BACILLUS CHOLERA SUIS 8 1 



EXERCISE XXX 



BACILLUS CHOLERA SUIS AND BACILLUS TYPHOSUS 



(continued) 



121. Work for this exercise. Reexamine all of the cultures 

 of B. cholera suis and B. typhosus. Note especially the con- 

 dition of the fermentation tubes. Keep the milk and the lit- 

 mus-milk cultures in the incubator for about 5 weeks and note 

 any changes which may take place from week to week. 



Examine and carefully describe the colonies on the gelatin 

 plates. 



Try the indol test ( 115) with the culture in sugar- free 

 bouillon. 



Make and stain with alkaline methylene blue a few (3 or 4) 

 cover- glass preparations from the organs (liver, spleen, kidney, 

 or blood) of a rabbit which has died from the effects of the 

 inoculation with hog-cholera bacilli. Note the number (few 

 or many) of bacteria in the preparations and preserve one 

 of them to accompany the notes. Make a drawing of a few 

 bacilli. 



Examine and complete the notes on the culture of B. coli 

 communis and the paracolon bacillus. Compare them with 

 the cultures of hog-cholera and typhoid bacteria. 



122. Making cover-glass preparations from tissues. With a 

 pair of fine forceps take up a bit of tissue from the freshly cut 

 liver, spleen, or kidney, and rub it gently over the surface of 

 a clean cover glass, care being taken that the film of tissue 

 is thin. Allow this to dry in the air, after which pass the 

 cover glass, film up, three times through the flame to fix the 

 tissue to the glass. It can be stained the same as the cover- 

 glass preparations from the cultures. When carbol fuchsin 

 is used for staining, the preparation should be wet before 

 applying. These are often spoken of as smear preparations. 



