Medical Bacteriology. 121 
B. influenzae does not grow on the ordinary artificial culture media but may be cul- 
tivated on agar slopes upon the surface of which blood has been smeared. The blood 
from man, rabbits, guinea-pigs and frogs can be used, but that from pigeons is best. 
The blood may be obtained from a needle prick and spread over the medium with a loop. 
The skin should first be washed with alcohol and then ether and the first drops should 
not be used. The sterility of these tubes should be tested by placing them in an incu- 
bator for 24 hours previous to inoculation. 
