BACTERIUM INFLUENZA 401 



should be pale red). (Fig. 76.) It is decolorized by the 

 method of Gram. 



It develops only at temperatures ranging from 26° 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 



Fig. 76 



Bacterium influenzse in sputum. 



and its development most satisfactorily observed by the 

 following procedure: over the surface of ,a slanted agar tube 

 or over agar-agar solidified 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 



26 * 



