DISSOCIATION AND TRANSFORMATION 171 



tococci from cases of erysipelas, scarlet fever, puerperal sepsis, 

 arthritis, and tonsillitis, as well as from cows' milk, into Strepto- 

 coccus viridans; of changing three similar strains into S. viridans 

 and typical pneumococci, and one into Streptococcus mucosus as 

 well. Seventeen strains isolated as S. viridans, chiefly from the 

 blood and tonsils in cases of chronic infectious endocarditis, and 

 two strains from cows' milk were converted into pneumococci while 

 two of the strains became S. mucosus. Ten of the viridans cultures 

 were made to take on the cultural and morphological characters of 

 hemolytic streptococci, in two of which the pathogenic powers 

 were shown to be those of hemolytic streptococci, while one strain 

 was converted into a hemolytic streptococcus, into S. viridans, and 

 then into a pneumococcus. 



Rosenow claimed to have converted into hemolytic streptococci 

 eleven strains isolated as pneumococci from sputum, blood, and 

 the lung in pneumonia and from human empyema fluids and Cole's 

 Type I and II strains, while seven cultures took on the features 

 of S. viridans. The streptococci derived by animal passage from 

 three of the pneumococcal strains were alleged to acquire all the 

 essential features of the streptococci of rheumatism, and two or- 

 ganisms were said to have been converted into hemolytic strepto- 

 cocci, the streptococci of rheumatism, S. viridans, and back again 

 into Pneumococcus. 



Rosenow further alleged that the transformation of some of 

 these strains, checked in a few instances by single-cell isolations, 

 was found to be complete by every test known. The tests included 

 the study of morphological features, the demonstration of cap- 

 sules, and observations on fermentative powers, solubility in bile 

 and in saline solution, the behavior toward the respective broth- 

 culture filtrates (Marmorek's test), the specific immunological re- 

 sponse as manifested by the appearance of opsonin and agglutinin 

 in antistreptococcic and antipneumococcic serum, and the more or 

 less specific pathogenic powers of the various organisms. 



