IMMUNIZATION 



153 



phase." After that comes a slow, and later a rapid 

 increase. 



Agglutinin in a Goat, actively immunized with a Culture 



of Cholera Vibrions 



The time of rapid increase, between the time 25 

 days and 9 days, is characterized by the fact that the 

 content of agglutinin increases by nearly the same 

 quantity, 20 units, every day. The process is some- 

 what similar to the increase of gastric juice in the 

 stomach after introduction of food through a tube 

 (see p. 92). The corresponding stage with increas- 

 ing illness in small-pox is called the prodromal stage. 

 This stage ends with a maximum, the so-called 



