DESCRIPTIONS OF PATHOGENIC BACTERIA. 1 79 



the cultures. The bacteria are able to form 

 this toxin synthetically in nutrient media free 

 from proteid as well as by splitting up the pro- 

 teids in albuminous media. The effect pro- 

 duced by the bacteria upon the animal or- 

 ganism is to be attributed to the action of 

 the poison, since the effect runs parallel with 

 the quantity of poison carried with or formed 

 by the bacteria, and not with the number of 

 bacteria themselves. The poison, like strych- 

 nine, acts upon the spinal cord and not upon 

 the muscles or peripheral nerves. Mice, 

 rabbits, sheep and horses are susceptible, fowls, 

 dogs and men somewhat less so. Tetanus 

 spores when alone do not usually germinate 

 in the body, but they can germinate when in- 

 troduced along with particles of soil or splinters 

 of wood, or with pus. Accordingly infection 

 in this disease is usually a mixed infection, 

 and the tetamis bacillus is not to be regarded 

 as a strict parasite. In the soil and in ooze 

 it may perhaps participate in the marsh-gas 

 fermentation. 



These latter statements may also be true of 

 the bacteria of malignant cedema. These or- 

 ganisms were first described by Pasteur as the 

 Vibrio septique, and were afterwards studied 

 accurately by Koch. The motile rods have 

 flagella on the ends and sides. The rods grow 



