g4 Hemurrhagic Se])tic'Ciiiia 



is also a possibility of the bacteria producing strongly acting 

 exogenic toxic substances and aggressins in the living body. 



According to the investigations of Klett & Braun, the bacilli of 

 fowl cholera and swine plague secrete even in artiiicial fluid cultures 

 soluble poisons in large ({uantities which can be demonstrated. These 

 toxins have an identical poisonous action (in pigeons and chickens 

 lethargy and intoxication) and their endotoxins are also identical; a 

 difference is indicated in that the Bacillus avisepticus produces greater 

 quantities of filterable toxins and endotoxins, and these are also more 

 constant. 



According to Weil the virulence of the bacteria is considerably 

 increased when heated to 44" C. in the exudate of artificially infected 

 animals, and also, according to Citron, in extracts of cultures. Accord- 

 ing to Bail's theory the bipolar bacilli, like the other pathogenic bac- 

 teria, produce specific substances in the animal body (aggressins) which 

 possess the character of changing non-fatal amounts of bacteria to 

 fatal ones, without themselves having marked toxic properties. Further, 

 Tschistovitch believes that virulent fowl cholera bacilli contain strictly 

 specific thermo-stable antiphagins which protect them from the digestion 

 by leucocytes. 



The bipolar bacilli manifest a particular affinity towards 

 certain organs, and therefore pathological changes develop in 

 the less acute cases only in certain organs. In such predisposed 

 organs either acute or chronic inflammations may be present. 

 The serous membranes in general, the lungs, the synovial mem- 

 branes of the joints and tendons and probably the liver are the 

 favored organs. 



According to Lignieres the bipolar bacilli may also give 

 rise to the development of secondary disease processes. 

 Through their toxins and probably indirectly through a tem- 

 porary arrest of the phagocytosis, the resistance of the body 

 may l)e reduced, whereby bacteria which are more or less harm- 

 less may produce disease processes, while the bipolar bacilli 

 may in the meantime disappear from the body. Even in many 

 of the acute cases which are associated with an inflammation 

 of the lungs and joints other probably pathogenic organisms 

 may be found in the affected tissues, or in the inflammatory 

 products in addition to the bipolar ]3acilli. However, in the 

 chronic cases only secondary bacteria are as a rule present. 



The intravenous injection of a weak virus, for instance older 

 cultures of the bipolar bacillus, produces as has already been mentioned, 

 a chronic affection which results in cachexia. In these cases the bac- 

 teriological examination of the affected tissues and exudates discloses 

 other bacteria (streptococci, colon bacteria, etc.) in spite of the fact that 

 the infection was brought on by the bipolar bacilli. Similar results may 

 occasionally be obtained from the injection of filtrate free from bacteria 

 made from cultures of the bipolar bacillus. 



The very frequent occurrence of mixed infections makes it 

 possible for other bacteria to prepare the field for the propa- 



