INFECTION AND IMMUNITY 3 



stances these substances are broken up within the 

 leucocytes and the poisons thus set free at once 

 neutralized by neutralizing bodies present within 

 the cells. According to this, conception the leu- 

 cocytes exercise a double function, one bactericidal 

 and bacteriolytic, the other a poison-neutralizing 

 one. The bactericidal and bacteriolytic bodies 

 appear to escape from the leucocytes quite readily, 

 and can be demonstrated in the blood plasma; the 

 neutralizing bodies, on the other hand, do not appear 

 to be given off from the cell. It is obvious, there- 

 fore, that the bacterial substances may be broken 

 up in the blood plasma, and from them may thus 

 be liberated a poisonous body. When this poison- 

 ous body is assimilated in sufficient quantity by the 

 higher cells of the animal organism, death ensues, 

 and ensues the more quickly the more rapid the 

 process of liberation. 



A somewhat different conception is that advanced 

 by Friedberger, who believes that it is unnecessary 

 to assume the existence of specific endotoxins in 

 bacteria to account for the various symptoms seen 

 in bacterial infections. By repeatedly injecting 

 sensitized animals with minute doses of sheep or 

 horse serum, he found it possible to produce all 

 manner of fever curves at will, merely by varying the 

 size of the dose and the interval between injections. 

 From this he concludes that the diversity of clinical 

 symptoms of various infectious diseases can readily 



