124 LABORATORY GUIDE IN BACTERIOLOGY 



place, as is noticed in subcutaneous inoculations. 

 Care is necessary not to puncture the intestines. 



When the animal has died, perform an autopsy and 

 study the lesions. Make cultures from the heart and 

 internal organs in the usual manner, and make capsule 

 stains from the heart's blood. 



SECTION 6 



THE DIPHTHERIA GROUP 



Members 



Bacillus diphtheriae. 

 B. hofmannii. 

 B. xerosis. 



Use great caution in handling B. diphtheriae. 

 Inoculate' agar slants from laboratory cultures of 

 B. diphtheriae and B. hofmannii. 



i. Routine study. Stain B. diphtheriae with Lof- 

 fler's methylene blue instead of gentian violet. The 

 staining may be facilitated by the application of mild 

 heat. Observe the darkly stained granules and make 

 sketches of some of the bacilli. 

 2. Special study. 



Neisser's Granule Stain (Gin's Modification) 

 i. 5 per cent alcoholic solution. Methy- 

 lene blue (Grubler) 20 c.c. 



5 per cent glacial acetic acid 1,000 c.c. 



a. 10 per cent alcoholic solution. Crys- 

 tal violet (Hochst) 10 c.c. 



Distilled water 300 c.c. 



Two parts of i with one part of 2 ; call solution a. 



b. Acid lactic i c.c. 



Lugol's solution 99 c.c. 



c. Chrysoidin (i gram in hot water) .... 300 c.c. 



