176 PATHOGENIC BACTERIA 



organism, a large one, from T2~tf o"o to ^.^ inch in length * 

 grows in chains, best at 44 C. or 111 F., in milk, but 

 may be cultivated on other media. The souring 

 of milk takes place within twenty-four hours if the 

 temperature be correct (see Chapter on Milk). 



Bacillus Aerogenes Capsulatus of Welch. A very 

 important putrefactive organism in the intestine is 

 the Bacillus aerogenes capsulatus of Welch. This 

 organism grows only in the absence of oxygen. It is 

 a large, straight, or slightly curved rod, from ^3iro"o 

 inch up to YIJQ" inch long by about ^oirro mcn w i^ e ' 

 non-motile, and encapsulated. It has the power of 

 fluidifying gelatin and clotting milk. It is introduced 

 to the human body by wounds, probably, or it may go 

 out from the intestinal tract through a solution of the 

 mucous membrane. When lodging in the organs it 

 forms gases, giving an appearance to the liver called 

 a foam or sponge liver. It has an importance in 

 obstetrics as gas-infection sometimes appears after 

 mechanical treatment within the uterus. It is prob- 

 ably not pathogenic to entirely healthy tissue, but 

 when an injury devitalizes a part an entrance is 

 afforded. It is responsible for the early bloating of 

 some cadavers. 



Bacillus of Malignant Edema. The bacillus of 

 malignant edema is a common inhabitant of the soil 

 and may be found in dust. It grows only in the absence 

 of free oxygen, but may be cultivated with ease in 

 the laboratory particularly if sugar be added to the 

 medium. It is a long delicate rod measuring about 

 STTTfriF inch in thickness and -ginyTF to -oVo" inch in 

 length. It moves by flagella arranged along the sides. 



