172 



ESSENTIALS OF BACTERIOLOGY 



Staining. All the ordinary stains, Gram's method also, the 

 spores being colored in the usual way. 



Pathogenesis . A small amount of the pure culture injected 

 under the skin of experiment animals will cause, in two to three 



Fig. 104. Bacillus tetani: cul- 

 ture four days old in glucose-gela- 

 tin (Frankel and Pfeiffer). 



Fig. 105. Six days' culture of 

 bacillus of tetanus in gelatin (deep 

 stab) (Frankel and Pfeiffer). 



days, death from true tetanus, the tetanic condition starting 

 from the point of infection. At the autopsy nothing charac- 

 teristic or abnormal is found, and the bacilli have disappeared, 

 except near the point of entrance. This fact is explained as 

 follows : 



