326 AGRICULTURAL BACTERIOLOGY 



premature discharge of a firecracker or some other form of 

 fireworks. 



Symptoms. The organism grows only at the point at 

 which it was introduced into the tissues, and only to a small 

 extent even there. In fact, so little evidence of its growth 

 is shown by the tissues that it is sometimes impossible to 

 determine the point of infection. The organism produces 

 its powerful toxin, which is absorbed and which has a spe- 

 cific action on the nerves, resulting in muscular contractions 

 in various parts of the body. The tetanic spasms usually 

 begin in the muscles of the head and neck, extending from 

 these parts to the muscles of the throat, trunk, and extrem- 

 ities. In the head, the muscles of mastication are first 

 attacked, giving rise to the disease commonly known as 

 lockjaw. In the horse, the muscles of the tail may be the 

 first to show the spasmodic contractions. 



The duration of the disease in the horse may be a few 

 days, or it may continue for several weeks. In cattle the 

 disease is usually less rapid, but rarely runs longer than 

 two weeks. Tetanus is usually fatal in sheep, and about 

 75 per cent, of the horses affected die. In man the disease 

 manifests itself in much the same manner as in the lower 

 animals. It was a very common disease in the early months 

 of the Great War. In certain portions of the Western 

 front, the soil apparently contained many tetanus bacilli. 

 The contamination of wounds with the soil presented ample 

 opportunity for the tetanus organism to enter. Later in the 

 struggle, one of the first treatments each wounded man re- 

 ceived was a dose of tetanus antitoxin. 



Preventive measures. A preventive and, to some extent, 

 a curative treatment has been developed in the tetanus an- 

 titoxin. This antitoxin is comparable to the preventive 

 serum used in hog cholera, and the diphtheria antitoxin- 

 used so widely in human medicine. 



