CHAP. XV] ANAEROBIC BACILLI 369 



of the liquefaction of grape-sugar gelatine, («) the size of the 

 bacilli and spores and the position of the latter in the former, 

 and (/) the distribution and number of flagella and the 

 greater or lesser tendency of the bacilli to form filaments. 



To this group belong : the bacillus of malignant oedema 

 of Koch, the bacillus of tetanus, the bacillus of symptomatic 

 charbon, quarter evil, or Rauschbrand, and the bacillus 

 enteritidis sporogenes. 



Material, containing the spores of either of the above 

 microbes, is transferred to sterile grape-sugar gelatine con- 

 tained in a test-tube plugged with sterile cotton-wool — the 

 gelatine to the height of about four inches — the test-tube is 

 then placed in water of which the temperature is main- 

 tained at 78-80° C. for from ten to fifteen minutes, then in 

 cold water so as to allow the gelatine to set, and after 

 sealing the top with gutta-percha paper ife finally incubated 

 at 20- 2 1° C. After twenty-four hours or latest after thirty-six 

 or forty-eight hours a number of spherical colonies are 

 noticed in the deeper parts of the sugar gelatine, the 

 rapidity with which these grow, their general aspect, and the 

 rapidity and nature of the liquefaction differ for the dif- 

 ferent species. As the colonies increase in size they become 

 gradually confluent, and the liquefaction of the gelatine 

 extends till the whole is liquefied, at the same time more or 

 less copious gas evolution takes place, the gas bubbles being 

 on the top of the liquefied gelatine, and when the liquefac- 

 tion has extended to the top the gas bubbles escape into the 

 space between the gelatine and cotton-wool plug. 



In order to obtain uniform and characteristic growths in 

 sugar gelatine tubes from an already established pure 

 gelatine culture, the method of inoculation described in a 

 former chapter as the capillary pipette method is by far the 

 most reliable and best : by means of a freshly drawn-out 



B B 



