104 LABORATORY BACTERIOLOGY 



EXERCISE XLIV 



BACTERIUM DIPHTHERIA (continued) 



152. Work for this exercise. Examine microscopically, in 

 stained cover-glass preparations, the bacteria from the glycerin 

 agar and Loeffler's blood-serum cultures. Stain with alkaline 

 methylene blue and note especially the way the bacteria stain. 

 Stain a few preparations after Neisser's method (the staining 

 solutions will be furnished) and compare with the methylene- 

 blue stain. 



Note with special care the morphology of the bacteria and 

 make a drawing of a few of them. Compare the preparations 

 with those made from the same cultures in previous exercise 

 and note any differences in the morphology of the bacteria. 



Examine very carefully a guinea pig (furnished) which has 

 died from the effect of inoculation with diphtheria organisms. 



Expectorate into a watch glass which has been wiped with 

 a cloth moistened in a 5% solution of carbolic acid. From 

 this sputum inoculate a tube of bouillon and one of slant agar, 

 and make a series of 2 agar and one of 2 gelatin plate cul- 

 tures. Use a small loopful of sputum for each tube culture 

 and the same for the first tube in the plate series. 



