IMMUNIZATION OF STRESSED ANIMALS 



norma 

 serums 



Midwest 



2 serums I serum 



Human serums from 

 Ladd Field 



Figure 1. Electropheretic patterns of serums from active (normal) and hibernating 

 Arctic squirrels. 



Normol 



Hibernoting squirrels 



Figure 2. Electropheretic patterns of human serums obtained during late winter from 

 Chicago area and Fairbanks area. 



83 



