456 APPLICATION OF METHODS OF BACTERIOLOGY 



is so like that of the bacillus of diphtheria that they might 

 easily be mistaken for that organism if subjected to only 

 the usual method of microscopic examination; and again, 

 the genuine diphtheria organism is sometimes found in the 

 mouth-cavities of healthy persons in attendance upon diph- 

 theria cases, such persons being at the time insusceptible 

 to the pathogenic activities of the organism. In the vast 

 majority of instances, however, where the clinical condition 

 of the patient justifies a suspicion of diphtheria, a micro- 

 scopic examination alone of the deposit in the throat, made 

 by an experienced person, will serve to confirm or contradict 

 this opinion, and such examinations very frequently reveal 

 the diphtheritic nature, etiologically speaking, of mild con- 

 ditions of the throat which are not associated with grave 

 constitutional manifestations. 



BACTERIUM DIPHTHERI.® (LOFFLEE), MIGULA, 1900. 



Synonyms: Bacillus diphtheriae, LoflBer, 1884; Klebs-Loflaer bacillus; 

 Corynebacterium diphtherise, Lehmann and Neumann, 1896. 



Bacterium diphtheriae, discovered microscopically by 

 Klebs, and isolated in pure culture and proved to stand in 

 causal relation to diphtheria by Loffler, can readily be 

 identified by its cultural peculiarities and by its pathogenic 

 activity when introduced into tissues of susceptible animals. 

 In guinea-pigs and kittens the results of its growth are his- 

 tologically identical with those found in the bodies of human 

 beings who have died of diphtheria. 



When studied in pure culture its morphological and cul- 

 tural peculiarities are as follows : 



MoBPHOLOGY. — As obtained directly from the diphtheritic 

 deposit in the throat of an individual sick of the disease, 



