64 STUDY AND IDENTIFICATION OF BACTERIA. 



but also from those of mucous mem- 

 brane. The usual period before 

 symptoms occur is fifteen days. The 

 shorter the period of incubation, the 

 more probably fatal the disease. The 

 horse is the most susceptible animal, 

 next the guinea pig, then the mouse. 

 Fowls are practically immune. 



In examining for tetanus, scrape 

 out the material from the suspected 

 wound with a sterile Volkmann spoon 

 and put it in a tube containing blood- 

 serum. Place this in an incubator. 

 We have here the principle of the 

 septic tank the cocci and other 

 aerobes grow luxuriantly and enable 

 the tetanus bacillus to develop. From 

 day to day smell the culture, and if an 

 odor similar to the penetrating, sour, 

 foul smell of the stools of a man who 

 has been on a debauch be detected, it 

 is suspicious. The nondevelopment 

 of a foul odor is against tetanus. Also 

 make smears from the material and 

 examine for drum- stick spores. If 

 these are found, heat the material to 

 80 C. for one-half hour, to kill non- 

 sporing aerobes and facultative anae- 

 robes, and then inoculate a deep 

 glucose agar tube and cultivate by 

 Wright's method. The fusiform lateral 

 outgrowth about the middle of the 



stab is characteristic, 

 ric. 24. B. aerogenes capsulatus ^ i 



agar culture showing gas formation. B- AerOgCnesCapSUlatuS 



(Welch, 1891). This bacillus is ap- 

 parently widely distributed. It is possibly the same organism as 



