454 BIOLOGY OF PNEUMOCOCCUS 



pigs to the anaphylactic action of the soluble specific substance 

 and brought about partial desensitization to the cellular carbo- 

 hydrate. When capsular polysaccharide prepared according to the 

 original method of Heidelberger and Avery (probably the deacety- 

 lated carbohydrate) was added to the minimal dose of serum neces- 

 sary to sensitize, and the mixture injected at once into guinea 

 pigs, the animals failed to become hypersensitive to subsequent 

 intracardial injection of the same preparation, but acquired sensi- 

 tivity to the cellular carbohydrate. However, when cellular carbo- 

 hydrate was substituted for soluble specific substances in the ex- 

 periment, no sensitization to either capsular or cellular carbo- 

 hydrate could be demonstrated. 



The results reported by Brown were in accord with observations 

 previously described by Wadsworth and Brown (1933). 1468 Spe- 

 cific immune serum, from which the precipitate, formed on the ad- 

 dition of SSS, had been removed, was still capable of sensitizing 

 guinea pigs to the cellular carbohydrate but not to soluble specific 

 substance. Antiserum, after precipitation with cellular carbohy- 

 drate, failed to sensitize the animals to either substance. The dif- 

 ference in the action of the two preparations of specific pneumo- 

 coccal polysaccharides was undoubtedly due to the lack of molecu- 

 lar completeness of the preparation of soluble specific substance 

 employed in the experiments. 



RELATION OF PNEUMOCOCCAL ALLERGY TO PNEUMOCOCCAL IM- 

 MUNITY 



The experiments of Mackenzie 844 suggest a lack of correlation 

 between the hypersensitive and the immune states in guinea pigs 

 treated with Pneumococcus or its extracts. During the course of 

 immunity produced by the intraperitoneal injection of killed and 

 living broth cultures of virulent pneumococci, while the animals 

 showed high resistance to infection and possessed strong protec- 

 tive power in their serum, hypersensitiveness might or might not 

 be present. Mackenzie concluded that anaphylaxis to pneumo- 



