404 BIOLOGY OF PNEUMOCOCCUS 



the biologically comparable alveolar epithelia, as well as the fixed 

 tissue cells with phagocytic properties underlying them, must have 

 experienced in the immune animal a specific alteration in the sense 

 of acquiring the power to ingest pneumococci and to retain and 

 eventually to kill the organisms. To Singer and Adler, leucocytic 

 phagocytosis merely exerted a secondary chemotactic action, but 

 had nothing to do with specific immunity toward a given organ- 

 ism. In a second communication in the same year, Singer and Ad- 

 ler 1291 reported analogous results obtained in experiments of the 

 same nature with pneumococci of Types I and II. The authors 

 maintained that in passive immunity the cellular system played the 

 main part, the action of the serum being purely a bacteriotropic 

 one. The phenomenon was definitely type-specific and the elements 

 of the reaction were located in the reticuloendothelial tissues, 

 since functional blockade of that system caused a disappearance 

 of the manifestations of immunity. 



Tudoranu 1427 disagreed (1926) with the theory of Singer and 

 Adler that immunity toward Type III Pneumococcus was devoid 

 of specific humoral elements and quoted the latter's own experi- 

 ments to refute the claim. Although in passively immunized rab- 

 bits injected with Type III cultures the organisms for a time mul- 

 tiplied in the blood, the animals eventually recovered, whereas 

 normal rabbits similarly inoculated succumbed to infection. Tu- 

 doranu, in support of the contention, cited his success in passively 

 immunizing rabbits by the subcutaneous, intraperitoneal, and in- 

 travenous injection of specific immune serum, and suggested that 

 the successful result was merely a question of dosage of serum. 

 The author concluded that the action of the serum was to neutral- 

 ize the aggressins, thus permitting the production of an exudate 

 rich in leucocytes, which modified the cocci in such a way as to 

 render phagocytosis possible. 



In the interval between the publication of the papers of Singer 

 and Adler and of Tudoranu, Neufeld and Meyer (1924) 995 re- 

 ported the results of a study of the origin of antipneumococcal 



