INTESTINAL GROUP 85 



will be observed, due to a solvent action of the alkali 

 produced by the organism upon the proteid content. 



3. Special study B. — Inoculate fermentation-tubes the 

 same as for B. coli. Measure and test gas. Compare 

 the results with those obtained in the study of the colon 

 group. What difference do you notice ? 



4. Special study C. — Inoculation of a rabbit sub- 

 cutaneously with B. choleras suis. Subcutaneous inoc- 

 ulations of rabbits are Usually made in the following 

 manner: An assistant, in a sitting position, places the 

 rabbit back-down in his lap. The head projects beyond 

 the knees of the assistant. The ears and hind-legs are 

 grasped, and the animal is thus held in position. The 

 hair is then cut off on a portion of the abdomen, and the 

 place is treated with mercuric chlorid and alcohol in the 

 usual manner. With sterilized fingers the skin is then 

 pulled up, the syringe inserted, and the material injected. 



After the rabbit has died, study the lesions produced 

 by the organism, and make smears from the site of the 

 inoculation, the heart's blood, and other organs. Note 

 the polar staining, i. e., stained portions at the two ends 

 of the cell and an unstained area between. Make cul- 

 tures on agar from the heart's blood and other internal 

 organs. 



EXERCISE III. STUDY OF SUBGROUP III 

 THE TYPHOID-DYSENTERY GROUP 



Use great care in handling members of this group. 



Inoculate agar-slants from stock-cultures of B. typho- 

 sus, B. dysenteriae (Shiga), and B. jaecalis alcaligenes. 



I. Routine study. — Study carefully the reaction on 

 milk, and test for indol. Preserve glucose-agar-cultures 

 for two weeks. 



