ANTIBODIES TO PNEUMOCOCCUS 421 



in 1916 by Dochez and Avery, 320 who found that immune serum 

 temporarily inhibited the multiplication of pneumococci and, at 

 the same time, depressed the proteolytic and glycolytic functions 

 of the bacterial cell. The retardation of growth and inhibition of 

 metabolic activity of the cocci was ascribed by the authors to anti- 

 enzymatic substances in antipneumococcic serum, and to the phe- 

 nomenon they applied the term "antiblastic immunity." Blake 

 (1917) 124 differed with Dochez and Avery in the explanation of the 

 effect, and since it was found that the inhibitory action of serum 

 paralleled the agglutinative power and, moreover, since serum ex- 

 hausted of its agglutinins no longer interfered with the metabolic 

 activities of the cell, Blake denied the participation of any anti- 

 enzymatic principle in the phenomena. Barber (1919) 78 observed 

 the inhibitory effect on the vital activities of pneumococci of whole 

 fresh blood, coagulated plasma, and the serum of normal or im- 

 mune horses and pigeons and, while attempting no analysis of the 

 factors involved, believed that the action was antiblastic in na- 

 ture. Bordet (1931 ), 140 noting the effect of normal rabbit serum 

 on cultures of Pneumococcus, as manifested by changes in the 

 morphology of the cocci, queried whether the disturbance in the 

 metabolism of the organisms could be due to alexin or to the pro- 

 duction of acid in cultures containing rabbit serum. The influ- 

 ences displayed by immune serum on the vital functions of pneu- 

 mococci, as just described, are probably the same as those leading 

 to the dissociation and degeneration of the pneumococcal cell. 



IMMUNOLOGICAL RELATIONSHIPS BETWEEN PNEUMOCOCCUS AND 

 OTHER MICROBIC SPECIES AND UNRELATED SUBSTANCES 



Analogous to the apparent serological relations already de- 

 scribed in Chapter VIII existing between Pneumococcus and such 

 varied entities as gum arabic, Bacillus coli, Leuconostoc mesen- 

 teroides, Friedlander's bacilli, and tubercle bacilli, are the cross- 

 reactions demonstrated by Sugg and Neill (1929) 1855 between 

 yeast and Type II Pneumococcus. The reader may recall that 



