430 



PRINCIPLES OF VETERINARY SURGERY 



whitish, creamy flake, surrounded by a zone of solid gela- 

 tine. On gelatine plates at the temperature of 20 to 22 de- 

 grees the cultures also have the radiating character. Gelose 

 is not liquefied, but, like gelatine, liberates gas. The col- 

 onies are less flaky and the streaks coarser. Serum, when 

 coagulated, is a good medium. It is inoculated by punctur- 

 ing, and then covered over with hot gelose. After forty- 

 eight hours in the incubator at 37 degrees the colonies are 

 already apparent. The serum is not liquefied. 



The bacillus of tetanus grows poorly on potato. It forms 



Fig. 43. 



Culture of the Tetanus Bacillus in Glucose Gelatine, Inoculated by a 



Deep Stab. Six Days Old. 



Fig. 44. 



Culture of the Tetanus Bacillus in Glucose Gelatine, after Separation 



of the Inoculated Substance. (Frankel and Pfeiffer.) 



but fine, slight beds, keeps in the filamentous form, and 

 does not form spores, even after months. Egg albumen, 

 fresh serum and aqueous humor are not favorable media. 

 Cultivation is favored when reducing substances (glucose, 

 2 per cent ; blue litmus tincture, 5 per cent, or sulpho-in- 

 digotate of sodium, o. 10 per cent) are added to the media. 

 RESISTANCE.— Cultures of Nicolaier's bacillus pre- 

 serve their vitality for a long time in the incubator, or at 

 ordinary temperatures when air is excluded. The spores 

 are very resistant to the action of heat. They are not killed 

 when exposed to a temperature of 80 degrees for six hours. 



