XYI. 

 PATHOGENIC ANAEROBIC BACILLI. 



STRICTLY anaerobic bacilli are not able to multiply in the blood 

 of living animals ; but some of them may multiply in the subcuta- 

 neous connective tissue or in the muscles, when introduced by in- 

 oculation, and are pathogenic because of the local inflammatory or 

 necrotic processes to which they give rise, or because they produce 

 soluble toxic substances which are absorbed and cause death by 

 their special action upon the nervous system or by general toxaemia. 



BACILLUS TETANI. 



Synonyms. The bacillus of tetanus ; Tetanusbacillus, Ger. 



Nicolaier (1884) produced tetanus in mice and rabbits by intro- 

 ducing garden earth beneath their skin, and showed that the disease 

 might be transmitted to other animals by inoculations with pus or 

 cultures in blood serum containing the tetanus bacillus, which, how- 

 ever, he did not succeed in obtaining in pure cultures. Carle and 

 Rattone (1884) showed that tetanus is an infectious disease, which 

 may be transmitted by inoculation from man to lower animals a 

 fact which has since been verified by the experiments of Rosenbach 

 and others. Obtained in pure cultures by Kitasato (1889). 



The writer produced tetanus in a rabbit in 1880 by injecting be- 

 neath its skin a little mud from the street gutters in New Orleans. 

 The tetanus bacillus appears to be a widely distributed microorgan- 

 ism in the superficial layers of the soil in temperate and especially in 

 tropical regions. In Nicolaier's experiments it was not found in soil 

 from forests or in the deeper layers of garden earth. 



Morphology. Slender, straight bacilli, with rounded ends, 

 which may grow out into long filaments. Spores are developed at 

 one extremity of the bacilli, which are spherical in form and consid- 

 erably greater in diameter than the rods themselves, giving the 

 spore-bearing bacilli the shape of a pin. 



Stains with the usual aniline colors and also by Gram's method. 

 The method of Ziehl may be employed for double-staining bacilli and 

 spores. 



