PUTREFYING MATERIAL FROM VARIOUS SOURCES. 587 



such a mass, or in organic liquids to which the air has free access. 

 Among the most common putrefactive bacteria are the Proteus vul- 

 garis, Proteus mirabilis, and Proteus Zenkeri of Hauser. Formerly 

 the minute motile bacteria found in putrefying animal infusions, etc. , 

 were commonly spoken of as belonging to the species " Bacterium 

 termo," but recent researches show that several different species were 

 included 'Under this name by those whose researches were made be- 

 fore the introduction of Koch's method for isolating and differentiat- 

 ing microorganisms of this class by the use of solid' culture media. 

 The different species of Proteus are all facultative anaerobics. They 

 are more or less pathogenic, and according to Hauser produce a chem- 

 ical poison which, when injected into small animals, causes death with 

 all of the symptoms of putrid intoxication. The bacillus of mouse 

 septicaemia, which was first obtained by Koch from a putrefying meat 

 infusion, is also pathogenic, as are the writer's Bacillus cadaveris 

 and various other anaerobic bacteria found in putrefying material. 



Some account of the various products of putrefaction and the 

 microorganisms concerned in their production will be found in Sec- 

 tion IV., Part Second, of the present volume. 



