MIYA, MARCUS AND PHELPS 



Number of 



Organisms 



Ambient Temperature 



21° C 20 C 2° C 



(grouped) (grouped) (single) 



immu- immu- immu- 



normal nized normal nized normal nized 



LD^^ and 10 x 10 "^ 

 50 



95% 



(U.9 x lO"^ 



Confidence to 



Limits 22 x lo'') 



3.5 x lo"' 6.5 x 

 10"7 

 (1.2 X 10*7(1.7 X 

 107 

 to to 



9.8 X 10'') 2U X 

 lO*') 



Agglutinin 

 titer 



1:32 



1:32 



1:32 



Table IV. Effect of acute cold (2° C) on mortality of mice challenged with Staphylo - 

 coccus aureus , strain Fritchie. Unacclimatized animals immunized and challenged 

 at room temperature, then placed at noted temperatures. *7 day mortality (dead/total). 



either in groups or individually were kept at this temperature 

 for 21 days. These acclimatized mice were immunized at this 

 temperature and were subsequently challenged one week after 

 the last immunizing injection. Table V illustrates that the im- 

 munization of the animals kept at 21° C afforded protection to 

 the challenged animals. However, immunized mice kept in groups 

 or individually at 2° C did not obtain the benefits of immuniza- 

 tion as well as the animals kept at 21° C. In addition, the singly 

 caged animals at 2° C showed even less benefit from immuni- 

 zation than did the grouped counterpart animals kept at the same 

 low temperature. As with the K. pneumoniae experiments, agglutinin 

 antibody formation was not Impaired in mice chronically ex- 

 posed to low ambient temperatures, whether the animals were 

 caged in groups or individually. In contrast to the K. pneumoniae 



172 



