126 The Story of the Bacteria 



germ manufactures as it grows, and which is 

 absorbed into the blood. This disease is 

 therefore a toxczmia. 



The bacillus of diphtheria is readily cul- 

 tivated in beef tea or on the usual solid bac- 

 terial foods, where it produces the same poison 

 that is formed in the disease 

 process. We shall return to 

 this diphtheria poison or 

 toxin a little later, when we 

 look at the various ways in 



FIG. 13. BACIL- . 



LUS DIPHTHERIA which the body protects it- 

 self against pathogenic bac- 

 teria, and the ways which modern science has 

 discovered to help it. 



While diphtheria is a very serious disease, 

 the use of antitoxin, the nature of which we 

 shall consider farther on, has robbed it of its 

 greatest terrors and very much reduced its 

 frequency. It is rare in animals. 



The diphtheria bacilli are often conveyed 

 from the sick to the well by the material 

 discharged from the mouth and nose, either 

 directly, or by eating utensils, towels, etc. 

 Furthermore the bacilli often remain for 



