DIPHTHERIA. 4 X 9 



was first described by Loffler 1 as occurring in diphthe- 

 ria pseudomembraues and in the healthy mouth and 

 pharynx. It is also found upon the conjunctiva, espe- 

 cially in xerosis conjunctivae, and corresponds to the 

 previously described Bacillus xerosis conjunctivae. By 

 some authors this bacillus is thought to cause chronic 

 ulcerative keratitis and chalazion. The pseudodiphtheria 

 bacillus is also found in the nose and upon the skin, 

 where it usually associates itself with the Staphylococcus 

 aureus. It has been found in impetigo, acne, and vari- 

 ola pustules. It has also at times been isolated from the 

 internal organs, as in the cases of Egyptian dysentery 

 studied by Kruse and Pasquale. 2 Ohlmacher has also 

 found it with other bacteria in pneumonia, Babes in 

 gangrene of the lung, and Howard 3 in a case of ulcera- 

 tive endocarditis not succeeding diphtheria. 



While various authors have endeavored to point out 

 morphological and cultural differences by which the 

 diphtheria and pseudodiphtheria bacilli can be differen- 

 tiated, it must be admitted that the variations of the 

 latter organism are so numerous that all rules fail. The 

 only criterion for specific differentiation is the ability of 

 the true diphtheria bacillus to form toxin, in which 

 capacity the pseudodiphtheria bacillus is entirely lack- 

 ing. The introduction of the diphtheria bacillus into 

 animals is characterized by an indurated serofibrous in- 

 flammatory area, that of the pseudodiphtheria bacillus 

 by no pathological changes. 



Park 4 carefully studied this subject, and found that 

 all bacilli with the exact morphology of the diphtheria 

 bacillus, found in the human throat, are virulent Klebs- 

 Loffler bacilli, while forms found in the throat closely 

 resembling them, but more uniform in size and shape, 

 shorter in length, and of more equal staining properties 



1 Centralbl. f. Bakt. u. Parasitenk , ii., 105. 

 1 Zeitschrift fur Hygiene, xvi., I. 



3 Bull. Johns Hopkins Hospital, 93, 30. 



4 Scientific Bulletin No. 1, Health Department, City of New York, 1895. 



