CORYNEBACTERIUM XEROSIS. 407 



panied by atrophy of the conjunctiva. The statement of 

 Spronk (Deut. med. Wochenschr., 1896, 571) that a dif- 

 ferentiation from diphtheria bacteria is possible from the 

 absence of effect of diphtheria antitoxin against the Coryn. 

 xerosis is doubted by most authors, especially since no 

 pathogenic action is observed in the latter (for example, 

 Heinersdorff, Archiv. f. Oph., Bd. 46, p. 1). 



Kurth found in one-fifth of true diphtheria cases forms, probably 

 belonging here, which were absolutely non-virulent (Bac. pseudo- 

 diphtheriticus alkalifaciens, Kurth), and also three forms which pro- 

 duced acid as actively as the true diphtheria bacteria (Bac. pseudo- 

 diphtheriticus acidumfaciens). Gelpke (see below) found in his cul- 

 tures (in all?) less acid production in ordinary bouillon, nevertheless 

 much greater initial acid production in grape-sugar bouillon than with 

 diphtheria bacteria. 



Gelpke (Bact. septatum, etc., Karlsruhe, 1898) has 

 recently regularly isolated an organism as the cause of 

 "catarrhal swelling," which is a specific inflammation 

 of the eye characterized especially by bluish-red discolor- 

 ation and swelling of the fold of the conjunctiva, formation 

 of a fibrinous exudate, great pain and photophobia, to- 

 gether with general symptoms. He has called the organ- 

 ism Bacterium septatum Gelpke, considering it a new 

 variety, in spite of great similarity to the short xerosis 

 forms. So far as we see, aside from a not very great 

 pathogenic effect upon the human conjunctiva, as demon- 

 strated by Gelpke in some cases, there is nothing in the ex- 

 haustive description of the organism to distinguish it from 

 the Coryn. xerosis. Other authors appear to have obtained 

 the same impression. 



What we have said in the preceding pages shows that, as 

 in the case of the virulent ("true") diphtheria bacteria, 

 so also in the non-virulent, there is a long series of ex- 

 ceedingly closely related forms, which may be differen- 

 tiated by varying combinations of characteristics, luxuri- 

 ance, length of rods, granule formation, production of acid, 

 etc., and which form a gradational series, into which the 

 true diphtheria bacterium also fits. 



This is rendered still clearer in the following brief tabu- 

 lation of a part of our findings : 



