82 BIOLOGY OF PNEUMOCOCCUS 



was supplied by the reports of Schnabel, 1238 and of Schnabel and 

 Ninamiya. 1243 Although few new facts were given in these papers, 

 the authors found that the activity was not lessened by the addi- 

 tion of high concentrations of optochin or sodium glycocholate to 

 broth cultures, while, on the other hand, the alkaline reaction and 

 reducing power of blood serum and of tissue cells interfered with 

 its operation. 



Another effect of oxygen consumption by Pneumococcus is the 

 relation between respiration and virulence as described Vy Sevag 

 and Maiweg, 1258 who presented the following facts in support of 

 their theory: Virulent pneumococci on being transformed into the 

 avirulent forms consume much larger amounts of oxygen than do 

 the parent organisms, but this gain in activity is only temporary. 

 After a time, the avirulent organisms degenerate into forms which 

 consume very much less oxygen than do either the virulent or the 

 avirulent cells recently derived from the parent strain. 



The phenomenon of oxidation-reduction by Pneumococcus is 

 given here in considerable detail because of its important bearing 

 on the metabolic process of the cell and because of the thorough- 

 ness with which this activity has been studied. It involves the life 

 of Pneumococcus ; it affects by inhibition or destruction the lytic 

 and synthetic ferments of the bacterial cell ; it is responsible for 

 the conversion of the vitally necessary hemoglobin into methemo- 

 globin and for the lessened oxygen-carrying capacity of the red 

 blood corpuscles ; it may play a part in determining virulence of a 

 strain ; and it is undoubtedly concerned in the production of hemo- 

 toxin and hemolysin and possibly of other substances harmful to 

 the human economy. 



Hemolysin and Hemotoxin 

 Pneumococcus, upor lysis, whether natural, or artificially in- 

 duced, yields a substance or principle that is actively hemolytic 

 for sheep, guinea pig, and human erythrocytes. The substance is 

 labile, much of its activity is lost on passing through a filter, and 



