336 MANUAL OF BACTERIOLOGY. 



Bacillus Influenzas. 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 







" 







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 little drops of water, not becoming confluent. 



Of a large number of bacilli, 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 fur Bakteriologie. Bd. XXXII. Original, p. 267. 



