BACTERIUM INFLUENZA. 203 



hour to 50-60, is a specially favorable nutrient medium. 

 According to Grassberger, the influenza bacterium grew 

 with very much greater luxuriance upon unheated blood- 

 media in proximity to colonies of the Micr. pyogenes. It 

 may be supposed that heat and the growth of the Micr. 

 pyogenes alter the blood-medium in a similar manner 

 (Z. H. xxv, 453). 



Vitality and Duration of Life. In water, even in the 

 dark, they die in from twenty-eight to thirty-two hours ; 

 in agar and bouillon cultures, after two or three weeks. 

 In fresh sputum they are preserved about the same length 

 of time. Rapid drying kills in two hours ; slower drying, 

 in from eight to twenty-four hours. 



Distribution. (a) Outside the body : Not found. 



(6) In influenza in man: Very abundant in the charac- 

 teristic, clear, yellowish-green, lumpy, tenacious sputum. 

 They are found purest in the secretion of the finer bronchi ; 

 at first free in clumps, later especially within the pus 

 cells. Also, extensive colonization occurs in the lung tis- 

 sue, leading to lobular and pseudo-lobular influenza pneu- 

 monia. They are often abundant in the nasal secretion in 

 cases of influenza. R. Pfeiffer found them rarely in the 

 blood, and never cultivated them from the blood. In the 

 organs, especially the brain, they are demonstrable rel- 

 atively seldom (Nauwerck, C. B. xvm, 395 ; Pfuhl, Z. 

 H. xxvi, 112). E. Frankel traced a suppurative menin- 

 gitis to the I. B. alone (Z. H. xxvn, 315). 



Animal Experiments. Influenza can be transferred to 

 the monkey only, among all the numerous available exper- 

 imental animals. Devitalized cultures in large quantities 

 are intensely toxic (dyspnea, paralysis) for animals, espe- 

 cially rabbits. 



Immunity and Serum Reaction. Animals which 

 are treated for a long time with I. -toxins do not yield a 

 serum with antitoxic or bactericidal properties, but suc- 

 cumb to infection with a larger quantity of culture 

 (Delius and Kolle). 



Special Culture Methods. The bronchial mucus 

 washed in sterile water is triturated somewhat superficially 

 with a little sterile water ; and of this, small quantities are 

 smeared over slanted agar and slanted agar smeared with 



