Influenza 



By a series of experiments he was able to make the organism 

 grow when he transferred it to agar-agar, the surface of which 

 was coated with a film of blood taken, with precautions as to 

 sterility, from the finger-tip. Later it was found that the 

 addition of hemoglobin to the culture-medium was equally 

 efficacious. By the use of such blood-smeared agar and gly- 

 cerin-agar the organism can now be successfully cultivated. 

 The isolation is best achieved through the use of bronchial 

 secretions, carefully washed in sterile water or salt solution 

 to remove contaminating organisms from the mouth. 



Fig. 167. Bacillus of influenza; colonies on blood agar-agar. Low 

 magnifying power (Pfeiffer). 



Cultivation. Upon blood-spread glycerin agar-agar, 

 after twenty-four hours in the incubator, minute colorless, 

 transparent, dewdrop-like colonies may be seen along the line 

 of inoculation. They look like condensed moisture, and Kita- 

 sato makes a special point of the fact that they never become 

 confluent. The colonies may at times be so small as to 

 require a lens for their detection. 



No growth takes place at room temperature. The organ- 

 isms die quickly and must be transplanted every three or four 

 days if they are to be kept alive. 



