SPECIFIC BACTERIAL PRODUCTS 461 



less poisonous effect upon the cells but which combine with 

 the antitoxin equally. 



The liberation and action of bacterial endotoxins or 

 proteids. The bacterial poisons which reside in the bodies of 

 the bacteria are mostly yielded up only after the death of the 

 organism. Here, in the invaded animal, the disease processes 

 are more closely associated with the actual presence of the 

 bacteria in the immediate vicinity than in the case of the 

 extracellular toxins. The endotoxins are extracted by crush- 

 ing or grinding the bacteria in a moist or dried condition. In 

 this way a large series of impure bacterial proteids is ob- 

 tained. The immunization processes produced by the cell 

 substances of bacteria seem to have nothing to do with the 

 toxic action of the cell proteids, but rather depend upon the 

 introduction of suitable receptors which give rise to the bac- 

 tericidal protective powers lysin, precipitin, and agglutinin. 



Bacteria have been grouped according to their toxin and 

 proteid producing power as follows. (1) Those bacteria which 

 produce as free secretions true toxins, such as the bacteria of 

 diphtheria and tetanus. (2) Those bacteria which possess 

 apparently only endotoxins, true toxins which are more or 

 less closely bound to the living cell, and which are only in a 

 small degree separable in unchanged condition perhaps outside 

 of the body. On the death of the organism they become partly 

 free, partly remain united, or become secondary poisonous 

 modifications no longer of the nature of toxins. The micro- 

 spira of. cholera and the colon bacillus are examples of this 

 group. (3) Bacteria which yield perhaps no true toxins, not 

 even intraplasmatically. The cell plasma contains poisons of 

 another kind which obscures the typical proteid action. The 

 bacterium of anthrax and of tuberculosis are examples of this 

 group. 



The pyogenic action of the bacterial proteids common to 

 all bacteria depends principally upon their being extraneous 

 albuminous substances. Pyogenic effects may be produced in 

 a like manner by extraneous albumins of non-bacterial origin. 

 That extraneous albuminous substance is harmful to the or- 



