BACTERIA AND DISEASE 315 



Friedlander' s Pneumo -bacillus is a capsulated oval coccus, 

 assuming the form of a small bacillus. It is inconstant in 

 pneumonia, unequally distributed, and scarce ; it is aerobic, 

 and facultatively anaerobic; it occasionally occurs in long 

 forms and filaments; it is non-motile, non-liquefying, and 

 has no spores; it does not stain by Gram's method, which 

 stain is therefore used for differential diagnosis ; it will grow 

 fairly well in ordinary gelatine at 20 C. ; and it is a denitri- 



BACILLUS OF INFLUENZA 



fying organism, and also an actively fermentative one, even 

 fermenting glycerine. It is not unlike Bacillus coli corn- 

 munis, and to distinguish it from that organism we may 

 remember that the B. coli is motile, never has a capsule, 

 produces indol, and does not ferment glycerine. 



Influenza. In 1892, during the pandemic of influenza, 

 Pfeiffer discovered a bacillus in the bronchial mucus of 

 patients suffering from the disease. It is one of the small- 

 est bacilli known, and frequently occurs in chains not unlike 

 a streptococcus. Carron obtained the same organism from 

 the blood. In the bronchial expectoration it can retain its 

 virulence for as long as a fortnight, but it is quickly de- 

 stroyed by drying. The bacillus is aerobic, non-motile, and 

 up to the present spores have not been found. It grows 

 somewhat feebly in artificial media, and readily dies out. 

 Blood serum, glycerine agar, broth, and gelatine have all 

 been used at blood-heat. It does not grow at room tern- 



