92 Infection 



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 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 restricted 

 to 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 which, when mild, 

 occasions multiplication of the cells of the connective and 

 lymphoid tissues, and, when extreme, effects the death of 

 the cells, the products are strongly chemotactic, suppuration 

 will occur. 



Fever and suppuration are, therefore, non-specific actions, 

 because numerous micro-organisms share the qualities pro- 

 ductive of these conditions in common. 



If the bacteria are rapidly invasive, but still have injurious 

 products of the intracellular variety, they are apt to share 

 certain qualities, such as the swelling of the lymph-nodes, 

 etc., in common, so that such lesions cannot be considered as 

 specific. So soon as any one of the products is discovered to 

 give some single lesion peculiar to that organism by which 

 it is produced, or so soon as the total effect of the activity 

 of the various products of any micro-organism produces a 



