THE ANAEROBIC BACILLI 735 



A definite period of incubation elapses between the time of in- 

 fection with tetanus bacilli and the development of the first symp- 

 toms. 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. Bacilli 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 re- 

 cently, Tizzoni 34 and Creite 35 have succeeded in cultivating tetanus 

 bacilli out of the spleen and heart 's blood of infected human beings. 



The researches of Tarozzi 86 and of Canfora 37 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 practiced 

 and dead tissue or blood clot produced, the spores may develop and 

 tetanus ensue. These experiments may explain cases of so-called 

 crypto genie tetanus. 



In man tetanus may take either an acute or chronic form, the 

 word "chronic" here meaning simply that the onset is less abrupt, 

 the incubation time longer, the symptoms slower in development and 

 the prognosis more favorable. In the acute form, the incubation 

 time ranges from three or four days to ten or fourteen days, the 

 common very rapid cases taking about seven. In the so-called 

 chronic form the incubation time may occasionally exceed a month. 

 The first symptoms usually consist in headache and general depres- 

 sion; followed rather rapidly by difficulties in opening the mouth, 

 due to spasms or trismus of the masseters. There is slight stiffness 

 of the neck which makes it difficult for the patient to bring the 



34 Tizzoni, Ziegler's Beit., vii. 



35 Creite, Cent. f. Bakt., xxxvii. 



36 Tarozzi, Cent. f. Bakt. Orig. xxxviii. 



37 Canfora, Cent. f. Bakt. Orig. xlv. 



