126 ESSENTIALS OF BACTERIOLOGY 



disease, it requires but a slight wound to allow it to gain 

 entrance. 



In horses the primary sore seems to be at the nasal mucous 

 membrane. In man it affects those attending horses and is 

 usually on the fingers, and terminates fatally within three 

 weeks. Chronic glanders may last several years and end in 

 recovery. 



Mallein. A substance called mallein has been obtained 

 from the cultures grown in glycerin bouillon. It gives a re- 

 action when injected into cattle suffering from glanders, and 

 is said to be useful in diagnosing the disease. The reaction is 

 specific and never fails to reveal the presence of infection. 



The inoculation of a guinea-pig intraperitoneally with some 

 of the suspected discharge will produce an orchitis if the 

 glanders bacillus is present, which is quite characteristic and 

 helpful in the diagnosis. 



CHAPTER XIX 

 DIPHTHERIA BACILLUS 



Bacillus of Diphtheria (Klebs-Loffler) . Origin. 

 Klebs found it in diphtheritic membrane in 1883; it was iso- 

 lated by LofBer in 1884. 



Form. Small, slightly curved rods about as long as tu- 

 bercle bacilli and twice as broad; i p to 6 /z in length; the 

 ends are at times swollen; spores have not been found. Their 

 form is, however, very variable sometimes much longer 

 than usual, one end often greatly knobbed. Normal bacilli 

 are found only in membrane. 



Stained forms are characteristic, since the ends are more eas- 

 ily colored than the center, and usually the bacillus stains in 

 segments, so that it seems to be made up of very short sec- 

 tions or beaded. At first sight it appears like a chain of cocci. 



