58 PA THOGNEIC BA CTERIA. 



bacteria produce powerful metabolic poisons toxins, 

 ptomaines, etc. which either cause widespread destruc- 

 tion of the tissues immediately acted upon, or, circulating 

 throughout the organism, produce fever, nervous excita- 

 tion, and a general overthrow of the normal physiological 

 equilibrium. These peculiarities serve to divide the bac- 

 teria into 



Phlogistic bacteria, 



Toxic bacteria, 

 Septic bacteria. 



The bacteria of suppuration probably act in several 

 ways. Their products may be of a violently chemotactic 

 nature, or their virulence, exerted upon the surrounding 

 tissue, may destroy large numbers of the cells, whose 

 dead bodies may be chemotactic. When the suppura- 

 tion is violent the toxic product of the bacterium is itself 

 most probably strongly chemotactic. 



The great majority of suppurations depend upon bac- 

 teria, but there are sterile suppurations which sometimes 

 follow the use of croton oil, turpentine, etc. The differ- 

 ence between infectious and sterile pus is marked, for 

 the former, containing the virulent germs, tends to invade 

 new tissue or distribute its disease-producers to new parts 

 of the body, while the latter remains local. 



There are few purely toxic bacteria, the tetanus and 

 diphtheria bacilli serving as typical examples. By sep- 

 tic bacteria, I mean those whose habitual tendency is to 

 grow in the blood and lymph and distribute to all the 

 organs. Anthrax is a type of the class. 



How the disease-producing bacteria effect their en- 

 trance into the tissues is an interesting question. The 

 channels naturally open to them are those leading into 

 the interior of the organism, and must be separately con- 

 sidered. 



(//) //// /V s ', stive Tract. Attention has already been 

 called to the facility with which the bacteria enter the 

 digestive tract in foods and drinks. Once their metabo- 

 lism i- in active progress, the poisons which they produce 



