62 STUDY AND IDENTIFICATION OF BACTERIA. 



B. Tetani (Nicolaier, 1885; Kitasato, 1889). This is the most 

 important organism of the anaerobic spore bearers. Its character- 

 istics are the tetanic symptoms produced by the toxin and the strictly 

 terminal drum-stick spores. Spores are difficult to find in material 

 from wounds infected with tetanus, but readily develop in cultures. 

 Prior to the formation of spores the organism is a long thin bacillus 

 (4 x .4 ft). It is motile and Gram positive. It liquefies gelatin slowly 

 and does not coagulate milk. Theobald Smith recommends growing 

 it in fermentation tubes containing ordinary bouillon, but to which 

 a piece of the liver or spleen of a rabbit or guinea-pig has been 



FIG. 23. Tetanus bacilli showing end spores. (Kolle and Wassermann.) 



introduced at the junction of the closed arm and the open bulb. By 

 this method spores develop rapidly in from twenty-four to thirty-six 

 hours. Sporulation is most rapid at 37 C. As there is always lia- 

 bility to postmortem invasion of viscera by ordinary saprophytes, 

 Smith recommends that great care be taken not to handle the animal 

 roughly in chloroforming and in pinching off pieces of the organ at 

 autopsy. The animal must be healthy, and the tubes to which the 

 piece of tissue is added must be proven sterile by incubation. Smith 

 calls attention to the uncertainty of the temperature at which tetanus 

 spores are killed. He shows that some require temperatures only 

 possible with an autoclave. In view of the danger of tetanus, it is 



