548 BACTERIOLOGY. 



Endotoxins may also be freed from bacteria by what 

 may be called spontaneous disintegration, i. e., by the 

 phenomenon of autolysis. In this process we conceive 

 a sort of self digestion to go on, whereby the bacteria 

 are dissolved and their poisons liberated. It may be 

 seen in old cultures of a variety of endotoxic bacteria, 

 and if, for example, an old culture of the cholera spi- 

 rillum be examined microscopically and at the same 

 time toxicologically, a rough parallelism may be ob- 

 served between the degeneration and disintegration of bac- 

 terial cells and the increase of poison dissolved in the fluid 

 in which such cells had been growing. While such autolysis, 

 with liberation of endotoxin, is conspicuously seen in cul- 

 tures of the cholera and typhoid organisms, the bacillus 

 of tuberculosis seems to be particularly free from it. 



ENDOTOXINS DISTINCT IN THEIR ACTION FROM 

 TOXINS. Both toxins and endotoxins may cause death 

 when injected into animals in sufficient doses. Both, 

 when injected repeatedly in sublethal doses, may induce 

 immunity in the injected animal ; but the immunity 

 resulting from the injection of toxins is characterized by 

 the presence of antitoxins in the blood, which are spe- 

 cifically antidotal for the toxin used ; whereas, immuni- 

 zation with endotoxin does not result in inducing the 

 antitoxic or the antiendotoxic state in the animal, but 

 rather in increasing the bacteriolytic activities of its 

 fluids, which are at the same time almost devoid of real 

 antitoxic characteristics. 



Moreover, if the serum from an animal in the anti- 

 toxic state be injected into a normal animal, the latter? 

 by " passive immunization/ 7 becomes at once immune 

 from either the toxin with which the original animal had 



