68 IMMUNITY NOT DEPENDENT ON ANTITOXIN 



of antitoxin. Thus the two phenomena do not run paripassu with 

 one another. This, is illustrated in the foregoing diagram, which 

 represents in a purely schematic way the period of immunization 

 and utility of an antitoxin horse, the height of the continuous line 

 from the base representing the degree of immunity, that of the 

 dotted line the amount of antitoxin in the blood. 



