334 



BACTERIOLOGY. 



to 43 C. Its optimum temperature for growth is 

 37 C. It possesses the peculiarity of developing upon 

 only those artificial culture-media to which blood or 

 blood-coloring-matter has been added. Its cultivation 

 is best conducted and its development most satisfac- 

 torily observed by the following procedure: over the 



FIG. 68. 



Bacterium influenzse in sputum. 



surface of a slanted agar tube or over agar-agar solid- 

 ified in a Petri dish smear a small quantity of sterile 

 blood (not blood-serum). A bit of the mucus from the 

 sputum of the influenza patient is then taken up with 

 sterilized forceps or on a sterilized wire loop, rinsed 

 in sterile bouillon or water and rubbed over the sur- 

 face of the prepared agar-agar. The plate or tube is 

 then placed in the incubator at 37 to 38 C. If in- 

 fluenza bacilli be present, they will develop as minute, 

 transparent, watery colonies that are without structure, 

 and which resemble somewhat minute drops of dew. 



