BACILLUS DIPHTHERIA 



525 



and has been recently worked out systematically by Knapp/ and con- 

 firmed by various observers.^ The results of this work, carried out with 

 the serum-water media of Hiss to which various sugars were added, 

 show that B. Hoffmanni forms acid upon none of the sugars used, while 

 B. diphtheria acidifies and coagulates media containing monosaccharids 



Fig. 109. — Bacillus xerosis. 



and several of the more complex sugars, as given in the diagram in the 

 section following, dealing with B. xerosis. 



Differentiation can finally be made on the basis of animal pathogen- 

 icity, B. Hoffmanni being entirely innocuous to the ordinary laboratory 

 animals. B. Hoffmanni forms no toxins, and animals immunized with it 

 do not possess increased resistance to B. diphtherise. 



Bacillus xerosis. — In 1884, Kutschert and Neisser' described a 

 bacillus which they had isolated from the eyes of patients suffering from 



' Kmpp, Jour. Med. Res., vii, 1904. 



2 Graham Smith, Jour, of Hyg., vi, 1906; Zinsser, Jour. Med. Res., xvii, 1907. 



' Kvtsckert und Neisser, Deut. med. Woch., xxiv, 1884. 



