270 MANUAL OF BACTERIOLOGY. 



very well by Buchner's method. It may be cultivated at 

 the room temperature, but better in the incubator. It grows 

 upon ordinary culture-media, preferably those containing dex- 

 trose. Gelatin is liquefied slowly; the colonies in gelatin pres- 

 ent characteristic radiating filaments and look like a bristle 

 brush. It grows on the other culture-media. Gas formation 

 is not pronounced. 



This organism appears to be widely spread in external nature, 

 especially in the soil. It is often found in garden-earth and 

 in the feces of herbivorous animals. McFarland claims that 

 it may occur in vaccine virus when this is carelessly prepared, 

 and this would explain those rare cases of tetanus which occur 

 after vaccination.* Tetanus bacilli have been found in gelatin, 

 and it is stated that tetanus has followed the injection of gelatin 

 as a hemostatic. The infection appears usually, if not always, 

 to be introduced through some wound.f Clinically, persons 

 having the disease suffer from spasms of the muscles about the 

 neck and the lower jaw (lock-jaw). The spasms finally be- 

 come general. 



Inoculation with a pure culture produces tetanus in mice; 

 also in rats, guinea-pigs and rabbits. The tetanic spasms 

 begin in the vicinity of the point of inoculation and after- 

 ward become general. The baciUi are not widely scattered 

 through the body; they occur only in the immediate vicinity 

 of the original lesion, and there are no important macro- 

 scopic alterations in the internal viscera. 



Tetanus is the type of the purely toxic disease. Its symp- 

 toms may be produced in animals by the injection of liquid 

 cultures which have been deprived of their bacteria by fil- 

 tration. The toxic substance appears not to be a ptomaine, 

 as was at first supposed, and its exact nature is not determined. 



* Journal Medical Research. Vol. VII. 1902. 



t Wells. Fourth of July Tetanus. American Medicine. June 13, 1903. 



