276 SPECIFIC MICRO-ORGANISMS 



tive, some of the cells being decolorized by prolonged treatment 

 with alcohol. The spores are central, or intermediate in position 

 with bulging of the cell. 



In cultures B. edematis is a strict anaerobe. It liquefies gela- 

 tin. Milk is slowly coagulated and the coagulum digested, the 

 reaction remaining alkaline to litmus. The cultures have a foul 

 odor. The spores withstand boiling sometimes for 2 to 3 hours. 

 The morphological and physiological properties of this organism 

 are quite variable and the many intermediate types between it 

 and B. feseri make distinction between the two species somewhat 

 difficult. 



In animals and man, malignant edema occurs spontaneously 

 as a wound infection, but it is not very common. It has been 

 observed most frequently in horses and in new-born calves. The 

 guinea-pig is susceptible. In general a mere injection of the 

 bacilli fails to produce serious disease. The presence of foreign 

 bodies or extensive tissue destruction favors the infection. 



Bacillus Feseri. Feser and Bollinger (1875-1878) observed 

 the large narrow rods in the diseased tissues and exudates of 

 symptomatic anthrax or black leg, a fatal disease of cattle and 

 sheep. Man is not affected. Arloing, Cornevin and Thomas 

 (1884) obtained the organism in culture. The organism is a 

 strict anaerobe and resembles B. edematis very closely. Black 

 leg is a local emphysematous inflammation usually beginning in 

 one leg of cattle or sheep, rapidly extending and resulting in death 

 as a rule. Immunity is obtained by injecting small doses of the 

 virulent bacteria or by injecting attenuated organisms, and also 

 by injecting the virus together with an immune serum. 1 



B. Welchii. Welch and Nuttall in 1892 discovered this organ- 

 ism at autopsy in a body showing general emphysema of the 

 tissues and gas bubbles in the blood-vessels. They obtained 

 cultures by anaerobic methods and caused similar post-mortem 

 emphysema in the bodies of rabbits. The organism lives and 

 multiplies in the intestine of man and other mammals, is widely 

 1 Kitt, Kolle and Wassermann, Handbuch, 1912, Bd. IV, S. 819-836. 



