84 THE BACTERICIDAL SUBSTANCES OF THE BLOOD 



sive measures, as the capsulated organisms which alone are present 

 are not susceptible to phagocytosis, and as bactericidal substances 

 are no longer formed, owing to the paralyzing effect of the aggressin 

 upon the leukocytes, so that boundless multiplication and a general 

 invasion of the body are the outcome. 



If the infection of the guinea-pig is started subcutaneously instead 

 of intraperitoneally the picture is somewhat different. In this case 

 a primary destruction of the organisms, comparable to what occurs 

 in the peritoneal cavity, is not seen; on the contrary, there is active 

 multiplication from the start. The explanation of this difference is 

 no doubt to be sought in the greater difficulties which would present 

 themselves to a prompt collection of cells and serum at the point of 

 attack. 



In either event the infection, when once it has started, progresses 

 without resistance and ultimately leads to the death of the animal. 

 How this is brought about is unknown. So much, however, seems 

 to be certain that unlike the infections with the so-called necropara- 

 sites (tetanus, diphtheria, botulismus) toxins do not play a role in 

 anthrax, and we can accordingly only say that the fatal end in infec- 

 tions of this order must result in an indirect way. Significant in 

 this connection is the fact that anthrax infection in animals that 

 are naturally somewhat resistant, or in others in which a certain 

 degree of resistance has been artificially produced, is followed by 

 symptoms of actual disease and a gradual decline in health until 

 death ultimately occurs. 



Similar considerations apply to infections with streptococci and 

 possibly also with pneumococci. While culture streptococci readily 

 succumb to phagocytosis, the animalized organism is highly re- 

 sistant. But while the anthrax bacillus (in the absence of aggres- 

 sins) is readily destroyed by living leukocytes aphagocitically (i. e., 

 without phagocytosis, through the agency of the liberated leukins), 

 this does not occur in the case of the streptococcus. Against this 

 organism the body apparently possesses no defence excepting the 

 phagocytic function of the leukocytes, and this the truly infectious 

 streptococcus can overcome only too readily through the agency of 

 its aggressins. The importance of the latter will be appreciated, if 

 we bear in mind that a streptococcus exudate, which has been 

 rendered cell- and bacterium-free by centrifugation, is capable, in 

 suitable quantity, of completely inhibiting the bacteriotropins of a 



