460 PATHOGENIC MICROORGANISMS 



sules the spores were protected from the leucocytes, not from the body 

 fluids. Nevertheless, tetanus developed in the animals. The nature of 

 the wound and the simultaneous presence of other microorganisms seem 

 to be important factors in determining whether or not the tetanus bacilli 

 shall be enabled to proliferate. Deep, lacerated wounds, in which there 

 has been considerable tissue destruction, and in which chips of glass, 

 wood splinters, or grains of dirt have become embedded, are particularly 

 favorable for the development of these germs. The injuries of compound 

 fractures and of gunshot wounds are especially liable to supply these 

 conditions, and the presence in such wounds of the common pus cocci, 

 or of other more harmless parasites, may aid materially in furnishing an 

 environment suitable for the growth of the tetanus bacilli. Apart from 

 its occurrence following trauma, tetanus has been not infrequently ob- 

 served after childbirth,' and isolated cases have been reported in which 

 it has followed diphtheria and ulcerative lesions of the throat.^ 



A definite period of incubation elapses between the time of infection 

 with tetanus bacilli and the development of the first symptoms. In 

 man this may last from five to seven days in acute cases, to from four 

 to five weeks in the more chronic ones. Experimental inoculation of 

 guinea-pigs is followed usually in from one to three days by rigidity of 

 the muscles nearest the point of infection . This spastic condition rapidly 

 extends to other parts and finally leads to death, which occurs within 

 four or five days after infection. 



Autopsies upon human beings or animals dead of tetanus reveal few 

 and insignificant lesions. The initial point of infection, if at all evident, 

 is apt to be small and innocent in appearance. Further than a general 

 and moderate congestion, the organs show no pathological changes. 

 BacilH are found sparsely even at the point of infection, and have been 

 but rarely demonstrated in the blood or viscera. Nicolaier succeeded 

 in producing tetanus with the organs of infected animals in but eleven 

 out of fifty-two cases. More recently, Tizzoni ' and Creite ' have suc- 

 ceeded in cultivating tetanus bacilli out of the spleen and heart's blood 

 of infected human beings. 



The researches of Tarozzi ^ and of Canfora ^ have shown also that 

 spores may be transported from the site of inoculation to the liver, 

 spleen, and other organs, and there lie dormant for as long as fifty-one 

 days. If injury of the organ is experimentally practised and dead tissue 



1 Baginsky, Deut. med. Woch., 1893. * Creite, Cent. f. Bakt., xxxvii. 



' Foges, Wien. med. Woch., 1895. ' Tarozzi, Cent. f. Bakt. Orig. xxxviii. 



' Tizzoni, Ziegler's Beit., vii. ° Canfora, Cent, f . Bakt. Orig. xlv. 



