336 MANUAL OF BACTERIOLOGY. 



Bacillus Influenzae. — A small bacillus, 0.2 to 0.3 ^by 0.5 /*, 

 with rounded ends. It does not form spores, is not motile 

 and is decolorized by Gram's method. It is aerobic, grows 

 only in the incubator, and upon media containing hemoglobin. 

 The medium is prepared by smearing sterile blood over the 

 surface of a tube of agar. Fresh, uncoagulated blood may, 

 with care, be mixed with melted agar sufficiently cooled; the 

 mixture may be poured into tubes and slanted; the tubes should 



'0^ 









Fig. 85. — Anthrax bacilli in the capillaries of the liver of a mouse, sketched 

 from a. section stained with fuchsin. 



be tested in the incubator before using. The blood of some 

 animals, as the pigeon and rabbit, may be used instead of 

 human blood.* The colonies are small and transparent, look- 

 ing like httle drops of water, not becoming confluent. 



Of a large number of bacilh, the majority are destroyed in 

 twenty-four hours or less by drying. They die out in a similar 

 manner in water. Experiments upon animals up to this time 

 are not conclusive. For diagnostic purposes, the sputum 



*Centralblatt jiir Bakteriologie. Bd. XXXII. Original, p. 267. 



