!10 SCIENCE BULLETIN, No. 21. 



can be grown serobically by adopting Tarozzi's method or one of its modifica- 

 tions. Nissa's liver-piece broth has been found very convenient, with a slight 

 modification as follows : The minced liver is placed, whilst fresh, in the 

 tubes or flasks, instead of being previously boiled. A sufficient quantity of 

 .bouillon is then added, and the tubes, &c., sterilised in the usual manner. 

 The medium, which has coagulated into a solid mass, is broken up by means of 

 a sterile glass rod, and, just prior to inoculation, the tubes are boiled for a 

 short time to drive out the air which gains entrance during the storage of 

 the tubes, the latter being cooled immediately before actual inoculation. 

 Growth in such medium is more abundant than if the liver is cooked before it 

 is placed in the tubes. In this medium the bacillus grows well, spores form 

 readily, and the virulence is maintained for some months without the need 

 for re-inoculation of cultures, provided, of course, that fresh sub-cultures 

 .are made when required for animal inoculation. 



Serum broth. Growth is abundant in this medium, and usually complete 

 in from twenty-four to thirty hours. The growth settles at the bottom of 

 the tube in a flocculent mass. Spores are readily formed. In plain broth 

 the growth is very scanty. There is no gas formation. 



Glucose-serum broth. Growth is abundant, but very few spores are formed 

 and the culture soon dies out. Cultures in media containing glucose soon 

 lose their virulence, and then even large amounts fail to infect. In glucose 

 there is a little gas formation. 



Liver-piece broth. Growth in this medium is abundant, whether under 

 petroleum oil, or exposed to the air, and is complete in twenty-four to thirty- 

 six hours. Numerous spores are formed. The production of gas is con- 

 siderable. It has a peculiar but not putrefactive odour. The medium is 

 rendered very acid. 



Milk. Grows well. The milk commences to peptonise in twenty-four 

 hours. There is little gas formation. In forty-eight hours the whole of the 

 milk is peptonised, leaving a cloudy, whey-like fluid with loose clot-like 

 deposit. The odour is most unpleasant. 



Alkaline egg broth. Growth is profuse. There is no gas formation. 

 $ pores are formed freely. A thick deposit of bacteria forms at the bottom 

 of the tube. 



Brain broth. Grows freely, but the medium is not blackened. 



Cultures in liquid media can be readily obtained by floating about half an 

 inch of soft petroleum or liquid petroleum on the surface of the tube before 

 sterilisation. Such, however, does not form a permanent air seal, and the 

 tubes must, therefore, be boiled just prior to inoculation in order to drive out 

 the infiltrated air. Olive oil was not used as an air seal, because it has been 

 found to be quite inefficient for that purpose. 



Glucose-agar stab culture. Growth is evident in less than twenty-four hours 

 along the needle track. No lateral branching is seen. There is a moderate 

 amount of gas formation, and the medium is soon shattered. There is little 

 or no spore formation, and the culture soon dies out. 



