1 58 ESSENTIALS OF BACTERIOLOGY 



Colonies. Glucose or Glycerin A gar Plates. Growth slow, 

 of small, round, moist colonies, separated. 



Stab-cultures. Along the needle-track small separate white 

 granules, one above the other, like a string of beads. 



Blood Bouillon. Bouillon containing one-third blood-serum 

 or ascitic fluid favors the growth. They grow better here than 

 in the other media, remaining alive a longer period of time. 



Blood-serum or Blood-agar. Growth more vigorous. A 

 good growth on blood-serum or blood-agar. 



:\ 



A 



Fig- 73- Pneumobacillus in blood (Xiooo) (Frankel and Pfeiffer). 



Staining. Takes Gram's method and the other anilin 

 stains very readily. The capsule stained by Hiss method 

 (p. 61) or Welch. 



Resistance. Cultures in sugar media must be frequently 

 transplanted, as the organism is destroyed in a few days by 

 the acid generated. In albumin alkaline media (blood-serum, 

 etc.) the cultures can be kept active two weeks or more. In 

 sputum the pneumococcus may survive several days. When 

 dried but exposed to sunlight, death occurs in a few hours. 



