Special Action of Bacterio-Toxins 71 



etc. of the bacteria, as well as because of changes produced 

 in the medium by the abstraction of those molecular con- 

 stituents upon which the bacteria have fed. This com- 

 plexity makes it difficult to accurately study the toxins, 

 which we scarcely know apart from their associated products. 



The chemic nature of the toxins differs. Undoubtedly 

 some are tox-albumins, but others are of different composi- 

 tion and fail to give the reactions belonging to the compounds 

 of this group. 



The variations observed in toxicogenesis under experi- 

 mental conditions in the test-tube indicate that similar 

 variations occur in the bodies of animals, and a few experi- 

 ments conducted with slight variations in the composition 

 and reaction of the media in which the bacteria grow will 

 suffice to show that the exact effect of toxicogenic bacteria 

 in the bodies of different animals cannot always be accurately 

 prejudged. 



The physiologic and pathogenic action of the extracellular 

 soluble toxins differs from that of the intracellular and dif- 

 ficultly soluble toxins in that it is more easily diffused 

 throughout the animal juices, and that its diffusion is inde- 

 pendent of the invasiveness of the bacteria, so that a few 

 organisms growing at some focus of unimportant magnitude, 

 and causing but little local manifestation, may be able to 

 produce a profound impression upon remote organs. This 

 is best exemplified in the case of the Bacillus tetani, which, 

 finding its way into the tissues under proper conditions, 

 produces scarcely any local reaction, indeed, the lesion may 

 be undiscoverable, yet may cause the death of the animal 

 through the intensity of its action upon the central nervous 

 system. 



SPECIFIC ACTION OF BACTERIO-TOXINS. 



The metabolic products of the greater number of injurious 

 bacteria are characterized by irritative action upon those 

 body cells with which they come into contact. If through 

 the intracellular nature of the poisons and the mildly invasive 

 character of the micro-organisms this action is localized at 

 the seat of original infection, a local manifestation will result. 

 Its exact nature will, however, be modified to some extent 

 by other qualities of the bacterial products. Thus, when in 

 addition to their irritative action, the products are strongly 

 chemotactic, suppuration will follow. 



