubtful. In no case where there is a reason- 

 able suspicion of diphtheria should treatment with antitoxin 

 be delayed until the bacteriological report is obtained. 



The bacilli from the throat are frequently associated 

 with other organisms, especially micrococci and torulae ; 

 and those cases in which the temperature tends to be high 

 and the throat fetid are usually a mixed infection of 

 diphtheria bacilli with the Streptococcus pyogenes or Micro- 

 coccus pyogenes, var. aureus. The fact of such mixed 

 infection cannot, however, be definitely decided from the 

 cultures, as these organisms may be present in the mouth 

 or throat without necessarily taking part in the infective 

 process. Nor can the severity of the disease be gauged 

 from the characters or numbers of the diphtheria bacilli 

 and other organisms present, though perhaps in a number 

 of cases those which yield practically pure cultures will 

 probably be more severe than the cases which yield cultures 

 with few bacilli. It has been stated that the long form 



